Giving the ISS a Doorway 

to Space

WWW.SHUTTLEPRESSKIT.COM

Updated June 22, 2001

Atlantis OV104

Three Spacewalks Set for Airlock Installation

STS-104
STS-104

Table of Contents

Mission Overview ........................................................................................................ 1

Mission Objectives ....................................................................................................... 5

Crew Members .............................................................................................................. 8

Flight Day Summary Timeline .................................................................................. 11

Rendezvous ............................................................................................................... 12

Spacewalks

STS-104 EVAs ........................................................................................................... 14

Payloads

Joint Airlock ................................................................................................................ 18

High Pressure Gas Tanks ........................................................................................... 20

Space Shuttle Main Engine ....................................................................................... 21

DTO/DSO/RME

DSO 493 Monitoring Latent Virus Reactivation and Shedding in Astronauts................ 24

DSO 496 Individual Susceptibility to Post-Space Flight Orthostatic Intolerance........... 25

DSO 498 Space Flight and Immune Function .............................................................. 26

DSO 634 Sleep-Wake Actigraphy and Light Exposure During Spaceflight................... 27

DSO 635 Spatial Reorientation Following Spaceflight.................................................. 28

DTO 261 International Space Station On-Orbit Loads Validation................................. 29

DTO 262 On-Orbit Bicycle Ergometer Loads Measurement......................................... 30

DTO 692 International Space Station Waste Collector Subsystem Refurbishment...... 31

DTO 700-14 Single-String Global Positioning System.................................................. 32

DTO 805 Crosswind Landing Performance .................................................................. 33

HTD 1403 Micro-Wireless Instrumentation System (Micro-WIS).................................. 34
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Shuttle Reference and Data

Shuttle Abort History ................................................................................................... 35

Shuttle Abort Modes ................................................................................................... 37

Space Shuttle Rendezvous Maneuvers ...................................................................... 41

Space Shuttle Solid Rocket Boosters ......................................................................... 42

Space Shuttle Super-Lightweight Tank (SLWT) ......................................................... 49

Acronyms and Abbreviations .................................................................................. 50

Media Assistance ..................................................................................................... 56

Media Contacts ......................................................................................................... 58
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Mission Overview 

Giving the ISS a Doorway to Space 

Another International Space Station phase reaches completion during the STS-104 (ISS 

Assembly Flight 7A) mission aboard Atlantis, the fourth shuttle mission of the year, the 10th 

shuttle flight to the expanding station and the 105th flight in Space Shuttle Program history. 

Five astronauts, commanded by veteran shuttle flier Steve Lindsey, an Air Force lieutenant 

colonel, with help from ISS Expedition Two Flight Engineers Susan Helms and Jim Voss, 

will install a 61⁄2-ton Joint Airlock to the starboard berthing mechanism of the station's Unity 

module. It will be used by resident crewmembers and visiting shuttle crews to conduct 

spacewalks, using either American or Russian spacesuits. Expedition Two Commander 

Yury Usachev will monitor ISS systems during the delicate airlock installation procedure 

and the initial testing of the airlock itself. 

Once it is installed and activated, the airlock will symbolize the completion of the ISS Phase 

Two, giving the station a capability for spacewalks with no shuttle present. 

Scheduled for launch from Launch Pad 39B at Kennedy Space Center (KSC), Atlantis will 

reach the ISS for a docking two days after liftoff. Its arrival will set the stage for three 

spacewalks by veterans Mike Gernhardt and Jim Reilly to install the massive chamber and 

four high-pressure tanks, two oxygen and two nitrogen. 

The tanks will be used to pressurize and depressurize the new airlock. The third 

spacewalk will be the first to be conducted from the new ISS airlock. 

Lindsey is joined on Atlantis by Pilot Charlie Hobaugh, a Marine Corps captain and firsttime flier, and Janet Kavandi, a shuttle veteran. She will be responsible for shuttle robot 

arm operations in support of the spacewalks. 

Helms and Voss will use the station's Canadarm2 robot arm to grapple and install the 

airlock on Unity on the first spacewalk by Gernhardt and Reilly. 

Built at a cost of $164 million (including associated tanks), the airlock consists of two 

separate chambers. The equipment lock, the larger of the two, has room for spacesuits and 

environment equipment, which will be used by spacewalkers to suit up and prepare for their 

excursion outside the station. The crew lock, which is separated from the equipment lock 

by a hatch, is the portal from which the spacewalkers will open the outer hatch to begin 

their excursions. The crew lock contains lighting, handrails and internal umbilical 

assemblies to provide power and communications for the spacewalkers until they put their 

suits on internal battery power. It is similar in size to the shuttle's airlock. 

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Once installed, the airlock will undergo a series of tests by ground controllers and station 

crewmembers to verify that its environmental, communications and telemetry systems work 

before Gernhardt and Reilly venture out of it for the first time on the ninth day of the 

mission. 

During the second and third spacewalks, Helms will use the Canadarm2 to grapple and 

unberth two pressurized oxygen tanks and two pressurized nitrogen tanks from the 

Spacelab double pallet in Atlantis' cargo bay. She will hand them off, one by one, to 

Gernhardt and Reilly for installation on the new airlock. 

Kavandi will operate the shuttle's smaller Canadian-built robot arm from Atlantis' aft flight 

deck to maneuver the spacewalkers. It will be the second time robotics from two spacecraft 

will be employed in ISS assembly. 

The hatches between Atlantis and the ISS will be closed and opened twice for the first two 

spacewalks to maintain the proper cabin pressure for each vehicle. But once the new 

airlock is installed and activated, hatches can stay open between visiting shuttles and the 

station during future flights during docked operations. 

Most of Atlantis' mission will be devoted to installing and outfitting the airlock, but the 

shuttle crewmembers also will transfer cargo and water to the station. Kavandi will be in 

charge of cargo transfer operations, helped by Lindsey, Hobaugh and Reilly. 

In addition, during a week of joint activity between the shuttle and station crews, Atlantis' 

astronauts will conduct an experiment called SIMPLEX, an acronym for Shuttle Ionospheric 

Modification with Pulsed Local Exhaust. It studies the sources of high frequency radar 

echoes created by shuttle engine firings in space. The crew will also shoot scenes of its 

visit to the ISS on the large format IMAX camera, a 65mm color movie camera system. 

More than a mile of film will be shot during the mission. 

The 11-day flight will end with Atlantis' landing on the 3-mile-long runway at KSC. 

Day 1 - Launch 

Atlantis' crew will launch at the end of its day during a precisely timed, few-minutes-long 

launch window that begins the process of rendezvous with the International Space Station. 

Once in orbit, they will power up and activate heaters on the airlock in the cargo bay to 

keep it from being damaged by the cold of space. Crewmembers will go to sleep about five 

hours after launch. 

Day 2 - Equipment Checkouts, Rendezvous Preparations 

Atlantis' crew will spend its first full day in space checking out equipment that will be used 

for upcoming major activities -- spacesuits and spacewalking gear; the shuttle's robotic 

arm; and the controls and tools used for the final rendezvous and docking with the station. 

The crew also will power up and prepare the shuttle's docking system and perform several 

engine firings to optimize the rate at which Atlantis closes in on the station. 

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Day 3 - Rendezvous and Docking 

Plans call for Atlantis to dock with the International Space Station on Flight Day 3. The 

shuttle and station crews will open hatches and transfer some equipment and supplies, 

including water bags. They will then close the hatches and Atlantis' cabin pressure will be 

lowered to 10.2 pounds per square inch in preparation for the next day's spacewalk. 

Day 4 - First Spacewalk; Joint Airlock Installation 

The first spacewalk focuses on airlock installation. The spacewalkers will help as Helms, 

using the station's robotic arm, lifts the new station airlock from Atlantis' payload bay and 

moves it to the station's Unity module. During much of the almost seven-hour spacewalk, 

Reilly will work from a foot platform attached to the end of the shuttle's robotic arm, 

operated by Kavandi. After the spacewalk, crewmembers inside the station will attach 

connections to the airlock to prevent thermal damage. 

Day 5 - Airlock Activation 

After an overnight Airlock leak check, the day's activities will be largely devoted to airlock 

activation. Tasks include removing Common Berthing Mechanism motor controllers and 

connecting remaining utilities in the vestibule linking Unity with the airlock. Crewmembers 

will enter the airlock to do more activation tasks, stow some equipment and check out the 

oxygen and nitrogen activities. 

Day 6 - Spacewalk Preparation, Additional Airlock Activities 

Astronauts will check out spacesuits and other spacewalking equipment and install a hatch 

between the equipment lock and the crew lock of the new airlock. The hatch was launched 

in the endcone of the airlock. The airlock's depressurization pump will be checked out and 

the newly installed hatch's seal will be verified. The station and shuttle arms will be 

prepared for the next day's activities. 

Day 7 - Second Spacewalk 

The second spacewalk is to last about 51⁄2 hours. The internal hatches between the shuttle 

and station will be closed at the end of Flight Day 6 so Atlantis' cabin pressure can be 

lowered in preparation for the second spacewalk. The major objective is to attach and 

connect an oxygen and a nitrogen tank. Helms will operate the station arm to lift the tanks 

from the shuttle's payload bay and maneuver them to the new airlock. At the airlock, 

Gernhardt and Reilly will latch the tanks in place and connect cables and hoses. 

Day 8 - Rest and Spacewalk Preparation 

Shuttle and station crews are to get the first half of the day off. The second half will be used 

to prepare for the third spacewalk. Some equipment and supplies will be transferred, 

including the Protein Crystal Growth - Enhanced GN2 Nitrogen Deware experiment. 

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Day 9 - The Third Spacewalk 

The third spacewalk will be the first conducted from the new space station airlock. It may 

include a new protocol, developed by former commercial diver Gernhardt, to purge nitrogen 

from the spacewalkers' bodies -- essentially exercising while breathing oxygen. Primary 

objective is to install the final two tanks -- one oxygen and one nitrogen -- outside the 

airlock. 

Day 10 - Shuttle-Station Hatch Closing, Undocking, Flyaround 

The shuttle and station crews will close hatches between the spacecraft. Lindsey and 

Hobaugh will undock Atlantis from the station. With Hobaugh at the controls, Atlantis will do 

a flyaround of the complex before departing. 

Day 11 - Pre-Landing Checkouts, Cabin Stow 

Activities include the standard day-before-landing flight control checks of Atlantis by 

Lindsey and Hobaugh as well as the normal steering jet test firing. The crew will spend 

most of the day stowing away gear on board the shuttle and preparing for the return home. 

Day 12 - Entry and Landing 

The Kennedy Space Center, Fla., is the preferred landing site. 

Updated: 06/21/2001 

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Mission Objectives 

Top priority of the STS-104 mission of Atlantis is installation on the International Space 

Station of the Joint Airlock. This will give station crewmembers the capability of conducting 

spacewalks from the orbiting laboratory using either the Russian Orlan spacesuits or U.S. 

spacesuits. 

The airlock will be attached to the station's Unity Node, on the module's starboard Common 

Berthing Mechanism, and its "survival heaters" activated. The installation will use the 

station's new Canadarm2 robotic arm during the mission's first spacewalk. 

Again helped by the station's robotic arm, astronauts performing a second spacewalk from 

Atlantis will install an oxygen and a nitrogen tank on the airlock. The tanks, called highpressure gas tanks or oxygen/nitrogen tank orbital replacement units, must be installed 

before a spacewalk can be performed from the airlock without a shuttle present. 

A third spacewalk will be performed to attach an additional oxygen and an additional 

nitrogen tank on the airlock. This spacewalk, by shuttle crewmembers, will be from the 

airlock itself. All four tanks, two oxygen and two nitrogen, must be installed to give station 

crewmembers the capability to do spacewalks without oxygen- or nitrogen-related 

constraints. 

Crewmembers and flight controllers on the ground will activate airlock core systems. Those 

systems must be checked out to be ready for extended work in the airlock and to confirm 

that it is ready to serve as the base for future spacewalks. 

They will connect oxygen and nitrogen lines and check the lines for leaks. If the tank lines 

leaked into the airlock, it would require isolation and perhaps repair before it could be used 

for normal spacewalks. The checks are performed both by spacewalkers and by 

crewmembers inside the space station. 

Astronauts will transfer spacewalk and airlock outfitting equipment from Atlantis' middeck to 

the ISS. They also will install a spacewalk work site on the airlock and other equipment for 

use by spacewalkers on subsequent missions. 

Another priority is to transfer water for the Expedition Two crew. Water bags to last the 

crew until the next resupply opportunity will be transferred from Atlantis to the ISS through 

the course of the shuttle's stay at the space station. 

Supplies will be transferred from Atlantis to the station, and unused cargo will be 

transferred from the station to Atlantis to be returned to Earth. 

Additional priorities include: 

--Transfer of science payloads from Atlantis to the ISS. 

--IMAX 3D filming. 

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--The SIMPLEX experiment, using ground sites to track shuttle thruster firings. The 

acronym is for Shuttle Ionospheric Modification with Pulsed Local Exhaust. 

