Mission Name: STS-69 (71)
  Endeavour (9)         
  Pad 39-A (55)
  71st Shuttle Mission
  102nd US Manned Mission
  9th Flight OV-105
  30th Shuttle EVA
  10th Rollback 

 NOTE: Click Here for Countdown Homepage

Crew:
  David M. Walker (4), Commander
  Kenneth D. Cockrell (2), Pilot
  James S. Voss (3), Payload Commander
  James H. Newman Ph.D.(2), Mission Specialist 2
  Michael L. Gernhardt (1), Mission Specialist 3

Milestones:
     OPF -- 3/28/95
     VAB -- 6/28/95
     PAD -- 7/05/95

(Rollback)
     VAB -- 08/1/95
     PAD -- 08/8/95


  (Reference KSC Shuttle Status Jul 1995)
  (Reference KSC Shuttle Status Aug 1995)
  (Reference KSC Shuttle Status Sep 1995)

Payload:
 SPARTAN 201-03, WSF-2, IEH-01, CAPL-02/GBA, EDFT-02, MSX-02, STL/NIH-C-04, CGBA-03, BRIC-06, EPICS, CMIX-04, G-726

Mission Objectives:

     The 11-day mission will feature the second flight of the Wake
Shield Facility (WSF), a saucer-shaped satellite that will fly free of
the Shuttle for several days.  The WSF will grow thin films in a near
perfect vacuum created by the wake of the satellite as it it moves
through space.  The crew also will deploy and retrieve the Spartan 201
astronomy satellite, perform a six-hour spacewalk to test assembly
techniques for the international Space Station and test thermal
improvements made to space suits used during space walks.

    The Spartan 201 free-flyer will be making its third flight aboard
the Shuttle.  The Spartan 201 mission is a scientific research effort
aimed at the investigation of the interaction between the Sun and its
outflowing wind of charged particles.  Spartan's goal is to study the
outer atmosphere of the Sun and its transition into the solar wind
that constantly flows past the Earth.

     STS-69 will see the first flight of the International Extreme
Ultraviolet Hitchhiker (IEH-1), the first of five planned flights to
measure and monitor long-term variations in the magnitude of absolute
extreme ultraviolet (EUV) flux coming from the Sun, and to study EUV
emissions from the plasma torus system around Jupiter originating from
its moon Io.

     Also flying aboard Endeavour will be the combined Capillary
Pumped Loop-2/Gas Bridge Assembly (CAPL-2/GBA) payload.  This
experiment consists of the CAPL-2 Hitchhiker payload designed as an
in-orbit microgravity demonstration of a cooling system planned for
the Earth Observing System Program and the Thermal Energy Storage-2
payload, part of an effort to develop advanced energy generation
techniques.  Also a part of this payload are several Get Away Special
(GAS) experiments which will investigate areas such as the interaction
of spacecraft attitude and orbit control systems with spacecraft
structures, fluid-filled beams as structural dampers in space and the
effects of smoldering combustion in a long-term microgravity
environment.

   Another payload being flown with a connection to the
development of the Space Station is the Electrolysis
Performance Improvement Concept Study (EPICS).  Supply of
oxygen and hydrogen by electrolyzing water in space will play
an important role in meeting NASA's needs and goals for
future space missions.  On-board generation of oxygen is
expected to reduce the annual resupply requirement for the
Space Station by approximately 12,000 pounds. 

     Other payloads aboard are the National Institutes of Health-
Cells-4 (NIH-C4) experiment that investigates bone loss during 
space flight; the Biological Research in Canister-6 (BRIC-6) that 
studies the gravity-sensing mechanism within mammalian cells.  Also
flying are two commercial experiments. (CMIX-4) whose objectives 
include analysis of cell change in microgravity along with studies of
neuro-muscular development disorders and the Commercial Generic 
Bioprocessing Apparatus-7 (CGBA-7).  CGBA is a secondary payload that 
serves as an incubator and data collection point for experiments in 
pharmaceuticals testing and biomedicine, bioprocessing and biotechnology, 
agriculture and the environment.

     The Thermal Energy Storage (TES-2) experiment also is 
part of the CAPL-2/GBA-6.  The TES-2 payload is designed to 
provide data for understanding the long-duration behavior of 
thermal energy storage fluoride salts that undergo repeated 
melting and freezing in microgravity.  The TES-2 payload is 
designed to study the microgravity behavior of voids in 
Lithium Fluoride-Calcium Fluoride eutectic, a thermal energy 
storage salt.  Data from this experiment will validate a 
computer code called TESSIM, useful for the analysis of heat 
receivers in advanced solar dynamic power system designs.

Launch:  
  Thursday, September 7 at 11:09:00.052 am EDT. The launch window was
2 hours 30 min.  Solid Rocket Boosters (SRB's) seperation
successful.  At 7min 45sec SSME throttled back while Endeavour 
traveling at more than 4miles per sec and 640 miles downrange.
SSME cutoff confirmed at 8min 30sec.

  Operations to load the External Tank began at 2:20am 
9/7/95 and were completed at 5:15am.  The crew suited up at 7:30am EDT 
and left the Operations and Checkout Building (O&C) at 7:58am EDT.  The 
crew arrived at launch Pad 39-A at 8:10am EDT.  The hatch was closed 
and sealed but failed to pass its leak check at 9:50am EDT.  The crew 
hatch was reopened and the seals checked.  Then a retest was performed.
Another problem late in the count was with Water Spray Boiler # 2.  
The Water Spray Boilers normally pressurize to 39 PSI but unit #2 showed 
a pressure of 38.7 PSI.  This did not violate any Launch Commit Criteria 
and the Mission Management Team determined the lower pressure was not a 
constraint to launch.   Also, there was a minor problem with a "safe" 
talkback indicator on a safe and arm device on the Solid Rocket Booster.   
This problem has been seen before and is understood.  It was not expected 
to be of any concern to the Solid Rocket Booster Recovery team.

  Earlier in the launch flow,  Endeavour's Fuel Cell #2 was replaced and 
the countdown picked up on September 4, 1995 at 4:30pm at the T-41.5 hour mark 
(Reference KSC Shuttle Status 9/01/1995) and (Reference KSC Shuttle Status 9/05/1995).

  The Mission Management Team (MMT) decided to scrub the August 31,
1995 scheduled launch of Endeavour on mission STS-69 due to a failure
of one of three fuel cells aboard the vehicle.  The scrub was called
at 3:30am on 8/31/95 prior to tanking operations.  Fuel cells provide
electricity to the vehicle while in orbit.  Mission rules state all
three fuel cells must be up and operational prior to launch. 

  At the 10:30am press conference on 8/31/95, Bob Sieck estimated the
countdown would pick back up on Monday with a launch late in the week.
The scrub was called due to a temperature spike in the Fuel Cell #2
exit temperature. The fuel cell is located in the right side of the
payload bay.  Fuel cell #2 had 1700 hours of operation and cells are
typically kept in service until 2400 hours of operation.  A similar
fuel cell problem was previously detected on orbit during the Spacelab
D-1 mission STS-61A and on the launch pad during STS-6.  During STS-6, 
the fuel cell was replaced on the pad and similar procedures will be 
used for STS-69.

  The countdown had begun at 3pm EDT on 8/28/95.  
(Reference KSC Shuttle Status 8/29/1995).  The previous launch date of 11:04am
8/31/95 was decided after NASA officials held a Flight Readiness
Review to consider remaining issues in preparing Endeavour for the
flight.  Among the items reviewed and closed out was the issue of
minor O-ring erosion seen in a joint of the Reusable Solid Rocket
Motor (RSRM) nozzle during the last two Shuttle launches.

  The launch was previously placed on hold pending analysis of the
solid rocket booster (SRB) nozzle o-ring seals. Possible air paths 
in the RTV behind the RSRM Nose Inlet Assembly to Throat Assembly joint
were investigated. (Reference KSC Shuttle Status 8/23/1995).

  There was a rollback of Endeavour on 8/1/95 to the VAB due to 
Hurricane ERIN.  (Reference KSC Shuttle Status 8/01/1995).  Endeavour was 
returned to Pad 39-A on 8/08/95 with first motion occuring at 1:55am.  
(Reference KSC Shuttle Status 8/08/1995).

   Old launch date was August 5, 1995 at 10:45am with a 2 hours 30 minute
launch window.  Launch date was pending resolution of open items including 
the post flight assessment of an anomaly on one of the STS-71 
solid rocket booster nozzle joints. (Reference KSC Shuttle Status 7/25/1995)

    Rollout to Launch pad 39-A occured on 7/5/95 with first motion out of 
the Vehicle Assembly Building (VAB) at around 11 p.m.  The Vehicle was hard 
down on the pad at about 4:30am on 7/6/95.  Hot fire of auxiliary power
units APU units 2 and 3 occured on 7/6/95.
(Reference KSC Shuttle Status 7/06/1995) 

Orbit:
  Altitude:  190 statute miles
  Inclination:  28.4 degrees
  Orbits:  
  Duration:   10 days,  20 hours, 28 minutes,  55 seconds.
  Distance:  4.5 million miles

Hardware:
  SRB: BI-074
  SRM:
  ET :  SN-72
  MLP : 
  SSME-1: SN-2035
  SSME-2: SN-2109
  SSME-3: SN-2029

Landing:  
  At KSC September 18, 1995 at 7:37:56am EDT.  KSC Shuttle Landing Facility 
Runway 33 (south-east to north-west). Sonic booms at 7:35am EDT.  Banking 
right-hand turn of 270 degrees.   Main landing gear touchdown at Mission 
Elapsed Time of 10days 20hr 28 56sec. Nose gear touchdown at MET 
10days 20hours 29min 8 sec with Wheel Stop at 10 days 20hr 29min 52 sec 
or 7:38:52 EDT.

Mission Highlights:

  STS-69 Flight Day 1 Highlights:

 On Thursday, September 7, 1995, 5 p.m. CDT, STS-69 MCC Status Report #01
reports: 
   
 Once on orbit the crew members began to configure Endeavour for
on-orbit operations. Endeavour's payload bay doors were opened about
90 minutes into the flight, followed by a 'GO' for on-orbit
operations.
   
   Crew members and ground controllers in Houston recycled a circuit
breaker on board Endeavour as a system on board the shuttle that
automatically scrubs the air to remove carbon dioxide did not start up
as expected. After cycling the breaker and reactivating the system, it
is now performing perfectly. Activation of payloads also got under way
with the SPARTAN-201 spacecraft systems and the Wake Shield Facility
carrier in the payload bay activated. SPARTAN-201 will be deployed
from Endeavour using the shuttle's robot arm Friday morning about
10:44 a.m. central time.
   
   Mission Specialists Jim Newman and Mike Gernhardt powered up
Endeavour's robot arm and conducted a photographic survey on
Endeavour's cargo bay. The five-member crew -- Commander Dave Walker,
Pilot Ken Cockrell, and Mission Specialists Jim Voss, Newman and
Gernhardt -- will begin an eight-hour sleep period at 6:09 p.m.
central time.

  STS-69 Flight Day 2 Highlights:

 On Friday, September 8, 1995, 7 a.m. CDT, STS-69 MCC Status Report #02
reports: 
   
   Astronauts Mike Gernhardt and Jim Newman aboard Space Shuttle
Endeavour were scheduled to power up the 50-foot long Canadian-built
robot arm this morning for the grapple and deployment of the SPARTAN
solar science satellite by Gernhardt at 10:42 AM Central
time. Endeavour will separate to a distance of about 40 nautical miles
from SPARTAN, leaving the 2800 pound probe on its own for about 48
hours for observations of the phenomena of the solar corona and the
solar wind. SPARTAN will be retrieved by Gernhardt through the
operation of the robot arm on Sunday morning.

  The five astronauts on board Endeavour began their first full day in
space this morning at 2:09am Central time as Mission Control awakened
the crew with Elvis Presley's "You Ain't Nothing But A Hounddog",
marking the start of a busy day in orbit for the so-called "Dog Crew",
the nickname adopted for the STS-69 crew by Commander Dave Walker.

  Walker, a four-time Shuttle veteran, was awakened twice during the
night by alarms on board Endeavour triggered by a temporary problem in
the data path between the ship's on-board computers and the Shuttle's
KU-band communications system. Walker reset the KU-system on both
occassions and the entire system was rebooted by Astronaut Jim Newman
after the crew was formally awakened. The KU system is currently
healthy, with flight controllers reported a strong lock between
Endeavour's KU-band antenna and the Tracking and Data Relay Satellite
system.

  Engineers are trying to troubleshoot one other problem with an audio
speaker in the Shuttle's middeck which apparently failed shortly after
Endeavour reached orbit. It is a similar problem to one which was
noted on the last flight of Endeavour in March, STS-67.  The speaker
problem will have no impact on any payload operations for the duration
of the STS-69 mission.

 On Friday, September 8, 1995, 5 p.m. CDT, STS-69 MCC Status Report #03
reports: 

  The Spartan 201 spacecraft was flying free approximately 22 miles ahead
of Endeavour following its successful deployment at 10:42 a.m. central
time.

  Mission Specialist Mike Gernhardt released the 2800 lb. free-flyer
from the shuttle's robot arm and a few minutes later the Spartan
spacecraft performed its characteristic 45 degree pirouette maneuver
signaling the flight crew and controllers on the ground that its
internal attitude control system was functioning properly.

  On the flight deck, Commander Dave Walker and Pilot Ken Cockrell
initiated two separation burns to move Endeavour away from the Spartan
solar investigation spacecraft.  The NC-1 rendezvous burn set for late
Friday afternoon was deleted from the crew's flight plan. That burn,
which would have slowed the opening rate between the two spacecraft,
would have resulted in the spacecraft being about 60 miles apart at
the time of a scheduled Saturday morning engine firing.  Tracking
figures indicate that, even without the afternoon burn, the distance
between the two spacecraft will be about 61 nautical miles by Saturday
morning.

  Spartan will fly free of Endeavour for about 48 hours before being
retrieved and reberthed in the shuttle's cargo bay for its return
trip to Earth. During its free flight, the two complementary
instruments on board Spartan will study the sun's corona and solar
winds.

  Crew members also kept busy with the wide variety of payloads housed
both on Endeavour's middeck and in the cargo bay. In addition, the
astronauts exercised and performed routine housekeeping chores on
board the orbiter.  Mission Specialist Jim Newman took time from his
work routine to talk with KABC Talk Radio host Michael Jackson in Los
Angeles and to take phone calls from listeners.

  STS-69 Flight Day 3 Highlights:

 On Saturday, September 9, 1995, 8 a.m. CDT, STS-69 MCC Status Report #04
reports:

  Endeavour's astronauts pressed ahead with a variety of experiments in
their third day in orbit as they prepared for tomorrow's rendezvous
and retrieval of the SPARTAN solar science satellite.

  Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's
reaction control system jets this morning to refine the Shuttle's
orbit in order to maintain a distance of about 65 statute miles from
the SPARTAN satellite. Another rendezvous maneuver designed to adjust
Endeavour's altitude was deleted from the flight plan because of
the precision with which Endeavour is flying in relation to SPARTAN.
Payload controllers say SPARTAN's systems are functioning normally,
although the amount of data gathered by the satellite during its 48
hours of free-flying science operations will not be known until the
probe is returned to Earth. SPARTAN is scheduled to be grappled by
Astronaut Mike Gernhardt through the use of Endeavour's robot arm
at 9:24 AM Central time tomorrow following a series of complex
rendezvous maneuvers by Walker and Cockrell to catch up to SPARTAN.

  The astronauts conducted work with the GLO experiment in the cargo
bay, designed to measure the luminescence created around the Shuttle
as it plows through atomic oxygen in low Earth orbit at a speed of
five miles a second. They also monitored several experiments in the
middeck area designed to capture data on materials and life science.

  A pair of problems continue to impact the operation of two of
Endeavour's payloads. The U-V STAR experiment, which is part of the
International Extreme Ultraviolet Hitchhiker payload in the cargo bay,
has not worked properly since launch because of a pressure problem and
a glitch in a system which enables the telescope to swivel back and
forth.  Another telescope in the IEH payload is working normally.

  The EPICS experiment in the Shuttle's middeck, designed to test the
capability to separate hydrogen and oxygen components in water
generated by the Shuttle, has yet to yield any results because of a
suspected problem in its data acquisiton system. Troubleshooting
efforts are underway for both EPICS and U-V STAR.

  One minor problem was resolved this morning when Astronaut Jim Voss
successfully activated an audio-speaker system in the Shuttle's
middeck area. Voss plugged in a different handheld microphone unit
than one which was used shortly after launch and the middeck system
checked out in good shape.

  Astronaut Gernhardt took a few minutes out this morning to discuss the
progress of the flight with Scott Carpenter, one of the original
Mercury 7 astronauts, who was linked to Gernhardt from an underwater
research laboratory off the coast of Key Largo, Florida.  Carpenter
and Gernhardt discussed the interdependence of underwater research and
outer space exploration. thirty years ago, Carpenter conducted a
similar discussion with fellow Mercury 7 astronaut Gordon Cooper as
Cooper flew in space on the Gemini 5 mission.

  As they passed over the Atlantic at the start of their 31st orbit, the
astronauts downlinked video of Hurricane Luis swirling with maximum
sustained winds of 109 miles an hour. The huge eyewall of the storm
was clearly visible as Endeavour passed overhead.

 On Saturday, September 9, 1995, 3 p.m. CDT, STS-69 MCC Status Report #05
reports:

  With the Spartan spacecraft flying ahead of Endeavour, the stage is
set for Sunday morning's planned rendezvous and retrieval of the
free-flying science satellite.

  Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's
reaction control system jets in a two-second burn designed to maintain
a distance of at least 40 nautical miles between the two orbiting
spacecraft until the rendezvous activities begin early Sunday
morning. Those rendezvous activities will start with Walker and
Cockrell conducting a series of complex maneuvers designed to bring
Endeavour to a point about 350 feet away from Spartan by 8:59
a.m. Central on Sunday.  After Walker edges Endeavour closer to
Spartan, Mission Specialist Mike Gernhardt will reach out with the
Shuttle's robot arm and grapple Spartan at 9:24 a.m. Central, placing
it back in Endeavour's payload bay.

  Work with the GLO experiment mounted in the payload bay will continue
overnight as the five astronauts on board sleep. The GLO instruments
will measure the luminescence created around the Shuttle as it plows
through atomic oxygen in low Earth orbit at a speed of five miles a
second.

  The EPICS experiment in the Shuttle's middeck, designed to test the
capability to separate hydrogen and oxygen components in water
generated by the Shuttle, has been powered down after all three
self-contained electrolysis units experienced an automatic shutdown.
After reviewing their options for restoring power to at least two of
those units, payload controllers opted to completely power off the
experiment. Troubleshooting efforts continue to resolve a problem with
the UV-STAR experiment which comprises a part of the International
Extreme Ultraviolet Hitchiker payload.  Pressure problems and
difficulty commanding an elevation gimble which enables the telescope
to swivel back and forth have kept the telescope from its study of the
sun's coronal plasma.  A second telescope is performing normally.

  STS-69 Flight Day 4 Highlights:

 On Sunday, September 10, 1995, 10 a.m. CDT, STS-69 MCC Status Report #06 
reports:
 
  Endeavour's astronauts Sunday successfully grappled the SPARTAN
solar science satellite following two days of data gathering
independent of the Shuttle Orbiter. The grapple came about 45 minutes
later than planned after the SPARTAN was in an unexpected attitude as
Endeavour approached.
 
  Commander Dave Walker and pilot Ken Cockrell manually flew Endeavour
around the SPARTAN to line up the satellite's grapple fixture with the
orbiter's robot arm.  Astronaut Mike Gernhardt captured the
free-flying spacecraft at 10:02 a.m. CDT, concluding SPARTAN's study
of the solar corona and the solar wind.
 
  With SPARTAN safely berthed in the cargo bay, the astronauts turn
their attention to the major payload of the mission, the Wake Shield
Facility. Walker and Cockrell will conduct two firings of the Ship's
Orbital Maneuvering System Engines to raise Endeavour's orbit about 15
nautical miles in preparation for the Wake Shield
operations. Astronaut Jim Newman plans to use the robot arm later
today to grapple the 2-ton Wake Shield, but will not unberth the
saucer-shaped satellite from its carrier platform until Monday
morning.  The Wake Shield is scheduled to be deployed by Newman
tomorrow at about 4:40 AM Central time to begin 50 hours of thin film
growth in an engineering demonstration for possible use in the future
in improving the quality of components for semiconductors and
high-tech electrical instruments.
 
  The astronauts were awakened just after Midnight Central time today
to the sound of "Bingo Was His Name", another tune involving a canine
theme for the self-proclaimed "Dog Crew", sung by Madeline Cockrell,
the 5-year old daughter of Endeavour's Pilot.

 On Sunday, September 10, 1995, 3:30 p.m. CDT, STS-69 MCC Status Report #07
reports:

   With the Spartan spacecraft back in Endeavour's payload bay, the
shuttle's robot arm has a firm grip on the Wake Shield Facility,
ready to send it on its free flight away from Endeavour early Monday
morning.

  Earlier this afternoon, Commander Dave Walker and Pilot Ken Cockrell
twice fired Endeavour's orbital maneuvering system engines bringing
Endeavour to a 215 nautical mile circular orbit required to support
Wake Shield deploy activities.  With that complete, Mission Specialist
Jim Newman took control of Endeavour's robot arm and grappled the
12 foot diameter satellite.  Wake Shield will remain in that
configuration overnight, latched in its cross-bay carrier and attached
to the robot arm.

  The crew's attention turned to Wake Shield operations following the
successful retrieval of the Spartan spacecraft at 10:02 a.m. Central
today.  Retrieval of Spartan occurred 38 minutes late when it was
found to be in an attitude, or position, other than what was expected
when Endeavour made its rendezvous approach. Walker and Cockrell
manually flew Endeavour in a 180 degree maneuver around Spartan,
aligning the shuttle's robot arm with the grapple fixture mounted
on the spacecraft. Mike Gernhardt then reached out with the arm and
grabbed Spartan, tucking it into Endeavour's payload bay at 10:21
a.m.  Central.

  Preliminary indications are that Spartan put itself in a "safe"
mode, shutting down its power systems which kept it from achieving its
anticipated rendezvous attitude. The exact cause of the safing will be
determined once Spartan is returned to Earth, however, payload
controllers believe Spartan successfully completed its mission
gathering data on the sun's corona and solar winds and the shutdown
likely was caused by low battery readings on board.

  Shortly after 3 p.m., Gernhardt began an 8-hour sleep period, to be
followed an hour later by his crewmates, who will have an abbreviated
7-hour sleep period. For the next few days, Gernhardt and Newman will
vary their sleep schedules so that one or both of them is awake during
all critical commanding to the Wake Shield Facility.

  STS-69 Flight Day 5 Highlights:

 On Monday, September 11, 1995, 7 a.m. CDT, STS-69 MCC Status Report #08
reports:

   Endeavour's astronauts successfully deployed the 2-ton Wake Shield
Facility satellite this morning to begin its 50-hour free flight from
the Shuttle for the growth of thin films for semiconductor and
electrical component use.

  Astronaut Jim Newman used the ship's robot arm to release the
experimental satellite at 6:25 AM CDT over Western Africa at an
altitude of almost 250 miles above the Earth.  Within seconds of the
deploy, the Wake Shield fired a small cold gas nitrogen thruster to
maneuver away from Endeavour for the start of the chemical growth of
the thin films. It was the first time a deployed satellite had
maneuvered itself away from the Shuttle, rather than the other way
around.

  Wake Shield's deployment had been delayed for almost two hours to
enable flight controllers to troubleshoot a series of communications
dropouts between the satellite and the Wake Shield's carrier
platform in the Shuttle's cargo bay which acts as a radio relay
system for data, telemetry and television signals. Wake Shield hung at
the end of the robot arm during its night-long systems checkout.

  Before its deployment, the satellite was positioned over the port
side of the payload bay to allow a stream of atomic oxygen in low
Earth orbit to "cleanse" the side of the satellite which will
fly in the direction of travel around the Earth. The satellite will
create a wake behind it during its freeflight in which scientists
believe a nearly perfect vacuum will be created for the pristine
growth of thin film wafers to be used in semiconductors and other
hight-tech electrical components.

  The last major step prior to the deployment was the checkout of the
Wake Shield's attitude control system, which developed a problem
during the STS-60 mission in February 1994, preventing the satellite
from being set free. This time, the so-called Attitude Determination
and Control System checked out in good shape, clearing the way for
Wake Shield's release.

  The Wake Shield is scheduled to be retrieved by Newman through the
use of the robot arm on Wednesday, but not before the satellite is
used as a target for a series of jet thruster plume tests by Commander
Dave Walker and Pilot Ken Cockrell to collect data on the effect of
jet firings on a free-flying satellite.

  Endeavour is currently orbiting the Earth at an altitude of 250
statute miles, completing an orbit of the Earth every 90 minutes. All
of Endeavour's systems are functioning in excellent shape.

 On Monday, September 11, 1995, 5 p.m. CDT, STS-69 MCC Status Report #09 
reports:

  Trailing Endeavour by just over 14 nautical miles, the 2-ton Wake
Shield Facility began its first thin film processing run at 3:33
p.m. Central today.

  Payload controllers successfully commanded the Wake Shield through a
series of activities to prepare its surface for the epitaxial film
growth process, handing command duties over to Mission Specialist Jim
Newman when Endeavour moved out of range of the Tracking and Data
Relay Satellite System.  With Wake Shield's sample materials and
substrate surfaces prepared, the first of seven planned thin film
growth runs began. The first run is expected to last about three hours
and be a "dirty" run, removing any residual contamination
present in the containers housing the sample growth materials.

  Earlier this afternoon, Commander Dave Walker and Pilot Ken Cockrell
fired Endeavour's reaction control system jets in a burn that
slowed the rate at which the two spacecraft are separating. By the
time of a scheduled rendezvous burn at 4:36 a.m. Tuesday, the Wake
Shield will be approximately 30 nautical miles behind Endeavour.

   The Wake Shield is scheduled to be retrieved on Wednesday following
more than 48 hours of thin film growth activities, but will spend the
final five hours of its free-flight serving as a target as Commander
Dave Walker and Pilot Ken Cockrell aim Endeavour's jet thrusters
toward Wake Shield, to determine the effects of the jet firings on a
free-flying satellite.

   On board, the five astronauts are asleep.  Mission Specialist Mike
Gernhardt will wake up at 9:09 p.m. following a 7-hour sleep period.
His four crew mates began an 8-hour sleep period at 4:09 p.m. and will
awaken at 12:09 a.m. Tuesday.  Endeavour is currently orbiting the
Earth at an altitude of 250 statute miles, completing an orbit of the
Earth every 90 minutes. All of Endeavour's systems are functioning
in excellent shape.

  STS-69 Flight Day 6 Highlights:

 On Tuesday, September 12, 1995, 8:30 a.m. CDT, STS-69 MCC Status Report #10
reports:

  The manufacture of thin film compounds for improved semiconductor and
electrical component use proceeded on schedule overnight aboard the
free-flying Wake Shield Facility as Endeavour's astronauts
monitored the process from their orbiting spaceship.

  However, about 7 a.m. CDT the 4300-pound, saucer-shaped satellite
put itself in a safe mode after three successful growths of thin
films. Scientists plan to complete seven growths before the
satellite's scheduled retrieval Wednesday morning. Just before the
fourth growth began, the Wake Shield pitched forward slightly after
sensing a temperature increase. Wake Shield's systems were shut
down and science activities temporarily halted to allow temperatures
on the satellite to cool. Payload controllers are assessing the
situation and its impact on the satellite's continued operations.

   The Wake Shield is trailing Endeavour by about 40 miles, just where
officials hoped it would be to avoid any possible contamination from
the Shuttle's jet thrusters. Wake Shield must maintain as clean an
environment as possible as it orbits the Earth to enhance the quality
of the thin film compounds.

  Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's
reaction control system jets to stop the opening rate between the
Shuttle and the Wake Shield in preparation for tomorrow's rendezvous
and retrieval of the satellite. The Wake Shield is scheduled to be
grappled by robot arm operator Jim Newman 9/13/95 at about 10:15 AM
Central time.

  Walker took a few minutes out of his schedule to discuss the
progress of the STS-69 mission with reporters from television stations
in Atlanta and Boston. Later this morning, Walker planned to conduct a
ship-to-ship conversation with STS-73 Commander Ken Bowersox, who
along with his six crewmates, climbed aboard Columbia on Launch Pad
39-B at the Kennedy Space Center for the final hours of a dress
rehearsal of the countdown which will lead to their launch in just
over two weeks on a 16-day Spacelab microgravity research mission.

 On Tuesday, September 12, 1995, 6 p.m. CDT, STS-69 MCC Status Report #11
reports:

   The manufacture of semiconductor thin film compounds aboard the Wake
Shield Facility satellite, released from Endeavour on Monday, is
planned to resume later tonight following about a 12-hour rest to
allow the satellite's attitude control system to cool from previous
operations.

