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Updated March 20, 2001

STS-110 F R A M E W O R K F O R 

E X P A N D I N G S T A T I O N 

R E S E A R C H
STS-110

Table of Contents 

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

Mission Objectives .................................................................................................. 7 

New, Safer Engines to Propel Atlantis ................................................................... 9 

Crewmembers ......................................................................................................... 11 

Flight Day Summary Timeline ............................................................................... 15 

Rendezvous and Docking ..................................................................................... 16 

Spacewalk 

STS-110 Extravehicular Activity ............................................................................... 20 

Payloads 

Payload Overview .................................................................................................... 28 

Central Integrated Truss Structure ........................................................................... 30 

Mobile Transporter ................................................................................................... 35 

Experiments: DTOs and DSOs 

Science Payloads .................................................................................................... 39 

Biomass Production System .................................................................................... 50 

DSOs and DTOs ...................................................................................................... 55 

Appendix 

Mobile Transporter Hardware and Software ............................................................ 59

Shuttle Reference Data 

Shuttle Abort History ................................................................................................ 64 

Shuttle Abort Modes ................................................................................................ 66 

Shuttle Rendezvous Maneuvers .............................................................................. 70 

Shuttle Solid Rocket Boosters .................................................................................. 71 

Shuttle Super-lightweight Tank ................................................................................ 78 
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Acronyms and Abbreviations ............................................................................... 79 

Media Assistance ................................................................................................... 91 

Media Contacts ...................................................................................................... 93 
STS-110

Overview 

A Framework for Station Expansion and Increased Research 

The Space Shuttle Atlantis will begin expanding the International Space Station on mission 

STS-110 (ISS Assembly Flight 8A), installing the initial section of a framework that 

eventually will hold systems needed to provide power and cooling for future research 

laboratories. 

This line art highlights the S0 truss and Mobile Transporter additions that will be 

made to the International Space Station on STS-110/8A. 

Atlantis’ mission will be one of the most complex station assembly flights to date, including 

four spacewalks and operations with both the shuttle’s robotic arm and the station’s robotic 

arm. During the spacewalks, astronauts will truly take on the appearance of high-rise 

construction workers as they assemble beams, attach work lights, bolt girders and plug in 

electrical connections. The station’s Canadarm2 robotic arm will be used exclusively to 

hoist the 13-ton truss section, called the S-Zero (S0) Integrated Truss Structure, from 

Atlantis and attach it to the station. The flight will be the first time the station’s arm is used 

as a space “cherry picker” to maneuver spacewalkers. It also will be the first shuttle flight to 

have all spacewalks originate from the station’s airlock. 

Michael J. Bloomfield, 43, Lt. Col., USAF, a veteran of two previous spaceflights, will 

command Atlantis. Stephen N. Frick, 37, Cmdr., USN, will serve as pilot and will be making 

his first spaceflight. Rex J. Walheim, 39, Lt. Col., USAF, will be mission specialist 1, also 

making his first spaceflight. Ellen Ochoa, 43, will be flight engineer and mission specialist 2, 

making her fourth spaceflight. Lee M. E. Morin, 49, will be mission specialist 3, making his 

first spaceflight. 

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Jerry L. Ross, 54, will be mission specialist 4 and will be making a record seventh flight 

aboard the shuttle, the most of anyone in history. Ross also is the most experienced 

spacewalker in the U.S. astronaut corps, having completed seven previous spacewalks. 

Steven L. Smith, 43, will be mission specialist 5, making his fourth spaceflight. Smith and 

Walheim will form one team of spacewalkers while Ross and Morin will form a second 

spacewalking team. 

Assisting with Atlantis’ assembly work from aboard the International Space Station will be 

the current station residents, the Expedition Four crew, Commander Yury Onufrienko and 

Flight Engineers Dan Bursch and Carl Walz. The station crew has been aboard the 

complex since early December 2001. 

The S0 truss is lifted into its transport canister at the Kennedy Space Center. 

Atlantis will carry the first major external truss section for the station, a 43-foot-long girderlike segment that will lay the foundation for an eventual cross-beam that will stretch more 

than 350 feet. Nine additional truss segments will be linked on future missions to the 

centerpiece segment carried by Atlantis to form the finished structure. The finished truss 

will support almost an acre of solar panels and giant cooling radiators. Although the 

International Space Station already is a fully functional research complex with a single 

United States laboratory, the additional solar panels and radiators will provide the electricity 

and cooling necessary for Japanese and European laboratories to be attached to the 

station as well as a future U.S. centrifuge laboratory. 