--Installation of airlock trunnion pin covers and oxygen/nitrogen gas tank quick disconnect 

thermal covers for long-term protection against condensation and heat loss. 

Crew

 

Commander: Steven W. Lindsey

Pilot: Charles O. Hobaugh

Mission Specialist 1: Michael L. Gernhardt

Mission Specialist 2: Janet L. Kavandi

Mission Specialist 3: James F. Reilly

Launch

 

Orbiter: Atlantis OV104

Launch Site: Kennedy Space Center Launch Pad 39B

Launch Window: 2.5 to 5 Minutes

Altitude: 122 Nautical Miles

Rendezvous: 240 Nautical Miles 

Inclination: 51.6 Degrees

Duration: 10 Days 19 Hrs. 40 Min.

Vehicle Data

 

Shuttle Liftoff Weight: 4520042 lbs.

Orbiter/Payload Liftoff Weight: 258222 lbs.

Orbiter/Payload Landing Weight:

 

207251 lbs.

Software Version: OI-28

Space Shuttle Main Engines

SSME 1: 2056 SSME 2: 2051 SSME 3: 2047

External Tank: ET-109A (Super Light Weight Tank)

SRB Set: BI-108/RSRM-80 

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Shuttle Aborts 

Abort Landing Sites 

 RTLS: Kennedy Space Center Shuttle Landing Facility

 TAL: Zaragoza primary; Ben Guerir, Moron alternates

 AOA: Kennedy Space Center Shuttle Landing Facility 

Landing

 

Landing Date: 07/23/01

Landing Time: 1:02 AM (eastern time)

Primary Landing Site: Kennedy Space Center Shuttle Landing Facility

Updated: 05/25/2001 

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Crew Profile Menu 

Commander: Steven W. Lindsey 

Steven W. Lindsey, 40, an Air Force lieutenant colonel and former 

test pilot, will be responsible for the overall safety and success of the 

STS-104 mission. He will be responsible for the rendezvous and 

docking of Atlantis to the International Space Station on the fourth 

shuttle mission of the year. He will serve as backup operator of the 

shuttle's robotic arm. He will play a primary or backup role in Joint 

Airlock /vestibule outfitting, pressure leak checks and activation. He 

will serve as backup in water transfer from Atlantis to the space 

station. Lindsey also will assist pilot Charles Hobaugh at the controls 

for Atlantis' flyaround of the space station after undocking, and will be at the controls for the 

shuttle's landing at the end of the mission.

Lindsey flew as pilot on STS-87, the fourth U.S. Microgravity Payload flight, in November 

and December of 1997 and pilot on STS-95, a research flight in October and November of 

1998.

Ascent Seating: Flight Deck - Port Forward

Entry Seating: Flight Deck - Port Forward

RMS 

Pilot: Charles O. Hobaugh 

Charles O. Hobaugh, 39, a Marine Corps major and former test pilot, 

will be in charge of monitoring critical shuttle systems during Atlantis' 

ascent to orbit and its re-entry and landing. He also will be 

responsible for the operation of many of the shuttle's navigational 

tools during its rendezvous with the space station. Hobaugh will 

serve as the intravehicular crewmember during the three 

spacewalks, helping with checklists and providing direction and 

coordination to the astronauts outside and helping keep them on 

their timeline. He also is designated as the backup spacewalker. 

After undocking, Hobaugh will be at the controls of Atlantis during its flyaround of the 

station. 

Hobaugh is making his first space flight.

Ascent Seating: Flight Deck - Starboard Forward

Entry Seating: Flight Deck - Starboard Forward

IV1 

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Mission Specialist 1: Michael L. Gernhardt 

Michael L. Gernhardt, 44, a former commercial diver who holds a 

Ph.D. in bioengineering from the University of Pennsylvania, will 

perform three spacewalks while Atlantis is docked to the space 

station. Focus of the spacewalks is installation of the Joint Airlock and 

four high-pressure tanks, two oxygen and two nitrogen, outside it. 

Gernhardt also has primary responsibility for airlock systems and 

stowage within it. He also is tasked with the payload bay door opening 

and rendezvous photography and television. Gernhardt will assist with 

rendezvous as backup with a handheld laser range finder and with 

operating the shuttle's docking system. He also has backup responsibilities for postinsertion activities and prime responsibility for deorbit preparation. He will conduct Earth 

observations focusing on oceanography and meteorology.

Gernhardt was a mission specialist on STS-69, which deployed and retrieved the Spartan 

satellite and the Wake Shield Facility, in September 1995; STS-83, the Microgravity 

Science Laboratory Spacelab mission, in April 1997; and STS-94, a reflight of that Spacelab 

mission, in July 1997. 

Ascent Seating: Flight Deck - Starboard Aft

Entry Seating: Mid Deck - Port

EV1 

Mission Specialist 2: Janet L. Kavandi 

Janet L. Kavandi, 40, holds a doctorate in analytical chemistry from 

the University of Washington-Seattle. Kavandi will serve as flight 

engineer on the flight deck of Atlantis during launch, landing and 

rendezvous. Kavandi is the mission's primary shuttle arm operator. 

In addition to moving spacewalking astronauts, she will use the 

shuttle arm cameras to provide vital views to Susan Helms as Helms 

uses the space station's Canadarm2 to unberth the airlock from 

Atlantis's cargo bay. Kavandi also will use those cameras to help 

provide a Space Vision System solution to help Helms berth the 

airlock to the space station. She will have primary responsibility in airlock/vestibule 

outfitting. She also will be loadmaster on the shuttle side for logistics transfer to and from 

the space station.

Kavandi served as a mission specialist on STS-91, the last shuttle flight to Mir, in June 

1998, and on STS-99, the Shuttle Radar Topography Mission, in February 2000. 

Ascent Seating: Flight Deck - Center Aft

Entry Seating: Flight Deck - Center Aft

RMS 

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Mission Specialist 3: James F. Reilly 

James F. Reilly, 46, a former offshore oil and gas exploration 

geologist and holder of a Ph.D. in geosciences from the University of 

Texas at Dallas, will perform three spacewalks outside the space 

station during Atlantis' docked operations. Purpose of the 

spacewalks centers on installation of the Joint Airlock and the four 

high-pressure tanks for oxygen and nitrogen outside it. He also will 

have primary responsibility for post-insertion operations and for 

handheld laser range finder operations during rendezvous. He also is 

responsible for numerous shuttle computer functions, crew and 

equipment transfer operations and airlock activation. He will conduct Earth observations 

focusing on geography.

Reilly flew on STS-89, the eighth Shuttle-Mir docking mission, in January 1998. 

Ascent Seating: Mid Deck - Port

Entry Seating: Flight Deck - Starboard Aft

EV2 

Updated: 05/22/2001 

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Flight Day Summary

DATE TIME (EST) DAY MET EVENT

07/12/01 5:04:00 AM 1 000/00:00 Launch

07/13/01 8:33:00 PM 3 001/15:29 TI Burn

07/13/01 10:52:00 PM 3 001/17:48 Docking

07/14/01 12:14:00 AM 3 001/19:10 ISS Ingress

07/14/01 10:09:00 PM 4 002/17:05 EVA 1 Start

07/15/01 6:49:00 AM 4 003/01:45 Ingress 2

07/17/01 10:14:00 PM 7 005/17:10 EVA 2 Start

07/18/01 5:44:00 AM 7 006/00:40 Ingress 3

07/19/01 11:44:00 PM 9 007/18:40 EVA 3 Start

07/20/01 9:49:00 PM 10 008/16:45 ISS Egress

07/21/01 12:17:00 AM 10 008/19:13 Undocking

07/23/01 12:00:00 AM 12 010/18:56 Deorbit Burn

07/23/01 1:02:00 AM 12 010/19:58 Landing

Updated: 06/22/2001

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Rendezvous 

Rendezvous and Docking Overview 

Rendezvous and Docking 

Atlantis' rendezvous and docking with the International Space Station begins with the 

precisely timed launch of the shuttle on a course for the station. During the first two days of 

the mission, periodic engine firings will gradually bring Atlantis to a point about 9 1/2 statute 

miles behind the station, the starting point for a final approach to the station. 

About 2 1⁄2 hours before the scheduled docking time on Flight Day 3, Atlantis will reach a 

point about 50,000 feet behind the ISS. At that time, Atlantis' jets will be fired in a Terminal 

Intercept (TI) burn to begin the final phase of the rendezvous. Atlantis will close the final 

miles to the station during the next orbit. 

As Atlantis closes in, the shuttle's rendezvous radar system will begin tracking the station 

and providing range and closing rate information to the crew. During the approach toward 

the station, the shuttle will have an opportunity to conduct four small mid-course corrections 

at regular intervals. Just after the fourth correction is completed, Atlantis will reach a point 

about half a mile below the station. At that time, about an hour before the scheduled 

docking, Commander Steve Lindsey will take over manual control of the approach. 

Lindsey will slow Atlantis's approach and fly to a point about 600 feet directly below the 

station, from which he will begin a quarter-circle of the station, slowly moving to a position 

in front of the complex, in line with its direction of travel. Pilot Charlie Hobaugh will assist 

Lindsey in controlling Atlantis' approach. Mission Specialist James Reilly also will play key 

roles in the rendezvous, assisting with the rendezvous navigation and operating a handheld 

laser ranging device. Mission Specialists Janet Kavandi and Mike Gernhardt will operate 

the shuttle's docking mechanism to latch the station and Atlantis together after the two 

spacecraft make contact. 

Lindsey will fly the quarter-circle of the station, starting 600 feet below it, while slowly 

closing in on the complex, stopping at a point a little more than 300 feet directly in front of 

the station. From that point, he will begin slowly closing in on the station -- moving at a 

speed of about a tenth of a mile per hour. Using a view from a camera mounted in the 

center of Atlantis' docking mechanism as a key alignment aid, Lindsey will precisely center 

the docking ports of the two spacecraft. Lindsey will fly to a point where the docking 

mechanisms are 30 feet apart, and pause for about five minutes to check the alignment. 

For Atlantis' docking, Lindsey will maintain the shuttle's speed relative to the station at 

about one-tenth of a foot per second, and keep the docking mechanisms aligned to within 

three inches of one another. When Atlantis makes contact with the station, preliminary 

latches will automatically attach the two spacecraft together. Immediately after Atlantis 

docks, the shuttle's steering jets will be deactivated to reduce the forces acting at the 

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docking interface. Shock absorber-type springs in the docking mechanism will dampen any 

relative motion between the shuttle and the station. 

Once relative motion between the spacecraft has been stopped, Kavandi and Gernhardt 

will secure the docking mechanism, sending commands for Atlantis's mechanism to retract 

and close a final set of latches between the shuttle and station. 

Undocking, Separation and Flyaround 

Once Atlantis is ready to undock, Kavandi and Gernhardt will send a command that will 

release the docking mechanism. The initial separation of the spacecraft will be performed 

by springs in the docking mechanism that will gently push the shuttle away from the station. 

Atlantis's steering jets will be shut off to avoid any inadvertent firings during this initial 

separation. 

Once the docking mechanism's springs have pushed Atlantis away to a distance of about 

two feet, when the docking devices will be clear of one another, Hobaugh will turn the 

steering jets back on and fire them to begin very slowly moving away. From the aft flight 

deck, Hobaugh will manually control Atlantis within a tight corridor as he separates from the 

ISS, essentially the reverse of the task performed by Lindsey when Atlantis docked. 

Atlantis will continue away to a distance of about 450 feet, where Hobaugh will begin a 

close flyaround of the station, circling the complex almost one and a quarter times. 

Hobaugh will pass a point directly above the station, then behind, then underneath, then in 

front and then reach a point directly above the station for a second time. At that point, 

passing above the station for a second time, Hobaugh will fire Atlantis's jets for final 

separation from the station. The flyaround is expected to be completed about an hour and 

20 minutes after undocking. 

Updated: 05/22/2001 

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EVAs 

STS-104 Spacewalks: Installing a Spacewalking Portal 

Overview 

Astronauts Mike Gernhardt and Jim Reilly will conduct three spacewalks while Atlantis is 

docked to the International Space Station to install, outfit and flight test a new airlock. 

Called the Joint Airlock, the new station component will accommodate both Russian and 

U.S. spacesuits and space-walking gear for future excursions from the station. 

During the Extravehicular Activities (EVAs), as the spacewalks are technically described, 

Gernhardt will be designated extravehicular crew member 1 (EV1), distinguishable by red 

stripes around the legs of his spacesuit, and Reilly will be EV2, with an all-white spacesuit. 

Atlantis' Pilot Charlie Hobaugh will serve as the intravehicular activity crew member (IV), 

coordinating the spacewalk activities from within the shuttle cabin. 