  Due to the delay and subsequent plans to allow future such cooling
periods, shuttle managers this afternoon decided to extend the time
Wake Shield will spend flying free of Endeavour by about 24 hours. The
extra time will mean the satellite will not be retrieved until
Thursday. Previously, it would have been recaptured on Wednesday. The
additional 24 hours of free-flying time will be gained by scheduling
the crew activities that had been planned to occur the day after Wake
Shield was retrieved to now take place during the extra day the
satellite spends away from the shuttle. The overall duration for
Endeavour's mission has not been changed and landing remains
scheduled for September 18.

  Controllers for the Wake Shield Facility believe the extra
operations time will allow them to complete almost all of the thin
film growths that had been originally planned. The satellite may be
taken out of the "safe" mode that it has been in for cooling
purposes and resume operations as early as 10 p.m. CDT today. Prior to
the heating problems experienced with the attitude control system,
three of the planned total of seven film manufacturing runs had
already been completed. For the remainder of operations, cooling
periods that could last as long as eight to ten hours will take place
in between film manufacturing runs. Due to the slower-than-anticipated
thin film operations, some secondary experimental objectives of the
satellite, such as operations with the Charging Hazards and Wake
Studies and the Shuttle Plume Impingement Experiment, may be reduced
from what was originally planned. Operations with all of the secondary
experiments are still expected, however, although in a limited
fashion.

   With the change in plans for Endeavour's retrieval of the
satellite, activities for the crew when they awaken will include some
off-duty time, operations with the secondary payloads aboard
Endeavour, and checkouts of the spacesuits that will be used by
astronauts Mike Gernhardt and Jim Voss during a spacewalk on Saturday.

  The crew is currently in the midst of an eight-hour sleep period and
will awaken for day seven of the mission at 10:39 p.m. CDT today. The
Wake Shield Facility is trailing about 39 miles behind Endeavour and
closing in on the shuttle at less than one mile with each hour and a
half long orbit of Earth. 

  STS-69 Flight Day 7 Highlights:

 On Wednesday, September 13, 1995, 7 a.m. CDT, STS-69 MCC Status Report #12
reports:

  The resumption of the growth of thin films aboard the free-flying
Wake Shield Facility was delayed again today by the inability of
payload controllers to trigger the flow of arsenic from source cells
on the Wake Shield onto a substrate platform on the experiment side of
the disc-shaped satellite.

  Wake Shield project engineers continue to troubleshoot the problem
in the hope of growing up to four additional films for enhanced
semiconductor production.

  Given a bonus day in orbit after having science operations suspended
yesterday by an attitude control system problem, Wake Shield's
molecular beam epitaxy instruments were turned on just before 3 AM
CDT, some 20 hours after the satellite was placed in a so- called
"safe mode" because of a temperature increase in the spacecraft's
attitude control system and a slight pitch in its orientation. The
science instruments on the Wake Shield were once again shut down after
the arsenic flow problem developed to enable them to cool off in the
hope of making additional attempts to grow thin films. Plans had
called for two thin films to be grown during the day today before the
instruments would be shut down and cooled off for a 10-hour period.

  Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's
maneuvering jets early this morning for 15 seconds to slightly narrow
the distance between the Shuttle and the Wake Shield. Endeavour will
stay about 25 miles ahead of Wake Shield throughout the day, setting
the stage for its rendezvous and retrieval of the 4300-pound
disc-shaped satellite tomorrow about 9:39 AM Central time.

  While Wake Shield operations were restored, Payload Commander Jim
Voss and Mission Specialist Mike Gernhardt conducted a thorough
checkout of the spacesuits they will don Saturday for the second
Shuttle spacewalk of the year. The spacewalk is designed to test
thermal improvements to the bulky spacesuits as well as the tools and
techniques which may one day be used in the assembly of the
International Space Station.

  The astronauts were awakened late Tuesday night for their seventh
day in space to the theme song from the movie, "Patton", a tribute to
Voss, who was promoted to the rank of Colonel-select in the U.S. Army.

  Endeavour and the Wake Shield Facility are orbiting the Earth every
92 minutes at an altitude of about 250 miles with all of their systems
operating normally.

 On Wednesday, September 13, 1995, 3 p.m. CDT, STS-69 MCC Status Report #13
reports:

   After resolving some initial difficulties with the flow of arsenic
from a source cell, the Wake Shield Facility resumed its thin film
growth activities.

  During the film growth, the shutter on an aluminum source cell
apparently failed to close on command, but payload controllers report
that will not affect the quality of the film sample. A second
epitaxial film growth will be conducted overnight as the crew sleeps,
following a minimum 6-hour cool-down period of the Wake Shield
instruments.  Tonight's run should last about three hours and will
be followed by a final 6-hour instrument cool down in anticipation of
Thursday morning's rendezvous and retrieval of the 4,300 pound
satellite.

  The five astronauts on board Endeavour -- Commander Dave Walker,
Pilot Ken Cockrell and Mission Specialists Jim Voss, Jim Newman and
Mike Gernhardt -- enjoyed a few hours of off-duty time today,
following several busy days on orbit that saw them deploy two
spacecraft and retrieve one.  Wake Shield will be retrieved at 9:39
a.m. CDT Thursday when Walker maneuvers Endeavour into position
allowing Jim Newman to use the shuttle's robot arm to pluck Wake
Shield from orbit.

  Endeavour will begin its approach toward Wake Shield about 6:30
a.m. Central and for about 2 1/2 hours Walker and Cockrell will
maneuver Endeavour into position and fire its jet thrusters at
pre-determined distances to measure the effects of the firings on the
free- flying Wake Shield.

  STS-69 Flight Day 8 Highlights:

 On Thursday, September 14, 1995, 7 a.m. CDT, STS-69 MCC Status Report #14
reports:

   Endeavour's astronauts closed in on the Wake Shield Facility this
morning for a retrieval of the space manufacturing satellite following
three days of free-flying production of semiconductor material.

  Commander Dave Walker and Pilot Ken Cockrell maneuvered Endeavour to
a point just 400 feet in front of the 4300-pound satellite, where a
series of jet thruster firings were planned to gather data on the
effect of thruster plumes against orbiting space structures.  Flight
controllers were expected to make a real-time decision on whether or
not to proceed with the jet thruster tests based on an evaluation of
the Wake Shield's attitude control system, which has held the
stainless steel spacecraft in a steady orbit since its deployment from
Endeavour on Monday.

   Astronaut Jim Newman is expected to grapple Wake Shield with the
Shuttle's robot arm between 8:09 AM and 8:30 AMCentral time to
complete the Wake Shield's three-day freeflight. During that time,
four thin films of semiconductor material were grown in a carousel on
the back side, or wake side of the satellite. An attempt to grow a
fifth and final thin film was called off late Wednesday when Wake
Shield officials detected a low reading in one of four batteries
providing power to the satellite.

  Following its retrieval, the Wake Shield will be berthed onto its
carrier platform in Endeavour's cargo bay. Tomorrow, Newman will
unberth the satellite once again and maneuver it over the Shuttle's
bay for additional experiments spanning several hours to gather
information on the electrically charged environment around the Orbiter
as it plows through atomic oxygen in low Earth orbit at a speed of
five miles a second.

   The astronauts were awakened late last night at 11:09 PM Central
time to the theme song of the cartoon show, "Underdog", in tribute to
Astronaut Mike Gernhardt, who carries the same nickname.

 On Thursday, September 14, 1995, 3 p.m. CDT, STS-69 MCC Status Report #15
reports:

With the Wake Shield Facility stowed securely in Endeavour's
payload bay, the five astronauts on board are enjoying a well-deserved
rest.

  After Commander Dave Walker and Pilot Ken Cockrell manuevered
Endeavour alongside the 4300-pound satellite, Mission Specialist Jim
Newman reached out with the shuttle's robot arm and plucked it from
orbit.  Capture came at 8:59 a.m. CDT, with berthing of Wake Shield
back in its carrier platform at 10:18 a.m.

  Prior to capturing Wake Shield, Walker and Cockrell performed a
series of 14 thruster firings at distances of 290 and 200 feet
respectively. These jet firings were designed to gather data on the
effect of thruster plumes against orbiting space structures. The Wake
Shield's attitude control system performed well during the thruster
firings as sensors measured the force and pressure of the jet plumes.

  During Wake Shield's three days of free flight, four of seven
possible epitaxial film runs were successfully completed.  The films
will be evaluated once the satellite is returned to Earth.

  With its two free-flying payloads retrieved and secured in the
payload bay, Endeavour's astronauts turned their attention to the
remaining four days of activity.  Walker and Cockrell fired
Endeavour's orbital maneuvering system jets this afternoon to lower
Endeavour's orbit from 216 nautical miles to 183 nautical miles.
At the same time, Mission Specialists Jim Voss, Jim Newman and Mike
Gernhardt began preparing Endeavour for Saturday morning's planned
spacewalk, lowering the cabin pressure to 10.2 psi from the standard
14.7 psi.  Voss and Gernhardt will conduct a 6-hour spacewalk to
evaluate thermal modifications to their spacesuits and test tool
handling techniques for possible space station assembly.

  Shortly before beginning an 8-hour sleep period at 3:09 p.m., Walker
reported to ground controllers that the handles of the rowing machine
used during exercise were stuck in the extended position. While
engineers on the ground are reviewing repair options, a bicycle
ergometer is available on board for the crew to use. The crew will be
awakened by Mission Control at 11:09 p.m. to begin another day on
orbit. Endeavour is orbiting the Earth every 92 minutes at an altitude
of 183 nautical miles with all of its systems operating normally.

  STS-69 Flight Day 9 Highlights:

 On Friday, September 15, 1995, 7 a.m. CDT, STS-69 MCC Status Report #16
reports:

  Endeavour's astronauts completed work with the Wake Shield
Facility today by lifting the satellite out of its platform in the
Shuttle's cargo bay one more time to gather data about electrically
charged particles which stream over a spacecraft in low Earth orbit.

  The Wake Shield was unberthed about 2 Central time and was hung over
the side of Endeavour's cargo bay at the end of the ship's robot
arm by Astronaut Jim Newman for CHAWS, the Charging Hazards and Wake
Studies Experiment. It is an Air Force sponsored experiment designed
to collect data on the buildup of electrical fields around an orbiting
space vehicle. Engineers intend to use the information to better
understand how the ionized particles interfere with spacecraft
communications and the operation of orbiting spacecraft.

  The Wake Shield remained fixed to the end of the Shuttle's
mechanical arm for about 5 hours for CHAWS data-gathering, before
Newman maneuvered the satellite back down onto its berthing platform
where it was latched it in place to wrap up the Wake Shield's
scientific investigations.

  Payload Commander Jim Voss and Mike Gernhardt also reviewed their
timeline once again for tomorrow's six-hour spacewalk in Endeavour's
cargo bay to test new thermal improvements made to their spacesuits
and some of the tools and techniques which may be used to assemble the
International Space Station.

  Voss and Gernhardt are scheduled to float out into the cargo bay to
begin their six-hour extravehicular activity at about 3 Central time
Saturday.

  The crew was awakened late Thursday night for their ninth day of
work in space to the tune "He's A Tramp", taken from the cartoon 
movie, "Lady and the Tramp".

 On Friday, September 15, 1995, 4 p.m. CDT, STS-69 MCC Status Report #17
reports:

  Shortly after waking up, Jim Voss and Mike Gernhardt will begin
preparing for their spacewalk which will test new thermal improvements
made to their spacesuits and some of the tools and techniques which
may be used to assemble the International Space Station.  Pilot Ken
Cockrell will assist Voss and Gernhardt as they climb into their
spacesuits and prepare for the second spacewalk of the year.

  During the spacewalk, Mission Specialist Jim Newman will hoist Voss
and Gernhardt outside the warmth of Endeavour's payload bay using
the shuttle's robot arm to maneuver them into a colder attitude to
validate thermal modifications made to the suits' liquid cooling
garments and gloves.

  Voss and Gernhardt are scheduled to float out into the cargo bay to
begin their six-hour extravehicular activity at about 3 a.m. Central
time Saturday.

  The Wake Shield Facility is once again back in Endeavour's
payload bay following five hours of investigations into how ionized
particles in the plasma field around a spacecraft may interfere with
communications and operations. Wake Shield was supporting CHAWS, the
Charging Hazards and Wake Studies Experiment, an Air Force-sponsored
experiment.

  The crew also spent time discussing Endeavour's mission and
activities with media during an inflight press conference this
afternoon.

 On Saturday, September 16, 1995, 5:30 a.m. CDT, STS-69 MCC Status Report #18
reports:

  Astronauts Jim Voss and Mike Gernhardt floated out into Endeavour's
cargo bay early this morning for a 6 1/2 hour spacewalk designed to
test new thermal improvements made to their spacesuits and the tools
and techniques which may be used one day in the assembly of the
International Space Station.

  The spacewalk began at 3:20 a.m. Central, after Voss and Gernhardt
breathed pure oxygen in Endeavour's airlock to cleanse the nitrogen
from their bloodstreams in a standard pre-spacewalk procedure.

  The first task for the spacewalkers was to install thermal sensors
on Endeavour's robot arm and at a work site mounted on the starboard
wall of the Shuttle's payload bay.  The sensors measure temperature
levels in the cargo bay to provide data on how hot and cold the
spacewalkers can get as they perform their work.

  Voss and Gernhardt removed a debris shield from the work site,
manipulated a duplicate of a computer control box for a robot arm
under development for the Space Station and tested new helmet lights
and suit heaters as they maneuvered around the cargo bay with relative
ease.

  The spacewalk is scheduled to conclude at about 10 a.m. when the two
astronauts climb back into Endeavour's airlock.  The remaining
three astronauts, Dave Walker, Ken Cockrell and Jim Newman have been
assisting with the spacewalk from the flight deck of the orbiter with
Newman serving as the primary choreographer with Voss and Gernhardt.
Newman performed a spacewalk on a Shuttle flight two years ago to
evaluate tools and techniques for future spacewalks.

 On Saturday, September 16, 1995, 2:30 p.m. CDT, STS-69 MCC Status Report #19
reports:

 With a 6-hour 46-minute spacewalk under their belts, Endeavour's
astronauts completed the final major milestone of the flight.

  Jim Voss and Mike Gernhardt began the spacewalk at 3:20 a.m. Central
today, evaluating thermal improvements made to their spacesuits and a
variety of tools and techniques which may be used in the assembly of
the International Space Station.  In turn, Gernhardt and Voss each
spent 45 minutes on the end of Endeavour's mechanical arm as Jim
Newman maneuvered them away from the radiated warmth of the payload
bay.  With the Shuttle's payload bay pointed away from the Sun, the
spacewalkers were exposed to temperatures as low as minus 120 degrees
Fahrenheit during this "cold soak" evaluation.  Voss and
Gernhardt continually provided subjective ratings on their comfort
levels to flight controllers on the ground.  Temperature measurement
devices mounted on the robot arm and in the payload bay will provide
objective data that will be correlated with their evaluations.
Throughout the entire spacewalk activity, both Voss and Gernhardt
reported they were very comfortable, both during their cold soak
evaluation and as they worked through a series of repetitive
tool-handling tasks in Endeavour's payload bay.

  With all their objectives complete and after stowing their tools and
equipment, the two spacewalkers made their way back into the airlock,
closed the hatch and began to repressurize the airlock.  With the
pressure at about 10.2 psi, Ken Cockrell opened the hatch to
Endeavour's middeck and welcomed his crewmates back on board.
Endeavour's crew cabin was then repressurized back to 14.7 psi
while Voss and Gernhardt were helped out of their spacesuits.

  Following an 8-hour sleep period, Endeavour's astronauts will be
awakened at 10:09 p.m.  to begin their final full day on orbit. Early
Sunday morning, Commander Dave Walker, Cockrell and Newman will check
out Endeavour's flight control surfaces and conduct a hot fire test
of the reaction control system jets in anticipation of Monday
morning's return trip to Earth.

  STS-69 Flight Day 10 Highlights:

 On Sunday, September 17, 1995, 7 a.m. CDT, STS-69 MCC Status Report #20
reports:

  Endeavour's astronauts tested their ship's systems and packed up
the Orbiter for their trip home tomorrow to complete the fifth Shuttle
mission of the year.

  With all of the mission's objectives completed, Commander Dave
Walker and Pilot Ken Cockrell fired up one of Endeavour's hydraulic
power units and conducted a thorough checkout of the Shuttle's
flight control systems to insure that the Orbiter is in top shape for
tomorrow's high-speed return to Earth. Walker and Cockrell also
tested the Shuttle's reaction control system jets as part of the
standard pre-landing inspection of key Shuttle components.

  With that out of the way, the astronauts reviewed their entry and
landing checklists and began to pack up their gear aboard Endeavour,
deactivating secondary experiments and stowing the cabin for landing.

  The preliminary weather forecast for landing calls for acceptable
weather for Endeavour's homecoming at the prime landing site at the
Kennedy Space Center. The backup landing site at California's Edwards
Air Force Base will not be called up for support. There are two
landing opportunities available tomorrow in Florida, the first calling
for a deorbit burn at 6:35 AM Eastern time, leading to a landing at
7:38 AM Eastern time.

  Early in the morning, astronauts Jim Voss and Mike Gernhardt, who
successfully conducted a lengthy spacewalk on 9/16/95, turned to repair
chores, freeing up a blocked waste water dump line through a plan
developed by flight controllers in Mission Control. The in-flight
maintenance procedure cleared the way for a dump of accumulated waste
water aboard Endeavour.

 On Sunday, September 17, 1995, 1 p.m. CDT, STS-69 MCC Status Report #21
reports:

  Endeavour and its five astronauts are ready for their return trip to
Earth, concluding a voyage of about 4.5 million miles.

   The crew spent much of its day packing up equipment and checklists
used during 10 days of on-orbit activity.  The astronauts also
transferred some of the accumulated waste water onboard Endeavour into
a contingency water container when attempts to free up a blocked waste
water dump line were unsuccessful.

   The five member crew -- Commander Dave Walker, Pilot Ken Cockrell
and Mission Specialists Jim Voss, Jim Newman and Mike Gernhardt --
will receive a wake-up call from Mission Control at 10:09 p.m. Central
to begin final preparations for Endeavour's reentry and landing at
the Kennedy Space Center.

   Shortly after 1:30 a.m. Central the crew will begin its deorbit
preparations and at 2:49 a.m., Endeavour's payload bay doors will
be closed.  There are two landing opportunities available tomorrow,
both to the Kennedy Space Center.  The first opportunity calls for a
deorbit burn at 5:35 a.m., with a landing on Runway 33 at 6:38
a.m. Central. The second landing opportunity comes one orbit later,
with Endeavour's orbital maneuvering system jets being fired for
the deorbit burn at 7:12 a.m., resulting in a landing at 8:15 a.m.
Central.

  The preliminary weather forecast for Monday's landing calls for
acceptable weather at the Kennedy Space Center in Florida with
scattered clouds, light winds from the northwest and only a slight
chance of early-morning ground fog. The backup landing site at
California's Edwards Air Force Base will not be called up to
support tomorrow's landing.

Endeavour continues to circle the Earth every 91 minutes at an
altitude of 214 statute miles.
  STS-69 Flight Day 11 Highlights:

 On Monday, September 18, 1995, 9 a.m. CDT, STS-69 MCC Status Report #22
reports:

  Commander Dave Walker and Pilot Ken Cockrell guided Endeavour to a
smooth touchdown at the Kennedy Space Center at 6:38 a.m. Central time
today to wrap up an 11-day mission that saw crew members successfully
deploy and retrieve two satellites and conduct a 6-hour 46-minute
spacewalk.

  After firing Endeavour's braking rockets at 5:35 a.m., Walker and
Cockrell brought Endeavour home to Runway 33 at the Kennedy Space
Center's Shuttle Landing Facility to complete its 4.5 million mile
mission.

  Main gear touchdown occurred at 6:38 a.m., with nose gear touchdown
nine seconds later and wheel stop at 6:38:55 a.m.  The STS-69 mission
duration was 10 days 20 hours 28 minutes and 55 seconds.

  The STS-69 crew members are expected to return to Ellington Field
about 10 hours after landing.

<end of mission>

Mission Name: STS-73 (72)
  Columbia (18)         
  Pad 39-B (34)
  72nd Shuttle Mission
  18th Flight OV-102

 NOTE: Click Here for Countdown Homepage

Crew:
  Kenneth D. Bowersox (3), Commander
  Kent V. Rominger (1), Pilot
  Kathryn C. Thornton (4), Payload Commander
  Catherine G. Coleman Ph.D (1), Mission Specialist
  Michael E. Lopez-Alegria (1), Mission Specialist
  Fred W. Leslie Ph.D (1), Payload Specialist
  Albert Sacco Jr Ph.D (1), Payload Specialist

  David H. Matthiesen (0) Ph.D, Alternate Payload Specialist
  R. Glynn Holt (0) Ph.D, Alternate Payload Specialist
  
Milestones:
     OPF -- 4/14/95
     VAB -- 8/21/95
     PAD -- 8/28/95
    TCDT -- 9/11/95
     FRR -- 9/14/95

  (Reference KSC Payload Status Sep 1995) 
  (Reference KSC Shuttle Status Sep 1995)
  (Reference KSC Shuttle Status Oct 1995)

Payload:
  USML-2/EDO, OARE-06, 3DMA, STABLE 

Mission Objectives:

   The second United States Microgravity Laboratory (USML-2) 
Spacelab mission will be the prime payload on STS-73. The 16-day 
flight will continue a cooperative effort of the U.S. government, 
universities and industry to push back the frontiers of science 
and technology in "microgravity", the near-weightless environment 
of space.

   Some of the experiments being carried on the USML-2 
payload were suggested by the results of the first USML 
mission that flew aboard Columbia in 1992 during STS-50.  
The USML-1 mission provided new insights into 
theoretical models of fluid physics, the role of gravity in 
combustion and flame spreading, and how gravity affects the 
formation of semiconductor crystals.  Data collected from 
several protein crystals grown on USML-1 have enabled 
scientists to determine the molecular structures of those 
proteins.

    USML-2 builds on that foundation.  Technical knowledge 
gained has been incorporated into the mission plan to 
enhance procedures and operations.  Where possible, 
experiment teams have refined their hardware to increase 
scientific understanding of basic physical processes on 
Earth and in space, as well as to prepare for more advanced 
operations aboard the international Space Station and other 
future space programs.  

   USML-2 experiments include the Surface Tension Driven Convection
Experiment (STDCE), the Drop Physics Module, the Drop Dynamics 
Experiment; the Science and Technology of Surface-Controlled 
Phenomena experiment; the Geophysical Fluid Flow Cell Experiment; 
the Crystal Growth Furnace, the Orbital Processing of High Quality 
Cadmium Zinc Telluride Compound Semiconductors experiment; the 
Study of Dopant Segregation Behavior During the Crystal Growth of
Gallium Arsenide (GaAs) in Microgravity experiment; the Crystal
Growth of Selected II-VI Semiconducting Alloys by Directional 
Solidification experiment; the Vapor Transport Crystal Growth
of Mercury Cadmium Tellurida in Microgravity experiment; the 
Zeolite Crystal Growth Furnace (ZCG), the Interface Configuration 
Experiment (ICE), the Oscillatory Thermocapillary Flow Experiment; 
the Fiber Supported Droplet Combustion Experiment; the Particle 
Dispersion Experiment; the Single-Locker Protein Crystal Growth
experiment; (including the Protein Crystallization Apparatus for 
Microgravity (PCAM) and the Diffusion-controlled Crystallization 
Apparatus for Microgravity (DCAM)). the Crystal Growth by Liquid-Liquid
Diffusion, the Commercial Protein Crystal Growth experiment; the
Advanced Protein Crystallization Facility, Crystallization of 
Apocrystacyanin C experiment; Crystal Structure Analysis of the 
Bacteriophage Lamda Lysozyme, Crystallization of RNA Molecules Under 
Microgravity Conditions experiment; Crystallization of the Protein Grb2 
and Triclinic Lysozyme experiment; Microgravity Crystallization of 
Thermophilic Aspartyl-tRNA Synthetase and Thaumatin experiment; 
Crystallization in a Microgravity Environment of CcdB experiment; A 
Multivariate Analysis of X-ray Diffraction Data Obtained from Glutathione 
S Transferase experiment; Protein Crystal Growth: Light-driven Charge 
Translocation Through Bacteriorhodopsin experiment; Crystallization of 
Ribosome experiment; Crystallization of Sulfolobus Solfataricus Alcohol 
Dehydrogenase experiment; Crystallization of Turnip Yellow Mosaic Virus, 
Tomato Aspermy Virus, Satellite Panicum Mosaic Virus, Canavalin, 
Beef Liver Catalase, Concanavalin B experiment; Crystallization of the 
Epidermal Growth Factor (EGF);  Structure of the Membrane-Embedded 
Protein Complex Photosystem I; Crystallization of Visual Pigment Rhodopsin;  
Commercial Generic Bioprocessing Apparatus; Astroculture Facility and 
Experiment.  Spacelab Glovebox Facility experiments 
include the Zeolite Crystal Growth Glovebox, Protein Crystal Growth 
Glovebox and the Colloidal Disorder-Order Transitions,   

   USML-2 flight controllers and experiment scientists 
will direct science activities from NASA's Spacelab Mission 
Operations Control facility at the Marshall Space Flight 
Center.  In addition, science teams at several NASA centers 
and universities will monitor and support operations of a 
number of experiments.

  Other payloads on board include the Orbital Acceleration 
Research Experiment (OARE),  Space Acceleration Measurement System (SAMS),
Three Dimensional Microgravity Accelerometer (3DMA), Suppression of 
Transient Accelerations By Levitation Evaluation (STABLE) and the 
High-Packed Digital Television Technical Demonstration system.

Launch:  
  Friday, October 20, 1995 at 9:53:00 a.m. EDT. Launch window was
2 hours 30 min.  The countdown clock picked up at 7:30pm at the 
T-11 hour mark with a scheduled T-0 at 9:50 a.m.  Loading of fuel 
was completed at 3:53am.  The crew suited up at 6:00am and traveled 
out to Launch Pad LC-39B. (Reference KSC Shuttle Status 10/18/1995).

  At the post-launch press conference, Jim Harrington, Director of
Shuttle Operations mentioned the launch countdown went relatively
smoothly.  At the beginning of the count there was a problem with one
of 3 redundant sensors on Liquid Oxygen (LOX) portion of the External
Tank toggling from wet to dry.  The sensor was bypassed.  After
tanking, one of the relief valves in the LOX storage area had a slow
leak internally that will be fixed during ground operations.  There
was also a fire alarm that went off accidently at the 155ft level 
during the later part of the count while the close out crew was
still on the pad.  No fire was detected.  Also, a right hand mid joint 
heater trimmed down and the launch team switched over to the backup
system.   Finally, the range command destruct system lost communications
between the ROCC and the antenna.  A contingency plan was work and
the count was picked back up.
 
  The launch scheduled for October 15 10:46 a.m EDT was scrubbed at
1:25pm EDT due to weather conditions at KSC that were unacceptabledue
for launch.  Due to the scheduled launch of the Atlas launch vehicle
on Tuesday morning (10/17/95), the next available time frame in which
Columbia could have been launched was Thursday, Oct. 19 at 9:49
a.m. EDT.  Bad weather delayed the Atlas launch which slipped the
launch of Columbia till Friday.  The launch window extended until
12:19 p.m. that day.  (Reference KSC Shuttle Status 10/16/1995). Fueling
operations had started around 1:20 a.m. EDT with the loading of 1/2 
million gallons of liquid hydrogen and liquid oxygen into the 
External Tank and were completed at 4:03am.  Since the available 
launch period extended to 1:35 p.m. EDT based on the 
Transoceanic Abort Landing (TAL) lighting conditions at Ben Guerir,
Morocco the crew was boarded one hour later than planned to provide a
increased opportunity for favorable weather towards the end of the
launch window. They departed the Operations and Checkout Building
(O&C) at 7:20am EDT.  

  On 10/14/95, the Mission Management Team closed the two open issues
with flight hardware which caused a one day postponement of the launch
of Columbia on Mission STS-73.  The issue with a duct on the main
engines was resolved by technicians taking ultrasonic measurements of
the duct to verify adequate wall thickness.  That work along with
additional data analysis have allowed engine managers to conclude that
there are 3 good SSMEs on Columbia.  The issue with a General Purpose
Computer (GPC) was resolved by removing and replacing the suspect
unit.  The new GPC installed in Columbia has been tested and approved
for flight support. (Reference KSC Shuttle Status 10/14/1995).

   On 10/13/95, NASA managers postponed the launch of Space Shuttle
Columbia on Mission STS-73 to 10/15/95 in order to work an issue with
the Space Shuttle Main Engine (SSME) and another with the orbiter's
onboard computer (GPC). The issue with the Shuttle main engines
involves inspection work that is required because of a crack found in
a high pressure oxidizer duct on a main engine (SSME SN# 2015) being
tested at the Stennis Space Center in Bay St. Louis, Mississippi on
10/11/95.  Inspection of the failed duct indicates the crack happened
in a weld area and was due to the duct wall being too thin.  The work
on Columbia involves ultrasonic inspection of the welds on each
engine's high pressure oxidizer duct to ensure proper wall
thickness. There are seven different welds on each engine duct. 