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The truss segment carried to the station by Atlantis also will include the first space railroad. 

Attached to the truss before launch will be a space railcar called the Mobile Transporter 

and a section of track that will span the length of the truss segment. The Mobile 

Transporter, when it is coupled with a base system for the station’s Canadian robotic arm 

later this year, will allow the station’s robotic arm to ride up and down the length of the 

football-field-long finished truss. The rail system will allow the arm to be positioned 

wherever it may be needed along the truss for maintenance or assembly work. 

The mission is planned to last 11 days, with Atlantis returning to the Kennedy Space 

Center, Fla., for landing. An overview of the flight activities includes: 

Flight Day One: Launch 

Atlantis’ crew will launch near the end of their day, and they will begin a sleep period only a 

few hours after reaching orbit. Atlantis’ orbital maneuvering engines will be fired to adjust 

the rate at which the shuttle closes in on the station and backup systems on the shuttle will 

be powered down to conserve electricity before the crew goes to sleep. 

Flight Day Two: Spacewalk, Rendezvous, Docking Preparations 

The second day of the mission day will be devoted to checks of the spacesuits and spacewalking gear that will be used later in the mission. Atlantis’ robotic arm also will be powered 

up and checked out, and television cameras on the arm will be used to survey the cargo 

bay. The crew also will check the operation of navigation aids and other equipment that will 

be used during the final phase of rendezvous with the station. Atlantis’ thrusters will be fired 

periodically during the day to fine-tune the rate at which the shuttle is approaching the 

station, and the docking mechanism in Atlantis’ cargo bay will be powered up and extended 

in readiness for the docking. 

Flight Day Three: Rendezvous and Docking; Truss Installation Practice 

Atlantis will rendezvous and dock to the International Space Station on the third day of the 

mission. Less than two hours after docking, the hatches between the shuttle and station will 

be opened and the crews will greet one another. The remainder of the day will be spent 

transferring supplies and equipment, including two crystal growth experiments, between the 

two spacecraft as well as a joint review by the two crews of plans for installation of the S0 

truss and the first spacewalk. Ochoa and Bursch will power up the station’s robotic arm and 

maneuver it through a practice run, going through the same motions that will be required to 

install the truss to the station. The station arm is planned to be left overnight in a position 

near the fixture it will latch onto to lift the truss out of Atlantis’ payload bay. 

Flight Day Four: S0 Truss Installation and First Spacewalk 

Ochoa and Bursch will work together aboard the station to use the complex’s Canadarm2 

to lift the truss segment from Atlantis’ cargo bay and attach it atop the station’s Destiny 

laboratory. Frick will operate the shuttle’s robotic arm aboard Atlantis to use views from 

television cameras on that arm to assist Ochoa and Bursch. As the truss is being installed, 

Smith and Walheim will be in the station’s Quest airlock preparing to begin the first 

spacewalk. Once the truss has been latched to the Destiny lab via a mechanical “claw” 

closed remotely from within the station, they will begin their work outside. The 6 1⁄2-hour 

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spacewalk will be highlighted by completing initial connections to provide power and data to 

the truss and by the bolting of forward struts into place that will permanently attach the 

truss to the station. Mission Control will send commands to begin the activation of the initial 

S0 truss equipment and heaters. 

Flight Day Five: Cargo Transfers, Spacewalk Preparations, Off-duty Time 

The crews will turn their attention to continuing the transfer of supplies, equipment and 

experiments between the station and shuttle. Nitrogen and oxygen will be transferred from 

tanks aboard Atlantis to replenish tanks on the station’s Quest airlock. All crewmembers 

also will have time set aside for a group review of plans for the upcoming second and third 

spacewalks. The crewmembers will have a couple of hours of off-duty time at the end of the 

day. 

Flight Day Six: Second Spacewalk 

The sixth day of the mission will see Ross and Morin conduct the second spacewalk, 

planned to last about 6 1⁄2 hours. They will focus on completing more power and data 

connections on the S0 truss as well as bolting two aft struts into place to complete its 

permanent mechanical connection to the station. After the spacewalk has been completed, 

Bloomfield will set Atlantis’ small thrusters to fire periodically over the course of an hour to 

gently boost the station’s altitude by a few miles. 