Astronaut Janet Kavandi will be operating the shuttle's robotic arm during the space walk 

while, aboard the station, Expedition Two Flight Engineer Susan Helms, assisted by fellow 

Expedition Two crew member Jim Voss, will operate the station's robotic arm. The internal 

hatches will be closed between Atlantis and the station during the first two spacewalks, 

although they are planned to be open for the third spacewalk, which is planned to begin 

from the newly installed station airlock rather than from Atlantis' airlock. 

The first spacewalk is planned for Flight Day 4 of the mission, the day after Atlantis docks 

to the station. During the first spacewalk, planned to last almost seven hours, the space 

walkers will assist as Helms, using the station's robotic arm, lifts the new station airlock 

from Atlantis' payload bay and attaches it to a port on the station's Unity connecting 

module. During much of the first spacewalk, Reilly will work from a foot platform attached to 

the end of the shuttle's robotic arm, operated by Kavandi. 

The first major task for the spacewalkers will be for Gernhardt to remove an insulating 

cover, nicknamed the "shower cap," from the airlock's Common Berthing Mechanism, the 

mechanism that will attach to Unity, while the airlock is in the payload bay. Gernhardt also 

will remove protective covers from the berthing mechanism's seals. The "shower cap" and 

seal covers will later be stowed by the spacewalkers in a tool locker in Atlantis' payload bay 

for the trip back to Earth. 

While Gernhardt is removing the covers, Reilly will work on the side of the airlock, installing 

devices, nicknamed "towel bars," that will later serve as attachment points for four highpressure oxygen and nitrogen tanks outside the new airlock. Reilly also will temporarily affix 

several thermal covers to the airlock exterior, positioning them for a later full installation on 

the third spacewalk. 

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Next, Gernhardt will disconnect a cable that provided shuttle electrical power to heaters on 

the airlock, called Launch To Activation or LTA heaters. Then Reilly will take the 

disconnected power cable and the removed airlock covers to a Tool Stowage Assembly 

(TSA) on the starboard side of the shuttle's payload bay to stow them. With the power cable 

between the shuttle and new airlock disconnected, Helms will begin to latch the station's 

Canadarm2 onto a fixture on the new airlock. 

While Helms and Voss lift the airlock from Atlantis' cargo bay and maneuver it into position 

to attach to the Unity module, Gernhardt and Reilly will wait inside the still-depressurized 

shuttle airlock, recharging their spacesuits by connecting to air and power from the shuttle. 

As Helms works with the station's arm, Kavandi will maneuver the shuttle's arm into 

positions to provide television camera views to assist Helms. 

Once the station airlock is poised high above the shuttle payload bay only a few feet from 

its attachment point on the station, Gernhardt and Reilly will leave the shuttle's airlock. If 

needed, the two spacewalkers will provide on-the-spot observations for Helms to assist 

with aligning the airlock as it is attached to Unity. Once the new airlock has been attached 

to the station, Gernhardt will then connect a cable that will provide station power to the new 

component, the final major task planned for the spacewalk. 

Second Spacewalk: Air for the Airlock 

The second spacewalk, planned to last about 51⁄2 hours, will be on Flight Day 7. The 

internal hatches between the shuttle and station will be closed at the end of Flight Day 6 to 

prepare for the second spacewalk, allowing the shuttle's cabin pressure to be reduced 

slightly as part of a protocol that protects spacewalkers from decompression sickness. 

The major objective of the second spacewalk is to attach and connect two -- one oxygen 

and one nitrogen -- of four oxygen and nitrogen tanks to the exterior of the new station 

airlock. The remaining two tanks are planned to be installed during the mission's third 

spacewalk. During the second spacewalk, Gernhardt will be tethered to the end of the 

shuttle's robotic arm for much of the work. 

Helms will be operating the station's arm to lift the tanks from the shuttle's payload bay and 

maneuver them to the new airlock on the station. As the spacewalk begins, Helms will latch 

the station arm onto the first tank, an oxygen tank, in Atlantis' payload bay. After the station 

arm is latched onto the tank, Gernhardt will release latches that held it in place in the 

shuttle for launch. Helms will then lift it from the shuttle bay and maneuver it to the new 

station airlock. After releasing the latches, Gernhardt will get on the shuttle's robotic arm 

and Kavandi will fly him up to the station airlock. Meanwhile, Reilly will install foot platforms 

and guideposts at the station airlock in preparation for installing the tank. 

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When Helms has moved the tank into position near the airlock, Gernhardt and Reilly, both 

working in foot platforms on the station's exterior, will take the tank from the arm as Helms 

releases it. The spacewalkers will then latch it into place on the airlock exterior, clamping it 

to some of the "towel bars" installed on the first spacewalk and using guideposts installed 

by Reilly to ensure that the tank is properly aligned. Gernhardt will then connect hoses from 

the tank to the airlock. 

The same tasks will basically be repeated to lift the second tank, a nitrogen tank, from the 

shuttle's cargo bay and install it onto the station airlock, although some foot platforms will 

have to be repositioned. Then, while Reilly finishes connections for the second tank, 

Gernhardt will install insulating covers on several airlock fixtures, including the four pins 

that helped latch the airlock in place during its time in the shuttle bay and the grapple fixture 

held by the station's robotic arm to attach the airlock to the station. 

Third Spacewalk: The First from the International Space Station Airlock 

The third spacewalk will be conducted on Flight Day 9 and is planned to last about 5 1/2 

hours. Although it can be conducted successfully from the shuttle airlock if needed, the 

third spacewalk is planned to begin from the new station airlock, both to serve as a flight 

test of the new station addition and to make the spacewalk and mission's work as efficient 

as possible. 

Preparations for the third spacewalk also are planned to include a new protocol to purge 

nitrogen from the body before the start of a spacewalk and thus protect the spacewalkers 

from decompression sickness. The new protocol, which involves breathing pure oxygen 

while exercising vigorously, will preclude the need for spacewalkers to spend long hours at 

reduced cabin pressure immediately before a spacewalk. It will allow the internal hatch 

between the new airlock and the station to remain open longer before a spacewalk begins 

yet still reduce the time that spacewalkers must prebreathe pure oxygen in their spacesuits 

before venting air from the airlock and venturing outside. 

The primary objective of the third spacewalk will be to install the final two tanks -- one 

oxygen and one nitrogen -- on the exterior of the new station airlock. The task will basically 

mirror the procedures used during the second spacewalk to remove the first two tanks from 

the shuttle's payload bay and install them on the airlock exterior. 

In addition to installing the final two tanks, the spacewalkers will connect a cable to the 

airlock that will enable communications with Russian spacesuits during future station 

spacewalks. They also will install several handholds on the airlock exterior and install 

insulating covers over grapple fixtures on the newly installed air tanks. 

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EVA Timeline for STS-104 

Spacewalks: Installing a Spacewalking Portal 

Time Event

002/17:10 EVA 1 Start

002/17:20 EVA 1 Setup

002/17:50 EVA 1 PCBM Cover Removal

002/17:50 EVA 1 Towel Bar Installation

002/18:30 EVA 1 Launch To Activation (LTA) Jumper Removal

002/18:55 EVA 1 Cleanup/Airlock Ingress

002/20:05 EVA 1 SSRMS Maneuver Airlock to Pre-Install

002/20:55 EVA 1 Airlock Egress to continue EVA

002/21:10 EVA 1 Starboard CBM Inspection

002/22:00 EVA 1 Airlock Attached to Unity

002/22:25 EVA 1 Mate Airlock-Unity Jumper

002/23:15 EVA 1 Cleanup

003/23:55 EVA 1 Ingress

005/17:05 EVA 2 Start

005/17:15 EVA 2 Setup

005/17:30 EVA 2 Oxygen-Nitrogen Tank 1 Installation

005/18:40 EVA 2 Oxygen-Nitrogen Tank 4 Installation

005/20:15 EVA 2 Grapple Fixture & Trunion Cover Installation

005/21:45 EVA 2 Cleanup

005/22:15 EVA 2 Ingress

007/18:40 EVA 3 Start

007/18:55 EVA 3 Setup

007/19:25 EVA 3 Oxygen Tank 2 Installation

007/20:35 EVA 3 Nitrogen Tank 3 Installation

007/22:25 EVA 3 Lab Launch To Activation (LTA) Cable Stow

007/22:40 EVA 3 Grapple Fixture Cover Installation

007/23:10 EVA 3 Cleanup

007/23:40 EVA 3 Ingress

Updated: 06/21/2001 

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Payloads 

Airlock Offers New Gateway to Space 

Overview 

Atlantis will deliver the Joint Airlock to the International Space Station on the STS-104 

mission, giving station crewmembers the ability to conduct spacewalks using either U.S. or 

Russian suits. The airlock also will vent less precious air into space than the shuttle 

airlock. 

The airlock is a critical space station element because of design differences between 

American and Russian spacesuits. American suits will not fit through Russian-designed 

airlocks. During a series of integration tests, the Russian suits were connected to the airlock 

to assure that they worked together. The airlock is specially designed to accommodate both 

suits, providing a chamber where astronauts from every nation can suit up for spacewalks to 

conduct science experiments and perform maintenance outside the station. 

Once the airlock is carried into space aboard Atlantis, the astronaut crew, using the 

station’s newly installed robotic arm, will secure it to the starboard side of the Unity node. 

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The airlock serves two key purposes: to keep air from escaping when the hatch to space is 

opened and to regulate the air pressure before an astronaut enters or leaves the ISS. It has 

two compartments: the crew lock, from which astronauts will enter and leave the station; 

and the equipment lock, where the spacewalkers will change into and out of their suits and 

stow all necessary gear. 

The airlock was designed and built by Boeing at NASA's Marshall Space Flight Center 

(MSFC) in Huntsville, Ala. Boeing-MSFC manufactured the equipment lock pressure shell, 

mated the equipment lock with the crew lock, installed all subsystems, and successfully 

performed airlock qualification testing. 

The airlock was shipped to the Kennedy Space Center last September aboard NASA's 

"Super Guppy" cargo aircraft. There it underwent leak testing and ground processing while 

multi-layer insulation and debris shields were installed on its exterior. 

The airlock was shipped to the Kennedy Space Center last September aboard NASA's 

"Super Guppy" cargo aircraft. There it underwent leak testing and ground processing while 

multi-layer insulation and debris shields were installed on its exterior. 

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Airlock Specifications

Material: Aluminum 

Length: 5.5 meters (18 ft.) 

Diameter: 4 meters (13 ft.) 

Weight: 6,064 kilograms (13,368 lbs.) 

Volume: 34 cubic meters (1,200 cu ft.) 

Cost: $164 million, including tanks 

Updated: 06/19/2001 

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Payloads

High-Pressure Gas Tanks

Overview

In addition to the airlock, the High-Pressure Gas Assembly also is being delivered by 

Atlantis. The assembly includes four high-pressure gas tanks -- two oxygen and two 

nitrogen. Each tank is just over 3 feet (.9 meter) in diameter. A meteor debris shield and a 

multi-layer insulation blanket to protect them from the harsh elements of space cover each 

tank. For the STS-104 flight, the tanks are on an adaptor that is mounted on the double 

Spacelab pallet in the shuttle cargo bay. The tanks and adapters also were designed and 

built by Boeing at MSFC.

The Russian Service Module "Zvezda" has been supplying these gases for the ISS. The 

High-Pressure Gas Assembly will augment the Service Module gas re-supply system.

High-Pressure Gas Assembly Specifications 

(Note: There are four High-Pressure Gas Assemblies on board.)

Tank Material: Carbon Fiber Wrap

Tank Diameter: .9 meter (3 ft.) each

Tank Volume: .42 cubic meter (15.1 cubic ft.) each 

Weight per unit: 545.4 kilograms (1,200 lbs.) each

Updated: 05/22/2001

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New Main Engine Promises Even Safer Shuttle Ride

The next space shuttle crew can expect an even safer ride into orbit, thanks to the 

completion of a new Space Shuttle Main Engine. Workers installed one of the new engines, 

called the Block II configuration, on Atlantis April 24 at NASA's Kennedy Space Center, Fla.

Atlantis' first flight using the new engine is targeted for launch no earlier than July 12 on the 

STS-104 mission to the International Space Station. Atlantis will use one Block II Main 

Engine and two Block IIA Main Engines to complete its full complement of three engines.

Improvements to the main engines, managed by NASA’s Marshall Space Flight Center in 

Huntsville, Ala., continue to evolve to produce the safest, most reliable and reusable space 

transportation system in the world. 

The Block II Main Engine configuration includes a new Pratt & Whitney high-pressure fuel 

turbopump. The primary modification to the engine is elimination of welds by using a 

casting process for the housing, and an integral shaft/disk with thin-wall blades and ceramic 

bearings. This makes the pump stronger and should increase the number of flights 

between major overhauls. Although the new pump adds 300 pounds (135 kilograms) of 

weight to the shuttle, the results are a more reliable and safer engine because of increased 

pump robustness.

"With this design change, we believe we have more than doubled the reliability of the 

engine," said George Hopson, manager of the Space Shuttle Main Engine Project at 

Marshall.