     A separate issue was worked by the launch team with one of
Columbia's General Purpose Computers (GPC).  During prelaunch testing,
the ground crew noticed an unusual response in the data transmission
between the GPC and associated electronics hardware.  

  The launch scheduled for Saturday, 10/7/95 at 9:41am EDT was scrubbed
at 10:05am EDT ( T-minus 20 minute mark ) by KSC Launch Director Jim 
Harrington and the Mission Management Team due to a problem with one 
of Columbia's two Master Events Controllers (MEC).  The MECs control 
all critical functions that occur on the Shuttle at T-0 and through 
flight, including routing commands from the Shuttle s onboard computers 
to fire the explosive bolts that hold the solid rocket boosters to 
the Mobile Launch Platform (MLP) and the pyrotechnics that separate 
the boosters from the external tank during flight.  
(Reference KSC Shuttle Status 10/07/1995).

  The countdown had started and proceeded with little difficulty.
During tanking operations, the only minor problem was an overvoltage
failure of a ground pump (Primary Pump 126). Tanking was picked up
using the backup pump 127 and the count proceeded normally. The flight
crew had departed the Operations and Checkout Building for Pad 39-B at
6:25am EDT and was onboard Columbia. At 8:56am (T-minus 29 minute mark), 
the launch team called a Launch Commit Criteria violation due to a failed 
self test on B-Core (Port 1, bit 5) of Columbia's Master Events Controller 
#1. The four cores are all redundant allowing the Shuttle
quad-redundancy. Launch commit criteria rules require all four cores
to be operating properly for safe flight. The launch countdown was placed 
on hold at the T-minus 20 minute mark while commands were issued to 
determine if the problem was with the controller or with instrumentation.  
It was determined the problem was with the controller which will need to be
replaced.

     At this time, the external tank will be drained and purged, the 
Rotating Service Structure (RSS) moved back around the vehicle and 
preparations made to gain access to the aft engine compartment to remove 
and replace the MEC. The MEC is scheduled to be removed on Monday 10/9/95 
and the replacement MEC tested on Tuesday 10/10/95.  Some of the experiments 
in the USML-2 spacelab module must be serviced before another launch attempt 
can be made and the onboard cryogenic tanks must be off-loaded and then 
re-loaded with liquid hydrogen and liquid oxygen reactants.

  The launch on 10/6/95 was scrubbed at 3:33am for a minimum of 24 hours 
due to a problem in the orbiters #1 hydraulic system which services 
Columbia's nose wheel steering system. On 10/6/95, during pre-launch 
checkout, engineers noticed a problem with the volume of hydraulic fluid 
in the system.  They will cycle the hydraulic system's fill and dump valve 
and run a compressibility test. (Reference KSC Shuttle Status 10/06/1995).

  The launch scheduled for 10/5/95 was posponed 24 hours due to bad
weather from Hurricane Opal. (Reference KSC Shuttle Status 10/05/1995)
The launch attempt of Columbia on September 28, 1995 at 9:35 a.m was
scrubbed due to indications of a hydrogen leak in Space Shuttle Main
Engine (SSME) #1 (SN#-2037) .  The scrub was called at 4 a.m. on
9/28/95.  The hydrogen main fuel valve needed to be replaced which
delayed the launch approximately one week.
(Reference KSC Shuttle Status 9/28/1995).

 During the launch postponement press conference, Jim Harrington, KSC
Launch Director and John Plowden, Rocketdyne Site Director reported that
Tanking operations had begun approximately an hour later than planned
primarily due to lightning in the area of the launch pad.  Liquid
hydrogen was in recirculation for about 30 minutes and the main fuel
valve had begun to chill down.  When it reached the temperature of
-10F degrees the valve started to leak.  Tanking operations were
stopped when the temperature on the valve reached the Launch Commit
Criteria cuttoff limit of -250F degrees at the downstream side of the
valve.  Normal temperature on the valve runs at -100F to -150F
degrees.

  This would have been the first launch of SSME engine SN#-2037 and
the failed valve but it had been thru 7 static firings during ground
tests.  The engine and valve were last tested at cryogenic
temperatures during hot firing June 15, 1995 at Stennis Space Center
in Mississippi.  A failure of this nature has occured only once before
during the STS-2 tanking test.  That failure was due to metallic
contamination in the downstream seal of the valve.  The valve is
accessable via the AFT engine compartment.  It weighs about 75 pounds
with a flow path of 2.5 inches.  It will be replaced at the pad.  The
bad valve will be sent back to the Rocketdyne factory in California
for testing.

  The launch countdown had begun at 4am on Monday, September 25, 1995 and the
crew arrived at the KSC Shuttle Landing Facility (SLF) at 8:20 a.m.
(Reference KSC Shuttle Status 9/25/1995).

  RTV backfilling for both solid rocket boosters of Space Shuttle Columbia 
was performed on 9/5/95. (Reference KSC Shuttle Status 9/05/1995).  
Earlier, on 8/8/95, engineering analysis indicated that
the No. 2 main engine on Columbia was unacceptable for flight and was
removed and replaced with an engine originally slated to fly on
mission STS-74.  (Reference KSC Shuttle Status 8/08/1995).  The
replacement engine does not have a block one liquid oxygen pump.
(Reference KSC Shuttle Status 8/15/1995).

Orbit:
  Altitude:  150 nm (172 statute miles)
  Inclination:  39.0 degrees
  Orbits: 255 
  Duration:   15 days,  21 hours, 53 minutes, 16 seconds.
  Distance:  6.6 million miles

Hardware:
  SRB: BI-075
  SRM:
  ET :  SN-73
  MLP : 
  SSME-1: SN-2037
  SSME-2: SN-2031
  SSME-3: SN-2038

Landing:  
   November 5, 1995 at 6:45:21am EST at KSC Runway 33.  Main gear
touchdown at 6:45:21 EST (MET 15days 21hr 52min 21sec). Nose gear
touchdown at 6:45:35 EST (MET 15days 21hr 52min 35sec). Wheels stop
at 6:46:16 EST (MET 15days 21hr 53min 16sec).

  Two landing opportunities were possible for a landing on 11/5/95..
Columbia took the first opportunity which began with a deorbit engine
firing by Columbia at 5:46 a.m. EST, on the mission's 255th orbit,
leading to a touchdown at the Kennedy Space Center at 6:45
a.m. EST. The second opportunity would have begun with a deorbit burn
at 7:20 a.m. EST on orbit 256 leading to a 8:19 a.m. EST touchdown.
Mission duration was 17hours short of the existing shuttle record
set by Endeavour.

Mission Highlights:
     The seven-member crew will work in two 12-hour shifts, for 16
days conducting 14 major experiments and a variety of other medical
and engineering investigations.  The experiments are part of the
planned operations of the United States Microgravity Laboratory 2
payload.

   STS-73 Flight Day 1 Highlights:

 On Friday, October 20, 1995, 12 p.m. CDT, STS-73 MCC Status Report #01
reports:

   The Space Shuttle Columbia blasted off from its Florida launch pad
at 8:53 a.m. CDT today after a heavy cloud cover that earlier had
shrouded the area cleared.  Today's launch tied the record for
launch attempts set by STS 61C which launched on its seventh try in
January of 1986.

  Once on orbit, the crew members set to work configuring Columbia for
on-orbit operations.  Columbia's payload bay doors were opened
about 90 minutes into the flight, followed by a "go" for
on-orbit operations.

   With all systems aboard Columbia performing well, the orbiter
continues to circle the Earth every 92 minutes at an altitude of 150
nautical miles or 172 statute miles.

 On Friday, October 20, 1995, 5 p.m. CDT, STS-73 MCC Status Report #02
reports

  The astronauts set up the Spacelab module mid-day Friday and began
work which will cover 14 major research activities and a number of
other medical and engineering studies.

  Columbia is in a 172-statute mile high orbit with all systems
functioning well.  Handover from the Red Team to the Blue Team of
astronauts is scheduled for approximately 7:30 p.m. Friday.  The Red
Team picks up work again Saturday morning at about 6:30 a.m.  CDT
after their wakeup call.

 On Friday, October 20, 1995 at 11 p.m. CDT, STS-73 Payload Status Report #01 
reports:

  This 16-day mission will build on the foundation 
of its predecessor, USML-1, which flew in 1992.  USML-2 will 
continue microgravity investigations in fluid physics, 
materials science, biotechnology, combustion science and 
commercial space processing technology.  These experiments 
support work that historically yields long-range benefits to 
the quality of life, and will play a vital role in work on 
the International Space Station.  Mission Scientist Marcus 
Vlasse observed, "The results from these experiments will 
provide important input into our future technology needs."          

More than 400 hours of the crew's time will be dedicated to 
the USML-2 experiments.  The seven-member crew onboard 
Columbia will work dual 12-hour shifts which allows the 
experiment operations to continue around the clock in the 
"shirt-sleeve" microgravity environment of the Spacelab 
module.  Microgravity is approximately one millionth the 
gravity experienced on Earth, made possible in low Earth 
orbit by a condition known as freefall.  Freefall provides 
the microgravity environment for the occupants and 
experiments onboard as the Shuttle falls around the Earth in 
such a way that it stays the same height above ground.
   
  About two hours after launch, red team Payload Commander 
Kathy Thornton and Payload Specialist Al Sacco went to work 
activating the Spacelab, while the blue team members slept in 
preparation for their shift.

  Thornton began processing experiment samples in the 
Commercial Generic Bioprocessing Apparatus, a tool which 
allows a variety of sophisticated biological experiments to 
be performed in one piece of hardware.  Its 132 test-tube 
size chambers allow multiple commercial customers to take 
advantage of the microgravity environment.  Major areas of 
investigation include biomedical testing and drug 
development, ecological test systems, and biomaterials 
products and processes.  Thornton mixes the samples by 
turning a plunger or activator on the facility.  After 
mixing, some of the samples will then be placed in an 
incubator at a prescribed temperature, while others will be 
placed in a rack at room temperature.  

  Thornton also activated and began check-out of the Crystal 
Growth Furnace, a facility to further understand and find 
better ways of processing semiconductor crystals which are 
used for products such as computer chips and infrared 
detectors.  In microgravity, melting and resolidifying the 
specialized semiconductor materials or growing crystals by 
vapor diffusion (heating the substance to a vapor and then 
cooling it, causing material to deposit in thin layers), the 
elements are distributed more evenly.  This makes a purer 
metal and a better end product.  

  Crew members activated one of two protein crystal growth 
facilities on this flight:  the European Space Agency's 
Advanced Protein Crystallization Facility.  Because a 
protein's structure determines its function, scientists are 
aiming to grow the largest, most perfect crystals possible.  
That way they can more easily see how a particular protein 
functions in the human body.  

  Later in the day,  the crew lowered the Shuttle's cabin 
temperature after it caused a slight rise in the temperature 
of a Commercial Protein Crystal Growth experiment 
thermoelectric cooler.  Ideal temperature in the coolers is 
four degrees Celsius.  Investigators anticipate the situation 
will be resolved soon as the Shuttle naturally cools to its 
normal post-launch temperature.   There has been no impact on 
crystal growth.

Pa yload Specialist Sacco activated two instruments which will 
determine what effect crew movements, equipment operations 
and Shuttle maneuvers can have on sensitive USML-2 
experiments.  The Space Acceleration Measurement System 
collects data for post-mission evaluation, while the Three 
Dimensional Microgravity Accelerometer collects acceleration 
data for both post mission and real time data analysis.  
Armed with data collected by these instruments, scientists 
can make changes to their experiments to compensate for on-
orbit disturbances, thus utilizing their microgravity time to 
the fullest. 

  Sacco powered on the High-Packed Digital Television Technical 
Demonstration, a new digital television system which will be 
tested on this flight.  This experiment could allow 
researchers on the ground at the Marshall Space Flight Center 
in Huntsville, Ala., and at numerous remote research sites 
around the country, to choose from up to six channels of 
experiment video being transmitted simultaneously from orbit.

  During the next 12 hours, blue team Mission Specialist 
Catherine Coleman and Payload Specialist Fred Leslie will 
continue activating experiments in the Spacelab, including 
the Surface Tension Driven Convection experiment  and the 
Astroculture plant growth facility.  

   STS-73 Flight Day 2 Highlights:

 On Saturday, October 21, 1995, 7 a.m. CDT, STS-73 MCC Status Report #03
reports:

 Columbia's crew continued research work in the United States
Microgravity Lab-2 during the night uninterrupted by any problems with
the spacecraft.

  The Blue Team crew members -- Mission Specialists Mike Lopez-Alegria
and Cady Coleman and Payload Specialist Fred Leslie -- wrapped up
their first, full 12-hour shift in the lab at about 6:38 a.m. CDT.
During the last part of the Blue shift, new shuttle equipment being
carried aboard Columbia for the first time this mission that allows
television to be sent from the ground to the crew was tested. The
ground-to- air television test, which included live scenes from
Mission Control, appeared good onboard the shuttle, reported Columbia
Pilot Kent Rominger.

  The Red Team crew -- Commander Ken Bowersox, Rominger, Payload
Commander Kathy Thornton and Payload Specialist Al Sacco -- awoke from
their first night in orbit at about 3:53 a.m. CDT today and relieved
the Blue Team in the lab module this morning. The Red Team will remain
on duty until 6:53 p.m. CDT.

  Highlights of NASA Television today will include the Flight Day 2
Mission Update program airing at 11:30 a.m. CDT; a Mission Status
Briefing press conference at 1 p.m.; and an interview of the Red Team
by the Florida Radio Network at 5:58 p.m. CDT that may include
phone-in questions from listeners

 On Saturday, October 21, 1995, 2 p.m. CDT, STS-73 MCC Status Report #04
reports:

  All systems aboard the Space Shuttle Columbia continue to work well
as the orbiter's seven member crew continues its microgravity work in
the United States Microgravity Lab-2 (USML-2).

  The Red Team crew -- Commander Ken Bowersox, Pilot Kent Rominger,
Payload Commander Kathy Thornton and Payload Specialist Al Sacco --
spent today in the lab module working on a variety of experiments and
tasks.  The Red Team hands over its duties to the Blue Team at 6:53
p.m.  today.  The Blue Team crew - Mission specialists Mike
Lopez-Alegria and Cady Coleman, and Payload Specialist Fred Leslie --
then will take a turn in the lab.  The Blue Team's shift ends at
6:38 a.m. Sunday.

  The first in-flight special event is scheduled for 5:58 p.m. CDT
today when available crew members talk to Alan McBride of the Florida
Radio Network.  The event will be audio only.

 On Saturday, October 21, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #02 
reports: (0/21:07 MET)

  The second United States Microgravity Laboratory's "blue 
team" -- Mission Specialists Mike Lopez-Alegria and Cady 
Coleman, and Payload Specialist Fred Leslie -- spent a busy 
first shift putting more of the mission's microgravity 
experiments into operation.

  Alegria activated the Protein Crystallization Apparatus for 
Microgravity experiments located in two Shuttle middeck 
lockers.  During USML-2, the experiments will grow more than 
800 protein crystals -- six times the number normally 
accommodated in the same space.  Principal Investigator Dr. 
Dan Carter of NASA's Marshall Space Flight Center who has 
flown the apparatus on several Shuttle missions has grown 
protein crystals with enhanced internal order.  

  Because a protein's structure determines its function, 
researchers analyze the improved crystals to understand the 
structure in greater detail.  For instance, a number of 
pharmaceutical companies have samples in USML-2 protein 
crystal growth facilities.  Improved crystals will aid their 
design of new drugs.  The superior crystals grown in space 
contribute insights that otherwise might not have been 
possible, despite huge investments in ground-based research. 

  Another USML-2 protein facility,  the University of Alabama 
at Birmingham's Commercial Protein Crystal Growth vapor 
diffusion apparatus, had experienced somewhat elevated 
temperatures yesterday due to warmer than normal crew cabin 
temperatures after launch.  After the cabin cooled, the 
temperature in the  refrigerated incubator was down to about 
40 degrees Fahrenheit (4.5 degrees Celsius), well within 
satisfactory limits.  

  Coleman spent the first portion of her shift activating more 
of the biological samples in NASA's Commercial Generic 
Bioprocessing Apparatus.  The facility, managed by Bioserve 
Space Technologies at the University of Colorado in Boulder, 
is a generic research tool for a wide variety of life-science 
experiments.  Subjects range from molecules and cells to tiny 
organisms.  Groups of eight syringe-like fluid containers are 
packaged together so they can be activated simultaneously by 
turning a crank on the pack.

  Leslie's first major assignment was loading six samples into 
the Marshall Center's Crystal Growth Furnace, a multi-user 
facility for growing crystals of semiconducting material, 
metals and alloys.  Crew members also installed a flexible 
glovebox atop the furnace, which they will use later in the 
mission to remove crystallized samples and replace them with 
new sample cylinders.  An automatic sample exchanger within 
the furnace allows ground controllers to command processing 
of multiple crystals in sequence, freeing the Spacelab crew 
for other duties.

  Just after midnight, Crystal Growth Furnace team members 
began vapor crystal growth of their first semiconductor 
sample, a mercury cadmium telluride compound provided by Dr. 
Heribert Wiedemeier of the Rensselaer Polytechnic Institute 
in Troy, New York.  Wiedemeier is examining the initial phase 
of vapor crystal growth in a complex alloy semiconductor.  
The vapor transport method deposits layers, or thin films, of 
mercury cadmium telluride on a cadmium telluride substrate, 
or base.  The material is used in infrared detectors for 
products such as cancer detection devices and the military's 
night-vision goggles. 

  Wiedemeier's analysis of the mercury cadmium telluride 
crystal he grew during USML-1 revealed new information about 
how microgravity affects formation of the initial layer on 
the substrate.  His USML-2 experiment zeros in on that stage 
of growth, which determines the atomic arrangement of the 
entire crystal and thus the ultimate quality of the material. 

  Later, Coleman checked out power, lighting, ventilation and 
video in the versatile Glovebox facility, provided by the 
European Space Agency.  The transparent enclosure, which also 
flew on USML-1, is a self-contained work area for experiment 
handling and observation that protects against possible 
contamination of the Spacelab environment.  USML-2 crew 
members will use the Glovebox for seven investigations, 
several of which will enhance other mission experiments.
  
The Spacelab crew then turned their attention to the Lewis 
Research Center's Surface Tension Driven Convection 
Experiment, another facility returning after a USML-1 debut.  
The apparatus allows investigators to view in great detail 
the basic fluid mechanics and heat transfer of 
thermocapillary flows, motions created within fluids by non-
uniform heating of their free surfaces.  Though masked by 
gravity in ground-based processing, such flows during melting 
and resolidifying can create defects in high-tech crystals, 
metals, alloys and ceramics.  Leslie installed the facility's 
infrared imager, video cassette recorder, and the first test 
module.  Coleman then checked out the video system, which 
allows ground controllers to see how changes in heating and 
surface shape affect flows within the fluid.

  During the upcoming shift, Payload Specialist Al Sacco will 
work with his Glovebox Zeolite Crystal Growth experiment, and 
Payload Commander Kathy Thornton will start up the Drop 
Physics Module.  Initial operations for the Geophysical Fluid 
Flow Cell Experiment are scheduled for later this afternoon.  

   STS-73 Flight Day 3 Highlights:

 On Sunday, October 22, 1995, 7:30 a.m. CDT, STS-73 MCC Status Report #05
reports:

  Columbia sailed through a second smooth night in orbit, continuing
around-the- clock research in its cargo bay laboratory.

  The spacecraft remains in excellent condition, and the focus in
Mission Control has been on assisting with the experiment operations
when needed. The Red Team crew -- Commander Ken Bowersox, Pilot Kent
Rominger, Payload Commander Kathy Thornton and Payload Specialist Al
Sacco -- is now on duty in the United States Microgravity Lab-2,
having started a 12-hour shift at 6:38 a.m. CDT.  The Blue Team --
Mission specialists Mike Lopez-Alegria and Cady Coleman, and Payload
Specialist Fred Leslie -- will begin an eight-hour sleep period at
8:53 a.m.

  Highlights on NASA Television today include the Flight Day 3 Mission
Update program airing at 11:30 a.m.; the Mission Status Briefing at 1
p.m.; and a replay of video highlights from the past 24 hours of
STS-73 airing on the Flight Day Video File at 3:30 p.m. Other
activities upcoming today include a second test of a system that
allows television to be transmitted to the shuttle from Mission
Control to be conducted at about 5:03 p.m. The ground-to-air shuttle
television equipment is flying aboard Columbia for the first time on
STS-73 as a test objective of the mission.

 On Sunday, October 22, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #03 
reports: (1/21:07 MET)

  The seven-member crew of the second United States Microgravity
Laboratory had a busy 24 hours during their second day in space.
Experiments continue to operate smoothly and on schedule.

  Fluids physics Payload Specialist Fred Leslie spent his shift
overnight conducting initial experiment runs in the Surface Tension
Driven Convection Experiment.  The investigation examines subtle fluid
motions, called thermocapillary flows, created by variations in
temperature on a fluid's surface.  Though overshadowed by
gravity-driven flows on Earth, thermocapillary flows during melting
and resolidifying can create defects in high-tech crystals, metals,
alloys and ceramics.

  The goal of USML-2 surface tension experiments is to measure the
transition from steady, two-dimensional flows to oscillatory, or
three-dimensional, flows within silicone oil.  Leslie reported the
onset of oscillations early in the first experiment run, as ground
controllers watched three different views of the experiment chamber
transmitted simultaneously by Hi-Pac TV.  While data from the July
1992 flight confirmed the model for steady thermocapillary flows
proposed by the science team from Case Western Reserve University in
Cleveland, Ohio, it also indicated that smaller chambers and less
viscous fluid would be needed to study the transition from steady to
oscillatory flow.  These improvements were made, and a new optical
system was added so investigators can observe how changes in surface
shapes influence the beginning of oscillations.

  After crew members activated the Geophysical Fluid Flow Cell
experiment, the University of Colorado science team took over
operation from the ground.  The investigation models flows in oceans
and atmospheres of planets and stars using silicone oil between two
rotating hemispheres -- one of stainless steel inside another of
transparent sapphire.  Controllers can vary electrical charges which
simulate gravity, fluid temperature and rotation speed of the spheres
in order to reflect conditions in the different environments.

  The geophysical cell's first experiment run mimicked the sun's
plasma flows, repeating its primary study during Spacelab 3 in 1985.
"This allows us to compare USML-2 results with our previous
experiment," said Principal Investigator Dr. John Hart.  "The
instrument seems to be working great."  Solar physics researchers at
the University of Colorado will use data from this experiment to build
better computer models of fluid behavior on the sun.

  Glovebox Protein Crystal Growth experiments occupied Mission
Specialist Cady Coleman for the majority of last night's shift.
Coleman used a variety of procedures to manually mix protein and
activator solutions in the Glovebox enclosure.  Crew members will
observe crystallization of the samples as the mission progresses and
adjust upcoming Glovebox protein activations accordingly.  Shuttle
protein experiments over the past decade have frequently produced more
perfect crystals than those grown on Earth, and investigators are
constantly refining methods to improve that quality.  Modifications
made during the USML-1 Glovebox experiment resulted in several
crystals of much higher quality than had ever been grown before.

  Earlier in the day, Payload Commander Kathy Thornton made videotapes
of proteins growing in Principal Investigator Dr.  Alex McPherson's
handheld diffusion test cells.  In liquid- liquid diffusion, fluids
are not mixed but diffuse into each other by random motion of
molecules.  This method is difficult on Earth because gravity causes
solutions with different densities to mix.  Also, the denser crystals
settle to inappropriate parts of the cell.

  Thornton used sound waves to control positions of marked Styrofoam
and plastic balls inside the Jet Propulsion Laboratory's Drop Physics
Module.  In addition to giving her practice operating the equipment,
Thornton's success assured investigators that free-floating liquid
drops can be manipulated as desired during upcoming experiment
operations.  Improved understanding of fluid physics would produce
advances in industries from chemical engineering to pharmaceuticals.

  Payload Specialist Al Sacco is principal investigator for two USML-2
investigations into the growth of zeolite crystals, widely used as
catalysts and filters in the chemical processing industry.  Video
downlink Saturday from the Shuttle showed Sacco's hands in the
Glovebox facility as he mixed 16 samples of alumina and silica
solutions to initiate growth in the Zeolite Crystal Growth Glovebox
experiment.  Sacco then used the most effective mixing procedures to
prepare other samples for heating in the Zeolite Crystal Growth
Furnace.

  The Astroculture facility team was elated to see video downlink of
their potato plants on day two of the mission.  Ten small tubers are
being grown in the chamber to test how microgravity affects starch
accumulation in plants.  This information will play an important role
in future long- duration space missions such as the International
Space Station, where plants could provide food, water and oxygen for
crews, as well as removing carbon dioxide from the space habitat.

  On Saturday, the Crystal Growth Furnace completed its first sample,
a semiconductor crystal grown by the vapor transport technique.  A
six-hour growth period deposited a thin mercury cadmium telluride
crystal onto a cadmium telluride substrate, or base.  The
infrared-detecting semiconductor crystal will be analyzed to determine
whether defects from the base material were translated to the atomic
structure of the crystal grown in microgravity.

  Furnace team members then began melting a semiconductor sample aimed
at eliminating defects in a substrate material.  The alloying element
zinc is added to this cadmium telluride substrate to minimize strain
where the two crystals join.  Processing of the semiconductor
compound, from the Northrop- Grumman Corp. in Bethpage, New York, will
continue for more than 90 hours.

 On Sunday, October 22, 1995, 12 p.m. CDT, STS-73 MCC Status Report #06
reports:

  Space Shuttle Columbia continues to perform well in its supporting
role for the U.S.  Microgravity Lab-2.  Since Friday morning's launch,
the orbiter has remained a steady host, providing electrical power,
cooling and other needs to keep the orbiting laboratory in business.

The seven-member crew continues to work around the clock in two
shifts.  Columbia is in a 170x167 statute mile orbit, circling the 
Earth every 90 minutes. 

   STS-73 Flight Day 4 Highlights:

 On Monday, October 23, 1995, 9:30 a.m. CDT, STS-73 MCC Status Report #07
reports:

  The Red Team crew -- Commander Ken Bowersox, Pilot Kent Rominger,
Payload Commander Kathy Thornton and Payload Specialist Al Sacco --
began a 12-hour shift at 6:38 a.m. CDT. Their Blue Team crewmates
began eight hours of sleep at 8:53 a.m. CDT.

  Bowersox and Rominger took part in the third test thus of a new
shuttle system that allows the transmission of television from Mission
Control to Columbia. The crew discussed the progress of the flight
with Capcom Tom Jones and Flight Director Rob Kelso in Mission
Control. Bowersox reported that he has been impressed by Columbia's
performance so far and complemented workers at the Kennedy Space
Center that prepared the shuttle for flight. The test was the first to
involve two-way television -- simultaneous transmissions to and from
Columbia -- and was highly successful.

 On Monday, October 23, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #04 
reports: (2/21:07 MET)

   Research in microgravity continues around the clock as crew members
of the second United States Microgravity Laboratory (USML- 2) onboard
the Shuttle Columbia work in dual 12-hour shifts.  The red and blue
Spacelab teams devoted the majority of the time on their last shifts
to the Drop Physics Module, the Surface Tension Driven Convection
Experiment and Glovebox Protein Crystal Growth operations.

  Drop Physics Module Project Scientist Arvid Croonquist and his
science team watched downlink video of the first liquid drop
deployment in their facility during an initial test run on Sunday.
Payload Commander Kathy Thornton deployed the 3/4-inch (4 cubic
centimeter) drop of water, then released it, using precisely
controlled sound waves to manipulate the drop's movements.  Thornton
reported that the drop's performance was close to expectations, its
rotation visible by following the movement of tiny plastic particles
suspended in the water drops as reference points.

  Thornton spent a good portion of her shift deploying and
manipulating different-sized drops in the facility.  Mission
Specialist Cady Coleman also devoted several hours last night to
familiarizing herself with the operation of the Drop Physics Module.
These preliminary runs give crew members valuable practice injecting,
controlling and retrieving liquid drops in the unique environment of
weightlessness.  The runs also allow ground controllers to fine-tune
procedures in preparation for upcoming science investigations.
Insights gained into basic fluid physics and the properties of liquid
surfaces will benefit a variety of industries, from pharmacology to
industrial chemistry.