Flight Day Seven: Third Spacewalk 

Smith and Walheim will work outside again on the seventh day of the mission, performing 

the third spacewalk, also planned to last about 6 1⁄2 hours. The third spacewalk will include 

a release of the mechanical claw that provided the initial attachment of the S0 truss to the 

station, hookups of data and power to a robotic arm fixture located on the Mobile 

Transporter railcar, and the release of restraints that held the Mobile Transporter railcar 

secure during launch of the S0 truss. Smith and Walheim also will install a mechanical 

beam called the “airlock spur” between the Quest airlock and the new truss for use as a 

path for future spacewalkers. Because some of the connections to be made during this 

spacewalk will require powering off the station’s robotic arm temporarily, the shuttle’s 

robotic arm will be used to maneuver the astronauts for much of the day. A second boost of 

the station’s altitude by Atlantis will be performed. 

Flight Day Eight: Mobile Transporter Checks, EVA Preparations 

The Mobile Transporter railcar will be commanded to move for the first time on the eighth 

day of the mission. A checkout of the space railway will command the transporter to roll up 

and down its 43-foot-long rails. Television cameras on Atlantis’ robotic arm will be used to 

record the transporter checkout. Interior cargo will continue to be transferred during the day 

and preparations will be made for the fourth and final spacewalk. The crew also will have 

about a half-day off duty to rest. 

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Flight Day Nine: Fourth Spacewalk 

Ross and Morin will conduct the fourth and final spacewalk on the ninth day of the flight, an 

excursion planned to also last about 6 1⁄2 hours. The final spacewalk will include a variety of 

jobs, including the installation of two floodlights on the station’s exterior, partially 

assembling a work platform to be used during a later mission, attaching handrails on the S0 

truss, and several other “get-ahead” tasks designed to ease the workload on future crews. 

Flight Day Ten: Undocking and Flyaround 

After spending a week working together, the crews of Atlantis and the International Space 

Station will bid one another farewell and the shuttle will undock from the station. Before 

undocking, some final refrigerated experiment samples will be transferred from the station 

to Atlantis for the trip home, and a new experiment refrigerator will be installed on the 

station. After undocking, Atlantis will circle the station one and a quarter times before 

separating the vicinity. 

Flight Day Eleven: Landing Preparations 

Atlantis’ crew will spend the 11th day of the flight checking out the navigation, flight controls, 

steering jets, aero surfaces and other equipment needed for the shuttle’s descent to Earth. 

The last part of the day will be spent stowing away gear in the cabin in preparation for 

landing. 

Flight Day Twelve: Descent and Landing 

Atlantis will fire its engines to re-enter the atmosphere and descend to a landing. The prime 

landing site for Atlantis will be the Kennedy Space Center, Fla. 

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Crew

Commander: Michael J. Bloomfield

Pilot: Stephen N. Frick

Mission Specialist 1: Rex J. Walheim

Mission Specialist 2: Ellen Ochoa

Mission Specialist 3: Lee M.E. Morin

Mission Specialist 4: Jerry L. Ross

Mission Specialist 5: Steven L. Smith

Launch

Orbiter: Atlantis OV104 

Launch Site: Kennedy Space Center Launch Pad 39B

Launch Window: No greater than 5 Minutes

Altitude: 122 Nautical Miles

Inclination: 51.6 Degrees

Duration: 10 Days 18 Hrs. 57 Min.

Vehicle Data

Shuttle Liftoff Weight: 4,520,940 lbs.

Orbiter/Payload Liftoff Weight: 257,079 lbs.

Orbiter/Payload Landing Weight: 200,657 lbs.

Software Version: OI-29

Space Shuttle Main Engines:

SSME 1: 2048 SSME 2: 2051 SSME 3: 2045

External Tank: ET-114 (Super Light Weight Tank)

SRB Set: BI112PF

Shuttle Aborts

Abort Landing Sites 

RTLS: Kennedy Space Center Shuttle Landing Facility

TAL: Zaragoza

AOA: Kennedy Space Center Shuttle Landing Facility

Landing

Landing Date: 04/15/02

Primary Landing Site: Kennedy Space Center Shuttle Landing Facility

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Mission Objectives 

The primary objective of space shuttle mission STS-110 is to deliver the first segment of 

the International Space Station's external truss, the S0 (S-Zero) truss, together with various 

equipment that will be installed on the truss segment before launch. 