Previous improvements to the Space Shuttle Main Engine include the Block I configuration, 

which featured an improved high-pressure liquid oxygen turbopump, two-duct engine power 

head and single-coil heat exchanger. The turbopump incorporated ball bearings of silicon 

nitride — a ceramic material 30 percent harder and 40 percent lighter than steel. The Block 

I engine first flew in 1995. 

The Block IIA engine added a larger-throat main-combustion chamber to Block I 

improvements. The new chamber lowered the engine's operating pressures and 

temperatures while increasing the engine's operational safety margin. This engine first flew 

in 1998.

Developed in the 1970s by Marshall, the Space Shuttle Main Engine is the world's most 

sophisticated reusable rocket engine. Each powerful main engine is 14 feet long (4.3 

meters), weighs about 7,000 pounds (3,175 kilograms) and is 7.5 feet (2.3 meters) in 

diameter at the end of the nozzle.

The engines operate for about 81⁄2 minutes during liftoff and ascent and shut down just 

before the shuttle reaches low-Earth orbit. 

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The engines perform at greater temperature extremes than any mechanical system in 

common use today. At -423 degrees Fahrenheit (-250 degrees Celsius), the liquid 

hydrogen fuel is the second coldest liquid on Earth. When it and the liquid oxygen are 

combusted, the temperature in the main combustion chamber of the engine is 6,000 

degrees Fahrenheit (3,316 degrees Celsius), hotter than the boiling point of iron.

Boeing Rocketdyne in Canoga Park, Calif., manufactures the Space Shuttle Main Engine.

Space Shuttle Main Engine Enhancements

When a space shuttle lifts off, it does so with the help of three reusable, high-performance 

rocket engines.

The engines operate for about 81⁄2 minutes during liftoff and ascent -- long enough to burn 

more than 500,000 gallons (1.9 million liters) of super-cold liquid hydrogen and liquid 

oxygen propellants stored in the huge external tank attached to the underside of the 

shuttle. Liquid oxygen is stored at –298 degrees Fahrenheit (-183 degrees Celsius) and 

liquid hydrogen at -423 degrees Fahrenheit (-250 degrees Celsius). The engines shut down 

just before the shuttle, traveling at about 17,000 mph, reaches orbit.

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NASA continues to increase the reliability and safety of shuttle flights through a series of 

enhancements to the Space Shuttle Main Engines. The engines were modified in 1988, 

again in 1995, and more improvements were under development in 2000. 

The newest modifications include new high-pressure fuel and oxidizer turbopumps, a twoduct powerhead, a single-coil heat exchanger and a large-throat main combustion 

chamber. 

Each engine has two powerful high-pressure turbopumps that supply up to 970 pounds 

(440 kilograms) of liquid oxygen per second and up to 162 pounds (73 kilograms) of liquid 

hydrogen fuel per second to the engine's main combustion chamber. In this chamber, the 

hydrogen propellant and oxygen oxidizer mix and burn at high pressures and at 

temperatures exceeding 6,000 degrees Fahrenheit (3,316 degrees Celsius) to produce 

thrust. This year, the first flight is expected of a redesigned hydrogen turbopump. The new 

design uses a unique casting process to eliminate welds, significantly increasing the 

number of missions between major overhauls. In July 1995, a redesigned oxygen 

turbopump first flew on a shuttle. 

Considered the backbone of the engine, the powerhead consists of the main injector and 

two preburners, or small combustion chambers. Liquid oxygen and hydrogen are partially 

burned in the preburners, generating hot gases. The liquids continue to move through ducts 

into the main combustion chamber, while the gases created in these chambers drive the 

high-pressure turbopumps, which give the shuttle thrust. The two-duct hot gas manifold is a 

new powerhead design that first flew on the shuttle in July 1995. It significantly improves 

fluid flows in the system by decreasing pressure and turbulence, thus reducing 

maintenance and enhancing the overall performance of the engine. 

The shuttle's engines supply pressure to the external tank, which in turn provides 

propellants to the engines. This pressure is produced by the engine's heat exchanger, a 40-

foot-long (12-meter) piece of coiled stainless steel alloy tubing. Until mid-1995, the heat 

exchanger had seven welds in the 40-foot (12-meter) tube. The newly designed exchanger 

is a continuous piece of stainless steel alloy — thicker and with no welds. Beginning with 

the STS-70 mission in July 1995, a new enhanced single-coil heat exchanger has flown on 

each shuttle. 

A shuttle engine’s main combustion chamber is where the liquid hydrogen and liquid 

oxygen are mixed and burned to provide thrust. In January 1998, the first large-throat main 

combustion chamber flew on the STS-89 mission. The throat of the new chamber, made 

with fewer welds, is about 10 percent larger than the previous design -- improving the 

engine's reliability by reducing pressure and temperature in the chamber and throughout 

the engine. This allows the high-pressure pumps to operate at lower turbine temperatures 

and pressures. It improves chamber cooling and extends the life of the hardware. 

Updated: 05/25/2001 

24
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DTO/DSO/RMEs 

Monitoring Latent Virus Reactivation and Shedding in Astronauts 

DSO 493 

Overview 

The premise of this DSO is that the incidence and duration of latent virus reactivation in 

saliva and urine will increase during spaceflight. The objective is to determine the 

frequency of induced reactivation of latent viruses, latent virus shedding, and clinical 

disease after exposure to the physical, physiological, and psychological stressors 

associated with spaceflight. 

History/Background 

Spaceflight-induced alterations in the immune response become increasingly important on 

long missions, particularly the potential for reactivation and dissemination (shedding) of 

latent viruses. An example of a latent virus is Herpes Simplex Type 1 (HSV-1), which 

infects 70 to 80 percent of all adults. Its classic manifestations are cold sores, pharyngitis, 

and tonsillitis; and it usually is acquired through contact with the saliva, skin, or mucous 

membranes of an infected individual. However, many recurrences are asymptomatic, 

resulting in shedding of the virus. Twenty subjects have been studied for Epstein-Barr virus. 

Three additional viruses will be examined in an expanded subject group. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Individual Susceptibility to Post-Spaceflight Orthostatic Intolerance 

DSO 496 

Overview 

Susceptibility to postflight orthostatic intolerance -- lightheadedness or fainting upon return 

to Earth -- is highly individual. Some astronauts are little affected, while others have severe 

symptoms. Women are more often affected than men. The goal of this DSO is to discover 

the mechanisms responsible for these differences in order to customize countermeasure 

protocols. 

History/Background 

It has been well documented that spaceflight significantly alters cardiovascular function. 

One of the most important changes from a crew safety standpoint is postflight loss of 

orthostatic tolerance, which causes astronauts to have difficulty walking independently and 

induces lightheadedness or fainting. These effects may impair their ability to leave the 

orbiter after it lands. 

This DSO will perform a flight-related study, designed to clarify preflight and postflight 

differences in susceptible and nonsusceptible astronauts. There are no on-orbit activities 

associated with this DSO. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Spaceflight and Immune Function 

DSO 498 

Overview 

Astronauts face an increasing risk of contracting infectious diseases as they work and live 

for longer periods in the crowded conditions and closed environments of spacecraft such as 

the International Space Station. The effects of spaceflight on the human immune system, 

which plays a pivotal role in warding off infections, is not fully understood. Understanding 

the changes in immune functions caused by exposure to microgravity will allow researchers 

to develop countermeasures to minimize the risk of infection. 

History/Background 

The objective of this DSO is to characterize the effects of spaceflight on neutrophils, 

monocytes, and cytotoxic cells, which play an important role in maintaining an effective 

defense against infectious agents. The premise of this study is that the space environment 

alters the essential functions of these elements of human immune response. 

Researchers will conduct a functional analysis of neutrophils and monocytes from blood 

samples taken from astronauts before and after the flight. They will also assess the 

subjects' pre- and postflight production of cytotoxic cells and cytokine. 

This study will complement previous and continuing immunology studies of astronauts' 

adaptation to space. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Sleep-Wake Actigraphy and Light Exposure During Spaceflight 

DSO 634 

Overview 

Disruption of sleep during spaceflight, both short and long duration, is associated with 

inappropriately timed (non-24 hour) or insufficiently intense light exposure. Sleep disruption 

and circadian misalignment can lead to subjective dissatisfaction with self-reported sleep 

quality and daytime alertness. Both of these conditions are associated with insomnia and 

associated impairment of alertness and cognitive performance, which could impair mission 

success. 

History/Background 

This experiment will use state-of-the-art ambulatory technology to monitor sleep-wake 

activity and light exposure patterns obtained in flight. These data should help researchers 

better understand the effects of spaceflight on sleep, as well as aid in the development of 

effective countermeasures for both short- and long-duration spaceflight. 

Updated: 05/25/2001 

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DTO/DSO/RMEs 

Spatial Reorientation Following Spaceflight 

DSO 635 

Overview 

Spatial orientation is altered during and after spaceflight by a shift of central vestibular 

processing (from a gravitational frame-of-reference to an internal, head-centered frame-ofreference) that occurs during adaptation to microgravity and is reversed during the first few 

days after return to Earth. Discordant sensory stimuli during the postflight re-adaptive 

period will temporarily disorient/destabilize the subject by triggering a shift (state change) to 

the previously learned, internally referenced, microgravity-adapted pattern of spatial 

orientation and sensorimotor control. 

History/Background 

The purpose of this DSO is to examine both the adaptive changes in the spatial reference 

frame used for coding spatial orientation and sensorimotor control as well as the fragility of 

the adaptive process and the feasibility of driving state changes in central vestibular 

processing via discordant sensory stimuli using balance control tests and eye movement 

responses to pitch-axis rotation in a short-arm centrifuge. The findings are expected to 

demonstrate the degree to which challenging motion environments may affect postflight readaptation and lead to a better understanding of safe postflight activity regimens. The 

findings are also expected to demonstrate the feasibility of triggering state changes 

between sensorimotor control sets using a centrifuge device. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

International Space Station On-Orbit Loads Validation 

DTO 261 

Overview 

This DTO will use the shuttle's aft primary reaction control system jets to measure the 

structural dynamics (natural frequencies, modal amplitudes, and structural dampening) of 

the ISS and use the results to validate critical areas of the on-orbit loads prediction models. 

Three tests will be conducted to obtain various measurements. Test 1 will obtain 

photogrammetric measurements of the photovoltaic arrays. Test 2 will obtain 

photogrammetric measurements of the radiator. Test 3 will obtain acceleration and dynamic 

strain measurements in Unity, Zarya, Zvezda, and Destiny. The Internal Wireless 

Instrumentation System (IWIS) kit, which contains remote sensors, accelerometers, cables, 

and antennas for use on the shuttle or the ISS, will be used as part of Test 3. 

History/Background 

This is the sixth flight of DTO 261. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

On-Orbit Bicycle Ergometer Loads Measurement 

DTO 262 

Overview 

The purpose of this DTO is to study the possibility of reducing the engineering 

conservatism by measuring the joined shuttle/International Space Station natural 

frequencies, using the bicycle ergometer as the natural frequency excitation source. 

Reduction of conservatism would allow more operational flexibility by reducing preflight 

load predictions and, thus, operational constraints. 

History/Background 

This is the second of seven planned flights of DTO 262. 

Updated: 05/22/2001 

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STS-104

DTO/DSO/RMEs 

International Space Station Waste Collector Subsystem 

Refurbishment 

DTO 692 

Overview 

The Extended Duration Orbiter (EDO) Waste Collection Subsystem was originally designed 

for EDO flights and used three times on shuttle missions. It is now being provided to the 

International Space Station and is referred to as the ISS Waste Collector Subsystem 

(WCS). DTO 692 will test and verify the ISS WCS zero-g specific design changes before 

permanent installation on the ISS. 

History/Background 

This is the first of two flights of DTO 692. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Single-String Global Positioning System 

DTO 700-14 

Overview 

The purpose of the Single-String Global Positioning System (GPS) is to demonstrate the 

performance and operation of the GPS during orbiter ascent, on orbit, entry, and landing 

phases using a modified military GPS receiver processor and the existing orbiter GPS 

antennas. GPS data may be downlinked during all mission phases. 

History/Background 

The purpose of the Single-String Global Positioning System (GPS) is to demonstrate the 

performance and operation of the GPS during orbiter ascent, on orbit, entry, and landing 

phases using a modified military GPS receiver processor and the existing orbiter GPS 

antennas. GPS data may be downlinked during all mission phases. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Crosswind Landing Performance 

DTO 805 

Overview 

The purpose of this DTO is to demonstrate the capability to perform a manually controlled 

landing in the presence of a crosswind. The testing is done in two steps. 

1. Prelaunch: Ensure planning will allow selection of a runway with Microwave 

Scanning Beam Landing System support, which is a set of dual transmitters located 

beside the runway providing precision navigation vertically, horizontally, and 

longitudinally with respect to the runway. This precision navigation subsystem helps 

provide a higher probability of a more precise landing with a crosswind of 10 to 15 

knots as late in the flight as possible. 