  Payload Specialist Al Sacco and Coleman finished the mission's
initial round of protein crystal growth activations in the Glovebox
facility.  The experiment, provided by the Center for Macromolecular
Crystallography in Birmingham, Ala., will help improve protein crystal
growth procedures for future Shuttle missions and on the International
Space Station.  Among the proteins Sacco activated was feline
calcivirus, similar to a virus that causes digestive problems in
humans.  He also set up initial conditions for growth of a collagen
binding domain protein, important in the study of arthritis and joint
disease.  One of the proteins Coleman activated last night was duck
delta crystallin.  Derived from the eye of a duck, it is much like a
protein that causes a rare but deadly inherited disease in humans.

  Thornton and Payload Specialist Fred Leslie continued tests in the
Surface Tension Driven Convection Experiment, an investigation which
could eventually lead to better, stronger high-tech crystals, metals,
alloys and ceramics by modeling the transition from steady
thermocapillary fluid flows to oscillatory (or varying) flows.
Unsteady flows in materials processing such as crystal growth could
reduce the quality of the final product.  "Once we understand when and
how oscillations occur, we should eventually be able to design
processes to control them," said Co- Investigator Dr. Yasuhiro
Kamotani of Case Western Reserve University.

  In this series of convection tests, crew members drew down the
volume of silicone oil in the experiment chamber to create a concave
surface.  As a laser gradually heated the surface, team members were
able to identify the transition point where oscillations began to
occur in each run.  "We've never seen this kind of transition before,
because we have no way to create a large curved liquid surface on the
ground," said Lewis Research Center Project Scientist Alex Pline.

  Crew members initiated another Lewis Research Center investigation,
the Colloidal Disorder-Order Transition experiment.  This Glovebox
study researches what happens at the boundaries between solid and
liquid states during crystallization of a colloid.  Colloids are
suspensions of finely divided solids or liquids in gaseous or liquid
fields.  For instance, paint, ink and milk are colloids found in
everyday life.  Investigators will use results to model the complex
interactions of atoms -- the basic building blocks for everything in
the universe.

  Thornton worked Sunday with the Geophysical Fluid Flow Cell
Experiment, which models fluid flows on Earth, planets and stars.
Thornton set up different scenarios, adjusting fluid temperature,
speed of sphere rotation, and electrical charges (which simulate
gravity) to mimic various environments.  Investigators hope to one day
use information gleaned from experiments such as this to aid in
forecasting ocean flows and weather patterns.  The science team is
currently working a problem relaying scenario temperature parameters
to the experiment hardware, but Principal Investigator Dr. John Hart
says they are getting good data.

  The cadmium zinc telluride crystal is just over a third of the way
through its growth in the Crystal Growth Furnace.  The predecessor
experiment on USML-1 yielded a crystal of the infrared-detecting
semiconductor a thousand times more perfect than any cultivated on
Earth.  Principal Investigator Dr. David Larson hopes to demonstrate
that equivalent quality can be reproduced with the USML-2 crystal.

  The Astroculture team has noticed new growth on the 10 small potato
tubers in their facility onboard Columbia.  The potatoes will be
analyzed post-mission to determine how microgravity affected starch
accumulation.  In addition, this flight of Astroculture is the last in
a series to evaluate each of the critical subsystems needed for the
construction of a reliable plant growth unit.  After it is flight
qualified, the unit will be available for sale or lease to commercial
enterprises.  Plants may provide food, water and oxygen for crews on
long-duration space flights.

  Science activities scheduled for the next 12 hours include more Drop
Physics Module and Surface Tension Driven Convection Experiment
activities.

 On Monday, October 23, 1995, 6:30 p.m. CDT, STS-73 MCC Status Report #08
reports:

  Circling the Earth at over 17,000 miles an hour and at an altitude
of approximately 170 statute miles, Columbia is flying in the gravity
gradient attitude, tail to Earth in its most stable and vibration-free
condition to facilitate the delicate microgravity experiments being
conducted.  The astronaut crew, divided into Red and Blue teams, works
shifts for around-the-clock science in 14 major areas of
experimentation.

   STS-73 Flight Day 5 Highlights:

 On Tuesday, October 24, 1995, 8 a.m. CDT, STS-73 MCC Status Report #09
reports:
  
  Columbia's crew worked through the night in the shuttle's cargo bay
research lab with no significant spacecraft problems encountered.
Flight controllers in Mission Control have virtually no issues of
concern with Columbia's systems, which continue to operate nearly
perfectly. The Red team began a 12-hour shift at 6:38 a.m. CDT,
relieving the Blue team crew members who had worked through the night.

  During the night, there was a short loss of communications with
Columbia. The shuttle was out of touch with the ground for a few
minutes longer than planned following a normal loss of communication
that occurs each orbit as it moves out of range of the NASA
communications satellites. The extended loss of signal was due to a
ground problem with the communications network and did not interrupt
any lab or spacecraft operations nor pose any problem for the
crew. The ground problem was quickly corrected and Columbia's
communication systems were confirmed to be in excellent condition with
no functional problems.

 On Tuesday, October 24, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #06 
reports: (3/21:07 MET)

   Experiments aboard the Shuttle Columbia continue to operate
extremely well as the second United States Microgravity Laboratory
enters its fifth day in space.  Fluid physics studies, unhampered by
the distortions caused by gravity, again took center stage.

   As he had for the previous two nights, Payload Specialist Fred
Leslie devoted most of his shift to the Lewis Research Center's
Surface Tension Driven Convection Experiment.  The study seeks a
precise understanding of flows created by temperature differences
across a liquid's surface, called thermocapillary flows.  In
particular, the USML-2 experiment should determine the conditions
under which thermocapillary flows begin to oscillate, or become
irregular.  While thermocapillary flows are almost impossible to study
on the ground because of the overpowering influence of gravity, they
can affect processing of molten materials on Earth such as formation
of semiconductor crystals or precision welding.

  Leslie used a larger experiment chamber than he had on previous
surface tension experiment runs -- 3/4-inch (2 cm) diameter as opposed
to 1/2-inch (1.2 cm) -- and heated the silicone oil surface with a
laser.  The surface was flat for the first three runs and curved for
the fourth.  Principal Investigator Dr. Simon Ostrach believes that
the onset of oscillations is affected by a number of factors,
including heat source, temperature distribution on the fluid surface,
surface shape and container size.  USML-2 experiments are using
multiple combinations of conditions to build a through understanding
of oscillatory thermocapillary flow in microgravity.

  The Geophysical Fluid Flow Cell Experiment team controlled their
investigation remotely from Marshall's Spacelab control center, with
input from colleagues at the University of Colorado in Boulder.
Payload Specialist Leslie, a co- investigator for the experiment,
calls it "a planet in a test tube."  Silicone oil between two rotating
hemispheres can be manipulated to simulate fluid flows in the
atmospheres of giant gas planets, the sun or the Earth.  Last night's
experiment simulated atmospheric dynamics of the sun .

  When ground-based experiments use spheres as planetary models,
gravity exerts force in a single direction.  Therefore, a uniform
gravitational force cannot be exerted on all the sphere's surfaces.
In space, simulated gravities can be varied as necessary.  This
experiment should give theorists insights for interpreting and
predicting problems in complex fluid systems, including Earth's
atmosphere, oceans, core and mantle.

  Mission Specialist Cady Coleman is conducting the mission's first
run of the Glovebox Interface Configuration Experiment for Principal
Investigator Dr. Paul Concus of the Lawrence Berkeley Laboratory in
California.  The study examines how movements of fluids in
microgravity, such as fuel in spacecraft tanks, are influenced by the
shapes of their containers.  On Earth, gravity causes fuel and other
liquids to drain from containers in predictable ways.  When planning
space-based operations, it is important to be able to predict the
locations and configurations that fluids will assume in containers
under low-gravity conditions.  Thus far, mathematical models exist for
only a few container shapes.  Coleman used a wedge-shaped vessel for
this run, adjusting the wedge angle to see how different angles affect
fluid behavior.

  Earlier, Coleman spent several hours following up on Glovebox
Protein Crystal Growth experiments she began on previous shifts.
Experiment team members at the Center for Macromolecular
Crystallography in Birmingham, Ala., sent Coleman instructions for
modifying conditions as she activated a new batch of proteins.  She
will compare growth progress in the various samples to determine which
conditions work best for specific types of proteins.

  Mission Specialist Mike Lopez-Alegria and Coleman also monitored
other protein crystal experiments onboard.  This mission carries a
record number of protein samples and protein crystal growth
facilities.  The European Space Agency's Advanced Protein
Crystallization Facility enables videotaping of three different
methods of crystal growth.  Marshall Space Flight Center has two
protein crystal growth experiments on USML-2, which use a total of
four facilities.  In addition to their Glovebox experiment, the Center
for Macromolecular Crystallography is growing more crystals in the
often-used Vapor Diffusion Apparatus as well as by a newer batch
method.

  Proteins are molecules which serve biological functions.
Understanding the structure of these molecules gives scientists an
idea what other molecules would interact with the protein and change
the way it functions, for instance to help cure or treat an illness.
Space-based protein crystal growth experiments have consistently
produced high-quality crystals for structural analysis, as well as
providing better understanding of the dynamics of protein crystal
growth.

  Red team members will devote the majority of their upcoming shift to
Drop Physics Module, Surface Tension Driven Convection Experiment and
Glovebox Protein Crystal Growth operations.

 On Tuesday, October 24, 1995, 6 p.m. CDT, STS-73 Payload Status Report #07
reports: (4/09:07 MET)

  "This mission is a beautiful example of interactive science due to
the collaborative efforts between the principal investigators, the
cadre and the crew," observed Mission Scientist Marcus Vlasse
referring to the second United States Microgravity Laboratory (USML-2)
mission.  USML-2 scientific investigations continue to operate
smoothly and on schedule.

  Downlink video from the Shuttle on Hi-Pac TV this morning displayed
a circular image that appeared to contain a swirling nocturnal
snowstorm.  This was actually an experiment run of the Surface Tension
Driven Convection Experiment which studies thermocapillary flows using
aluminum oxide particles suspended in silicone oil illuminated by a
laser light.  By relaying commands to Payload Commander Kathy Thornton
to adjust the temperature parameters on the surface of the liquid,
Project Scientist Alex Pline and his science team are able to study
the transition from steady fluid flows to more oscillating, or
unstable flows, that result when heat is applied to a liquid's
surface.

  Thermocapillary flows are present on Earth in many industrial and
materials processing methods, but are difficult to study due to the
presence of gravity-driven fluid flows.  By conducting this experiment
in microgravity, scientists can isolate the thermocapillary flows,
gaining insight on how and why they occur.

  The Astroculture plant growth facility continues to operate
smoothly, providing the proper water, humidity and light to the small
potato tubers growing within the apparatus.  Co- investigator Dr. Ted
Tibbitts commented on the progress of the 10 small potatoes.  "They
look very happy and well, staying very turgid, which means they have
not wilted, so the environment is good for them," he said.  Downlink
video shows only green leaves, since the tubers are buried in the
soil.  That's the exciting part, Tibbitts said, but something their
team won't see until the end of the mission.

  The potatoes will be studied after the mission to determine the
effects microgravity has on starch accumulation in plants.  Scientists
believe plants will play an important role in long-duration space
flights, such as missions on the International Space Station,
providing food and water to crews, replenishing oxygen and also
helping remove excess carbon dioxide from the air.  Investigators also
believe plants could provide a psychological lift to astronauts in an
otherwise sterile environment.

  "I think it's beautiful," exclaimed Payload Specialist Al Sacco
describing the 1 inch (8 cubic centimeter) drop of water he
successfully deployed and released from the Drop Physics Module
apparatus this morning.  A crew member manipulates the liquid drops
using sound waves in order to study their behavior under the influence
of external forces.  This type of research will help investigators
understand science and technology in which liquid drops have a role,
from rain formation and weather patterns to chemical processing.

  Later this week, an experiment known as Science and Technology of
Surface-Controlled Phenomena will be conducted with a surfactant added
to the water drop.  Surfactants, such as soap, reduce the holding
power of a liquid surface.  These chemicals play an important role in
industrial processes, among them the production of cosmetics, the
dissolution of proteins in synthetic drug production and the
enhancement of oil recovery.  Data from these observations should give
a better understanding of the molecular forces acting in the surface
layer of simple water drops and should provide a better basis for
industrial applications.

  Near the end of the red shift, Pilot Ken Rominger used a camcorder
to film a couple of unattended experiment operations starting with the
Commercial Generic Bioprocessing Apparatus.  This multi-user facility
allows a variety of sophisticated bioprocessing experiments to be
performed in one piece of hardware.  Major areas of focus on USML-2
include biomedical testing and drug development, ecological systems
development and biomaterials products and processes.

  Next Rominger focused his camera on the Crystal Growth by
Liquid-Liquid Diffusion apparatus sponsored by the Marshall Space
Flight Center in Huntsville, Ala.  The experiment consists of four
transparent hand-held diffusion test cells, attached to the outside of
a Shuttle middeck locker so they are easily seen.  In this unique
crystal growth facility, proteins and precipitants diffuse into one
another by random action of molecules instead of being mixed.

  Sacco spent about 4 hours this afternoon in the Glovebox facility
activating protein crystal growth samples.  Later the samples were
transferred to a specialized incubator maintained at a prescribed
temperature.  Proteins play important roles in daily life, from
providing nourishment to fighting disease.  Because a protein's
structure determines its function, researchers seek to grow large,
well-ordered crystals for post-mission structural analysis.

 On Tuesday, October 24, 1995, 5 p.m. CDT, STS-73 MCC Status Report #10
reports:

  The Red Team members will hand over science operations to their 
colleagues on the Blue Team at 6:38 p.m. CDT today, then resume work in the 
Spacelab at 6:38 a.m. CDT Wednesday.

  On Wednesday's schedule for televised events is an NBC News Channel
interview with Mission Specialist Michael Lopez-Alegria at 5:43
a.m. CDT and a special video downlink at 7:23 a.m. CDT in anticipation
of Game Five of the 1995 World Series. The crew will downlink video of
STS-73 Commander Ken Bowersox throwing out the ceremonial first
pitch. The video will be played on the Jacobs Field TV screen in
Cleveland before Thursday's game.

   STS-73 Flight Day 6 Highlights:

 On Wednesday, October 25, 1995, 7:30 a.m. CDT, STS-73 MCC Status Report #11
reports:

  As the Blue Team was finishing up it's shift, Mission Specialist
Mike Lopez- Alegria was interviewed by the NBC Newschannel. During the
5:23 a.m.  CDT interview, Lopez-Alegria said the crew was
well-adjusted to the onboard routine and "having a ball."

  The Blue Team completed it's shift at 6:38 a.m. CDT and the Red Team
-- Commander Ken Bowersox, Pilot Kent Rominger, Payload Commander
Kathy Thornton and Payload Specialist Al Sacco -- is now on
duty. During the Red Team shift today, Bowersox, Thornton and Sacco
will all have a half -day off. Shuttle crew members are each given a
day off to relax during long- duration shuttle missions such as
STS-73. Bowersox and Thornton will have time off during the first part
of the shift and Sacco will have time off during the later part of
today's shift.

  The port payload bay door on Columbia remains partially closed,
about 51 degrees from fully open. However, at about 8:43 a.m. CDT,
Bowersox will fully open the door. It will remain open for about one
hour to allow for a dump of water from the condensate tank associated
with the United States Microgravity Lab-2 module. The lab condensate
tank collects water from dehumidifiers in the lab and must be dumped
periodically, about each six days, during lab flights. The door is
being opened during the dump to ensure there is ample clearance for
the wastewater, which is ejected from a nozzle on top of the lab's
forward end cone. Once the dump is completed, the door will again be
closed partially to protect the radiators and cooling lines along its
interior from debris impacts in orbit due to the shuttle's orientation
and extended stay in space.

 On Wednesday, October 25, 1995, 6 a.m. CDT, STS-73 Payload Status Report #08
reports: (5/21:07 MET)

  Overnight activities aboard the second United States Microgravity
Laboratory were a balanced mix of crew-intensive fluid physics
experiments and ground-controlled investigations into both fluid
behavior and crystal growth.

  At around 1 a.m. CDT, the Crystal Growth Furnace team finished
solidifying a cadmium zinc telluride crystal for Principal
Investigator Dr. David Larson of the State University of New York in
Stonybrook.  The furnace will be allowed to gradually cool until this
afternoon.

  Cadmium zinc telluride is used as a substrate, or base material, for
infrared detecting crystals found in products such as cancer detection
devices and the militarys night- vision goggles.  A similar
crystal grown on USML-1 was a thousand times more defect-free than any
comparable crystals ever grown on the ground. Larson hopes to
demonstrate that the exceptional quality can be reproduced with the
USML-2 sample.

  "A sizable amount of effort and research money is going toward
Earth-based efforts to improve substrate material," said Larson.  The
space-grown crystals will give researchers the opportunity to prove
the widely held assumption that better substrate material would
dramatically improve infrared detectors.

  Mission Specialist Cady Coleman operated the Surface Tension Driven
Convection Experiment.  Initially, she lowered the level of silicone
oil within the chamber to create a deeply concave surface.  Later, she
added oil until the surface rounded outward -- the experiment's first
run with a convex surface.  The size of the laser beam on the oil
surface was adjusted to see how it affected the direction and nature
of fluid flows, and the temperature was gradually increased to
pinpoint when the flows began to oscillate.  As they varied experiment
conditions, ground team members saw a number of interesting
oscillation patterns never observed in Earth- bound research under the
influence of gravity.  These observations will help scientists better
understand manufacturing processes on Earth and how to improve them --
avoiding defects caused by unwanted flows when materials are cooled
from a liquid or gaseous form.

  With Coleman operating the surface tension experiment, Payload
Specialist Fred Leslie practiced drop deployment in the Jet Propulsion
Laboratory's Drop Physics Module.  He then began the mission's first
experiment for Principal Investigator Dr. Taylor Wang of Vanderbilt
University in Nashville.  A cheer went up from the science team as
Leslie finally succeeded in the delicate process of inserting an air
bubble inside a floating water drop.  This experiment examines the
fluid physics of the resulting liquid shell.  It could lay the ground
work for encapsulating living cells to treat hormonal disorders such
as diabetes.  An insulin- producing pancreatic cell could be injected
into the body encased in a polymer shell, which would protect the cell
from immunological attack and provide timed release of the drug.

  "There are actually two factors at work in liquid spherical shells:
fluid physics and chemical reactions," said Wang.  "With these space
experiments, we are able to separate them."  Ground-based studies of
these complex interactions are hampered by the small size of the drops
which must be used and the constant motion induced by gravity.  USML-2
experiments will allow experimentation with larger, stationary drops
over a longer period of time.

  The Geophysical Fluid Flow Cell team completed another six- hour run
to simulate atmospheric conditions on the sun.  They gradually stepped
up the electric charge on the experiment to simulate the increase in
gravitational force as the sun increases mass in later stages of its
evolution.  This instrument revealed several new types of convection
on its first flight, Spacelab 3, in 1985.  Improvements for USML-2,
including real-time video data, should allow even greater insights
into the often baffling fluid flows of complex stellar and planetary
atmospheres.

 On Wednesday, October 25, 1995, 6 p.m. CDT, STS-73 Payload Status Report #09
reports:  (5/09:07 MET)

  A short period of leisure time was built into the schedule for the
red shift science crew of the second United States Microgravity
Laboratory (USML-2) mission today.  Payload Commander Kathryn Thornton
took her break in the morning, leaving Payload Specialist Al Sacco to
enjoy his time off in the afternoon.

  Sacco spent the first part of his shift working in the Glovebox
facility on protein crystal growth experiments.  Various proteins from
laboratories around the world are being grown in this facility.
Activating one of these protein crystal growth experiments involves
mixing a selected protein solution with another solution, which
activates growth.  The crystals are then placed in an incubator
facility at a precise temperature.  Sacco today initiated new protein
crystal growth experiments, based on his observations of previous sets
of investigations.  He adjusted experiment parameters in order to
modify protein crystal growth conditions such as mixing procedures,
crystal seeding, crystal mounting and crystal preservation.

  Sacco brought on line the last of the 14 major experiment facilities
during his morning shift.  Marshall Space Flight Center's Suppression
of Transient Accelerations by Levitation Evaluation (STABLE) is a test
designed to isolate a small science experiment from high-frequency
accelerations, including Shuttle operations and crew activity.  The
device uses a suspended platform controlled by electromagnetic
actuators.  Accelerometers on the platform provide data on Shuttle
disturbances' data which allows position sensors to locate the
platform with respect to the base, keeping the platform centered
between disturbances.  This greatly reduces accelerations and gives
the experiment a smoother ride.  An experiment known as CHUCK will
debut on STABLE later in the mission.

  Sacco continued work today in the Geophysical Fluid Flow Cell
Experiment facility.  The experiment uses a stainless steel hemisphere
about the size of a baseball, surrounded by a sapphire hemisphere,
with silicone oil between the two.  By applying an electric charge to
the hemispheres, a crew member creates artificial gravity.  Other
parameters changed with each run are the temperature of the silicone
oil and the speed of the hemispheres' rotation.  In this way, a
variety of fluid flows in oceans, planets and stars are mimicked,
possibly helping forecast ocean flows and weather patterns.  According
to Principal Investigator Dr. John Hart, "We've already discovered
several interesting things, and we've been able to modify our
experiment operations and investigate things we wouldn't have been
able to do otherwise."

  Pilot Ken Rominger and Sacco kept a close check on growing zeolites
in the Zeolite Crystal Growth furnace today.  Zeolites are inorganic
compounds of aluminum, silicon and oxygen whose porous structures make
them valuable catalysts and purifiers for the chemical processing
industry.

  "We want to learn more about how zeolites nucleate and grow, and
more about their structure, so we can apply that knowledge to
different processes on Earth," said Co-principal Investigator
Dr. Nurcan Bac of the Worcester Polytechnic Institute.  "For instance,
one of the zeolites in this experiment is widely used by the petroleum
refining industry to crack heavy oils into gasoline.  If we can
increase the efficiency of this type of zeolite, we could get more
refined petroleum products from the same amount of crude oil."

  Near the end of his shift, Sacco conducted a purge of the argon gas
in the Crystal Growth Furnace.  Sacco vented the gas then pumped fresh
argon into the experiment chamber.  This prepared the furnace for the
third crystal to be grown in the facility on USML-2: a sample of
gallium arsenide, a semiconductor material.  Gallium arsenide crystals
are valuable for use in electronic devices and a variety of other
products.  Provided by the Case Western Reserve University, the
experiment principal investigator is Professor David Matthiesen, also
an alternate payload specialist for USML-2.

  This crystal of gallium arsenide will enable scientists to refine
techniques for more uniformly distributing a dopant, or impurity,
during growth.  Impurities are added to these semiconductor compounds
to improve or precisely control their electronic characteristics.  To
produce high quality gallium arsenide crystals, scientists need to
understand the process by which these impurities are distributed
within the compound during crystal growth.

  Sacco set up the Surface Tension Driven Convection Experiment,
getting it ready for Thornton to begin experiment runs after her
break.  While Thornton conducted constant temperature baseline tests
on the fluid's curved surface, creating a variety of kaleidoscope-like
patterns in the oil, video was downlinked to investigators on the
ground.  They periodically relayed commands to Thornton to increase or
decrease temperatures across the surface of the fluid, allowing
investigators to study the transition from stable fluid flows to the
more unstable ones that result when the temperature is increased.  One
key factor prompting this research is that unwanted fluid flows can
create defects in the production of high-tech crystals, metals, alloys
and ceramics.  Thus investigators are seeking to understand how and
why they occur.

 On Thursday, October 26, 1995, 5 p.m. CDT, STS-73 MCC Status Report #12
reports:

   Columbia's crew members participated in two special events during
their sixth flight day as the orbiter itself continued to perform
problem-free as did science investigations underway in the Spacelab.
Early Wednesday Mission Specialist Michael Lopez-Alegria participated
in an interview with NBC Newschannel.  Also on Wednesday, STS-73 crew
members gathered in the shuttle's middeck and taped the ceremonial
first pitch that will open Game Five of the World Series Thursday
night in Cleveland, Ohio. The taped message and the first pitch will
be played on the "Jumbotron" screen at Jacobs Field in Cleveland and
viewed by a nationwide audience on ABC-TV. Commander Ken Bowersox
wished the Atlanta Braves and the Cleveland Indians good luck before
he threw the slow-spinning pitch, marking the first time a World
Series first pitch thrower has not been in the ballpark to make the
pitch.  Columbia's astronauts will sign the on-board baseballs and
give them to Major League Baseball to be enshrined in the Baseball
Hall of Fame in Cooperstown, N.Y.

  Crew members on the Red Team mark the end of their work day at 6:38
p.m. CDT and will return to their work shift in the Spacelab at 6:38
a.m.  Columbia is in a 169 by 164 statute mile orbit, completing a
revolution of the Earth each 90 minutes.

   STS-73 Flight Day 7 Highlights:

 On Thursday, October 26, 1995, 8 a.m. CDT, STS-73 MCC Status Report #13
reports:

  Research work continued on schedule overnight aboard Columbia as the
crew also continued a schedule of staggered half-days off duty to
relax from the around-the-clock operations.

  Mission Specialist Cady Coleman and Payload Specialist Fred Leslie
each had a half-day off during the night. The Red Team of crew members
is now at work aboard Columbia, having begun their 12-hour shift at
6:38 a.m.  CDT

  Although it had no effect on the research work, a ground system
problem caused two extended communications outages between Columbia
and the ground during the night. The time frame for the outages was
known in advance by Mission Control and the crew was informed. All
data from the experiments and the shuttle itself during the
communications loss was recorded aboard Columbia and has since been
played back to the ground.

  The communications loss was due to an equipment failure at the
ground terminal for NASA's tracking and communications satellites. The
failure prohibited communications using the eastern Tracking and Data
Relay Satellite (TDRS-E), a satellite stationary above the Atlantic
Ocean used during about the last one-third of each orbit by
Columbia. On two successive orbits during the early morning hours,
communications were unavailable on TDRS-E, the first time for about 36
minutes and the second time for about 27 minutes, while the ground
equipment was being repaired.

  Columbia is in a 169 by 165 mile orbit, completing a revolution of
Earth every 90 minutes. The spacecraft remains in excellent condition,
and there are no issues of concern in Mission Control regarding its
performance.

 On Thursday, October 26, 1995, 6 a.m. CDT, STS-73 Payload Status Report #10
reports: (5/21:07 MET)

  Crew activities were relatively quiet aboard the second United
States Microgravity Laboratory overnight, as Mission Specialist Cady
Coleman and Payload Specialist Fred Leslie took turns getting a few
hours rest from their busy schedules.  The mission's many crystal
growth experiments continued uninterrupted, taking advantage of unique
opportunities for discovery available only in the low-gravity
environment of space.

  The Crystal Growth Furnace team finished melting Dr. David
Matthiesen's gallium arsenide crystal and began slowly resolidifying
the semiconductor sample.  At almost 2,300 degrees Fahrenheit (1,255
degrees Celsius), the furnace is operating at the highest temperature
it will reach during the mission.  A new Crystal Growth Furnace
feature for USML-2 will periodically mark the point where the melted
material is solidifying with an electric pulse.  When the crystal is
analyzed after landing, the marks will indicate the exact growth rate
of the crystal and the location of the solid/liquid boundary at each
stage of solidification.

  Electronic devices using gallium arsenide semiconductors, such as
high-speed digital circuits, operate at higher speeds and use less
power than those using silicon crystals.  Matthiesen's experiment
investigates techniques for uniformly distributing a small amount of
selenium within the crystal as it grows in microgravity.

  "There is less than one part per million of selenium in this
sample," said furnace team member Dr. Frank Szofran of Marshall Space
Flight Center.  "Yet it greatly alters the electrical conductivity of
the semiconductor."  Trace materials, called dopants, are often added
to semiconductors to improve or precisely control their electronic
characteristics.  To produce high quality crystals, scientists need to
understand the process by which dopants are distributed within a
compound during crystal growth.  Growing the crystals in microgravity
greatly reduces uneven dopant distribution caused by gravity on Earth,
allowing more subtle influences to be identified.

  Leslie and Coleman spent most of their on-duty hours working with
the Surface Tension Driven Convection Experiment (STDCE).  Last
night's runs were the first to use the experiment's largest chamber,
almost 1-1/4 inches (3 centimeters) in diameter.  As they have for the
past five days, the science team in Huntsville and the Spacelab crew
on orbit worked together to precisely adjust temperatures on the
silicone oil surface.  Again, they were able to pinpoint when
surface-temperature-driven flows within the fluid became unsteady, or
oscillatory.  This was the first time oscillatory flows had ever been
observed in such a relatively large container.  Coleman reported
seeing especially dramatic, wave-like oscillations near the center of
the fluid flow during some of her experiment runs.  Unwanted fluid
flows affect the quality of materials solidified from a molten state
on Earth.  Understanding the subtle factors which control those flows
gives researchers tools for eventually controlling them.