Equipment installed on the truss before launch includes: the Mobile Transporter (MT) and 

its associated power and data umbilical reels; four direct-current-to-direct-current switching 

units; two rate gyroscope assemblies; main bus switching units; four secondary power 

distribution assemblies; four Global Positioning System antennas; a 21-foot-long radiator 

panel located on the truss' aft face to provide cooling for the electronics; and rails on the 

truss' forward face to provide a track for the MT. 

The primary mechanical attachment of the S0 truss to the International Space Station is 

through four Module-to-Truss Structure struts, two forward and two aft. Various umbilicals 

provide power and data to and from units on the truss structure as well as to future 

additions that will be attached to other truss segments, such as radiators and solar arrays. 

Priorities for STS-110 mission, International Space Station mission 8A, are: 

• Unberth the S0 truss from the shuttle payload bay; install on Lab Cradle Assembly 

(LCA); install forward MTS struts on Destiny Lab; and provide minimum survival 

power for S0, including connection of primary trailing umbilical system (TUS 2) for 

the MT. 

• Install the remaining MTS struts on Destiny Lab. 

• Install S0-to-Destiny Lab avionics trays and connect umbilicals. 

• Perform critical transfers to the International Space Station, including an as yet-tobe-determined volume of water, Crew and Equipment Translation Aid lights and 

stanchions and Circuit Interrupt Devices. 

• Complete activation and checkout of S0 systems. 

• Perform space station robotic arm power and data reconfiguration, installing 

connections for MT power and data grapple fixture. 

• Perform transfer of powered experiments from shuttle to station. 

• Activate MT and configure for translation test by installing redundant trailing 

umbilical cable to MT and releasing MT launch restraints. 

• Remove and stow keel pins and drag links on S0. 

• Translate MT from launch site to first worksite. 

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• Install Circuit Interrupt Devices. 

• Perform remaining payload transfers from shuttle to station and station to shuttle and 

perform transfers of ISS crew provisions and resupply items. 

• Open Lab Cradle Assembly (LCA) capture latch and back out LCA load release 

bolts. 

• Install Quest Airlock Spur. 

• Install MT to Mobile Base System bolt debris covers. 

• Perform MT translation test in both directions. 

• Prepare and deploy Extravehicular Charged Particle Detection System (EVCPDS). 

• Deploy extravehicular activity lights. 

• Install CETA-to-MT energy absorbers. 

• Activate and check out external video switch system. 

• Perform UF-2 get-ahead tasks such as assemble portable work platform and 

perform EVA tool configuration. 

• Remove Z-1 thermal shrouds, install airlock handrail, install S0 face 2 handrails, 

deploy Unity node swing arm and reconfigure launch-to-activation cables. 

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New, Safer Engines to Propel Atlantis 

STS-110 will be the first space shuttle flight to rely exclusively on the latest redesign of the 

shuttle main engines, a design that has modified the engines to more than double 

estimates of their reliability and safety. All three Space Shuttle Main Engines on Atlantis will 

be Block II engines, the first time a shuttle has flown with a cluster of Block II engines. The 

first and only flight so far of a Block II main engine was a single engine that flew on shuttle 

mission STS-104 in July 2001 with the remaining two engines on that mission being of an 

older design. 

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

Huntsville, Ala., include a new Pratt & Whitney high-pressure fuel turbopump. The primary 

modification to the engine is the elimination of welds by using a casting process for the 

housing, and an integral shaft and 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. 

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. 

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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 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 perform at greater temperature extremes than any 

mechanical system in common use today. At minus 423 degrees Fahrenheit (minus 217 

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. Testing on the Block II Engine was completed at Stennis Space Center, Miss. 

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Crew Bios 

STS-110 Crewmembers 

Commander: Michael J. Bloomfield 

Michael J. Bloomfield, 43, a lieutenant colonel in the U.S. 

Air Force, a former instructor pilot and a veteran of two 

space flights, is commander for STS-110. He received a

bachelor of science in engineering mechanics from the U.S. 