2. Entry: This test requires that the crew perform a manually controlled landing in the 

presence of a 90-degree crosswind component of 10 to 15 knots steady state. 

During a crosswind landing, the drag chute will be deployed after nose gear touchdown 

when the vehicle is stable and tracking the runway centerline. 

History/Background 

This DTO has been manifested on 65 previous flights. 

Updated: 05/22/2001 

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DTO/DSO/RMEs 

Micro-Wireless Instrumentation System (Micro-WIS) 

DTO HTD 1403 

Overview 

This HTD will demonstrate the operational utility and functionality of Micro-WIS on orbit, 

initially in the crew cabin of the orbiter and then in the International Space Station. The 

Micro-WIS sensor/transmitter will provide important real-time temperature measurements. 

The Micro-WIS sensor/recorder will provide recorded temperature readings for postflight 

evaluation. 

History/Background 

This is the fifth flight of HTD 1403. 

Updated: 05/22/2001 

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Shuttle Reference Data 

Shuttle Abort History 

RSLS Abort History:

(STS-41 D) June 26, 1984

The countdown for the second launch attempt for Discovery’s maiden flight ended at T4 seconds when the orbiter’s computers detected a sluggish valve in main engine #3. 

The main engine was replaced and Discovery was finally launched on August 30, 1984. 

(STS-51 F) July 12, 1985

The countdown for Challenger’s launch was halted at T-3 seconds when on-board 

computers detected a problem with a coolant valve on main engine #2. The valve was 

replaced and Challenger was launched on July 29, 1985. 

(STS-55) March 22, 1993

The countdown for Columbia’s launch was halted by on-board computers at T-3 

seconds following a problem with purge pressure readings in the oxidizer preburner on 

main engine #2 Columbia’s three main engines were replaced on the launch pad, and 

the flight was rescheduled behind Discovery’s launch on STS-56. Columbia finally 

launched on April 26, 1993. 

(STS-51) August 12, 1993

The countdown for Discovery’s third launch attempt ended at the T-3 second mark 

when on-board computers detected the failure of one of four sensors in main engine #2 

which monitor the flow of hydrogen fuel to the engine. All of Discovery’s main engines 

were ordered replaced on the launch pad, delaying the Shuttle’s fourth launch attempt 

until September 12, 1993. 

(STS-68) August 18, 1994

The countdown for Endeavour’s first launch attempt ended 1.9 seconds before liftoff 

when on-board computers detected higher than acceptable readings in one channel of a 

sensor monitoring the discharge temperature of the high pressure oxidizer turbopump in 

main engine #3. A test firing of the engine at the Stennis Space Center in Mississippi on 

September 2nd confirmed that a slight drift in a fuel flow meter in the engine caused a 

slight increase in the turbopump’s temperature. The test firing also confirmed a slightly 

slower start for main engine #3 during the pad abort, which could have contributed to 

the higher temperatures. After Endeavour was brought back to the Vehicle Assembly 

Building to be outfitted with three replacement engines, NASA managers set October 

2nd as the date for Endeavour’s second launch attempt. 

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Abort to Orbit History:

(STS-51 F) July 29, 1985

After an RSLS abort on July 12, 1985, Challenger was launched on July 29, 1985. Five 

minutes and 45 seconds after launch, a sensor problem resulted in the shutdown of 

center engine #1, resulting in a safe "abort to orbit" and successful completion of the 

mission.

Updated: 05/22/2001 

37
STS-104

Shuttle Reference Data 

Shuttle Abort Modes 

RSLS ABORTS 

These occur when the onboard shuttle computers detect a problem and command a halt in 

the launch sequence after taking over from the Ground Launch Sequencer and before Solid 

Rocket Booster ignition. 

ASCENT ABORTS 

Selection of an ascent abort mode may become necessary if there is a failure that affects 

vehicle performance, such as the failure of a space shuttle main engine or an orbital 

maneuvering system. Other failures requiring early termination of a flight, such as a cabin 

leak, might also require the selection of an abort mode. 

There are two basic types of ascent abort modes for space shuttle missions: intact aborts 

and contingency aborts. Intact aborts are designed to provide a safe return of the orbiter to 

a planned landing site. Contingency aborts are designed to permit flight crew survival 

following more severe failures when an intact abort is not possible. A contingency abort 

would generally result in a ditch operation. 

INTACT ABORTS 

There are four types of intact aborts: abort to orbit (ATO), abort once around (AOA), 

transoceanic abort landing (TAL) and return to launch site (RTLS). 

Return to Launch Site 

The RTLS abort mode is designed to allow the return of the orbiter, crew, and payload to 

the launch site, Kennedy Space Center, approximately 25 minutes after lift-off. 

The RTLS profile is designed to accommodate the loss of thrust from one space shuttle 

main engine between lift-off and approximately four minutes 20 seconds, at which time not 

enough main propulsion system propellant remains to return to the launch site. 

An RTLS can be considered to consist of three stages--a powered stage, during which the 

space shuttle main engines are still thrusting; an ET separation phase; and the glide phase, 

during which the orbiter glides to a landing at the Kennedy Space Center. The powered 

RTLS phase begins with the crew selection of the RTLS abort, which is done after solid 

rocket booster separation. The crew selects the abort mode by positioning the abort rotary 

switch to RTLS and depressing the abort push button. The time at which the RTLS is 

selected depends on the reason for the abort. For example, a three-engine RTLS is 

selected at the last moment, approximately three minutes 34 seconds into the mission; 

whereas an RTLS chosen due to an engine out at lift-off is selected at the earliest time, 

approximately two minutes 20 seconds into the mission (after solid rocket booster 

separation). 

38
STS-104

After RTLS is selected, the vehicle continues downrange to dissipate excess main 

propulsion system propellant. The goal is to leave only enough main propulsion system 

propellant to be able to turn the vehicle around, fly back towards the Kennedy Space 

Center and achieve the proper main engine cutoff conditions so the vehicle can glide to the 

Kennedy Space Center after external tank separation. During the downrange phase, a 

pitch-around maneuver is initiated (the time depends in part on the time of a space shuttle 

main engine failure) to orient the orbiter/external tank configuration to a heads up attitude, 

pointing toward the launch site. At this time, the vehicle is still moving away from the launch 

site, but the space shuttle main engines are now thrusting to null the downrange velocity. In 

addition, excess orbital maneuvering system and reaction control system propellants are 

dumped by continuous orbital maneuvering system and reaction control system engine 

thrustings to improve the orbiter weight and center of gravity for the glide phase and 

landing. 

The vehicle will reach the desired main engine cutoff point with less than 2 percent excess 

propellant remaining in the external tank. At main engine cutoff minus 20 seconds, a pitchdown maneuver (called powered pitch-down) takes the mated vehicle to the required 

external tank separation attitude and pitch rate. After main engine cutoff has been 

commanded, the external tank separation sequence begins, including a reaction control 

system translation that ensures that the orbiter does not recontact the external tank and 

that the orbiter has achieved the necessary pitch attitude to begin the glide phase of the 

RTLS. 

After the reaction control system translation maneuver has been completed, the glide 

phase of the RTLS begins. From then on, the RTLS is handled similarly to a normal entry. 

Transoceanic Abort Landing 

The TAL abort mode was developed to improve the options available when a space shuttle 

main engine fails after the last RTLS opportunity but before the first time that an AOA can 

be accomplished with only two space shuttle main engines or when a major orbiter system 

failure, for example, a large cabin pressure leak or cooling system failure, occurs after the 

last RTLS opportunity, making it imperative to land as quickly as possible. 

In a TAL abort, the vehicle continues on a ballistic trajectory across the Atlantic Ocean to 

land at a predetermined runway. Landing occurs approximately 45 minutes after launch. 

The landing site is selected near the nominal ascent ground track of the orbiter in order to 

make the most efficient use of space shuttle main engine propellant. The landing site also 

must have the necessary runway length, weather conditions and U.S. State Department 

approval. Currently, the three landing sites that have been identified for a due east launch 

are Moron, Spain; Dakar, Senegal; and Ben Guerur, Morocco (on the west coast of Africa). 

To select the TAL abort mode, the crew must place the abort rotary switch in the TAL/AOA 

position and depress the abort push button before main engine cutoff. (Depressing it after 

main engine cutoff selects the AOA abort mode.) The TAL abort mode begins sending 

commands to steer the vehicle toward the plane of the landing site. It also rolls the vehicle 

heads up before main engine cutoff and sends commands to begin an orbital maneuvering 

system propellant dump (by burning the propellants through the orbital maneuvering 

39
STS-104

system engines and the reaction control system engines). This dump is necessary to 

increase vehicle performance (by decreasing weight), to place the center of gravity in the 

proper place for vehicle control, and to decrease the vehicle's landing weight. 

TAL is handled like a nominal entry. 

Abort to Orbit 

An ATO is an abort mode used to boost the orbiter to a safe orbital altitude when 

performance has been lost and it is impossible to reach the planned orbital altitude. If a 

space shuttle main engine fails in a region that results in a main engine cutoff under speed, 

the Mission Control Center will determine that an abort mode is necessary and will inform 

the crew. The orbital maneuvering system engines would be used to place the orbiter in a 

circular orbit. 

Abort Once Around 

The AOA abort mode is used in cases in which vehicle performance has been lost to such 

an extent that either it is impossible to achieve a viable orbit or not enough orbital 

maneuvering system propellant is available to accomplish the orbital maneuvering system 

thrusting maneuver to place the orbiter on orbit and the deorbit thrusting maneuver. In 

addition, an AOA is used in cases in which a major systems problem (cabin leak, loss of 

cooling) makes it necessary to land quickly. In the AOA abort mode, one orbital 

maneuvering system thrusting sequence is made to adjust the post-main engine cutoff orbit 

so a second orbital maneuvering system thrusting sequence will result in the vehicle 

deorbiting and landing at the AOA landing site (White Sands, N.M.; Edwards Air Force 

Base; or the Kennedy Space Center). Thus, an AOA results in the orbiter circling the Earth 

once and landing approximately 90 minutes after lift-off. 

After the deorbit thrusting sequence has been executed, the flight crew flies to a landing at 

the planned site much as it would for a nominal entry. 

CONTINGENCY ABORTS 

Contingency aborts are caused by loss of more than one main engine or failures in other 

systems. Loss of one main engine while another is stuck at a low thrust setting may also 

necessitate a contingency abort. Such an abort would maintain orbiter integrity for in-flight 

crew escape if a landing cannot be achieved at a suitable landing field. 

Contingency aborts due to system failures other than those involving the main engines 

would normally result in an intact recovery of vehicle and crew. Loss of more than one main 

engine may, depending on engine failure times, result in a safe runway landing. However, 

in most three-engine-out cases during ascent, the orbiter would have to be ditched. The inflight crew escape system would be used before ditching the orbiter. 

40
STS-104

ABORT DECISIONS 

There is a definite order of preference for the various abort modes. The type of failure and 

the time of the failure determine which type of abort is selected. In cases where 

performance loss is the only factor, the preferred modes would be ATO, AOA, TAL and 

RTLS, in that order. The mode chosen is the highest one that can be completed with the 

remaining vehicle performance. 

In the case of some support system failures, such as cabin leaks or vehicle cooling 

problems, the preferred mode might be the one that will end the mission most quickly. In 

these cases, TAL or RTLS might be preferable to AOA or ATO. A contingency abort is 

never chosen if another abort option exists. 

The Mission Control Center-Houston is prime for calling these aborts because it has a more 

precise knowledge of the orbiter's position than the crew can obtain from onboard systems. 

Before main engine cutoff, Mission Control makes periodic calls to the crew to tell them 

which abort mode is (or is not) available. If ground communications are lost, the flight crew 

has onboard methods, such as cue cards, dedicated displays and display information, to 

determine the current abort region. 

Which abort mode is selected depends on the cause and timing of the failure causing the 

abort and which mode is safest or improves mission success. If the problem is a space 

shuttle main engine failure, the flight crew and Mission Control Center select the best 

option available at the time a space shuttle main engine fails. 

If the problem is a system failure that jeopardizes the vehicle, the fastest abort mode that 

results in the earliest vehicle landing is chosen. RTLS and TAL are the quickest options (35 

minutes), whereas an AOA requires approximately 90 minutes. Which of these is selected 

depends on the time of the failure with three good space shuttle main engines. 

The flight crew selects the abort mode by positioning an abort mode switch and depressing 

an abort push button. 