  Several factors are contributing to the success of the USML-2
surface-tension experiments.  A new optics system developed by
Dr. H. Philip Stahl and students from Rose Hulman Institute of
Technology in Terre Haute, Indiana, gives the crew and ground
controllers precise pictures of oil surface shapes and flow patterns.
Spacelab's new six-channel Hi-Pac Television system is simultaneously
downlinking video of those images, along with a three-dimensional view
of the chamber and infrared temperature readings, giving the science
team a complete representation of the experiment.

  STDCE team members also have been keeping a close eye on real-time
data from the Three-Dimensional Microgravity Accelerometer, or 3-DMA.
The low-frequency vibration detector has a sensor located in the rack
next to the surface tension experiment.  "3-DMA allows us to make a
judgment as to whether to wait for external movements to settle down
before beginning an experiment run," said Project Scientist Alex
Pline.

  On its first Shuttle flight, 3-DMA was developed as a low- cost
commercial accelerometer system by the University of Alabama at
Huntsville's Consortium for Materials Development in Space.  The
instrument measures both the absolute level of microgravity
acceleration (the difference between zero acceleration and what is
experienced during the mission) and microvibrations which could affect
the investigations onboard.  Principal Investigator Jan Bijvoet worked
in Huntsville for the European Space Agency when it was developing the
Spacelab over a decade ago.  "It's good to have an experiment aboard
'my' Spacelab," he said.

  The Geophysical Fluid Flow Cell Experiment team is wrapping up
another six-hour solar atmosphere simulation, and growth continues in
the Zeolite Crystal Growth Furnace and the many USML-2 protein crystal
growth experiments.

 On Thursday, October 26, 1995, 5 p.m. CDT, STS-73 MCC Status Report #14
reports

   Work on board the Space Shuttle Columbia continued to go smoothly
as members of the Red Team monitored orbiter systems and conducted
scientific experiments in the Spacelab.

   Red Team members spent their seventh flight day working diligently
in the science lab which is nestled in Columbia's cargo bay. The
Red Team will wrap up its day at 5:38 p.m. CDT, a little earlier than
they have the last few days. They will hand over to Blue Team members
who will continue work in the Spacelab. The Red Team will return to
duty at 5:38 a.m. CDT.

  Friday's scheduled telelvision events include: an ABC "World News
Now" interview at 8:23 a.m. with STS-73 Commander Kenneth Bowersox and
Payload Commander Kathyrn Thornton; Mission Update at 11:30 a.m.; and
a Mission Status Briefing at 1 p.m.

  Columbia is in a 169 by 165 mile orbit, completing a revolution of
Earth every 90 minutes. The spacecraft is in excellent condition and
flight controllers did not have any issues they are working regarding
the orbiter's performance.
	
 On Thursday, October 26, 1995, 6 p.m. CDT, STS-73 Payload Status Report #11
reports: (6/09:07 MET)

  Payload Commander Kathy Thornton and Payload Specialist Al Sacco had
a busy day conducting a wide variety of experiments in the
microgravity environment aboard the Shuttle Columbia in the second
United State Microgravity Laboratory (USML-2).

  The Colloidal Order-Disorder Transition experiment, an investigation
into the solidification process in crystal growth, revealed unexpected
results today.  In studying electronic still photographs provided by
Sacco this morning, researchers saw that crystals of varying sizes
were formed in the samples.  This is something they haven't seen on
Earth.

  Sacco told researchers on the ground that particles in the 15 sample
vials were randomly spaced, and ranged in size from 10 to 150 microns
(millionth of a meter).  Scientists are interested in what happens at
the boundaries between solid and liquid states during crystallization
of a colloid, allowing them to see how atoms and molecules move and
arrange themselves when they form a crystal.  This may help improve
materials processing methods on Earth, as well as in microgravity.
 
  A crystal of the semiconductor material gallium arsenide has grown
about 1 inch (2-1/2 centimeters) since it was placed in the Crystal
Growth Furnace last night.  The temperature in the Crystal Growth
Furnace is the hottest it has been during this mission' between 22 and
23 hundred degrees Fahrenheit . The crystal is growing at a rate of
1.8 millimeters per hour.  Although this is a slow growth period,
gallium arsenide crystals have the potential to make computers,
satellites and other electronics work much faster than with silicon
chips.  Chips made of gallium arsenide are now too expensive for
widespread use - current processing techniques yielding only one good
chip out of every ten that are made.

   Thornton this morning began deploying liquid drops in the Drop
Physics Module in tests to help the science team finalize a procedure
to slow down the rotation of the drops.  Later, the USML-2 crew will
add a small amount of chemical, called a surfactant, to the drop in an
experiment known as Science and Technology of Surface Controlled
Phenomena, managed by Principal Investigator Dr. Robert E. Apfel, of
Yale University.  Scientists are comparing characteristics of drops
containing surfactants to drops of pure water.  Surfactants are
substances which alter the surface properties of a liquid, aiding or
inhibiting the way it adheres to or mixes with other substances.
Applications of this research apply to many industrial processes,
among them the production of cosmetics and improvement of oil
recovery.

    University of California's Riverside's Dr. Alex McPherson is 
principal investigator for the handheld diffusion test cells 
experiment.  The experiment is growing proteins by liquid-
liquid diffusion, a process in which fluids diffuse into each 
other by random motion of molecules, rather than being mixed 
together.  This method is difficult on Earth because gravity 
causes solutions with different densities to mix.  The 
experiment is a precursor for long-duration crystallization 
experiments aboard the International Space Station and Mir.

  The Three-Dimensional Microgravity Accelerometer experiment ground
support team continues to troubleshoot the cause and resolution of a
data downlink problem.  This has not impacted science since all data
is recorded onboard the Shuttle.  This experiment measures
accelerations and vibrations that could affect investigations in the
Spacelab.

  Thornton spent the afternoon working with the Surface Tension Driven
Convection Experiment.  Researchers on the ground relayed instructions
for Thornton to raise the temperature of the silicon oil surface in
order to study the change from steady thermocapillary fluid flows to
oscillatory (or unsteady) flows.  This investigation could one day
lead to better, stronger high-tech crystals, metals, alloys and
ceramics.

  Sacco spent the last part of his shift working in the Glovebox
activating new protein crystal growth experiments, based on his
observations of results from previous experiments.  An advantage of a
longer mission like USML-2 is that it allows science teams on the
ground to perform several experiment runs, analyze their data, and
have the crew devise a new set of experiments.  This allows
investigators to quickly capitalize on their observations in real
time.

   STS-73 Flight Day 8 Highlights:

 On Friday, October 27, 1995, 8 a.m. CDT, STS-73 MCC Status Report #15
reports:

  Flight controllers in Houston had a quiet shift last night as orbiter
systems continue to perform well, allowing work on board the Space
Shuttle Columbia continue uninterupted.

  Red Team members are now spending their their eighth day in
space. Earlier this morning, Commander Ken Bowersox and Payload
Commander Kathy Thornton took a moment to talk to ABC's World News
Now about the progress of the flight and life on board Columbia. In
response to a question about the living conditions on the orbiter,
Thorton explained that the extra space provided by the Spacelab
laboratory module and the fact that the crew is split into two teams
for 24-hour payload operations, makes the living space quite
comfortable.

 On Friday, October 27, 1995, 6 a.m. CDT, STS-73 Payload Status Report #12
reports: (6/21:07 MET)

  "We feel like we're back home at Marshall in the Payload Crew
Training Complex," said Mission Specialist Cady Coleman last night,
referring to the Marshall Space Flight Center Spacelab mockup where
she and her crewmates spent many hours preparing for the second United
States Microgravity Laboratory mission.  Overnight, Coleman and
Payload Specialist Fred Leslie performed now-familiar duties with
protein crystal growth and fluid flow experiments, and also tested a
new vibration- isolation facility.

  Coleman completed the mission's first technical demonstration with
the Suppression of Transient Acceleration by Levitation Evaluation, or
STABLE.  Developed cooperatively by the Marshall Space Flight Center
and McDonnell Douglas, STABLE is the first facility to use
electromagnetic levitation to isolate sensitive experiments from
disturbances in the Shuttle.

  Coleman activated a simple experiment within the levitation device
by heating a fluid-filled cell, then observed it with a laser light.
To the delight of the science team in Huntsville, the experiment's
small optical system recorded the resulting heat diffusion.  This
experiment, known as "CHUCK," was designed in Marshall's Space
Sciences Lab as a small, simple system to study materials processes in
microgravity that are applicable to crystal growth mechanics.  For the
first run, the STABLE platform floated free through the action of
electromagnets.  The platform was locked in place for a repeat run.
Comparisons should help determine the effectiveness of STABLE for
reducing background vibrations.

  Both STABLE and CHUCK were produced in less than five months, from
the time designers got the go-ahead for construction this past January
until they delivered the equipment to Kennedy Space Center in June.
Engineers on these projects were working under a new NASA committment
to streamline the development of lower cost space hardware.

  Later in the shift, Coleman examined growing protein crystals under
the Glovebox microscope.  Commercial Protein Crystal Growth team
members watched downlink video of the magnified crystals from their
home lab at the University of Alabama in Birmingham.  Coleman reported
that the crystals were bigger and seemed to be growing in isolation
rather than in clumps.  One crystal in particular was so well-formed
that the fist look at it elicited applause from the Birmingham team.
Coleman then activated more samples of the same proteins based on
observations of growth progress thus far.  She jokingly told the
experiment team that she has given up caffeinated coffee just for
them, "since you have to be so careful with these things," referring
to the delicate handling required for protein crystals.

  The Glovebox protein crystal growth evaluation is one of several
USML-2 experiments aimed at determining the best methods for growing
protein crystals.  In the middeck, the European Space Agency's
Advanced Protein Crystallization Facility is growing protein crystals
by three different methods.  An internal camera is recording video
images of the growing crystals.  After the mission, researchers will
study development of the crystals in microgravity to determine why and
how proteins nucleate and begin to form crystals.

  A decade of Shuttle protein crystal growth experiments has led to
improved methods for ground-based experiments, as well as producing
well-ordered crystals which have allowed the structures of several
proteins to be determined.  Understanding the structures of proteins,
such as those related to diseases, is important for developing custom-
tailored molecules, such as drugs, to interact with them.

  As has been true for the majority of the mission, Leslie spent most
of his shift working with the Surface Tension Driven Convection
Experiment.  The Lewis Research Center investigation is gathering
extyensive new data on subtle fluid flows created by surface
temperature variations.  In a typical operation, Leslie drew down the
volume of silicone oil within a 1-1/4 inch (3 centimeter) cylinder
until it formed a deeply concave surface -- a surface shape possible
only in microgravity with a container this large .  Leslie heated the
fluid, first very steadily, and again in several pronounced steps.
The Case Western Reserve University science team reported seeing
distinct differences in the heating power levels at which fluid flows
became unsteady, or began to oscillate, with the two heating
scenarios.  A thorough understanding of fluid physics forms a valuable
base for improvements in sophisticated materials processing.

  Also last night, Coleman reset a Drop Physics Module circuit breaker
which tripped yesterday when some film jammed, and the facility is
ready for experiment operations later today.  More Surface Tension
Driven Convection Experiment runs are also scheduled.  Growth of a
gallium arsenide semiconductor within the Crystal Growth Furnace will
continue until early tomorrow morning.

 On Friday, October 27, 1995, 5 p.m. CDT, STS-73 MCC Status Report #16
reports:

  Systems on board the Space Shuttle Columbia continue to work well
despite a temporary glitch concerning two steering jets.  About 1:15
p.m. CDT two vernier jets - R5R and R5D - failed off at the same time.
However, about 40 minutes later, after ground controllers reviewed
data, the crew hot fired the jets and they were recovered. There was
no loss of science data and minimal impact on the day's activities.

  Each orbiter has 38 primary thrusters and six smaller vernier
thrusters which provide vehicle steering.  Shortly after the two
vernier jets failed this afternoon, the crew took the orbiter from a
gravity gradient attitude, which requires sporadic firing of steering
jets, to free drift. Columbia had been flying in a gravity gradient
attitude - which has the tail of the orbiter facing the Earth and its
nose facing deep space - to minimize shuttle movement in support of
science operations in the Spacelab, particularly the growth of protein
crystals. The temporary loss of the two vernier jets occurred while
crystals growing in the Spacelab were cooling down so there was no
impact on the experiment.

  Early this afternoon crew members also downlinked views of a ding in
one of the orbiter's front windows.  There are six windows along
the front of the orbiter, three on the commander's side and three
on the pilot's side. The ding was in the center window on the
commander's side or the second window from the left.

Shuttle windows encounter dings from orbital debris or natural
material such as meteoroids from time to time. The dings are analyzed
by scientists after the shuttle has landed to determine size and
material source. JSC debris scientists said the largest ding returned
on a shuttle window thus far occurred on STS-59 in April 1994. The
ding measured one-half an inch in diameter and was caused by an
orbiting paint chip. Based on what they saw in the downlinked video,
scientists estimated the Columbia's ding was most likely no larger
than about one-eighth of an inch across, but said exact measurements
and a determination of the source material would have to await the
shuttle's return to Earth.

  Columbia is in a 169 by 165 mile orbit, completing a revolution of
the Earth every 90 minutes.

 On Friday, October 27, 1995, 6 p.m. CDT, STS-73 Payload Status Report #13
reports: (7/09:07 MET)

  Lead scientists for two USML-2 investigations, Astroculture and the
Geophysical Fluid Flow Cell Experiment, showed experiment pictures to
the crew early this morning, via the new Ground-to-Air Television
uplink being tested on this mission as STS 73 completed its first week
in space.

  "This is the first time that crop plants have been grown to produce
edible food in space," observed Astroculture co- investigator
Dr. Theodore Tibbitts.  Also, for the first time, scientists have been
able to obtain data on respiratory cycles and starch accumulation for
plants in a NASA controlled space environment.  Starch is an important
nutrient in plants, and these measurements will tell whether
space-grown potato tubers have the same nutritional value as their
Earth-grown counterparts.  The benefits of having plants in space go
well beyond providing a food source.  Plants will provide a naturally
recycling life support system in space by helping remove excess carbon
dioxide and replenishing oxygen, and by providing a natural way to
purify water in a space-borne habitat.

  Astroculture Principal Investigator Dr. Raymond Bula of the 
University of Wisconsin in Madison pointed out leaf patterns 
in a photo of potato plants growing in the plant growth 
chamber aboard the Shuttle.  "The thing that's been exciting 
to us is that, in the three images that have come down at 
different times, the leaves are in the same position.  This 
means that the plants are healthy.  If they had been having 
problems, the leaves would have shifted," Bula said. 

   "This is all kind of new and exciting stuff," explained Dr. 
John Hart of the University of Colorado  in Boulder, 
principal investigator for the Geophysical Fluid Flow Cell, 
while showing the crew a time lapse movie of simulated solar 
atmospheric flows.  The movie was made from the still photo 
images, snapped every 45 seconds, of fluid flows within the 
facility's rotating hemisphere.  "You can see a lot of the 
evolution of these solar dynamic flows we've been interested 
in, and we've seen some surprising turbulence," Hart told the 
crew.  "We are comparing these results with our computer 
simulations and other theoretical ideas to understand the 
extensive turbulence which starts near the polar region and 
spreads rapidly toward the equator."  This morning, the GFFC 
simulated the long-term changes that will eventually occur in 
the Sun.  

  Payload Specialist Dr. Al Sacco began his shift operating the
Surface Tension Driven Convection Experiment Apparatus.  Throughout
the day, researchers on the ground relayed instructions for Sacco and
Thornton to manipulate the temperature of the silicon oil surface in
order to study the change from thermocapillary fluid flows to unsteady
flows.  This investigation could one day lead to better, stronger
high-tech crystals, metals, alloys and ceramics.

  Working in the Glovebox, Sacco had an opportunity to demonstrate the
device's versatility, growing protein crystals in the morning then
switching to zeolites in the afternoon.  The system can offer one or
two levels of containment for toxic materials, liquids and particles.
It can operate with gloves for full containment, sleeves for more
sensitive surgical glove operation or with all doors removed as an
open workbench observation platform.  Al Sacco is principal
investigator for two USML-2 investigations into the growth of zeolite
crystals, widely used as catalysts and filters in the chemical
processing industry.

  A crystal of the semiconductor material gallium arsenide has
finished the crystal growing portion of the processing cycle in the
Crystal Growth Furnace.  The crystal grew to more than two inches in
length and will continue cooling until being removed tomorrow morning.
After cooling, the crystal will be removed from the furnace and stored
using a flexible glovebox.  Gallium arsenide is used in high-speed
digital circuits, solid-state lasers, and a variety of other
applications.

  Al Sacco worked at the Drop Physics Module, manipulating liquid
drops treated with a surfactant, or substance that changes the
properties of liquid surfaces.  Two drops were deployed and brought
together until they coalesced, or merged to form a single drop.  The
surfactant, called Bovine Serum Albumin, is an organic protein
typically used in chemical processing.  Sacco twice succeeded in
making the drops coalesce.  "These are the first and best drop
coalescences we've ever had," said DPM co-investigator Dr. Eugene
Trinh of NASA's Jet Propulsion Laboratory, adding, "it went very
nicely."  The Drop Physics Module allows investigators to study large
drops in which dynamic phenomena (such as coalescence) are slowed down
and more easily seen.  They can observe how flows inside a drop and
the drop's surface interact to provide a variety of dynamic events.
This fundamental knowledge can be beneficial for a variety of
industries on Earth, from pharmacology to industrial chemistry.

   STS-73 Flight Day 9 Highlights:

 On Saturday, October 28, 1995, 8 a.m. CDT, STS-73 MCC Status Report #17
reports:

  The Space Shuttle Columbia continues to perform well on its 18th
mission, allowing crew members and flight controllers time to
concentrate on the United States Microgravity Payload experiments.
This morning, Columbia passed the midway mark of its marathon mission.

  Flight controllers in Houston had another quiet shift last night with
orbiter systems functioning normally. This gave the team plenty of
time to fine tune the timeline for the Red Team's ninth day in
space. Columbia's smooth operation also is allowing orbiter crew
members to assist in the science operations in the Spacelab module.

 On Saturday, October 28, 1995, 6 a.m. CDT, STS-73 Payload Status Report #14
reports: (7/21:07 MET)

  Mission Specialist Cady Coleman and Payload Specialist Fred Leslie
took turns conducting investigations within the European Space
Agency's versatile Glovebox enclosure as the second United States
Microgravity Laboratory-2 mission reached its half-way point.

  Leslie worked with two Glovebox investigations sponsored by NASA's
Lewis Research Center in Cleveland, Ohio.  First, he photographed
several containers holding different concentrations of microscopic
plastic spheres suspended in liquid for the Colloidal Disorder- Order
Transition experiment.  Dr. Paul Chaikin of Princeton University hopes
to determine at which concentration the collisions between the spheres
change the mixture from a disordered fluid state, with the spheres
moving haphazardly, to an ordered crystalline state in which they are
arranged in a symmetrical way.

  "We are studying the most fundamental transition between liquid and
solid states, to find what is really important in the formation of
solids and crystals," said Chaikin.  The behavior of the spheres in
space, essentially free from the disruption of gravity, is a basic
model for the way atoms interact with one another.  All physical
properties of matter such as weight, hardness and color are determined
by the kind of atoms present and how they interact.

  Leslie's next Glovebox activity, the Interface Configuration
Experiment, studied the behavior of a fluid in microgravity as it
filled a specially shaped chamber.  Glovebox Investigator Dr. Paul
Concus of the University of California at Berkeley and Co-
Investigators Dr. Robert Finn of Stanford University, and Mark
Weislogel of NASA's Lewis Research Center watched live video as
ruby-tinted fluid began flowing into three containers, each with
slightly different internal angles.  The scientists were able to see
definite differences in the way the fluid adhered to chamber walls in
the various containers, and some of the behavior was different from
that predicted by the classic mathematical model.

  "This shows that we cannot rely completely on the current theory of
how surfaces form in low gravity, which is based on an equation
developed in the 1800's," said Weislogel.  "We saw that physical
factors which are not included in the purely mathematical theory do
indeed play a significant role."  Insights will aid design of fluid
systems for space such as those for liquid fuels.

  Coleman activated more proteins for the Glovebox Protein Crystal
Growth experiment, this time using larger drops of protein solution.
She has initiated growth of new protein samples during several recent
shifts, adjusting conditions based on the progress of previously
activated crystals.  This hands-on involvement of crew members will
help Dr. Larry DeLucas of the University of Alabama at Birmingham
determine the best growth methods for various proteins during future
Shuttle and Space Station experiments.

  Mission Specialist Mike Lopez-Alegria deactivated a crystal growth
chamber for a portion of Dr. Dan Carter's Protein Crystallization for
Microgravity Apparatus experiment.  This was one of eight chambers,
activated early in the flight, which contain two salt solutions rather
than actual proteins.  The two solutions, with different
concentrations of salt, will gradually diffuse into one another until
the salt concentration is uniform.  The crew is deactivating one
container about every two days to detect the point in time when the
diffusion is completed.  Carter will use results to estimate the rate
at which solutions will diffuse during actual protein crystal growth
experiments in microgravity.

  "We know that proteins grow more slowly in space than on Earth, but
we don't know why," said protein specialist Brenda Wright of Marshall
Space Flight Center.  "We've wanted to do an experiment for a long
time that would help us predict the rate at which certain crystals
will grow, so we can be more efficient with these valuable proteins
and our time in orbit.  But up until now, we haven't had the room to
fly anything but actual proteins."  Because Carter's apparatus holds
many times more samples in the same volume of space than traditional
crystallization facilities, room was available for the test on USML-2
.  Scientists use the well-formed crystals grown in space to analyze
protein structures, a key to determining how these "building blocks of
life" function in the human body and other biological systems.

  Early this morning, Lopez-Alegria rolled the orbiter's position
about 17 degrees to put its left wing directly into the path of
flight, an attitude the Geophysical Fluid Flow Cell (GFFC) experiment
scientists believe might further reduce disturbances to its
experiment.  The Shuttle will maintain that orientation until about 8
a.m. CDT.  The fluid flow cell team is running solar atmosphere
simulations at a slower rotation, to determine if the special Shuttle
attitude makes a discernible difference.  The facility uses a
combination of rotation, temperature and gravitational variables to
simulate fluid flows in the atmospheres of the sun and planets.

  The Suppression of Transient Acceleration by Levitation Experiment,
or STABLE, completed its final run for the mission during the Shuttle
maneuver.  After the mission, a Marshall Center team will analyze
video of a small experiment inside the levitation device to see if
STABLE isolated the experiment from disturbances as the orbiter
changed position.

 On Saturday, October 28, 1995, 5 p.m. CDT, STS-73 MCC Status Report #18
reports:

   With all continuing to proceed smoothly aboard Columbia on the 72nd
Space Shuttle mission, the seven astronauts that make up this
microgravity laboratory mission have passed the mid-point of the
flight.

  A short while ago, four the crew members completed their ninth
workday in space and were relieved by the remaining three astronauts.
The crew is split into two shifts working around the clock to support
the many experiments that make up this second dedicated United States
Microgravity Laboratory mission.  Ken Bowersox, Kent Rominger, Kathy
Thornton and Al Sacco turned in for the evening about 6 p.m. and are
scheduled to take over for Mike Lopez-Alegria, Cady Coleman and Fred
Leslie about three tomorrow morning.

   STS-73 Flight Day 10 Highlights:

 On Sunday, October 29, 1995, 9 a.m. CDT, STS-73 MCC Status Report #19
reports:

  After spending eight hours with its belly pointed toward the sun,
Columbia is back in position to support the sensitive United States
Microgravity Laboratory-2 experiments.  For this mission, Columbia's
normal attitude has its left wing pointing in the direction of travel
and its tail pointed toward the Earth.  This attitude, however,
exposes some portions of the orbiter to the extreme cold of space for
long periods of time.  To keep the pressure in the tires at the levels
necessary to support landing operations, the flight control team is
implementing its pre-flight plan for "thermal conditioning" of the
cold areas.

  The maneuver, which will be conducted four times during the mission,
calls for crew members to reposition Columbia so that the sun shines
directly on the lower portion of the orbiter.  At the conclusion of
the first conditioning period, the tire pressure was measured at 334
pounds per square inch (psi), an increase from 328 psi before the
period.  The nominal end of mission pressure is targeted at 330 psi.

 On Sunday, October 29, 1995, 6 a.m. CDT, STS-73 Payload Status Report #15
reports: (8/21:07 MET)

   Research in the unique laboratory environment of space continued at
a steady pace over the last 24 hours aboard the second United States
Microgravity Laboratory.

   During one experiment run yesterday, the Surface Tension Driven
Convection Experiment team observed a phenomenon that had never been
seen before.  Fluid flows were erratic, with no obvious organization
or pattern, as Payload Commander Kathy Thornton increased the silicone
oil surface temperature beyond the point at which flows within the
fluid began to oscillate, or become unsteady.  Overnight, the ground
team conducted several test runs remotely from the Spacelab control
center, freeing the crew for other activities.  The experiment seeks
to define the factors which cause subtle, surface-temperature-driven
fluid flows to become oscillatory.  Researchers from Case Western
Reserve University in Ohio will use the extensive data gathered during
USML-2 to graph the onset of oscillations under many conditions.  A
better understanding of how and why such fluid flows occur will be
valuable for industrial applications from fuel management and storage
to materials processing methods such as welding.

   In a related Glovebox investigation, Payload Specialist Fred Leslie
performed the mission's first run of the Oscillatory Thermocapillary
Flow Experiment.  Though it uses much simpler equipment, the purpose
and procedure are similar to Surface Tension Driven Convection
Experiment tests.  The major difference is the proportions of the
container.  The STDCE chamber's diameter is twice its own height,
while this Glovebox investigation used a very shallow chamber with a
diameter four times its height.  Different chamber sizes provide even
more variables for determining the onset of unstable
surface-temperature-driven fluid flows.

  Thornton and Payload Specialist Al Sacco exchanged sample cartridges
in the Crystal Growth Furnace yesterday, replacing three processed
samples with three new ones.  Last evening, the facility completed its
shortest crystal growth cycle, depositing a thin layer of
infrared-detecting mercury cadmium telluride on a base material, or
substrate, in just one and a half hours.

  "We're examining ways to reduce what we call crystal 'birth
defects,' which are transferred from defects in the substrate material
which can't be eliminated," said Principal Investigator Dr. Heribert
Wiedemeier of the Rensselaer Polytechnic Institute.  "In the crystal
we grew on USML-1, the interface between the substrate and the first
layer was much smoother than in crystals produced on the ground.  This
was totally new, something we had never seen before and had not
expected."

  On USML-2, Wiedemeier is growing much thinner layers to see how far
substrate defects propagate into the first crystal layer.  On the
ground, the crystal material first forms separate "islands" on the
base, which join to form a complete layer after about two hours of
growth.  Wiedemeier grew his first USML-2 crystal on Sunday for two
and one-half hours to be sure a compete layer was produced.  "With
last night's sample, we deliberately stopped growth in less time than
it takes for a layer to form on Earth.  However, there is a good
chance that under microgravity we may get a complete layer in the
shorter time period," he said.

  If this mission demonstrates that certain reduced convection
conditions produce more uniform initial layers in a shorter growth
time, Wiedemeier feels it could lead to crystal growth methods on
Earth that are faster, require less material and energy, and therefore
are less costly.

  Sacco completed activating protein crystal growth experiments in the
Glovebox facility yesterday afternoon.  Thus far, more than 50
individual experiments have been set up using seven different proteins
-- from viral disease proteins to several involved in the human immune
system.  USML-2 crew members will observe the samples on Thursday to
monitor the growth of the crystals.  Proteins play vital roles in
daily life, from providing nourishment to fighting disease.  Many
areas of biotechnology benefit from new information on the structure
of proteins, such as development of food crops with higher protein
content and basic research toward more effective drugs.

  Team members for the Geophysical Fluid Flow Cell Experiment slowed
down the rotation of their experiment hemisphere to get additional
data which relates to fluid motions in Earth's core -- motions that
cause such phenomena as the forced drift of the Earth's continents.
The fluid flow cell is an investigation in fluid dynamics that models
fluid flows in planets, stars and oceans, using silicone oil between
two rotating hemispheres.  Controllers can vary electrical charges
which simulate gravity, as well as fluid temperature and rotation
speed of the hemispheres, to reflect conditions in different
environments.

  Overnight, Mission Specialist Cady Coleman patiently worked through
problems with computer equipment to complete several runs of the
Glovebox Colloidal Disorder-Order Transition (CDOT) investigation.
CDOT uses microscopic plastic spheres suspended in a liquid to model
the behavior of atoms.  As planned, red shift crew members will
complete the CDOT activities later today.

  When he came back on duty early this morning, Payload Specialist Al
Sacco began a series of experiments in the Drop Physics Module to
examine how chemical additives, called surfactants, affect liquid drop
behavior.  The drop studies will continue throughout today's shift.

   STS-73 Flight Day 11 Highlights:

 On Monday, October 30, 1995, 8 a.m. CST, STS-73 MCC Status Report #20
reports:

  On its eleventh day on orbit, the Space Shuttle Columbia continues to
provide the United States Microgravity Laboratory-2 with a stable
platform above the Earth for the astronauts to conduct a myriad of
experiments.