Air Force Academy in 1981 and a master of science in 

engineering management from Old Dominion University in 

1993. He will be responsible for overall mission success and 

safety during STS-110, as well as the rendezvous and 

docking of Atlantis to the International Space Station. 

Bloomfield and pilot Stephen Frick will use the shuttle’s 

robotic arm cameras to take video on the first, second and 

fourth spacewalks. They also will use the shuttle arm to 

support the EVA crewmembers during most of the third spacewalk. Bloomfield will have 

primary responsibility for Earth observations, and will share responsibilities for the shuttle’s 

guidance and navigation systems, computer systems and life support systems. He will land 

Atlantis at the end of the mission. 

Selected by NASA in December 1994, Bloomfield has logged more than 494 hours in 

space, serving as pilot of STS-86 in 1997 and STS-97 in 2000. This flight will be his first as 

commander of a space shuttle mission.

Pilot: Stephen N. Frick

Stephen N. Frick, 37, a commander in the U.S. Navy, will 

serve as pilot. Frick received a bachelor of science in 

aerospace engineering from the U.S. Naval Academy in 

1986 and a master of science in aeronautical engineering 

from the U.S. Naval Postgraduate School in 1994. NASA 

selected Frick in April 1996. He will be responsible for a 

number of orbiter systems during ascent and landing. He will 

operate the shuttle’s robotic arm with the commander, 

supporting the installation of the S0 (S-Zero) truss and the 

four spacewalks. Frick also will be at the shuttle controls for 

the undocking from the ISS and subsequent flyaround. 

Frick will be making his first spaceflight. 

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Mission Specialist 1: Rex J. Walheim 

Rex J. Walheim, 39, a lieutenant colonel in the U.S. Air 

Force and a former flight test engineer, will be Mission 

Specialist 1. He received a bachelor of science in 

mechanical engineering from the University of California, 

Berkeley, in 1984, and a master of science in industrial 

engineering from the University of Houston in 1989. He was 

selected as an astronaut in March 1996. He will play a key 

role in the rendezvous, operating a handheld laser rangefinding device. Walheim and Mission Specialist Steve Smith 

will conduct the first spacewalk of the mission, on flight day 

four, and the third, on flight day seven. 

Walheim will be making his first spaceflight. 

Mission Specialist 2: Ellen Ochoa 

Ellen Ochoa, 43, will be flight engineer and Mission 

Specialist 2, making her fourth spaceflight. Ochoa received a 

bachelor of science in physics from San Diego State 

University in 1980 and a master of science and a doctorate 

in electrical engineering from Stanford University in 1981 and 

1985, respectively. Selected by NASA in January 1990, 

Ochoa became an astronaut in July 1991. For the first, 

second and fourth spacewalks, she will move to the station’s 

Destiny laboratory to operate Canadarm2, the station’s 

robotic arm, to work with the spacewalking astronauts. For 

the installation of the S0 truss, Ochoa and Expedition Four 

Flight Engineer Dan Bursch will work together to use 

Canadarm2 to lift the truss segment from Atlantis’ cargo bay and attach it atop the station’s 

Destiny laboratory. 

A veteran of three space flights, Ochoa has logged more than 719 hours in space. She was 

a mission specialist on STS-56 in 1993, the payload commander on STS-66 in 1994, and a 

mission specialist and flight engineer on STS-96 in 1999.

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Mission Specialist 3: Lee M.E. Morin 

Lee M. E. Morin, 49, a captain in the U.S. Navy, will be 

Mission Specialist 3. Morin received a bachelor of science in 

mathematical/electrical science from the University of New 

Hampshire in 1974, a master of science in biochemistry from 

New York University in 1978, a doctorate of medicine and 

microbiology degrees from New York University in 1981 and 

1982, respectively, and a master of public health degree 

from the University of Alabama at Birmingham in 1988. 

Selected as an astronaut candidate by NASA in April 1996, 

he reported to the Johnson Space Center in August 1996. 

Morin, teamed with Mission Specialist Jerry Ross, will 

participate in the second and fourth spacewalks on flight 

days six and nine, respectively. 

Morin will be making his first spaceflight. 

Mission Specialist 4: Jerry L. Ross

A retired Air Force colonel, Jerry L. Ross, 54, will be Mission 

Specialist 4 and will be making a record seventh flight 

aboard the shuttle, the most of anyone in history. Ross 

received bachelor of science and master of science degrees 

in mechanical engineering from Purdue University in 1970 

and 1972, respectively. He was selected as an astronaut in 

May 1980. Ross will be making his eighth and ninth 

spacewalks. 