Updated: 05/22/2001 

41
STS-104

Shuttle Reference Data 

Space Shuttle Rendezvous Maneuvers 

COMMON SHUTTLE RENDEZVOUS MANEUVERS

OMS-1 (Orbit insertion) - Rarely used ascent abort burn 

OMS-2 (Orbit insertion) - Typically used to circularize the initial orbit following ascent, 

completing orbital insertion. For ground-up rendezvous flights, also considered a 

rendezvous phasing burn 

NC (Rendezvous phasing) - Performed to hit a range relative to the target at a future 

time 

NH (Rendezvous height adjust) - Performed to hit a delta-height relative to the target 

at a future time 

NPC (Rendezvous plane change) - Performed to remove planar errors relative to the 

target at a future time 

NCC (Rendezvous corrective combination) - First on-board targeted burn in the 

rendezvous sequence. Using star tracker data, it is performed to remove phasing and 

height errors relative to the target at Ti 

Ti (Rendezvous terminal intercept) - Second on-board targeted burn in the 

rendezvous sequence. Using primarily rendezvous radar data, it places the Orbiter on a 

trajectory to intercept the target in one orbit 

MC-1, MC-2, MC-3, MC-4 (Rendezvous midcourse burns) - These on-board targeted 

burns use star tracker and rendezvous radar data to correct the post-Ti trajectory in 

preparation for the final, manual proximity operations phase 

Updated: 05/22/2001 

42
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Shuttle Reference Data 

Space Shuttle Solid Rocket Boosters 

The two SRBs provide the main thrust to lift the space shuttle off the pad and up to an 

altitude of about 150,000 feet, or 24 nautical miles (28 statute miles). In addition, the two 

SRBs carry the entire weight of the external tank and orbiter and transmit the weight load 

through their structure to the mobile launcher platform. 

Each booster has a thrust (sea level) of approximately 3,300,000 pounds at launch. They 

are ignited after the three space shuttle main engines' thrust level is verified. The two SRBs 

provide 71.4 percent of the thrust at lift- off and during first-stage ascent. Seventy- five 

seconds after SRB separation, SRB apogee occurs at an altitude of approximately 220,000 

feet, or 35 nautical miles (40 statute miles). SRB impact occurs in the ocean approximately 

122 nautical miles (140 statute miles) downrange. 

The SRBs are the largest solid-propellant motors ever flown and the first designed for 

reuse. Each is 149.16 feet long and 12.17 feet in diameter. 

Each SRB weighs approximately 1,300,000 pounds at launch. The propellant for each solid 

rocket motor weighs approximately 1,100,000 pounds. The inert weight of each SRB is 

approximately 192,000 pounds. 

Primary elements of each booster are the motor (including case, propellant, igniter and 

nozzle), structure, separation systems, operational flight instrumentation, recovery avionics, 

pyrotechnics, deceleration system, thrust vector control system and range safety destruct 

system. 

Each booster is attached to the external tank at the SRB’s aft frame by two lateral sway 

braces and a diagonal attachment. The forward end of each SRB is attached to the 

external tank at the forward end of the SRB’s forward skirt. On the launch pad, each 

booster also is attached to the mobile launcher platform at the aft skirt by four bolts and 

nuts that are severed by small explosives at lift-off. 

During the downtime following the Challenger accident, detailed structural analyses were 

performed on critical structural elements of the SRB. Analyses were primarily focused in 

areas where anomalies had been noted during postflight inspection of recovered hardware. 

One of the areas was the attach ring where the SRBs are connected to the external tank. 

Areas of distress were noted in some of the fasteners where the ring attaches to the SRB 

motor case. This situation was attributed to the high loads encountered during water 

impact. To correct the situation and ensure higher strength margins during ascent, the 

attach ring was redesigned to encircle the motor case completely (360 degrees). 

Previously, the attach ring formed a C and encircled the motor case 270 degrees. 

43
STS-104

Additionally, special structural tests were performed on the aft skirt. During this test 

program, an anomaly occurred in a critical weld between the hold-down post and skin of 

the skirt. A redesign was implemented to add reinforcement brackets and fittings in the aft 

ring of the skirt. 

These two modifications added approximately 450 pounds to the weight of each SRB. 

The propellant mixture in each SRB motor consists of an ammonium perchlorate (oxidizer, 

69.6 percent by weight), aluminum (fuel, 16 percent), iron oxide (a catalyst, 0.4 percent), a 

polymer (a binder that holds the mixture together, 12.04 percent), and an epoxy curing 

agent (1.96 percent). The propellant is an 11-point star-shaped perforation in the forward 

motor segment and a double-truncated-cone perforation in each of the aft segments and aft 

closure. This configuration provides high thrust at ignition and then reduces the thrust by 

approximately a third 50 seconds after lift-off to prevent overstressing the vehicle during 

maximum dynamic pressure. 

The SRBs are used as matched pairs and each is made up of four solid rocket motor 

segments. The pairs are matched by loading each of the four motor segments in pairs from 

the same batches of propellant ingredients to minimize any thrust imbalance. The 

segmented-casing design assures maximum flexibility in fabrication and ease of 

transportation and handling. Each segment is shipped to the launch site on a heavy-duty 

rail car with a specially built cover. 

The nozzle expansion ratio of each booster beginning with the STS-8 mission is 7-to-79. 

The nozzle is gimbaled for thrust vector (direction) control. Each SRB has its own 

redundant auxiliary power units and hydraulic pumps. The all-axis gimbaling capability is 8 

degrees. Each nozzle has a carbon cloth liner that erodes and chars during firing. The 

nozzle is a convergent-divergent, movable design in which an aft pivot-point flexible 

bearing is the gimbal mechanism. 

The cone- shaped aft skirt reacts the aft loads between the SRB and the mobile launcher 

platform. The four aft separation motors are mounted on the skirt. The aft section contains 

avionics, a thrust vector control system that consists of two auxiliary power units and 

hydraulic pumps, hydraulic systems and a nozzle extension jettison system. 

The forward section of each booster contains avionics, a sequencer, forward separation 

motors, a nose cone separation system, drogue and main parachutes, a recovery beacon, 

a recovery light, a parachute camera on selected flights and a range safety system. 

Each SRB has two integrated electronic assemblies, one forward and one aft. After 

burnout, the forward assembly initiates the release of the nose cap and frustum and turns 

on the recovery aids. The aft assembly, mounted in the external tank/SRB attach ring, 

connects with the forward assembly and the orbiter avionics systems for SRB ignition 

commands and nozzle thrust vector control. Each integrated electronic assembly has a 

multiplexer/ demultiplexer, which sends or receives more than one message, signal or unit 

of information on a single communication channel. 

44
STS-104

Eight booster separation motors (four in the nose frustum and four in the aft skirt) of each 

SRB thrust for 1.02 seconds at SRB separation from the external tank. Each solid rocket 

separation motor is 31.1 inches long and 12.8 inches in diameter. 

Location aids are provided for each SRB, frustum/drogue chutes and main parachutes. 

These include a transmitter, antenna, strobe/converter, battery and salt water switch 

electronics. The location aids are designed for a minimum operating life of 72 hours and 

when refurbished are considered usable up to 20 times. The flashing light is an exception. 

It has an operating life of 280 hours. The battery is used only once. 

The SRB nose caps and nozzle extensions are not recovered. 

The recovery crew retrieves the SRBs, frustum/drogue chutes, and main parachutes. The 

nozzles are plugged, the solid rocket motors are dewatered, and the SRBs are towed back 

to the launch site. Each booster is removed from the water, and its components are 

disassembled and washed with fresh and deionized water to limit salt water corrosion. The 

motor segments, igniter and nozzle are shipped back to Thiokol for refurbishment. 

Each SRB incorporates a range safety system that includes a battery power source, 

receiver/ decoder, antennas and ordnance. 

HOLD-DOWN POSTS 

Each solid rocket booster has four hold-down posts that fit into corresponding support posts 

on the mobile launcher platform. Hold-down bolts hold the SRB and launcher platform 

posts together. Each bolt has a nut at each end, but only the top nut is frangible. The top 

nut contains two NASA standard detonators, which are ignited at solid rocket motor ignition 

commands. 

When the two NSDs are ignited at each hold-down, the hold-down bolt travels downward 

because of the release of tension in the bolt (pretensioned before launch), NSD gas 

pressure and gravity. The bolt is stopped by the stud deceleration stand, which contains 

sand. The SRB bolt is 28 inches long and is 3.5 inches in diameter. The frangible nut is 

captured in a blast container. 

The solid rocket motor ignition commands are issued by the orbiter''s computers through 

the master events controllers to the hold-down pyrotechnic initiator controllers on the 

mobile launcher platform. They provide the ignition to the hold-down NSDs. The launch 

processing system monitors the SRB hold-down PICs for low voltage during the last 16 

seconds before launch. PIC low voltage will initiate a launch hold. 

SRB IGNITION 

SRB ignition can occur only when a manual lock pin from each SRB safe and arm device 

has been removed. The ground crew removes the pin during prelaunch activities. At T 

minus five minutes, the SRB safe and arm device is rotated to the arm position. The solid 

rocket motor ignition commands are issued when the three SSMEs are at or above 90-

percent rated thrust, no SSME fail and/or SRB ignition PIC low voltage is indicated and 

there are no holds from the LPS. 

45
STS-104

The solid rocket motor ignition commands are sent by the orbiter computers through the 

MECs to the safe and arm device NSDs in each SRB. A PIC single-channel capacitor 

discharge device controls the firing of each pyrotechnic device. Three signals must be 

present simultaneously for the PIC to generate the pyro firing output. These signals--arm, 

fire 1 and fire 2--originate in the orbiter general-purpose computers and are transmitted to 

the MECs. The MECs reformat them to 28-volt dc signals for the PICs. The arm signal 

charges the PIC capacitor to 40 volts dc (minimum of 20 volts dc). 

The fire 2 commands cause the redundant NSDs to fire through a thin barrier seal down a 

flame tunnel. This ignites a pyro booster charge, which is retained in the safe and arm device 

behind a perforated plate. The booster charge ignites the propellant in the igniter initiator; 

and combustion products of this propellant ignite the solid rocket motor initiator, which fires 

down the length of the solid rocket motor igniting the solid rocket motor propellant. 

The GPC launch sequence also controls certain critical main propulsion system valves and 

monitors the engine-ready indications from the SSMEs. The MPS start commands are 

issued by the onboard computers at T minus 6.6 seconds (staggered start--engine three, 

engine two, engine one--all approximately within 0.25 of a second), and the sequence 

monitors the thrust buildup of each engine. All three SSMEs must reach the required 90-

percent thrust within three seconds; otherwise, an orderly shutdown is commanded and 

safing functions are initiated. 

Normal thrust buildup to the required 90-percent thrust level will result in the SSMEs being 

commanded to the lift-off position at T minus three seconds as well as the fire 1 command 

being issued to arm the SRBs. At T minus three seconds, the vehicle base bending load 

modes are allowed to initialize (movement of approximately 25.5 inches measured at the tip 

of the external tank, with movement towards the external tank). 

At T minus zero, the two SRBs are ignited, under command of the four onboard computers; 

separation of the four explosive bolts on each SRB is initiated (each bolt is 28 inches long 

and 3.5 inches in diameter); the two T-0 umbilicals (one on each side of the spacecraft) are 

retracted; the onboard master timing unit, event timer and mission event timers are started; 

the three SSMEs are at 100 percent; and the ground launch sequence is terminated. 

The solid rocket motor thrust profile is tailored to reduce thrust during the maximum 

dynamic pressure region. 

ELECTRICAL POWER DISTRIBUTION 

Electrical power distribution in each SRB consists of orbiter-supplied main dc bus power to 

each SRB via SRB buses A, B and C. Orbiter main dc buses A, B and C supply main dc 

bus power to corresponding SRB buses A, B and C. In addition, orbiter main dc bus C 

supplies backup power to SRB buses A and B, and orbiter bus B supplies backup power to 

SRB bus C. This electrical power distribution arrangement allows all SRB buses to remain 

powered in the event one orbiter main bus fails. 

The nominal dc voltage is 28 volts dc, with an upper limit of 32 volts dc and a lower limit of 

24 volts dc. 

46
STS-104

HYDRAULIC POWER UNITS 

There are two self-contained, independent HPUs on each SRB. Each HPU consists of an 

auxiliary power unit, fuel supply module, hydraulic pump, hydraulic reservoir and hydraulic 

fluid manifold assembly. The APUs are fueled by hydrazine and generate mechanical shaft 

power to a hydraulic pump that produces hydraulic pressure for the SRB hydraulic system. 

The two separate HPUs and two hydraulic systems are located on the aft end of each SRB 

between the SRB nozzle and aft skirt. The HPU components are mounted on the aft skirt 

between the rock and tilt actuators. The two systems operate from T minus 28 seconds 

until SRB separation from the orbiter and external tank. The two independent hydraulic 

systems are connected to the rock and tilt servoactuators. 

The APU controller electronics are located in the SRB aft integrated electronic assemblies 

on the aft external tank attach rings. 

The APUs and their fuel systems are isolated from each other. Each fuel supply module 

(tank) contains 22 pounds of hydrazine. The fuel tank is pressurized with gaseous nitrogen 

at 400 psi, which provides the force to expel (positive expulsion) the fuel from the tank to 

the fuel distribution line, maintaining a positive fuel supply to the APU throughout its 

operation. 