  Flying at an altitude of 170 miles, Columbia is positioned with its
tail pointing toward the Earth and its port wing pointing in the
general direction of travel.  This "gravity gradient" attitude
is maintained with only minimal thruster firings.  The orbiter will
stay in this position until around midnight tonight when Columbia will
begin a 14-hour thermal conditioning period with its belly pointed
toward the sun.

 On Monday, October 30, 1995, 6 a.m. CST, STS-73 Payload Status Report #16
reports: (9/21:07 MET)

  Drop physics studies and Glovebox investigations dominated crew
activities during the tenth day in orbit for the United States
Microgravity Laboratory-2, while the mission's many remotely
controlled experiments collected valuable data as well.

  Geophysical Fluid Flow Cell (GFFC) experiment runs yesterday seem to
validate predictions in a mathematical model of planetary and solar
fluid flows designed by Co-Investigator Dr. Tim Miller.  GFFC
scientists saw different heat-driven, or thermocapillary, flow
patterns when the same conditions were initiated at different rates.
For instance, voltage, temperature and rotation speed parameters
applied slowly to the experiment's silicone-oil-filled hemispheres
produced one thermocapillary fluid flow, and a different flow resulted
when the same parameters were applied to the experiment quickly.

  "These particular flows are relevant to cases where you might have a
planet with a core that's still moving around -- still convecting --
and also planets with atmospheres that are rotating very slowly," said
Miller.  The experiment facility, which simulates fluid flows in
oceans, planets and stars, is operated from the ground with only
occasional adjustments and monitoring by the crew.  Research in
thermocapillary flow phenomena could one day aid in forecasting ocean
flows and weather patterns.

  The Crystal Growth Furnace finished melting its second gallium
arsenide semiconductor sample yesterday afternoon, then began slowly
moving the furnace module down the length of the sample cartridge to
solidify the crystal.  Early this morning, the experiment team changed
the furnace translation rate from seven one hundredths of an inch (1.8
millimeters) per hour to seven tenths of an inch (18 millimeters) per
hour.  This ten-fold increase will help Principal Investigator
Dr. David Matthiesen determine whether the solidification rate
influences the formation of bubbles in semiconductor crystals.
Gallium arsenide crystals promise important advantages for electronic
applications, operating at high speeds and using less power than
traditional silicon semiconductors.

  Over the past 24 hours, Payload Commander Kathy Thornton, Payload
Specialist Al Sacco and Mission Specialist Cady Coleman conducted a
series of Drop Physics Module experiment runs for Dr. Robert Apfel of
Yale University.  The experiment examines the influence of chemicals
called surfactants on the behavior of liquid drops.  Surfactants are
substances that migrate toward the free surfaces of liquids, resulting
in a reduction of surface tension, or a weakening in molecular
"skins."  For instance, soap contains surfactants which makes water
"wetter."  The various crew members levitated different sized drops
containing surfactants, then squeezed them with sound waves.  Drop
Physics Module team members observed the drops' oscillations and
surface distortions from two perspectives, both of which were
transmitted to the ground simultaneously by Hi-Packed Television.

  Dr. Apfel used results from related USML-1 experiments to confirm
and adjust theoretical models.  This mission's experiments will help
him refine these theories, which apply to processes as widespread as
the production of cosmetics to the recovery of oil spills and
environmental cleanup.

  Sacco performed operations for the Colloidal Disorder-Order
Transition investigation, a Glovebox study which seeks to answer
fundamental questions about how liquids become solids.  Tiny spheres
suspended in a fluid were clustered together in crystallized
formations, in a model of how atoms arrange themselves to transition
from liquid to solid states.  Research of this type could lead to
improvements in materials processing on Earth, such as developing
micromachines or better surgical tools.  The science team expects to
get at least a 90 percent return on science from their data, despite
time lost troubleshooting several equipment problems.

  Payload Specialist Fred Leslie followed up on two Glovebox studies
which delve into fundamental factors of fluid behavior.  He
photographed the position of red fluid inside a mathematically
designed, transparent container for the Interface Configuration
Experiment.  The study examines how angles within a container affect
the way fluids shift within it.

  Leslie also completed the mission's second run of the Oscillatory
Thermocapillary Flow Experiment, heating the surface of silicone oil
in a container whose depth equaled its diameter. The run successfully
pinpointed the transition between steady and unsteady heat-induced
fluid flows.  The investigation duplicates the Surface Tension Driven
Convection Experiment (STDCE), but uses containers with different
depths to provide additional insight into the fluid-flow phenomenon.
According to Project Scientist Alex Pline, results were consistent
with STDCE results from earlier in the mission.  The team is building
an extensive catalogue of data on these subtle fluid motions which can
affect materials processing on Earth.

  Leslie was unsuccessful in several attempts to coax fuel drops onto
a fiber in the Glovebox Fiber Supported Droplet Combustion
investigation.  The heptane fuel stubbornly adhered to deployment
needles, probably due to degradation of the needles' non-stick
coating.  The Glovebox team is comparing notes with members of other
experiment teams and USML-2 payload controllers to identify other
non-stick substances aboard which might be substituted.

 On Monday, October 30, 1995, 5 p.m. CST, STS-73 MCC Status Report #21
reports:

  Columbia will remain in the "gravity gradient" attitude, with its
tail pointing toward the Earth and its port wing in the line of
travel, until about midnight tonight when the orbiter will begin a
14-hour thermal conditioning period with its belly pointed toward the
Sun.  That change in attitude will mark the second of four scheduled
thermal conditioning periods designed to warm up some portions of the
orbiter that, in the gravity gradient attitude, have been exposed to
the extreme cold of space for long periods of time. The thermal
conditioning is necessary to warm the orbiter's tires to levels
necessary to support landing.

  The Red Team handed over science operations to their colleagues on
the Blue Team at 2:38 p.m. CST. The Blue Team will be on duty until
2:38 a.m.  Tuesday when the Red Team returns to work.

 On Monday, October 30, 1995, 6 p.m. CST, STS-73 Payload Status Report #17
reports: (10/09:07 MET)

  The USML-2 Crystal Growth Furnace experiment team today successfully
grew a crystal of gallium arsenide with a dopant, or impurity, added.
Later, the crystal will be tested to determine if the dopant was
evenly distributed during the crystal's growth.  Slightly more than
one-inch (7 centimeters) in length, the semiconductor crystal grew for
12 and one half hours.  To produce high-quality gallium arsenide
crystals, scientists need to understand the processes by which
chemical impurities are introduced, whether intentionally or
unintentionally.  Electronic devices made from these crystals operate
at higher speed and use less power.

  After setting up the Surface Tension Driven Convection Experiment
this morning, Payload Specialist Al Sacco stepped aside and surface
tension experiment team members on the ground were able to run the
experiment's heater power by remote commanding.  Team members observed
the experiment performance via a multi-channel digital television
link.  The remote commanding capability gave the team a chance to get
extra data on their experiment, while Sacco and Mission Specialist
Kathryn Thornton were working with other investigations.  The surface
tension experiment studies the transition between steady fluid flows
to oscillatory, or unstable, fluid flows.

  Today's surface tension experiment runs featured a test cell with a
spacer disk inserted into the bottom of the chamber.  This cut the
chamber's depth in half, thereby lowering the amount of fluid in the
cell.  An increase in power was necessary to push the fluid flows to
the transition point, giving the experiment team even more data for
discussion and post-mission analysis.  Studying surface tension-driven
fluid flows holds valuable applications in areas of materials
processing such as the production of high-tech crystals, metals,
alloys and ceramics.

  Dr. Robert Apfel with Yale University, whose experiment studies the
effect of surfactants, or chemicals, on the surface of a liquid drop
in the Drop Physics Module, says the drops' large oscillations, caused
by sound waves, have revealed detailed motions in the sample during
the experiment runs.  Data he has thus far received on his experiment
is clear, concise and definitive, allowing him to measure specific
oscillation points.  He will use this information in post-mission
analysis, comparing it to his numerical predictions.

  Crew members continue to keep an eye on a Spacelab VCR which
experienced a brief problem while recording Drop Physics Module data
early this morning.  The VCR is up and running, and the drop physics
team believes all their data was captured on the experiment film
magazine when the problem occurred.

  Sacco spent about two hours this afternoon photographing and filming
the progress of experiments in the Commercial Generic Bioprocessing
Apparatus, a facility which is used for a wide variety of life-science
experiments.  The development of the tiny brine shrimp living in the
facility are of interest to investigators, as they could shed light on
the importance of gravity in human development and aging.  The
different stages of the growing protein crystals within the facility
were also recorded in today's photo session.  Proteins are molecules
which serve biological functions.  Understanding the structure of
these molecules gives scientists an idea what other molecules would
interact with the protein and change the way it functions, for
instance to help cure or treat an illness.

   STS-73 Flight Day 12 Highlights:

 On Tuesday, October 31, 1995, 8 a.m. CST, STS-73 MCC Status Report #22
reports:

  With all orbiter systems and payload activities continuing to run
smoothly, members of the STS-73 Red Team are taking a break today from
their busy schedule.  STS-73 Commander Ken Bowersox and Payload
Specialist Al Sacco had their off-duty time during the first part of
the Red Team's shift, while Pilot Kent Rominger and Payload Commander
Kathy Thornton will have some free time during the second half of the
team's day. These "off duty" times are used by the flight control team
to keep the crew well rested for the duration of the 16-day mission.

  Columbia is nearing the end of a 14-hour thermal conditioning period
designed to warm the underside of the orbiter and increase the landing
gear tire pressure. For the United States Microgravity Laboratory-2
mission, Columbia usually flies in a stable gravity gradient attitude
with its tail pointing toward the Earth and its port wing pointing in
the direction of travel. The gravity gradient attitude requires only
minimal thruster firings to maintain the orbiter's position, but
shades the underside of the orbiter where the landing gear is housed.

 On Tuesday, October 31, 1995, 6 a.m. CST, STS-73 Payload Status Report #18
reports:  (10/22:07 MET)
	
  The second United States Microgravity Laboratory added to an already
bulging "portfolio" of scientific information as it completed an
eleventh day in space.  "It's really great to be collecting all this
data that we've been planning on for so long," said Mission Specialist
Cady Coleman as she sent video views of USML-2 experiment facilities
to scientists on the ground.

  Last night's Particle Dispersion Experiment confirmed a theory about
the behavior of dust and particle clouds proposed by Glovebox
Investigator Dr. John Marshall, who works with the SETI Institute and
NASA's Ames Research Center in California.  Payload Specialist Fred
Leslie agitated several small transparent chambers inside the
Glovebox, dispersing particles of volcanic material, rounded quartz,
angular quartz or copper within the various chambers.  Marshall
watched Glovebox video as dispersed particles in each of the chambers
gradually clumped together, or aggregated, due to electrostatic
attraction.

  This validates Marshall's hypothesis that aggregation occurs in all
dust clouds: the planetary nebulae which coalesce to form stars,
global dust storms on Mars, dust clouds from a meteor impact on Earth
(such as the one some believe led to extinction of the dinosaurs), and
clouds of dust and ash flung into Earth's atmosphere during volcanic
eruptions.  The particles are drawn together by static electrical
charges.  Because the resulting clumps are heavier than individual
particles, they fall to the ground to cleanse the atmosphere (or move
to the center to form stars) more rapidly than would be predicted by
gravitational theory alone.

  The USML-2 investigation built on results of a technology study on
USML-1, which tested methods for dispersing small particles in
microgravity.  "Because of the success of the USML-1 investigation, we
were able to flesh out our science objectives and test variables like
particle size, density of the cloud, and type of material.  All the
materials showed a similar propensity to aggregate," said Marshall.

  Leslie conducted several more runs for the Glovebox Oscillatory
Thermocapillary Flow Experiment, this time using a very shallow
silicone oil chamber to see how the shallow depth affects the onset of
unstable fluid flows.  A few small bubbles, introduced into the oil as
Leslie filled the chamber, moved in concert with aluminum tracer
particles to illustrate fluid flow patterns in the last experiment
run.  The Glovebox investigation complements the Surface Tension
Driven Convection Experiment's probe into the conditions which cause
heat-induced fluid flows to become unsteady, or oscillate.

  Geophysical Fluid Flow Cell Experiment controllers began their first
observation scenario simulating the atmosphere of the planet Jupiter.
The giant gas planet radiates more heat than it receives from the sun,
making its atmosphere of particular interest to Principal Investigator
Dr. John Hart and other atmospheric scientists.  "These early runs
show dramatic changes in flow types with very small variations in the
instrument settings," said University of Colorado Team Member Scott
Kittelman.  Investigations for the remainder of the flight will
concentrate on atmospheres like those of the gaseous planets Jupiter,
Saturn and Uranus.  Hart feels that lessons learned by studying these
"gas giants" can be brought forward to apply to fluid flows on the
Earth.

  Early in Coleman's shift, she stretched a "bridge" of liquid between
Drop Physics Module injector tips, in an operation designed to profile
the chamber's acoustic characteristics.  The Jet Propulsion Laboratory
facility's four loudspeakers produce precisely balanced sound waves,
used to position and manipulate liquid drops within the chamber.  The
acoustics system was upgraded after USML-1, and the experiment team
used last night's runs to refine their understanding of how various
acoustic controls affect drop manipulation in microgravity.

  Mission Specialist Mike Lopez-Alegria made several adjustments to
bring fuel deployment needles closer together in the Fiber Supported
Droplet Combustion experiment hardware.  Glovebox investigators hope
this will make it possible to deposit fuel drops onto a stretched
fiber during upcoming experiment runs.  Yesterday's planned combustion
study was thwarted when the needles would not come close enough to the
fiber for the fuel to adhere to it.

  The Crystal Growth Furnace has cooled down, after processing Dr.
David Matthiesen's gallium arsenide semiconductor crystal.  The
furnace is beginning to melt the next sample, another cadmium zinc
telluride semiconductor crystal for Dr. David Larson.  This sample is
contained in a modified ampoule designed to force the crystal to
adhere evenly to chamber walls, further reducing defects.

  As they have throughout the mission, the Space Acceleration
Measurement System (SAMS) and the Orbital Acceleration Research
Experiment (OARE) tracked accelerations caused by movements and
vibrations within the Shuttle, as well as by Shuttle maneuvers and
atmospheric drag.  Both are part of the Lewis Research Center's
Principal Investigator Microgravity Services project, which provides
information to help space scientists evaluate effects of accelerations
on sensitive microgravity experiments.  Both instruments make
continuous records of accelerations for analysis after the flight.  In
addition, OARE is providing profiles of relatively steady, or
low-frequency, accelerations to the USML-2 mission scientist every 12
hours.

  A Spacelab video cassette recorder which malfunctioned briefly
yesterday morning is back to normal operations, with no loss to USML-2
science data collection.

 On Tuesday, October 31, 1995, 5 p.m. CST, STS-73 MCC Status Report #23
reports:

  Shortly after 11 a.m. CST, crew members reported they were unable to
see the Cosmos 398 because of bright sunlight although the shuttle
passed within about 75 statute miles of the spacecraft. The Cosmos 398
is an old Soviet lunar module now circling the Earth at a lower orbit
than the shuttle.  It was launched into orbit by the former Soviet
Union in 1971 and, due to program changes, was left in space.

  About 1:04 p.m. ended its 14-hour thermal conditioning period and
returned to a gravity gradient attitude. Tuesday's conditioning period
marked the second of four planned warm-up sessions. The thermal
conditioning periods are designed to warm the underside of the orbiter
and subsequently increase the landing gear tire presssure.

  For the United States Microgravity Laboratory-2 mission, Columbia
usually flies in a stable gravity gradient attitude with its tail
pointing toward the Earth and its port wing pointing in the direction
of travel. The gravity gradient attitude requires only minimal
thruster firings to maintain the orbiter's position, but shades the
underside of the orbiter where the landing gear is housed. The
remaining two warm-up sessions are targeted to occur on Thursday and
Friday.

  The Red Team handed over mission activities to their colleagues on
the Blue Team at 2:38 p.m. CST and will resume their work at 2:38 a.m.
Wednesday.

 On Tuesday, October 31, 1995, 6 p.m. CST, STS-73 Payload Status Report #19
reports: (11/09:07 MET)

   USML-2's Crystal Growth Furnace has finished melting a second
sample of the semiconductor material cadmium zinc telluride, and the
crystal has begun to solidify.  This crystal is being slowly
solidified in one direction, for a more perfect structural
arrangement.  On Earth, cadmium zinc telluride is used as a substrate,
or base, for growing mercury cadmium telluride crystals, useful for
making infrared radiation detectors.  The alloying element, zinc, is
added to minimize the strain where the two crystals join, thereby
reducing defects.  Defects caused by gravity driven fluid flows on
Earth produce less perfect crystals and thus less perfect end
products.  This is the sixth semiconductor crystal to be grown on
USML-2 in the Crystal Growth Furnace.

   This afternoon Payload Specialist Al Sacco continued changing
parameters in the Geophysical Fluid Flow Cell Experiment to produce a
variety of fluid flows which mimic those in planets, atmospheres and
stars.  Today's experiments continued a series which study the
atmospheres of gaseous planets such as Jupiter and Saturn.  Scientists
hope lessons learned from these studies can apply to fluid flows on
Earth.  Researchers will use data from this experiment to build better
computer models of fluid behavior which could one day aid in
forecasting ocean flows and weather patterns.

  A demonstration used to isolate sensitive experiments from small
vibrations and disturbances in the Shuttle was deactivated today.
Earlier this week, the Suppression of Transient Acceleration by
Levitation Evaluation, or STABLE, was tested with an experiment called
"CHUCK," an investigation designed to study materials processes in
microgravity that are applicable to crystal growth mechanics.
Comparisons of these data will be made post-mission, and should help
determine the effectiveness of STABLE for reducing background
vibrations.  The STABLE experiment was designed and developed by
McDonnell Douglas of Huntington Beach, Calif., and NASA's Marshall
Space Flight Center.

   Early in the blue shift, Mission Specialist Cady Coleman began
setting up the Drop Physics Module for an experiment run which will
involve positioning a drop of water in the center of a silicon oil
drop.  Precise adjustments to sound waves within the drop chamber may
enable Coleman to maneuver the water drop to the oil's center.  The
ability to deploy and manipulate compound drops is an important step
towards uniform encapsulation -- a technique which could aid
scientists in using polymer systems to study the encapsulation of
living cells aimed at the possible treatment of hormonal disorders
such as diabetes.

  In other Drop Physics Module activity, scientists obtained detailed
observations of the water drops and how they are affected by
surfactants, or chemicals, that change the surface tension.  In
today's experiments, different concentrations of the same chemical
were added to the drops which Payload Commander Kathryn Thornton then
manipulated using sound waves.  Principal Investigator Dr. Robert
Apfel of Yale University gathered a plethora of data on the
oscillations of the drops which were squeezed and then released so
their shapes, thanks to microgravity, repeated themselves over a
period of time.

  Surfactants change the properties of a liquid drop, and are of
interest to scientists for the role they play in countless industrial
processes, from the production of cosmetics, to the dissolution of
proteins in synthetic drug production.  Another application could be
the production of new surfactants with more desirable properties.

  During the next 12 hours, crew members Coleman and Payload
Specialist Fred Leslie will alternate their four-hour breaks, working
with the Drop Physics Module, the Oscillatory Thermocapillary Flow
Experiment, and the Geophysical Fluid Flow experiment.

   STS-73 Flight Day 13 Highlights:

 On Wednesday, November 1, 1995, 8 a.m. CST, STS-73 MCC Status Report #24
reports:

  Columbia is currently maintaining its "gravity gradient" attitude
with the orbiter tail pointing towards the Earth and the port wing
pointing in the direction of travel. It will maintain its position,
which provides crew members with a stable platform in which to conduct
the USML-2 experiments, until a nine-hour thermal conditioning session
on Thursday beginning at 2:23 a.m. CST.

  Because the gravity gradient attitude shades portions of the
orbiter, the thermal conditioning periods are needed to warm the
underside of the orbiter and subsequently increase the landing gear
tire pressure.  Following Tuesday's 14-hour thermal conditioning
period, the flight control team recorded a 14 psi increase, from 325
psi to 339 psi, in the left landing gear tires.  After refining the
estimates for the orbiter's weight and center of gravity, flight
controllers are now gearing their thermal conditioning plans to
provide a minimum pressure of 326 psi in the landing gear tires at the
end of the mission. A fourth warm-up session is planned for Friday.

 On Wednesday, November 1, 1995, 6 a.m. CST, STS-73 Payload Status Report #20
reports: (11/21:07 MET)
 
   Successful science operations continue on flight day 12 of the
second United States Microgravity Laboratory Spacelab mission.  The
crew and investigators are interacting effectively, optimizing science
return and proving USML-2 to be a superb example of a true interactive
science laboratory.

  "The drop is right in the middle; I tell you the bubble is looking
great," observed Mission Specialist Cady Coleman, after successfully
centering a water drop within a drop of silicone oil in the Drop
Physics Module.  This compound drop configuration was achieved while
the interfaces of the water and oil drops were moving in opposite
directions, a condition known as "slosh mode."  According to Drop
Physics Module Program Scientist Arvid Croonquist of NASA's Jet
Propulsion Laboratory, this is the first time during the mission that
this has been accomplished, and Drop Dynamics Experiment Principal
Investigator Taylor Wang described the data gathered as "very
important" and as having "major significance."

   The Drop Dynamics Experiment, developed by Vanderbilt University,
serves to gather high-quality data on the motions of liquid drops in
low-gravity for comparison with theoretical predictions.  Data from
these studies may help scientists to design novel drug delivery
systems for medical treatment.  "I've been imagining it for eighteen
months," said Coleman regarding the centered drop, "so it's sure nice
to see it for real."

   Geophysical Fluid Flow Cell co-investigator Fred Leslie of NASA's
Marshall Space Flight Center monitored the experiment's simulations of
Jupiter's inner atmosphere.  The GFFC is intended to study how fluids
move in microgravity, helping researchers understand the large-scale
fluid dynamics of stellar and planetary atmospheres such as Jupiter's.
The large-scale motions of these atmospheres are strongly constrained
by rotation and gravity.  This creates forces that cause thermal
circulations, and these atmospheric structures are often surprising
and continue to baffle scientists seeking fundamental understanding of
such phenomena as Jupiter's zonal bands, especially of the atmospheric
layers that cannot be seen from Earth.

   "We hope this will give us ideas about the hidden inner atmosphere
of Jupiter." explained GFFC co-investigator Dan Ohlsen.  According to
Payload Specialist and co-investigator Fred Leslie, "Much of the
emphasis is on the sun and Jupiter, but there are also some areas of
applicability to the Earth.  We can isolate certain phenomena with the
experiment and take out some of the complicating things in terms of
climate-- things like rainfall and clouds."  Leslie and others on the
GFFC science team sometimes characterize the experiment system as
enabling studies of "a planet in a test tube."

   Fred Leslie next turned his attention to the Glovebox facility and
the Oscillatory Thermocapillary Flow Experiment, developed by NASA's
Lewis Research Center.  The purpose of this experiment is to study the
conditions under which thermocapillary flows change from steady to
oscillatory, or variable.  These flows result from surface tension
variation along a liquid/gas free surface.  In particular, OTFE
complements the Surface Tension Driven Convection Experiment by
allowing the science team to investigate the effect of changing the
shape of the test chamber during the beginning of oscillations or
variations.

   Oscillatory fluid flows are a type of phenomena which can affect
Earth-based materials processing and some engineering applications, by
causing unwanted flows when materials are cooled from a liquid or a
gas form.  Therefore, it is very important for scientists to
understand these phenomena and be able to predict the conditions under
which they occur, as well as their nature and extent.  Although these
oscillatory, or variable, flows can be studied on Earth under very
specific sets of conditions, the effects of thermocapillary flows are
hidden by the dominant effects of gravity-driven fluid motions.
Knowledge of the behavior of thermocapillary flows is important
because of the influence fluid flows have in areas such as fuel
management and material processing methods.

 On Wednesday, November 1, 1995, 5 p.m. CST, STS-73 MCC Status Report #25
reports:

  Members of the Red Team handed over to their Blue Team counterparts
at 2:38 p.m. CST. After a 12-hour workday, the Blue Team will hand
over to the Red Team at 2:38 a.m. Thursday.  During the afternoon,
mission specialists Michael Lopez-Alegria and Cady Coleman
participated in an interactive educational event with students in
Bozeman, Montana, and Las Cruces, New Mexico.

  Columbia continues to orbit the Earth at an 170-mile high altitude
in a gravity gradient attitude with the orbiter tail pointing towards
the Earth and the port wing pointing in the direction of
travel. Because the gravity gradient attitude shades portions of the
orbiter, thermal conditioning periods are needed to warm the underside
of the orbiter and subsequently increase the landing gear tire
pressure. Thus far in this mission, Columbia has undergone two warm-up
periods and two more are expected. The next session is scheduled for
Thursday and will last about nine hours.

 On Wednesday, November 1, 1995, 6 p.m. CDT, STS-73 Payload Status Report #21
reports: (12/09:07 MET)

  Today the USML-2 Colloidal Disorder-Order Transition team observed
something unusual -- and unexpected -- in one of their colloidal
sphere experiment samples.  Downlink video indicated uniform crystals
throughout the length of a sample team members thought was too densely
packed to grow crystals.  On Earth, this dense concentration causes
the spheres to move so slowly that the crystals only form on a
geological time scale (millions of years).

  The experiment, which is being performed in the Glovebox, studies
the fundamental theories that model atomic interactions.  One way to
learn how atoms interact is by studying groups of simple, larger
particles that behave in a similar manner.  This experiment, called a
colloid, uses microscopic solid plastic spheres suspended in a fluid
to model atomic interactions.  The Colloidal Disorder-Order Transition
experiment shares a fundamental characteristic with atomic systems --
both undergo a transition from a disordered liquid state to an ordered
solid state under the proper conditions.  An example is water
molecules becoming ordered to form ice.  Research in this field could
lead to improved materials processing on Earth.

  Payload Specialist Al Sacco sent down the first close-up views of
growing zeolite crystals to team members here on the ground this
morning.  The team saw a uniform population of suspended particles
throughout the samples, which was expected.  This space-based
experiment is unlike an identical mixture which is growing at the
Worcester Polytechnic Institute in Worcester, Mass.  Gravity on Earth
has caused the particles in that experiment to settle.

  Sacco, who is principal investigator for the zeolite furnace
experiment, refined the composition of USML-2 zeolites, which are
formed by mixing a silica solution and an alumina solution, in hopes
of growing even larger crystals with less, or controlled, defects for
post-mission structural analysis.  Zeolite crystals are used in the
chemical process industry as filters, catalysts, and adsorbents.

  Investigators for the Geophysical Fluid Flow Cell Experiment today
imposed parameters on their experiment which produced more
Earth-atmosphere-like flows than on previous runs.  The team sent
instructions to Payload Commander Kathryn Thornton to do a
"terrestrial" run of the experiment, mimicking the large temperature
gradient from the Earth's equator to its poles.  This produced waves
in the experiment fluid flows much like those in our jet stream.  The
fluid flow cell experiment uses silicone oil between two rotating
hemispheres to model flows in oceans and atmospheres of planets and
stars.  Rotation speed of the hemispheres, fluid temperature, and
electrical charges (which simulate gravity) are changed with each run
to reflect conditions in the different environments.  Information
gleaned from investigations such as this could aid in forecasting
ocean flows and weather patterns.

  The small potatoes in the Astroculture plant facility continue to
grow and are healthy.  Sacco observed the plants' growth today,
sending video downlink of the potato leaves which, though wilting, are
performing normally.  This tells investigators that the potatoes are
getting the proper nutrients, light, water, and humidity from the
facility, which is being tested on USML-2 as a viable apparatus for
growing plants in microgravity.  Long-duration space stays may
necessitate growing plants to minimize the cost of life support.
Plants can help provide food, oxygen, and pure water and can also
assist in removing carbon dioxide from human space habitats.  The
potatoes are being grown to study how starch accumulation in plants is
affected by the microgravity environment.

  The sixth semiconductor crystal to process in the Crystal Growth
Furnace continues its growth in a unique apparatus which prevents wall
contact, allowing the sample material to form a liquid bridge.  The
crystal is being grown for comparison to semiconductor crystals grown
on USML-1, which indicated the more defect-free areas occurred where
the sample material did not touch the wall of the container during
growth.  The crystal has grown a little over one-and- a-half inches (4
centimeters) and will continue its growth period for about 8 more
hours.  The crystal will be dissected post-mission to identify the
effects of gravity as a factor in causing structural defects in the
crystal system.  Crystals of cadmium zinc telluride are used for
infrared radiation detectors.

  Drop Physics Module investigators recorded the behavior of an oil
drop today, subjecting it to the same vigorous sound waves as those
imposed previously on a drop of water.  Comparisons between the
surface behavior of these two drops, and the behaviors of other drops,
will be made post-mission using a library of video recorded during the
USML-2 mission.  Other experiment runs today, part of Dr. Taylor
Wang's investigations on the behavior of liquid drops in low gravity,
include manpulating a bubble in a drop of oil and a drop of water with
a small amount of surfactant added.  With each experiment run,
Thornton increased the sound waves, or combined different sound wave
intensities to produce a variety of behaviors from these drops.

  Scientists will use data from these experiments for comparison with
theoretical predictions and ground-based studies using very small
drops.  It will provide scientific and technical inputs for the
development of new fields, such as containerless processing of
materials and polymer encapsulation of living cells.

  STS-73 Flight Day 14 Highlights:

 On Thursday, November 2, 1995, 8 a.m. CST, STS-73 MCC Status Report #26
reports:

   Columbia, with both payload bay doors fully open, currently is in
its third thermal conditioning session designed to warm the underside
of the orbiter.  It will remain in the "belly to sun" attitude until
about 2 p.m. Thursday afternoon.

 On Thursday, November 2, 1995, 6 a.m. CST, STS-73 Payload Status Report #22
reports: (12/22:07 MET)

  "Things are going fantastically well, and we're just looking forward
to getting as much science in the remaining time as we can," explained
USML-2 Alternate Payload Specialist Glynn Holt early this morning in
an interview for Mutual NBC Radio as fluid physics and combustion
science took center stage on the thirteenth night of the second United
States Microgravity Laboratory mission.

   Spacelab systems and facilities continued to operate well and
gather good data.  The crew worked with the Fiber Supported Droplet
Combustion experiment in the Glovebox, performed the fission
experiment in the Drop Physics Module, monitored fluid flows for the
Geophysical Fluid Flow Cell experiment, and initiated the last run of
the Supression of Transient Acceleration by Levitation Evaluation
(STABLE) vibration isolation system.

   "Fred gets an A+ in combustion theory," exclaimed investigators for
the Fiber Supported Droplet Combustion experiment (FSDC), offering
Payload Specialist Fred Leslie "a collective high-five" for his
"outstanding work" in the Glovebox facility.  Leslie had been placing
drops of fuel on a thin fiber, using needles in the experiment module,
and igniting them with a hot wire.  Earlier in the evening, Leslie
worked closely with the FSDC science team to successfully troubleshoot
difficulties with clogged drop accumulators, and then performed a
series of excellent burns, varying the quantities of methanol and
methanol/water fuel with each run.  Also varied were fiber size and
air flow rates.  These experiments resulted in some droplet extinction
diameters (the size of the drop as it burns out) larger than any
initial droplet size capable of being studied on Earth.  The science
team was very pleased with what they described as the "textbook
quality" data received and expressed their appreciation for the crew's
hard work and persistence.  Leslie showed his enthusiasm for the work
when he humorously responded, "I don't get to play with fire much up
here.  I'm kind of enjoying it."

  The NASA Lewis Center's FSDC investigation consists of new hardware
and is on its first flight.  The primary objective for this research
is to provide scientists new fundamental insights into the dynamics of
droplet burning which will be compared to state of the art analytic
and numerical models.

  "It did fission, and I got some good data," announced Mission
Specialist Cady Coleman referring to the initial drop fissioning runs
in the Drop Physics Module. Coleman used sound waves to manipulate
rotating drops of silicone oil until they split, or underwent fission.
Project Scientist Arvid Croonquist and his science team worked with
Coleman throughout the night, uplinking instructions and watching
downlink video.  They were testing one set of theories that describes
the breaking apart of distorted, or pre-flattened, drops while varying
the viscosity (or thickness) of the fluid.

  Drop Dynamics Experiment Principal Investigator Taylor Wang and his
co-investigators from Vanderbilt University observed and analyzed
conditions at which drops of various sizes and viscosities split, and
he described Coleman's first run of the procedure as "a very
successful drop fission."  Also, during this run, the science team was
able to get good pictures of the ligament, or thread of fluid,
connecting the two halves of the drop as it passed through its
critical "saddle" point while splitting in two.

  On the first USML mission, Wang's team used the Drop Physics Module
to confirm a theory that was more than 100 years old.  Using fluids
ranging from water to oils, the module spun single drops until they
formed a dog-bone, or two lobe shape. All the drops changed into the
same shape at the same point and at exactly the point that had been
predicted over a century ago by fluid dynamics pioneer Lord Raleigh.
Results from USML-2 are helping to develop theoretical models for the
drop fission process.

   Troubleshooting continues on the High Data Rate Recorder (HDRR),
which began experiencing intermittent data degradation between MET
12/14:30 and 12/14:58.  Scientific data is being stored on the
Orbiter's recorder during loss of signal periods and downlinked via
Hi-Pac TV.

   The Space Acceleration Measurement System (SAMS) and the
Orbital Acceleration Research Experiment (OARE) continued to track
accelerations caused by movements and variations within the Shuttle,
as well as by Shuttle maneuvers and atmospheric drag.  The Principal
Investigator Microgravity Services Project team, of NASA's Lewis
Research Center, is at the Spacelab Mission Operations Control Center
to help scientists evaluate the effects of accelerations on sensitive
microgravity experiments.  Both instruments make continuous records of
accelerations for analysis after the flight.  In addition, OARE is
providing data on the relatively steady, or low-frequency,
accelerations that occur in the Shuttle.  This information is being
provided to the USML-2 Principal Investigators in real-time throughout
the mission.

  The crew also activated the STABLE instrument, and unattended
monitoring continued during the final run of the device.  The STABLE
system was developed by NASA's Marshall Space Flight Center jointly
with McDonnell Douglas to test a device designed to isolate small
science experiments from high-frequency accelerations, including
Shuttle maneuver operations and crew activity.

 On Thursday, November 2, 1995, 4 p.m. CST, STS-73 MCC Status Report #27
reports:

  What flight controllers believe to be an occasional glitch with two
of Columbia's small steering jets reoccurred today, resulting in a
temporary shutdown of the two small, or vernier, jets located on the
tail of the spacecraft. The glitch has occurred twice before during
the mission, and has been resolved each time by turning the shuttle's
autopilot off and on. The same actions restored the jets function
during this afternoon's problem, and they are now functioning
normally.  The glitch poses no problem for the mission, since
Columbia's 38 primary jets are all in good working order. The small
vernier jets are only used to minimize interference with sensitive
experiments ongoing in the lab module.

  The four crew members on the Red Team handed over to the Blue Team
at 2:38 p.m. CST. The three Blue Team crew members will be on duty
till 2:38 a.m.  Friday when they hand over to the Red Team. Early in
the afternoon Pilot Kent Rominger, and payload specialists Kathryn
Thornton and Al Sacco conducted experiments in space and answered
questions from students in Worcester, Massachusetts, and Louisville,
Kentucky.  The experiments and questions focused on surface tension
and combustion concepts. Students were involved in ground based
adaptation experiments that have enabled them to work alongside their
counterparts in space.

  To demonstrate surface tension in space, Sacco squeezed out a ball
of orange juice which immediately formed a sphere. The demonstration
was designed to illustrate how surface tension can make a fluid form a
sphere when it doesn't have to contend with gravity. Shortly after the
demonstration, Sacco drank the experimental orange juice sphere.

  The surface tension experiment studies the transition between steady
fluid flows to unstable fluid flows. Scientists are interested in such
studies because of their applications in areas of materials processing
such as the production of high-tech crystals, metals, alloys and
ceramics. The combustion experiments will give scientists insight into
the dynamics of burning fuel.

  After completing its third thermal conditioning period earlier
today, Columbia returned to a "gravity gradient" attitude with the
orbiter tail pointing towards the Earth and the port wing pointing in
the direction of travel. Because the gravity gradient attitude shades
portions of the orbiter, thermal conditioning periods are needed to
warm the underside of the orbiter and subsequently increase the
landing gear tire pressure. One more warm-up period is expected on
Friday morning.

 On Thursday, November 2, 1995, 6 p.m. CST, STS-73 Payload Status Report #23
reports: (13/10:07 MET)

   As the past 12 hours unfolded on the second United States
Microgravity Laboratory mission, Payload Commander Kathryn Thornton
and Payload Specialist Al Sacco spent a good portion of their shift
working on experiments in the Glovebox facility.

  Investigators for the Fiber Supported Droplet Combustion Glovebox
experiment saw something this morning they hadn't expected.
Hydrocarbon-mix droplets deployed in the facility burned slower and
produced more soot than drops of an alcohol-mix.  Researchers also
learned that larger drops burned longer, as expected.  These tests,
which study combustion behavior in microgravity, were conducted using
various fuel mixtures in different-sized drops and changing air flow
rates to see how quickly the drops ignite and extinguish.  Throughout
the morning, Thornton deployed the drops onto thin fibers, and ignited
them by placing an electrical hot wire near the drop.  The longest
burn, that of a large hydrocarbon-mixed drop, lasted for about 40
seconds.

  Scientists will analyze their data post-mission to learn more about
the chemistry of the combustion process, information which will aid in
the development of combustion experiments for the International Space
Station.  Research in this field could spark a totally new approach in
the design of space- based safety equipment, such as fire alarms.  It
could also aid in cleaner fuel use on Earth.

  The first crystal growth experiment ever designed to produce a
crystal without the growing portion touching its container wall has
been completed in the Crystal Growth Furnace.  Principal Investigator
Dr. David Larson hopes to bring home an almost defect-free cadmium
zinc telluride crystal thanks to the unique container apparatus,
designed to grow the crystal as a liquid bridge.  The two-inch (five
centimeter) crystal, which grew for about 30 hours, is the sixth of
eight semiconductor crystal growths planned for the versatile,
high-temperature furnace.  Growing these semiconductors in
microgravity is necessary for a more uniform distribution of chemicals
in order to obtain crystals with a more perfect structure.  Cadmium
zinc telluride crystals are used to make infrared detectors.

  The next sample set for processing in the Crystal Growth Furnace is
a crystal of gallium doped germanium.  Growing this material, which
has well-known properties, provides an engineering test of a new
Crystal Growth Furnace capability to mark the boundary between the
melted and solidified portions of a crystal at given time intervals.
The marks make post-flight analysis of crystal growth more precise.

  Today's experiment runs of the Particle Dispersion Experiment
increased Principal Investigator Dr. John Marshall's data base for
future Shuttle and International Space Station aerosol dispersion
investigations.  Performed in the Glovebox facility, the experiment
demonstrates how fine natural particles, such as dust, disperse within
an atmosphere, then assemble back together (or reaggregate) into
larger clusters.  Earlier this week the experiment confirmed a theory
that aggregation occurs in all dust clouds.

  Investigators for the Geophysical Fluid Flow Cell Experiment today
set their experiment parameters to create flows mimicking those of the
sun's interior.  Information from this experiment run will be used to
validate data collected earlier in the mission on this same phenomena.
Rotation rate, temperature and voltage within the facility are varied
to simulate specific atmospheric conditions.  The fluid flows that
result are relevant to the study of oceans, planetary atmospheres, and
stars - information could one day aid in weather forecasting.

  Protein crystals activated earlier in the mission continue to grow,
ensuring investigators that there will be ample data for post-mission
analysis.  One of these experiments, the Protein Crystallization
Apparatus for Microgravity, holds more than six times as many samples
as are normally accommodated in the same amount of space.  These
crystals are being grown using the vapor diffusion method.  In vapor
diffusion, liquid evaporates from a protein solution and is absorbed
by a reservoir solution in a wicking material.  As the protein
concentration rises, the proteins form crystals.

  These experiments are a precursor to long-duration crystallization
investigations aboard the International Space Station, which would
greatly benefit from the ability to control crystal growth times of up
to approximately six months in length.  Proteins play important roles
in daily life, from providing nourishment to fighting disease.

When the blue shift comes on duty, Mission Specialist 
Catherine Coleman and Payload Specialist Fred Leslie will 
devote the majority of their time to Drop Physics Module and 
Glovebox experiments.

  STS-73 Flight Day 15 Highlights:

 On Friday, November 3, 1995, 8 a.m. CST, STS-73 MCC Status Report #28
reports:

  The STS-73 crew members told reporters this morning the experiments
comprising the United States Microgravity Laboratory-2 payload are
pathfinders for the type of work that will be performed regularly on
the International Space Station. The comments came as all seven crew
members took a break from their work to participate in the traditional
in-flight crew news conference. The astronauts answered a variety of
questions regarding the USML-2 science, life on orbit and Sunday
morning's planned landing at Kennedy Space Center.

  During the news conference, Payload Commander Kathy Thornton said the 
information gathered on Shuttle missions will be used to plan the science 
activities on the Space Station. She also said many of the telescience tools 
that were used and tested during STS-73 will help make operations on the 
Space Station run smoothly. 

  Columbia is once again positioned with its belly pointing toward the
Sun.  The attitude is designed to warm the underside of the orbiter
and subsequently increase the landing gear tire pressure. Previous
thermal conditioning sessions have maintained tire pressures at or
above the target levels for landing.  All systems on board Columbia
continue to perform well and are ready to support landing
operations.

 On Friday, November 3, 1995, 6 a.m. CST, STS-73 Payload Status Report #24
reports: (13/22:07 MET)

  "This is kind of a pathfinder for the kind of investigations we'll
have on the Space Station," said Payload Commander Kathy Thornton
during the crew news briefing early this morning, characterizing the
interactive nature of much of the science taking place on this Second
United States Microgravity Laboratory mission.  "There are very
complicated experiments on board, but they're working beautifully,"
she concluded.

  "These are large plates, larger than what I have seen; we're talking
millimeters," exclaimed Mission Specialist Cady Coleman, announcing an
unusual and surprising observation to Colloidal Disorder-Order
Transition (CDOT) experiment co- investigator Richard Rogers.  Coleman
was working in the Glovebox facility measuring the fundamental
properties of polymethyl-methacrylate, at the point where it
solidified, and describing them to the science team on the ground.

  The sample Coleman had been working with, essentially a
concentration of microscopic plastic spheres suspended in a liquid
medium, unexpectedly formed a stable disc-shaped crystal with
dendrites, or branches, projecting outward from its edges.  "What I
see is almost snowflake-like, with dendritic arms," Coleman added,
describing a phenomenon that has never been seen on Earth.  "This is
like having a snowflake remain in a glass of water without melting or
dissolving; the dendrites didn't collapse," noted CDOT co-
investigator Jixiang Zhu, referring to the phenomenon as "very
peculiar, really."

  Colloids are suspensions of finely divided solids or liquids
floating in a gaseous or liquid medium.  The CDOT experiment,
developed by NASA's Lewis Research Center, uses these colloidal
suspensions of solid spheres as models of atomic interactions to test
theories that describe these interactions.

  CDOT is the first of a series of Space Shuttle and Space Station
experiments that is helping scientists to determine the validity of
these theories.  This knowledge could enable them to reduce the trial
and error involved in developing new and better materials.  According
to co-investigator William Meyer, this most recent observation has
yielded an "extremely close analogy for atomic behavior" with
"profound implications for condensed matter physics," proving that
"significant and novel results can be obtained from doing this kind of
science in space."

  Early last night, drop fission experiments in the Drop Physics
Module went particularly well.  The efficiency of some of the earlier
successful runs was enhanced by the fact that some of the drops could
be reused because they re- coalesced after dividing.  Payload
Specialist Fred Leslie had success dividing and merging drops of 1,000
centistoke oil, and was consistently able to rotate the single drops
until they broke into two drops.  A centistoke is a unit of viscosity
or fluid thickness.  When he tried working with the much thicker
10,000 centistoke drops, however, they deployed too slowly and tended
to adhere to one of the two drop injectors.  He then switched to
thinner drop injectors, but the oil still proved too difficult to
deploy.

  According to DPM Program Scientist Arvid Croonquist of NASA's Jet
Propulsion Laboratory, "that's part of the science, pushing the limits
to find the right viscosity levels.  We're content with the results."
This Drop Dynamics Experiment is intended to gather high-quality data
on the dynamics of liquid drops in microgravity for comparison with
theoretical predictions.  Results from this mission should help
develop theoretical models for the drop fission process.

  "I'm looking forward to spending the next year or so analyzing the
data from this experiment," said Fred Leslie, during this morning's
news conference, regarding the Geophysical Fluid Flow Cell (GFFC).  He
and Mission Specialist Michael E. Lopez-Alegria monitored GFFC's fluid
flow patterns and film frame rate and reported their findings to
investigators in Huntsville, Ala.  One solar simulation was completed,
and a second has begun.  Both these scenarios operate under
high-voltage and high-rotation conditions.  During the film magazine
changeout, the crew adjusted the film camera, hoping to reduce the
frame rate going through the camera; however, the camera is still
running continuously.

  While responding to a question about zeolite crystal growth during
today's news conference, Payload Specialist Al Sacco described some of
ZCG's "outstanding results," adding that, "if we do well with
zeolites, we could have some major breakthroughs down the road,
pointing us in the right direction for Space Station research."  Last
night, the crew monitored the ZCG experiment, and unattended crystal
growth continues.

  In the Crystal Growth Furnace (CGF), processing of a gallium- doped
germanium sample has begun, the first of two samples to be
directionally solidified in a technology demonstration studying the
effects of different acceleration environments on crystal growth.
During this experiment, the Orbiter is using real-time Orbital
Acceleration Research Experiment (OARE) data to make a fine adjustment
of the orbital attitude by two degrees to line up the CGF axis with
the residual acceleration vector on board.

 On Friday, November 3, 1995, 5 p.m. CST, STS-73 MCC Status Report #29
reports:

  As the flight of STS-73 enters its home stretch, Columbia's crew
members continued science work in the Spacelab module today and began
some early preparations for the trip home.

  Also, Commander Ken Bowersox and Payload Specialist Al
Sacco talked to television and radio reporters from Worcester,
Massachusetts.  Sacco is a native of Boston and is on the faculty of
the Worcester Polytechnic Institute. Bowersox and Sacco answered a
variety of questions ranging from whether they were homesick to
whether they had experienced space motion sickness.

  Ground controllers again saw a glitch with some of Columbia's
smaller steering jets during the day today. The glitch has occurred
repeatedly during the flight and each time has been resolved by
turning the small, or vernier, steering jet system off and on. The
vernier jets are currently turned off and will be turned on again
later tonight. Flight controllers believe they will function normally
at that time.  The glitch poses no problem for Columbia, since all 38
of the primary steering jets on the spacecraft, the system used for
most maneuvers and for entry and landing, are working well. The small
vernier jets are only used when requested by scientists since they
cause minimal interference with sensitive experiments in the lab
module.

  To prepare for landing, crew members performed a communications
systems check through U.S. ground tracking sites today. All of the
systems are ready to support Sunday's landing. The crew will perform
additional checks over the next several hours in anticipation of a
Kennedy Space Center landing at 5:45 a.m.  CST Sunday.

  Members of the Red Team crew handed over to their colleagues on the
Blue Team at 2:38 p.m. CST. Blue Team members will be on duty until
1:23 a.m. CST Saturday when they hand over to the Red Team.

 On Friday, November 3, 1995, 6 p.m. CST, STS-73 Payload Status Report #25
reports: (14/10:07 MET)

  As the second United States Microgravity Laboratory (USML-2) mission
draws to a close, the seven member crew continues to work at a steady
pace attempting to glean as much science as possible out of the few
remaining hours in the mission.  A number of investigations have
already been deactivated, and others will be powered-down during the
next 12 hours.  Meanwhile, scientists on the ground are getting data
which will provide them with months of exciting post-mission study.

  "A picture is worth a thousand words - we'd seen it, now we've done
it," exclaimed USML-2 Drop Dynamics Lead Scientist Dr. Taylor Wang,
when a polymer membrane formed between two coalesced, or joined, drops
in the Drop Physics Module this morning.  Payload Specialist Al Sacco
deployed two drops of different chemicals, which coalesced to become
one drop.  The membrane which was formed by the ensuing chemical
reaction was an important step in an encapsulation study Wang hopes
will lead to living cell encapsulation. Wang and his team will analyze
such characteristics as the membrane's surface shape and roughness,
pore structure and chemical composition.
 
  The Crystal Growth Furnace completed growing a crystal of
gallium-doped germanium this afternoon.  The crystal grew a little
over five inches (128 millimeters) after almost nine hours in the
unique high-temperature furnace.  The final crystal to process in the
facility, a second gallium-doped germanium sample, will begin its
growth period tonight.  As with the first crystal of this type, an
electrical pulse will test a new Crystal Growth Furnace capability to
mark the boundary between the melted and solidified portions of a
crystal at given time intervals.  The marks provide information
crucial to post-flight analysis of the crystal growth process.

  During these Crystal Growth Furnace experiments, the Microgravity
Analysis Workstation (MAWS), uses mathematical computer models to
compute an analytic solution to the microgravity environment of the
growing crystal.  "Just as a carpenter uses a "plumb line" to align
his work on Earth, MAWS provides the crystal growth scientists with a
"plumb line" in space for aligning the direction of crystal growth
with the direction of orbiter disturbances," said Mission Manager Paul
Gilbert.  The MAWS team predicted last night that a slight adjustment
to the orbiter attitude - 2 degrees - would provide the best
microgravity environment for growing the Crystal Growth Furnace
crystal." "It's the first time ever the crew maneuvered the orbiter
based on a microgravity prediction," observed lead engineer Larry
French.

  Payload Commander Kathryn Thornton used the Shuttle's camcorder this
morning to record the progress of the experiments growing in the
Commercial Generic Bioprocessing Apparatus.  Tiny brine shrimp,
numerous forms of plant growth and a variety of protein crystals are
doing well.  The apparatus makes it possible for commercial industries
to fly experiments in the unique environment of space.  Early in the
blue shift, Mission Specialist Cady Coleman began terminating sample
processing and deactivating the protein crystal growth experiments in
the facility.

  The Geophysical Fluid Flow Cell Experiment continues to make maximum
use of the remaining time in the mission before the experiment is
deactivated.  The experiment has completed more than 150 hours of run
time, studying how fluids move in microgravity by modeling 29
different scenarios of fluid flows in oceans, atmospheres, planets and
stars.  Final runs for the experiment have centered around adjusting
experiment parameters of speed, temperature and voltage to mimic fluid
flows of Earth's atmosphere.  Additional data runs to study the
convection which exists in Earth's mantle will conclude the
experiment's flight on USML-2.

  During the next 12 hours, Mission Specialist Cady Coleman and
Payload Specialist Fred Leslie will continue to power down
experiments.  They will also get in some final run time with the
Geophysical Fluid Cell Experiment and the Surface Tension Driven
Convection Experiment.

  STS-73 Flight Day 16 Highlights:

 On Saturday, November 4, 1995, 8 a.m. CST, STS-73 MCC Status Report #30
reports:

   Columbia and crew turned attention homeward this morning, beginning
what is planned as the final full day in orbit for shuttle mission
STS-73 with several standard checks of landing equipment, all aiming
toward a touchdown in Florida at 5:45 a.m. CST Sunday.

  Early this morning, Commander Ken Bowersox, Pilot Kent Rominger and
Mission Specialist Mike Lopez-Alegria tested Columbia's flight control
systems, a standard task the day before entry on each shuttle
flight. The checks of the cockpit displays, aerosurfaces and
navigational equipment found all of the systems in good
shape. However, as one of the three cathode ray tube computer monitors
located in the forward cockpit was powered on, the crew noted an
intermittent flashing and garbling of the display. The monitor had
been powered off for most of the flight as part of a standard excess
systems power-down performed to conserve electricity on long missions.
Bowersox and Rominger will replace the monitor with a one from the aft
flight deck in a two hour procedure this morning.

   Also today, the crew test-fired Columbia's 38 primary reaction
control system steering jets that are used for entry and landing,
finding them all in excellent condition.

  Experiment work is continuing in the United States Microgravity
Lab-2, but the crew will begin deactivating the experiments as they
are completed.  This afternoon, the crew will begin stowing cabin gear
for tomorrow's return.  A final deactivation of the lab module is
planned for late tonight.


 On Saturday, November 4, 1995, 6 a.m. CST, STS-73 Payload Status Report #26
reports: (14/22:07 MET)

  The second longest Shuttle flight in history, the second United
States Microgravity Laboratory (USML-2) mission is winding down.
Operations continued overnight to get in some last-minute science
before deactivation of the experiments and the eventual power down of
the Spacelab in Columbia's cargo bay.  The USML-2 payload will be
deactivated at MET 15/12:45 (8:35 p.m. CST); Spacelab deactivation
will follow at MET 15/13:45 (9:35 p.m. CST).

  During the last 12 hours, crew members worked closely with
scientists on the ground to accomplish unique interactive science,
initiating the last run of the Geophysical Fluid Flow Cell Experiment,
deactivating the Containment Tubes in the Glovebox Protein Crystal
Growth experiment, and terminating several Group Activation Packs in
the Commercial Generic Bioprocessing Apparatus.  After conducting a
procedure to enhance science return, the crew performed two runs with
the Surface Tension-Driven Convection Experiment.  At the end of this
twelve hour shift, the Drop Physics Module, the Geophysical Fluid Flow
Cell, the Advanced Protein Crystallization Facility, the Commercial
Generic Bioprocessing Apparatus experiment, the Single-Locker Protein
Crystal Growth experiment, and the Commercial Protein Crystal Growth
experiment have been deactivated.

  Payload Specialist Fred Leslie monitored the final run of the
Geophysical Fluid Flow Cell (GFFC) experiment, a slow rotation
scenario that simulated fluid flows found in Earth's mantle.  Crew
members initiated the run through the Payload General Support
Computer, observed fluid flow patterns in this final experiment, and
reported the status to investigators on the ground.

  Working in the Glovebox, Mission Specialist Kathy Thornton performed
the final run of the Particle Dispersion Experiment (PDE).  A repeat
of a previous experiment run, this experiment completed a set of eight
science runs with samples of angular quartz.  Thornton agitated the
module and injected it with air to study the dispersion and collection
of the fine particles it contains.  Mission Specialist Cady Coleman
set up Protein Crystal Growth (PCG) equipment in the Glovebox
facility, deactivating and photographing containment tubes which she
then returned to the Commercial Refrigerator/Incubator for storage.

  After installing a thick, adjustable disc to change the test
chamber's proportions in the Surface Tension Driven Convection
Experiment (STDCE), the crew performed the final video-recorded
experiment runs with three-centimeter sample diameters.  Investigators
saw the highest-order oscillations to date and are very happy with the
results.  An inflight maintenance procedure was performed to install a
thick displacement disc in the two centimeter module in preparation
for the final STDCE run.

  In the Crystal Growth Furnace's Interface Demarcation Flight Test,
the second, and final, gallium-doped germanium sample initiated growth
last night, following a three hour soak period.  This sample will be
unique in that the sample has been exposed to a constantly changing
residual gravity vector as a result of a change in vernier thrusters,
and because the sample temporarily lost electrical continuity during
processing.  The exposure to changing residual gravity vectors, rather
than the stable vector normally required, could produce some unusual
structural variations.  It is anticipated that this sample could
provide investigators with both unusual results and challenges in
sample analysis, and they are looking forward to examining this
crystal.

  The crew monitored the Advanced Protein Crystallization Facility
(APCF) and reported the facility status to investigators on the
ground.  They also cleaned the fan intake screen, and unattended
protein crystallization continued until deactivation.

  During the next twelve hours, the crew will monitor the final runs
of the STDCE, and the Crystal Growth Furnace will continue cooling as
ground controllers and the crew prepare for final USML-2 Spacelab
deactivation.

  Science highlights for USML-2 mission demonstrated the efficiency of
interactive science in the operation of experiment hardware, as
science teams at Spacelab Mission Operations Control in Huntsville,
sent remote commands to their equipment or worked with scientists in
orbit to adjust their experiments on the spot.

  The Astroculture plant growth facility successfully grew 5 small
potatoes from tubers to verify Astroculture as a viable plant growth
facility and to study the possibility of growing edible foods in
space.  Both of these objectives were met.  Near the end of the
mission, the leaves began to yellow and deteriorate, an expected event
that leads investigators to believe the tiny potatoes were pulling
photosynthetic energy from the leaves.

  For the first time a crystal was grown as a liquid bridge to
minimize contact with the container wall, thus decreasing the number
of defects in the crystal.  A total of eight semiconductor crystals
were successfully grown in the Crystal Growth Furnace.  USML-2 also
saw the thinnest crystal growth, and the successful growth of two
crystals which could lead to products such as computer chips that are
faster and use less power than traditional computer chips.

  Scientists successfully achieved major steps toward drop
encapsulation in the Drop Physics Module, a facility which uses sound
waves to levitate and manipulate liquid drops for close study.  These
data will be studied post-mission for future development of
encapsulation methods, which could someday involve encapsulating
living cells in biological processing systems.  Several more firsts
were achieved as compound drops were formed, injecting one drop into
another, a step that led to successful coalescence -- two drops being
deployed separately and coming together to become one.  Another first
was the formation of a chemical membrane which formed when two drops
were deployed, coalesced and formed one drop.  Drop fissioning, one
drop being spun until it broke into two, also was achieved on USML-2.
Another study which looked at surface-altering chemical influences was
successful, providing scientists with a wealth of data on different
surface behaviors when water drops with surfactants were oscillated
using the sound waves.  Improved crude oil recovery, environmental
cleanup and synthetic drug production could result from this research.
 