The fuel isolation valve is opened at APU startup to allow fuel to flow to the APU fuel pump 

and control valves and then to the gas generator. The gas generator's catalytic action 

decomposes the fuel and creates a hot gas. It feeds the hot gas exhaust product to the 

APU two-stage gas turbine. Fuel flows primarily through the startup bypass line until the 

APU speed is such that the fuel pump outlet pressure is greater than the bypass line's. 

Then all the fuel is supplied to the fuel pump. 

The APU turbine assembly provides mechanical power to the APU gearbox. The gearbox 

drives the APU fuel pump, hydraulic pump and lube oil pump. The APU lube oil pump 

lubricates the gearbox. The turbine exhaust of each APU flows over the exterior of the gas 

generator, cooling it, and is then directed overboard through an exhaust duct. 

When the APU speed reaches 100 percent, the APU primary control valve closes, and the 

APU speed is controlled by the APU controller electronics. If the primary control valve logic 

fails to the open state, the secondary control valve assumes control of the APU at 112-

percent speed. 

Each HPU on an SRB is connected to both servoactuators on that SRB. One HPU serves 

as the primary hydraulic source for the servoactuator, and the other HPU serves as the 

secondary hydraulics for the servoactuator. Each sevoactuator has a switching valve that 

allows the secondary hydraulics to power the actuator if the primary hydraulic pressure 

drops below 2,050 psi. A switch contact on the switching valve will close when the valve is 

in the secondary position. When the valve is closed, a signal is sent to the APU controller 

that inhibits the 100-percent APU speed control logic and enables the 112-percent APU 

speed control logic. The 100-percent APU speed enables one APU/HPU to supply 

sufficient operating hydraulic pressure to both servoactuators of that SRB. 

47
STS-104

The APU 100-percent speed corresponds to 72,000 rpm, 110-percent to 79,200 rpm, and 

112-percent to 80,640 rpm. 

The hydraulic pump speed is 3,600 rpm and supplies hydraulic pressure of 3,050, plus or 

minus 50, psi. A high-pressure relief valve provides overpressure protection to the hydraulic 

system and relieves at 3,750 psi. 

The APUs/HPUs and hydraulic systems are reusable for 20 missions. 

THRUST VECTOR CONTROL 

Each SRB has two hydraulic gimbal servoactuators: one for rock and one for tilt. The 

servoactuators provide the force and control to gimbal the nozzle for thrust vector control. 

The space shuttle ascent thrust vector control portion of the flight control system directs the 

thrust of the three shuttle main engines and the two SRB nozzles to control shuttle attitude 

and trajectory during lift-off and ascent. Commands from the guidance system are 

transmitted to the ATVC drivers, which transmit signals proportional to the commands to 

each servoactuator of the main engines and SRBs. Four independent flight control system 

channels and four ATVC channels control six main engine and four SRB ATVC drivers, 

with each driver controlling one hydraulic port on each main and SRB servoactuator. 

Each SRB servoactuator consists of four independent, two-stage servovalves that receive 

signals from the drivers. Each servovalve controls one power spool in each actuator, which 

positions an actuator ram and the nozzle to control the direction of thrust. 

The four servovalves in each actuator provide a force-summed majority voting arrangement 

to position the power spool. With four identical commands to the four servovalves, the 

actuator force-sum action prevents a single erroneous command from affecting power ram 

motion. If the erroneous command persists for more than a predetermined time, differential 

pressure sensing activates a selector valve to isolate and remove the defective servovalve 

hydraulic pressure, permitting the remaining channels and servovalves to control the 

actuator ram spool. 

Failure monitors are provided for each channel to indicate which channel has been 

bypassed. An isolation valve on each channel provides the capability of resetting a failed or 

bypassed channel. 

Each actuator ram is equipped with transducers for position feedback to the thrust vector 

control system. Within each servoactuator ram is a splashdown load relief assembly to 

cushion the nozzle at water splashdown and prevent damage to the nozzle flexible bearing. 

SRB RATE GYRO ASSEMBLIES 

Each SRB contains two RGAs, with each RGA containing one pitch and one yaw gyro. 

These provide an output proportional to angular rates about the pitch and yaw axes to the 

orbiter computers and guidance, navigation and control system during first-stage ascent 

flight in conjunction with the orbiter roll rate gyros until SRB separation. At SRB separation, 

a switchover is made from the SRB RGAs to the orbiter RGAs. 

48
STS-104

The SRB RGA rates pass through the orbiter flight aft multiplexers/ demultiplexers to the 

orbiter GPCs. The RGA rates are then mid-value- selected in redundancy management to 

provide SRB pitch and yaw rates to the user software. The RGAs are designed for 20 

missions. 

SRB SEPARATION 

SRB separation is initiated when the three solid rocket motor chamber pressure 

transducers are processed in the redundancy management middle value select and the 

head-end chamber pressure of both SRBs is less than or equal to 50 psi. A backup cue is 

the time elapsed from booster ignition. 

The separation sequence is initiated, commanding the thrust vector control actuators to the 

null position and putting the main propulsion system into a second-stage configuration (0.8 

second from sequence initialization), which ensures the thrust of each SRB is less than 

100,000 pounds. Orbiter yaw attitude is held for four seconds, and SRB thrust drops to less 

than 60,000 pounds. 

The SRBs separate from the external tank within 30 milliseconds of the ordnance firing 

command. 

The forward attachment point consists of a ball (SRB) and socket (ET) held together by one 

bolt. The bolt contains one NSD pressure cartridge at each end. The forward attachment 

point also carries the range safety system cross-strap wiring connecting each SRB RSS 

and the ET RSS with each other. 

The aft attachment points consist of three separate struts: upper, diagonal and lower. Each 

strut contains one bolt with an NSD pressure cartridge at each end. The upper strut also 

carries the umbilical interface between its SRB and the external tank and on to the orbiter. 

There are four booster separation motors on each end of each SRB. The BSMs separate 

the SRBs from the external tank. The solid rocket motors in each cluster of four are ignited 

by firing redundant NSD pressure cartridges into redundant confined detonating fuse 

manifolds. 

The separation commands issued from the orbiter by the SRB separation sequence initiate 

the redundant NSD pressure cartridge in each bolt and ignite the BSMs to effect a clean 

separation. 

Updated: 05/22/2001

49
STS-104

Shuttle Reference Data 

Space Shuttle Super Light Weight Tank (SLWT) 

The super lightweight external tank (SLWT) made its first shuttle flight June 2, 1998, on 

mission STS-91. The SLWT is 7,500 pounds lighter than the standard external tank. The 

lighter weight tank will allow the shuttle to deliver International Space Station elements 

(such as the service module) into the proper orbit. 

The SLWT is the same size as the previous design. But the liquid hydrogen tank and the 

liquid oxygen tank are made of aluminum lithium, a lighter, stronger material than the metal 

alloy used for the shuttle's current tank. The tank's structural design has also been 

improved, making it 30% stronger and 5% less dense. 

The SLWT, like the standard tank, is manufactured at Michoud Assembly, near New 

Orleans, Louisiana, by Lockheed Martin. 

The 154-foot-long external tank is the largest single component of the space shuttle. It 

stands taller than a 15-story building and has a diameter of about 27 feet. The external tank 

holds over 530,000 gallons of liquid hydrogen and liquid oxygen in two separate tanks. The 

hydrogen (fuel) and liquid oxygen (oxidizer) are used as propellants for the shuttle's three 

main engines. 

Updated: 05/22/2001

50
STS-104 

A-1 

APPENDIX A ACRONYMS AND ABBREVIATIONS 

A/L Airlock (ISS Joint Airlock) 

AAP Airlock Adapter Plate 

ABC Audio Bus Coupler 

ACBM Active Common Berthing Mechanism 

ACS Assembly Contingency System 

Atmosphere Control System 

ACU Arm Computer Unit 

AL Airlock (ISS Joint Airlock) 

AOH Assembly Operations Handbook 

APAS Androgynous Peripheral Attachment System 

APCU Assembly Power Converter Unit 

APFR Articulating Portable Foot Restraint 

APS Automated Payload Switch 

ARIS Active Rack Isolation System 

ARS Atmospheric Revitalization System 

ASCR Assured Safe Crew Return 

ATCS Active Thermal Control System 

ATU Audio Terminal Unit 

AUAI Assembly Contingency System UHF Audio Interface 

AUX Auxiliary 

AVU Artificial Vision Unit 

BC Bus Controller 

BCA Battery Charger Assembly 

BCU Backup Drive Control Unit 

BSA Battery Storage Assembly 

BSP Baseband Signal Processor 

C&C Command and Control 

C&DH Command and Data Handling 

C&T Communications and Tracking 

C&W Caution and Warning 

C/L Crew Lock 

CB Control Bus 

CBM Common Berthing Mechanism 

CCAA Common Cabin Air Assembly 

CCC Containment Control Cartridge 

CCD Cursor Control Device 

CCH Crew Communication Headset 

CCSDS Consultative Committee on Space Data Systems 

CCTV Closed Circuit Television 

CDDT Common Display Development Team 

CETA Crew Equipment Translation Aid 

CEU Control Electronics Unit 

51
STS-104 

A-2 

CheCS Crew Health Care System 

Comm Communications 

CPA Control Panel Assembly 

CPC Control Post Computer 

CSA-H Compound Specific Analyzer-Hydrazine 

CTV Crew Transfer Vehicle 

CVIU Common Video Interface Unit 

CVT Current Value Table 

CWC Contingency Water Container 

CWR Collapsible Water Reservoir (aka EMU water recharge bag) 

CWU Crew Wireless Unit 

DAIU Docked Audio Interface Unit 

DAP Digital Autopilot 

DCM Display and Control Module 

DCSU Direct Current Switching Unit 

DDCU Direct Current-to-Direct Current Converter Unit 

DMCU Docking Mechanism Control Unit 

DPA Data Processing Assembly 

DSCU Docking System Control Unit 

DTO Detailed Test Objective 

E/L Equipment Lock 

EACP EMU audio control panel 

EAIU EMU Audio Interface Unit 

ECLSS Environmental Control and Life Support System 

ECS Early Communications Subsystem 

EDDA EMU Don/Doff Assembly 

EDP Electronic Data Processing 

EEATCS Early External Active Thermal Control System 

EEL Emergency Egress Lighting 

EMU Extravehicular Maneuvering Unit 

EPS Electrical Power system 

ESA European Space Agency 

ETSD EVA Tools Stowage Device 

EUE Experiment Unique Equipment 

EVA Extravehicular Activity 

EVR Extravehicular Robotics 

FD Flight Day 

FDS Fire Detection and Suppression 

FGB Functional Cargo Block 

FRGF Flight Releasable Grapple Fixture 

GFCI Ground Fault Interruption Circuit 

GFE Government Furnished Equipment 

GFI Ground Fault Interruption 

52
STS-104 

A-3 

GLA General Luminaire Assembly 

GLONASS Global Navigational Satellite System 

GNC Guidance and Navigation Computer 

GPS Global Positioning System 

GUI Graphical User Interface 

HCU Headset Control Unit 

HDR High Data Rate 

HEPA High-Efficiency Particulate Arrestor (a filter for the CCAA) 

HGA High Gain Antenna 

HPGT High Pressure Gas Tank (see ONTO) 

I/O Input/Output 

IAA Intravehicular Antenna Assembly 

IAS Internal Audio System 

ICBC3D IMAX Cargo Bay Camera 3-Dimensional 

IMV Intermodule Ventilation 

IOCU Input/Output Controller Unit 

IP International Partner 

IRU In-flight Refill Unit 

ISA International Sampling Adapter 

ISPR International Standard Payload Rack 

ISS International Space Station 

ISSP International Space Station Program 

ISSSH International Space Station Systems Handbook 

ITCS Internal Thermal Control System 

IVA Intervehicular Activity 

JEU Joint Electronics Unit 

JSC Johnson Space Center 

LAN Local Area Networl 

LB Local Bus 

LDR Low Data Rate 

LGA Low Gain Antenna 

LTA Launch to Activation 

LEE Latching End Effector (both SRMS and SSRMS) 

Mb Megabytes 

MBM Manual Berthing Mechanism 

MCS Motion Control System 

MDM Multiplexer/Demultiplexer 

MDP Maximum Design Pressure 

METOX Metal Oxide (for CO2 removal) 

MIP Mission Integration Plan 

MLE Middeck Locker Equipment 

MLI Multilayer Insulation 

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STS-104 

A-4 

MM/OD Micrometeoroid/Orbital Debris 

MOD Mission Operations Directorate 

MPEV Manual Pressure Equalization Valve 

MSD Mass Storage Device 

MSFC Marshall Space Flight Center 

MSS Mobile Servicing System 

MT Mobile Transporter 

N2 Nitrogen (DI-molecular) 

NPRV Negative Pressure Relief Valve 

O2 Oxygen (DI-molecular) 

OCA Orbital Communication Adapter 

OCAD Operational Control Agreement Document 

OCJM Operator Commanded Joint Position Mode 

OCPM Operator Commanded POR Mode 

ODS Orbiter Docking System 

OIU Orbiter Interface Unit 

ONTO Oxygen Nitrogen Tank ORU (see HPGT) 