  The Geophysical Fluid Flow Cell experiment modeled atmospheres and
other planetary attributes during 150 hours of run time on USML-2.
Several on-orbit scenarios simulated the atmosphere of the planet
Jupiter.  These early runs showed dramatic changes in flow types with
very small variations in the instrument settings.  The experiment
studied how fluids move in microgravity by modeling 29 different
scenarios of fluid flows in oceans, atmospheres, planets and stars.
Some experiment runs seemed to validate predictions in a mathematical
model of planetary and solar fluid flows. Scientists saw different
heat-driven, or thermocapillary flow patterns when the same conditions
were initiated at different rates. Lessons learned on USML-2 may be
applied to a better understanding of fluid flows on the Earth.

  The Particle Dispersion Experiment confirmed a theory about the
behavior of dust and particle clouds: that aggregation occurs in all
dust clouds, drawn together by static electrical charges.  This
includes the planetary nebulae which coalesce to form stars, global
dust storms on Mars, dust clouds from a meteor impact on Earth (such
as the one some believe led to extinction of the dinosaurs), and
clouds of dust and ash flung into Earth's atmosphere during volcanic
eruptions.  USML-2 tested variables like particle size, density of the
cloud, and type of material (volcanic material, rounded quartz,
angular quartz or copper).  All the materials showed a similar
propensity to aggregate due to electrostatic attraction.

  Scientists for the Interface Configuration Experiment, a Glovebox
experiment, were able to see definite differences in the way fluids
adhered to chamber walls in the experiments various containers,
and some of the behavior was different from that predicted by the
classic mathematical model.  This tells investigators they cannot rely
completely on the current theory of how surfaces form in low gravity,
finding instead that physical factors which are not included in the
purely mathematical theory play a significant role.  Insights will aid
design of fluid systems for space such as those for fuels.

  The Colloidal Disorder/Order Experiment team observed a stable
disc-shaped crystal with dendrites, or branches, projecting outward
from its edges, described as "snowflake- like."  This phenomenon,
which never had been seen on Earth, was described as being like a
snowflake in a glass of water not melting or dissolving.  This was
among the firsts investigators saw during USML-2.  Photos and downlink
data revealed growing crystals throughout a sample thought to be too
densely packed to grow crystals.  On Earth, this dense concentration
causes the spheres to move so slowly that the crystals only form on a
geological time scale (millions of years).  The Glovebox experiment,
which used a concentration of microscopic plastic spheres suspended in
a liquid medium, studied the fundamental theories that model atomic
interactions.

  More than twenty-five droplets of a variety of fuels were ignited as
they were suspended on a ceramic wire tether in the Fiber Supported
Droplet Combustion experiment.  This experiment, which made its first
flight in the Glovebox on USML-2, confirmed theories about how fuels
burn in microgravity. The experiments resulted in larger droplet
extension diameters (the size of the drop as it burns out) than any
initial droplet size capable of being studied on Earth.  The burning
time was 10 times longer than any other experiment runs.  The data
from this mission has confirmed scientific predictions about burn rate
and the amount of fuel leftover after the fire goes out.  This will
allow investigators to refine theories, and possibly develop new ones
about combustion byproducts such as soot and smog.  Practical
applications could involve controlling fires, and preventing them in
large scale space structures.

  The Particle Dispersion Experiment confirmed a theory about the
behavior of dust and particle clouds and the aggregation that occurs
in all dust clouds drawn together by static electrical charges.  This
includes the planetary nebulae which coalesce to form stars, global
dust storms on Mars, dust clouds from a meteor impact on Earth (such
as the one some believe led to extinction of the dinosaurs), and
clouds of dust and ash flung into Earth's atmosphere during volcanic
eruptions.  USML-2 tested variables like particle size, density of the
cloud, and type of material (volcanic material, rounded quartz,
angular quartz or copper).  All the materials showed a similar
propensity to aggregate due to electrostatic attraction.

 A record number of Protein Crystal Growth samples, around 1,500
total, were flown on USML-2.  In addition to providing higher quality
proteins than many grown on Earth for X-ray diffraction analysis,
these experiments give insights into how proteins crystallize to
improve ground-based experiments.  Video downlink provided on numerous
protein crystal growth experiments during the mission indicated
crystals had formed in those samples which will be analyzed
post-mission.  Knowledge gained from protein crystal research could
lead to custom tailored drugs, made possible by determining protein
structures of diseases, then designing drugs to fit these diseases
like a key fits a lock.

  During this flight, the Surface Tension Driven Convection Experiment
(STDCE) team gathered an extensive information base on unstable fluid
flows caused by variations in surface temperatures.  Except in very
tiny containers such as capillary tubes, such oscillations as observed
on USML-2, the second flight for this experiment, had never been
observed before on Earth.  Varied conditions such as chamber size and
proportions, surface shape (which can't be varied on Earth) and heat
location and intensity were applied to the silicone fluid surface.  By
downlink video, the science team was able to clearly pinpoint when the
fluid flows transitioned from stable to oscillatory, or unstable,
flows, and they found that when the temperature was increased past the
point where oscillations began, the flows became erratic.  Forty-nine
of 43 planned tests were completed, extra time being gained by science
team members who ran the experiment remotely, with minimal setup by
the crew.  A thorough understanding of fluid physics forms a valuable
base for improvements in sophisticated materials processing.

The Oscillatory Thermocapillary Flow Experiment 
successfully pinpointed the transition between steady and 
unsteady heat-induced fluid flows.  The investigation 
duplicated the Surface Tension Driven Convection Experiment 
(STDCE) but used containers with different depths to provide 
additional insight into the fluid-flow phenomenon.  Results 
were consistent with STDCE results on this mission.  The 
experiment team has built an extensive catalogue of data on 
these subtle fluid motions which can affect materials 
processing on Earth.  

  During USML-2, Zeolite Crystal Growth team members got the data they
hoped for prior to the mission when downlink video indicated a uniform
population of suspended particles throughout the samples in which
growth was expected.  This space-based experiment is unlike an
identical mixture which the team started growing on Earth before
USML-2.  Gravity on Earth has caused the particles in that experiment
to settle.  The composition of USML-2 zeolites (a combination of
silica solution and alumina solution ) were refined before the mission
in hopes of growing even larger crystals with less, or controlled,
defects for post-mission structural analysis.  Zeolite crystals are
used in the chemical process industry as filters, catalysts, and
adsorbents.  Some of the zeolites are the type used to crack crude oil
into refined petroleum.  Increasing their efficiency could result in
cheaper gasoline.

  Brine shrimp, plants, protein crystals and other investigations took
advantage of growing time in the microgravity environment in the
Commercial Generic Bioprocessing Apparatus.  This unique facility
enabled a large, diverse range of commercial investigators, such as
pharmaceutical companies, to fly an experiment in the Spacelab.  Some
of the 200+ experiments tested materials that could be used as
replacements for skin, tendons, blood vessels and corneas.

  The Hi-Pac digital TV demonstration provided 4 times the normal
amount of video data for scientist feedback during USML-2.  The system
collected more than 41,000 gigabits of digital data in its
demonstration of video communication techniques which will help pave
the way for Space Station.

  The Suppression of Transient Acceleration by Levitation Evaluation,
(STABLE), was the first facility to use electromagnetic levitation to
isolate sensitive experiments from disturbances in the Shuttle.  An
experiment, known as "CHUCK," a small, simple system to study
materials processes in microgravity that are applicable to crystal
growth mechanics, was tested in the facility.  For the first run, the
STABLE platform floated free through the action of electromagnets.
The platform was locked in place for a repeat run.  Comparisons should
help determine the effectiveness of STABLE for reducing background
vibrations.

  USML-2 science team members made ongoing adjustments to their
experiments based on readings from the Three Dimensional Microgravity
Accelerometer (3-DMA) experiment.  The 3- DMA measured both the
absolute level of microgravity acceleration (the difference between
zero acceleration and what is experienced during the mission) and
microvibrations which could affect the investigations onboard.  The
Surface Tension Driven Convection Experiment was one experiment which
benefited by the real time data from the accelerometer.

  Space Acceleration Measurement System (SAMS) and the Orbital
Acceleration Research Experiment (OARE), recorded acceleration
information throughout the mission.  OARE sent data down to scientists
real-time; while SAMS recorded information on low-frequency
accelerations for post-flight analysis and comparison with other
experiments.

 On Saturday, November 4, 1995, 8:30 p.m. CST, STS-73 MCC Status Report #31
reports:

  Columbia is in the final hours of it's 18th mission, as the crew
continues preparing the vehicle for Sunday's planned landing at the
Kennedy Space Center in Florida.  Managers have elected to attempt the
landing in Florida Sunday and Monday and only call up the California
landing site at Edwards Air Force Base for Tuesday, if required.  The
two landing opportunities Sunday are at 5:45 a.m. and 7:19
a.m. Central with the deorbit ignition firing about an hour prior to
each landing time.

  Much of the afternoon and evening was spent with Mike Lopez-Alegria,
Cady Coleman and Fred Leslie packing up the Spacelab and orbiter crew
compartment for entry and landing activities that begin with the
wakeup of the four remaining astronauts about 11 p.m.

  Ken Bowersox, Kent Rominger, Kathy Thornton and Al Sacco will assist
with landing preparations after wakeup as the seven crew members wind
down what will be the second longest Space Shuttle mission to date.  A
one day extension will put Columbia's STS-73 mission in the number one
spot for Shuttle mission duration.

  The current weather forecast for Sunday's landing attempts shows a
chance of low clouds hampering visibility on the first opportunity and
excessive crosswinds on the second.  Weather conditions improve
slightly for Monday and are even better on Tuesday.

  STS-73 Flight Day 17 Highlights:

 On Sunday, November 5, 1995, 6 a.m. CST, STS-73 MCC Status Report #32
reports:

  Space Shuttle Columbia returned to Earth Sunday morning, completing
the U.S.  Microgravity Laboratory-2 mission, the second longest space
shuttle mission to date.  Columbia and its seven-member astronaut crew
touched down at the Kennedy Space Center runway at 5:45 a.m. CST after
nearly 16 days conducting microgravity experiments in space.

  The astronauts, commander Ken Bowersox, pilot Kent Rominger, mission
specialists Kathy Thornton, Cady Coleman, and Mike Lopez-Alegria, and
payload specialists Al Sacco and Fred Leslie, are expect to return to
Houston's Ellington Field late Sunday afternoon.  The crew return
ceremony is open to the public.

<end of mission>

Mission Name: STS-74 (73)
  Atlantis (15)         
  Pad 39-A (56)
  73rd Shuttle Mission
  15th Flight OV-104
  27th KSC landing
  2nd Mir Docking

 NOTE: Click Here for Countdown Homepage

Crew:
  Kenneth D. Cameron (3), Commander
  James D. Halsell (2), Pilot
  Jerry L. Ross (5), Mission Specialist
  William S. McArthur Jr (2), Mission Specialist
  Chris A. Hadfield (1), Mission Specialist

Milestones:
     OPF -- 07/07/95
     VAB -- 10/03/95
     PAD -- 10/12/95
    TCDT -- 10/17/95

  (Reference KSC Shuttle Status Nov 1995)

Payload:
  S/MM-02-Mir Docking,ICBC-05, IMAX, GLO, DSO, MCSA, SAREX, GAS, GPP,
  Payload/Mir Download - Trek Experiment
 
Mission Objectives:

     The STS-74 mission is the second of seven planned Space
Shuttle-Mir link-ups between 1995 and 1997, including rendezvous and
docking and crew transfers, which will pave the way toward assembly of
the international Space Station beginning in November 1997. Major
objectives include docking with the Mir space station and delivery of
a Russian docking module and 2 solar arrays.

     This mission marks the first time astronauts from the 
European Space Agency, Canada, Russia and the U.S will be in 
space on the same complex at one time -- a prime example of 
nations that will be represented on the international Space 
Station.

     Atlantis will carry the Russian-built Docking Module, 
which has multi-mission androgynous docking mechanisms at 
top and bottom.  During the flight to Mir, the crew will use 
the Orbiter's Remote Manipulator System robot arm to hoist 
the Docking Module from the payload bay and berth its bottom 
androgynous unit atop Atlantis' Orbiter Docking System.  
Atlantis will then dock to Kristall using the Docking 
Module's top androgynous unit.  After three days, Atlantis 
will undock from the Docking Module's bottom androgynous 
unit and leave the Docking Module permanently docked to 
Kristall, where it will provide clearance between the 
Shuttle and Mir's solar arrays during subsequent dockings.  

     Atlantis will deliver water, supplies, and equipment, 
including two new solar arrays -- one Russian and one 
jointly-developed -- to upgrade the Mir.  It will return to 
Earth experiment samples, equipment for repair and analysis 
and products manufactured on the station.  

     Also flying aboard Atlantis is the GPP payload 
consisting of two experiments -- the GLO-4 experiment and 
the Photogrammetric Appendage Structural Dynamics Experiment 
(PASDE).  The payload is managed by Goddard Space Flight 
Center's Special Payloads Division.  

     The GLO-4 will study the Earth's thermosphere, 
ionosphere and mesosphere energetics and dynamics using 
broadband spectroscopy.  GLO-4  also will study spacecraft 
interactions with the atmosphere by observing Shuttle and 
Mir glow, Shuttle engine firings, water dumps and fuel cell 
purges.

     Three PASDE cannisters, located throughout the cargo 
bay, will photogrammetrically record structural response 
data of the Mir solar arrays during the docked phase of the 
mission.  These data will be analyzed on the ground to 
verify the use of photogrammetric techniques to characterize 
the structural dynamics of the array, thus demonstrating 
that this technology can result in cost and risk reduction 
for the international Space Station on-orbit structural 
verification.

   Atlantis will also carry back to earth the University of 
California at Berkeley Trek Experiment which has been in orbit 
onboard Mir for the past four years.

Launch:  
   Launch November 12, 1995 at 7:30:43.071 A.M. EST.  Launch Window was
10 min 09 sec but Atlantis lifted off at the begining of the window.
There were no unscheduled holds.  Winds at liftoff were from
approximately 289 degrees at 6.7 knots; the ambient temperature was 50
degrees F, the barometric pressure was 30.06in Hg; and the relative
humidity was 82%.  Transatlantic Abort Landing (TAL) sites were
Zaragoza, Spain for primary and Moron, Spain and Ben Guerir, Morocco
as alternates.  White Room close out completed at 6:18am EST.  At
7:12am EST the mission management team was polled and all stations
were "go for launch" except SRO.  Weather constraint, cloud ceiling below
6000ft for RTLS abort.  (Reference KSC Weather History 11/12/1995 0700).
Range cleared for launch at 7:20am EST. Main Engines cutoff at 7:39am EST.

   Launch attempt on November 11, 1995 at 7:56am EST was scrubbed due
to poor weather at the Transatlantic Abort (TAL) Site.  A scrub due to
a TAL site has only occured once before on 1/9/86 for Columbia's
launch attempt on mission STS-61C.  The mission management team decided 
to enter a 24 hour scrub turnaround and attempt a launch on
11/12/95.  Launch Window was 6 min 57 and the countdown had begun
on schedule.  The crew was onboard when the scrub was called at 
the T-minus 5 minute mark at approximately 7:51am EST. 
 
   On 11/09/95, Pad 39-A was cleared to load the onboard cryogenic tanks
with liquid hydrogen and liquid oxygen reactants. Reactant loading has been
completed. The reactants will provide electricity for the orbiter and crew
while in space and drinking water as a by-product during their 8-day
mission. (Reference KSC Shuttle Status 11/09/1995).

  On 11/07/95, Engineers have determined no additional work is required 
to verify the readiness for flight of the STS-74 solid rocket boosters 
in light of extremely small cracks found on hold-down posts
attached to other boosters that flew earlier this year. Previous
inspections on the boosters at the pad indicate no cracking is
present. Mission managers will be fully briefed on the matter at the
scheduled management team meeting to be held at KSC on Thursday.
(Reference KSC Shuttle Status 11/07/1995). 

  On 9/05/95, Main engine (SSME) installation was completed in OPF Bay 2 
and the Russian MIR-2 Docking Module closeout operations were completed 
in the Operations and Checkout Building. (Reference KSC Shuttle Status 9/05/1995). 
 
 On 8/25/95, three thrusters on the right hand OMS pod were replaced
in the OPF (Reference KSC Shuttle Status 8/25/1995). 

Orbit:
  Altitude:  213 nm
  Inclination:  51.6 degrees
  Orbits:  128
  Duration: 8 days, 4 hours, 31 minutes,  42 seconds
  Distance:  3.4 million miles

Hardware:
  SRB: BI-076
  SRM: 360T051A (left), 360T051B (right)
  ET :  SN-74
  MLP : MLP-2
  SSME-1: SN-2012
  SSME-2: SN-2026
  SSME-3: SN-2032

Landing:  

  KSC November 20, 1995 at 12:01:27 pm EST on Runway 33.  Deorbit burn
was done on orbit 128 at approximately 11:00am EST.  Dual sonic booms
heard in the KSC Industrial area at 11:58:30am EST. Main Landing Gear
touched down at the KSC Shuttle Landing Facility at a Mission Elapsed
Time of 8 days 4 hours 20 minutes and 44 seconds (12:01:27 EST).  
Nose Gear touched down at 8 days 4 hours 30 min 54 seconds (12:01:37 EST) 
and wheels stopped at an MET of 8 days 4 hours 31 min 42 sec (12:02:24 EST).
(Reference KSC Shuttle Status 11/20/1995). Weather was acceptable for landing 
(Reference KSC Weather History 11/20/1995 1200).

  A second opportunity existed but wasn't necessary for a KSC landing
at 1:37pm EST with a deorbit burn at 12:36p.m. on orbit 129.
(Reference KSC Shuttle Status 11/17/1995).

Mission Highlights:

 Due to the furlough of US government workers from 11/14/95 to 11/19/95, 
mission Status reports during those dates are not currently available.

  STS-74 Flight Day 1 Highlights:

 On Sunday, November 12, 1995, 11 a.m. CST, STS-74 MCC Status Report #01
reports: 

  About 43 minutes after launch, a two minute and 13 second engine
firing changed the shuttle's path into a 162 nautical mile circular
orbit. Once on orbit, the five crew members began configuring Atlantis
for on-orbit operations. Atlantis' payload bay doors were opened about
90 minutes into the flight, followed by a "go" for on-orbit
operations.

  STS-74 Commander Ken Cameron and Pilot Jim Halsell, about three
hours into the last flight of the year, fired the orbiter's reaction
control jets in the first of a series of rendezvous burns that refined
Atlantis' path to Mir.  Shortly after that jet firing, the first
Canadian mission specialist, Chris Hadfield, activated the Russian
built docking module and its systems. The docking module is housed in
Atlantis' payload bay. Hadfield will use the orbiter's robot arm early
Tuesday to mate the docking module with the Atlantis' Orbiter Docking
System prior to the orbiter's link-up with Mir early Wednesday. The
docking is scheduled for 12:28 a.m. CST Wednesday.

 On Sunday, November 12, 1995, 5 p.m. CST, STS-74 MCC Status Report #02
reports: 

  Activities for the coming day will focus on preparing to connect the
Russian Docking Module to the shuttle airlock and getting Mission
Specialists Jerry Ross and Bill McArthur ready for a contingency space
walk should anything unexpected happen during Tuesday's move of the
docking module.

  Maneuvers continuing the process of the shuttle rendezvous with
Russia's Space Station Mir will resume at 10:11 p.m. CST when
Commander Ken Cameron and Pilot Jim Halsell kick off the NC 2
burn. The NC 3 burn will occur at 10:09 a.m. CST Monday. Docking is
scheduled for 12:28 a.m. CST Wednesday.

  Mission Specialist Chris Hadfield will test the robot arm that will
lift the module out of its payload bay moorings. With the help of
Mission Specialist Bill McArthur, Hadfield also will power up and
check the Orbiter Space Vision system that will be used to precisely
align the robot arm. Cameron will set up the VHF radio gear that will
be used for shuttle/Mir communications during the rendezvous.

  Ross and McArthur will inspect their space suits and pre-breath pure
oxygen for an hour and a half to purge nitrogen bubbles from their
bodies and prevent a condition known as "the bends" should a space
walk be necessary. The pair is not expected to don the space suits
unless a space walk is required.  The STS-74 crew also is scheduled to
be interviewed by the Canadian news media beginning at 6:31 a.m. CST.

  STS-74 Flight Day 2 Highlights:

 On Monday, November 13, 1995, 5 a.m. CST, STS-74 MCC Status Report #03
reports: 

  The five member crew aboard the Space Shuttle Atlantis spent the
bulk of its second day in space readying the orbiter and its payloads
for Tuesday's mating of the Russian Docking Module to the Orbiter
Docking System in advance of Wednesday's docking to Russia's Space
Station Mir.  Both the module and the docking system are located in
Atlantis' payload bay.

  Mission specialists Jerry Ross and Bill McArthur early Monday
inspected the space suits they would don should a space walk become
necessary during Tuesday's mating operation or the actual linkup of
Atlantis to Mir at 12:28 a.m. Wednesday.

  Following the space suit inspection, Mission Specialist Chris
Hadfield powered up the orbiter's robot arm which he will use Tuesday
to move the docking module over to the docking system.  All systems
affiliated with the robot arm operated as expected and are ready to
support Tuesday's activities.

  Crew members also checked out the Orbiter Space Vision System, a
precise alignment system for the robot arm that is being tested on
STS-74.  The OSVS, which will be used during Tuesday's mating
operation, consists of a series of large dots placed on the exterior
of the docking module and the docking system.

  Today's schedule also included the installation and alignment of the
centerline camera in the center of the Orbiter Docking System.  The
camera will assist Commander Ken Cameron in final piloting tasks as
Atlantis moves into and docks with Russia's Space Station Mir.
Additionally, Atlantis' jets will be fired to further refine the
closing rate between the orbiter and Mir.  At 5 a.m. CST, Atlantis was
about 4,000 statute miles behind Mir, and was closing in to the space
station at a rate of about 380 statute miles per orbit.

  This morning, Cameron, Hadfield and other available crew members
answered questions posed by Canadian reporters who are in Montreal and
Toronto.  Hadfield is a Canadian Space Agency astronaut and the fourth
Canadian astronaut to fly on the shuttle.

 On Monday, November 13, 1995, 6 p.m. CST, STS-74 MCC Status Report #04
reports:

  With all of the systems that will be used to put the Russian Docking
Module in place for a Wednesday link-up with the Mir Space Station
checked out and ready to go, the STS-74 crew settled down for 8 hours
of sleep Monday afternoon.  Atlantis, orbiting flawlessly 238 miles
above the Earth, is about 2,000 miles away from Mir and catching up at
135 miles per orbit.

  Earlier in the day, Commander Ken Cameron, Pilot Jim Halsell and
Mission Specialists Chris Hadfield, Jerry Ross and Bill McArthur
checked out the docking module, the Orbiter Docking System, the
shuttle's robot arm and the Orbiter Space Vision System and found all
to be in good working order.  Ross and McArthur also inspected the
space suits they will don should a space walk become necessary during
Tuesday's mating operation or the actual linkup of Atlantis to Mir.

  After an 8:31 p.m. CST wake-up call, Atlantis' astronauts will begin
the process of moving the docking module.  At 11:31 p.m., Hadfield
will power up the Orbiter Space Visions System.  At 11:46 p.m.,
Hadfield and McArthur will grapple the module with the robot arm.  At
12:21 a.m. Tuesday, the pair will remove the module from its payload
bay moorings and Cameron and Halsell will prepare the Orbiter Docking
System for connection to the docking module.  At 12:56 a.m., Hadfield
and McArthur will use the robot arm to move the docking module over
the Orbiter Docking System, then place the arm in a "limp" mode with
the docking module and Orbiter Docking System just four inches apart.
Cameron will fire Atlantis' steering jets, forcing the hooks and
latches to engage and locking the Russian Docking Module in place.
Hadfield and Ross will then test the mated Russian docking module's
systems.

    After a rendezvous burn of the shuttle's steering jets at 2:16
a.m., the crew will continue work to configure the docking module
systems for Wednesday's docking with the Russian space station.
Another firing of the shuttle's thrusters is scheduled for 10:20 a.m.
The astronauts will end their day at 12:31 p.m. Tuesday, beginning a
six-hour sleep shift that will synchronize their sleep cycle with that
of the Mir 20 cosmonauts.

  STS-74 Flight Day 3 Highlights:

 On Tuesday, November 14, 1995, 5 a.m. CST, STS-74 MCC Status Report #05
reports: 

  STS-74 crew members early Tuesday successfully mated a 15-foot,
Russian built docking module from the Space Shuttle Atlantis's payload
bay to the shuttle's Orbiter Docking System.  The mating operation
went by the book with no problems reported.

  Chris Hadfield, a Canadian Space Agency astronaut and STS-74 mission
specialist, used the shuttle's robot arm to hoist the docking module
out of the aft portion of the payload bay, rotated it to a vertical
position, and moved it to within five inches of the Orbiter Docking
System.  At that point, the shuttle fired its downward steering jets
and moved the shuttle toward the docking module.  Once the two
spacecraft were locked together, the docking ring on the Orbiter
Docking System retracted, and a series of hooks and latches were
engaged insuring an airtight seal between the two spacecraft.

  The mating was confirmed at 1:17 a.m. CST with Atlantis was over the
eastern portion of Europe on its 30th orbit.  Shortly after the
capture, Commander Ken Cameron expressed the crew's appreciation for
the training that prepared them for the docking module installation.

  At about 3 a.m. CST, the crew received a go from ground flight
controllers to ungrapple the robot arm from the docking module.
Shortly after that, crew members raised the orbiter's cabin pressure
from 10.2 pounds per square inch to 14.7 psi.  The cabin's pressure
was lowered in the event that a problem during the mating process
neccessitated an emergency spacewalk.

  Crew members also mounted a centerline camera into the top hatch of
the docking module.  The camera will provide the primary visual cue
for Cameron as he maneuvers Atlantis to its docking with Russia's
Space Station Mir early Wednesday.

   Atlantis is trailing Mir by about 1450 statute miles and is closing
at a rate of about 180 statute miles every orbit.  A series of
rendezvous jet firings will further refine the closing rate, leading
up to a docking with Mir at 12:27 a.m. CST Wednesday.

  The crew is scheduled to begin a shortened sleep period at 12:31
p.m. today and will be awakened at 6:31 p.m. today.  Flight
controllers are working toward an earlier start to the crew's sleep
period to enable the astronauts to get additional rest time in advance
of tomorrow's docking.

  Because of the federal government furlough situation, it is likely
that the JSC Newsroom will close about 10 a.m. CST today and reopen
when the furlough is lifted.

  STS-74 Flight Day 9 Highlights:

 On Monday, November 20, 1995, 5 a.m. CST, STS-74 MCC Status Report #06
reports: 

  Fresh from a successful docking with the Russian Mir Space Station,
the Space Shuttle Atlantis and its crew are primed for landing today
at Kennedy Space Center in Florida.

  Commander Ken Cameron, Pilot Jim Halsell and Mission Specialists
Chris Hadfield, Jerry Ross and Bill McArthur are conducting the final
checks of the shuttle's steering systems this morning and watching
Florida weather, which is forecast to be favorable. Today's first
landing opportunity begins with a deorbit burn at 9:58 a.m. JSC time
and concludes with landing at 11:02 a.m. The second opportunity
involves a deorbit burn at 11:33 a.m. and landing at 12:37 p.m.

  Although weather is expected to be good at Edwards Air Force Base in
California, landing support teams have not been activated there. If
landing does not occur at KSC today, there are opportunities at both
sites Tuesday.

  Because the astronauts awakened about 12:30 a.m. today and will land
around midday, they are expected to remain in Florida overnight. A
welcome home ceremony is being planned for 11 a.m. Tuesday at
Ellington Field's Hangar 990.

  Atlantis' return to Earth follows a successful docking with Mir and
delivery of the Russian Docking Module that now becomes a permanent
docking port for future Phase 1 missions to the space station. The
STS-74 crew also participated in a number of joint medical and
environmental investigations with the Mir crew -- Commander Yuri
Gidzenko, Flight Engineer Sergei Avdeyev and Cosmonaut Researcher
Thomas Reiter of Germany. Atlantis delivered water, supplies and
equipment--including two new solar arrays--to Mir and is returning
with U.S., Russian and ESA experiment equipment and samples.

  The astronauts of the second shuttle-Mir docking flight also studied
the Earth's thermosphere, ionosphere and mesosphere with the GLO-4
experiment, and evaluated Mir's solar array structures remotely
through three Photogrammetric Appendage Structural Dynamics Experiment
canisters in the payload bay.

<end of mission>