OPS Operations (Operational) 

ORCA Oxygen Recharge Compressor Assembly 

ORU Orbital Replacement Unit 

OSVS Orbiter Space Vision System 

OSVU Orbiter Space Vision Unit 

PBA Portable Breathing Apparatus (mask) 

PCA Pressure Control Assembly 

PCBM Passive Common Berthing Mechanism 

PCR Portable Computer Receptacles 

PCS Portable Computer System 

PDGF Power and Data Grapple Fixture 

PEHG Payload Ethernet Hub Gateway 

PEP Portable Emergency Provision 

PEV Pressure Equalization Valve 

PG Product Group 

PL Payload 

PMA Pressurized Mating Adapter 

PPAM Pre-stored POR Auto-sequence Mode 

PPP Power Patch Panel 

PPRV Positive Pressure Relief Valve 

PRLA Payload Retention Latch Assembly 

PSA Power Supply Assembly 

psia pounds per square inch – absolute 

Psid pounds per square inch – differential 

PTT Push To Talk 

PTU Pan/Tilt Units 

54
STS-104 

A-5 

QD Quick Disconnect 

RAIU Russian Audio Interface Unit 

RAM Random Access Memory 

RF Radio Frequency 

RFG Radio Frequency Group 

RHC Rotational Hand Controller 

ROEU Remote Operated Electrical Umbilical 

ROS Russian Orbital Segment 

RPCM Remote Power Controller Module 

RSC-E Rocket Space Corporation - Energia 

RWS Robotic Workstation 

RS Russian Segment 

RSA Russian Space Agency 

RT Remote Terminal 

SASA S-Band Antenna Support Assembly 

SCU Servicing and Cooling Umbilical 

Sync and Control Unit 

SLDP Spacelab Logistics Double Pallet 

SPCE Servicing and Performance Checkout Equipment 

SPDA Secondary Power Distribution Assembly 

SPDM Special Purpose Dextrous Manipulator 

SPDU Secondary Power Distribution Unit 

SRMS Shuttle Remote Manipulator System 

SSC Station Support Computer 

Subsystem Computer 

SSP Space Shuttle Program 

Standard Switch Panel 

SSRMS Space Station Remote Manipulator System 

SSSR Space to Space Station Radio 

STS Space Transportation System 

SW Software 

TCS Thermal Conditioning System 

Thermal Control System 

TDRSS Tracking and Data Relay Satellite System 

THC Temperature and Humidity Control 

Translational Hand controller 

UB User Bus 

UIA Umbilical Interface Assembly 

UHF Ultrahigh Frequency 

UOP Utility Outlet Panel 

USOS United States Orbital Segment 

55
STS-104 

A-6 

 

VAJ Vacuum Access Jumper 

Vdc Volts (direct current) 

VDU Video Distribution Unit 

VOX Voice Operated Transmission 

VSU Video Switch Unit 

VTR Video Tape Recorder 

WAA Wireless Antenna Assembly 

WHS Workstation Host Software 

WIU Wireless Interface Unit 

WRM Water Recovery and Management 

56
STS-104

Media Assistance 

NASA Television Transmission 

NASA Television is available through the GE2 satellite system which is located on 

Transponder 9C, at 85 degrees west longitude, frequency 3880.0 MHz, audio 6.8 MHz. 

The schedule for television transmissions from the orbiter and for mission briefings will be 

available during the mission at Kennedy Space Center, FL; Marshall Space Flight Center, 

Huntsville, AL; Dryden Flight Research Center, Edwards, CA; Johnson Space Center, 

Houston, TX; and NASA Headquarters, Washington, DC. The television schedule will be 

updated to reflect changes dictated by mission operations. 

Status Reports 

Status reports on countdown and mission progress, on-orbit activities and landing 

operations will be produced by the appropriate NASA newscenter 

Briefings 

A mission press briefing schedule will be issued before launch. During the mission, status 

briefings by a flight director or mission operations representative and when appropriate, 

representatives from the payload team, will occur at least once each day. The updated 

NASA television schedule will indicate when mission briefings are planned. 

Internet Information 

Information is available through several sources on the Internet. The primary source for 

mission information is the NASA Human Space Flight Web, part of the World Wide Web. 

This site contains information on the crew and its mission and will be updated regularly with 

status reports, photos and video clips throughout the flight. The NASA Shuttle Web's 

address is: 

http://spaceflight.nasa.gov

General information on NASA and its programs is available through the NASA Home Page 

and the NASA Public Affairs Home Page: 

http://www.nasa.gov

or 

http://www.nasa.gov/newsinfo/index.html

Shuttle Pre-Launch Status Reports 

http://www-pao.ksc.nasa.gov/kscpao/status/stsstat/current.htm

57
STS-104

Information on other current NASA activities is available through the Today@NASA page: 

http://www.nasa.gov/today/index.html

The NASA TV schedule is available from the NTV Home Page: 

http://spaceflight.nasa.gov/realdata/nasatv/schedule.html

Resources for educators can be found at the following address: 

http://education.nasa.gov

Access by Compuserve 

Users with Compuserve accounts can access NASA press releases by typing "GO NASA" 

(no quotes) and making a selection from the categories offered. 

Updated: 06/21/2001 

58
STS-104

Media Contacts 

Carlos Fontanot 256 961-6225

NASA Johnson Space Center

Houston, TX

NASA Moscow PAO

carlos.fontanot1@jsc.nasa.gov

Beth Hill 714 372-4736

The Boeing Company

Huntington Beach, CA

Space Shuttle

sara.b.hill@boeing.com

Bruce Buckingham 321 867-2468

NASA Kennedy Space Center

Kennedy Space Center, FL

Launch Operations

bruce.buckingham-1@kmail.ksc.nasa.gov

Dan Beck 818 586-4572

Boeing Rocketdyne

Canoga Park, CA

Space Shuttle Main Engines

daniel.c.beck@boeing.com

Debbie Rahn 202 358-1638

NASA Headquarters

Washington, DC

International Partners

debbie.rahn@hq.nasa.gov

Dwayne Brown 202 358-1726

NASA Headquarters

Washington, DC

Space Shuttle/Space Station 

Policy

dwayne.brown@hq.nasa.gov

Eileen Hawley 281 483-5111

NASA Johnson Space Center

Houston, TX

Astronauts/Mission Operations

eileen.hawley1@jsc.nasa.gov

59
STS-104

Jack King 321 861-4358

United Space Alliance

Kennedy Space Center, FL

Shuttle Processing

KingJW@usafoo.unitedspacealliance.com

Kari Kelley Allen 281 336-4844

The Boeing Company

Houston, TX

International Space Station

kari.k.allen@boeing.com

Kyle Herring 281 483-5111

NASA Johnson Space Center

Houston, TX

International Space Station 

Operations

kyle.j.herring1@jsc.nasa.gov

June Malone 256 544-0031

NASA Marshall Space Flight Center

Huntsville, AL

Space Station Science

June.Malone@msfc.nasa.gov

Updated: 05/25/2001 

60
Table prepared by Richard W. Orloff, 06/02/2002 

SHUTTLE FLIGHTS AS JULY 2001 

104 TOTAL FLIGHTS OF THE SHUTTLE SYSTEM -- 79 SINCE RETURN TO FLIGHT 

STS-102 

03/08/01 – 03/21/01 

STS-92 

10/11/00 - 10/24/00 

STS-103 

12/19/99 - 12/27/99 

STS-93 

07/23/99 - 07/27/99 

STS-96 

05/27/99 - 06/06/99 

STS-90 

04/17/98 - 05/03/98 

STS-95 

10/29/98 - 11/07/98 

STS-87 

11/19/97 - 12/05/97 

STS-91 

06/02/09 - 06/12/98 

STS-94 

07/01/97 - 07/17/97 

STS-85 

08/07/97 - 08/19/97 

STS-98 

02/07/01 - 02/20/01 

STS-83 

04/04/97 - 04/08/97 

STS-82 

02/11//97 - 02/21/97 

STS-106 

09/08/00 - 09/20/00 

STS-80 

11/19/96 - 12/07/96 

STS-70 

07/13/95 - 07/22/95 

STS-101 

05/19/00 - 05/29/00 

STS-78 

06/20/96 - 07/07/96 

STS-63 

02/03/95 - 02/11/95 

STS-86 

09/25/97 - 10/06/97 

STS-75 

02/22/96 - 03/09/96 

STS-64 

09/09/94 - 09/20/94 

STS-84 

05/15/97 - 05/24/97 

STS-73 

10/20/95 - 11/05/95 

STS-60 

02/03/94 - 02/11/94 

STS-81 

01/12/97 - 01/22/97 

STS-65 

07/08/94 - 07/23/94 

STS-51 

09/12/93 - 09/22/93 

STS-79 

09/16/96 - 09/26/96 

STS-62 

03/04/94 - 03/18/94 

STS-56 

04/08/83 - 04/17/93 

STS-76 

03/22/96 - 03/31/96 

STS-100 

04/19/01 – 05/01/01 

STS-58 

10/18/93 - 11/01/93 

STS-53 

12/02/92 - 12/09/92 

STS-74 

11/12/95 - 11/20/95 

STS-97 

11/30/00 - 12/11/00 

STS-55 

04/26/93 - 05/06/93 

STS-42 

01/22/92 - 01/30/92 

STS-71 

06/27/95 - 07/07/95 

STS-99 

02/11/00 - 02/22/00 

STS-52 

10/22/92 - 11/01/92 

STS-48 

09/12/91 - 09/18/91 

STS-66 

11/03/94 - 11/14/94 

STS-88 

12/04/98 - 12/15/98 

STS-50 

06/25/92 - 07/09/92 

STS-39 

04/28/91 - 05/06/91 

STS-46 

07/31/92 - 08/08/92 

STS-89 

01/22/98 - 01/31/98 

STS-40 

06/05/91 - 06/14/91 

STS-41 

10/06/90 - 10/10/90 

STS-45 

03/24/92 - 04/02/92 

STS-77 

05/19/96 - 05/29/96 

STS-35 

12/02/90 - 12/10/90 

STS-51L 

01/28/86 

STS-31 

04/24/90 - 04/29/90 

STS-44 

11/24/91 - 12/01/91 

STS-72 

01/11/96 - 11/20/96 

STS-32 

01/09/90 - 01/20/90 

STS-61A 

10/30/85 - 11/06/85 

STS-33 

11/22/89 - 11/27/89 

STS-43 

08/02/91 - 08/11/91 

STS-69 

09/07/95 - 09/18/95 

STS-28 

08/08/89 - 08/13/89 

STS-51F 

07/29/85 - 08/06/85 

STS-29 

03/13/89 - 03/18/89 

STS-37 

04/05/91 - 04/11/91 

STS-67 

03/02/95 - 03/18/95 

STS-61C 

01/12/86 - 01/18/86 

STS-51B 

04/29/85 - 05/06/85 

STS-26 

09/29/88 - 10/03/88 

STS-38 

11/15/90 - 11/20/90 

STS-68 

09/30/94 - 10/11/94 

STS-9 

11/28/83 - 12/08/83 

STS-41G 

10/05/84 - 10/13/84 

STS-51-I 

08/27/85 - 09/03/85 

STS-36 

02/28/90 - 03/04/90 

STS-59 

04/09/94 – 04/20/94 

STS-5 

11/11/82 - 11/16/82 

STS-41C 

04/06/84 - 04/13/84 

STS-51G 

06/17/85 - 06/24/85 

STS-34 

10/18/89 - 10/23/89 

STS-61 

12/02/93 - 12/13/93 

STS-4 

06/27/82 - 07/04/82 

STS-41B 

02/03/84 - 02/11/84 

STS-51D 

04/12/85 - 04/19/85 

STS-30 

05/04/89 - 05/08/89 

STS-57 

06/21/93 - 07/01/93 

STS-3 

03/22/82 - 03/30/82 

STS-8 

08/30/83 - 09/05/83 

STS-51C 

01/24/85 - 01/27/85 

STS-27 

12/02/88 - 12/06/88 

STS-54 

01/13/93 - 01/19/93 

STS-2 

11/12/81 - 11/14/81 

STS-7 

06/18/83 - 06/24/83 

STS-51A 

11/08/84 - 11/16/84 

STS-61B 

11/26/85 - 12/03/85 

STS-47 

09/12/92 - 09/20/92 

STS-1 

04/12/81 - 04/14/81 

STS-6 

04/04/83 - 04/09/83 

STS-41D 

08/30/84 - 09/05/84 

STS-51J 

10/03/85 - 10/07/85 

STS-49 

05/07/92 - 05/16/92 

OV-102 

Columbia 

(26 flights) 

OV-099 

Challenger 

(10 flights) 

OV-103 

Discovery 

(29 flights) 

OV-104 

Atlantis 

(23 flights) 

OV-105 

Endeavour 

(16 flights)