Ross was a mission specialist on STS 61-B (1985), STS-27 

(1988) and STS-37 (1991), the payload commander on STS55/Spacelab-D2 (1993), and a mission specialist on STS-74, 

the second space shuttle to rendezvous and dock with the Russian space station Mir 

(1995) and the first International Space Station assembly mission, STS-88, in 1998. Ross 

has logged more than 1,133 hours in space, including seven spacewalks totaling 44 hours 

and 9 minutes. 

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Mission Specialist 5: Steven L. Smith 

Steven L. Smith, 43, a veteran of three spaceflights, is a 

mission specialist for STS-110. He received a bachelor of 

science in electrical engineering in 1981, a master of science 

in electrical engineering in 1982 and a master's degree in 

business administration in 1987. All three degrees are from 

Stanford University. Following his selection as an astronaut 

candidate by NASA in 1992, he completed one year of 

astronaut candidate training. Smith and Mission Specialist 

Rex Walheim will do the first spacewalk, on flight day four, 

and the third, on flight day seven. Smith will be making his 

sixth and seventh spacewalks. 

Smith is making his fourth spaceflight. He served as a mission specialist aboard the Space 

Shuttle Endeavour on STS-68 in September 1994. He was one of two crewmembers 

trained to perform a spacewalk had one been required. He performed three spacewalks as 

a member of the February 1997 STS-82 Discovery crew which serviced the Hubble Space 

Telescope. He was the payload commander for STS-103 in December 1999, the Hubble 

Space Telescope 3A Servicing Mission. The crew performed three spacewalks to return 

Hubble to science operations with several upgraded subsystems. Smith has logged 700 

hours in space, including five spacewalks totaling 35 hours. 

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Flight Day Summary Timeline 

FLIGHT 

DAY MET EVENT 

1 000/00:00 Launch 

1 000/00:50 OMS 2 Burn 

1 000/03:37 NC1 Burn 

2 000/16:32 NC2 Burn 

2 000/20:05 NPC Burn 

2 001/00:58 NC3 Burn 

3 001/14:00 NH Burn 

3 001/15:24 NC4 Burn 

3 001/16:15 Ti Burn 

3 001/18:36 ISS Dock 

3 001/20:25 ISS Hatch Open 

3 001/21:08 Hand Shake 

4 002/13:45 Grapple S0 Truss 

4 002/15:00 Install S0 Truss 

4 002/17:50 EVA-1 Start 

6 004/17:50 EVA-2 Start 

7 005/17:50 EVA-3 Start 

9 007/17:50 EVA-4 Start 

10 008/18:30 Farewell Ceremony 

10 008/18:50 ISS Hatch Close 

10 008/22:21 ISS Undock 

10 008/22:41 ISS Flyaround 

10 009/00:05 Final Sep Maneuver 

12 010/17:52 Deorbit Burn 

12 010/18:57 Landing 

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Rendezvous and Docking 

A precisely timed launch with a window of only about five minutes begins the process that 

ultimately will take Atlantis to its rendezvous and docking with the International Space 

Station. 

Atlantis will pursue the station during the first two days of the mission. Engine firings will 

adjust the orbit of the shuttle, bring Atlantis to a point about 91⁄2 statute miles behind the 

station about 21⁄2 hours before docking on flight day three. 

There Commander Michael Bloomfield and pilot Stephen Frick will fire Atlantis’ jets in a 

Terminal Phase Initiation (TI) burn to begin a final approach to the station. 

As Atlantis closes in, the shuttle’s rendezvous radar system will provide range and closing 

rate information to the crew. During the approach, the shuttle will have an opportunity to 

make four, small mid-course corrections at regular intervals. 

Just after the fourth correction, Atlantis will be about half a mile below and behind the 

station. There, about an hour before the scheduled docking, Bloomfield will take over 

manual control. 

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He will slow Atlantis’ approach. Then, beginning at a point about 600 feet directly below the 

station, he will begin a quarter-circle of the orbiting laboratory, slowly moving to a position 

in front of the station. 

Mission Specialists Rex Walheim and Ellen Ochoa also will play key roles in the 

rendezvous, with Walheim operating a handheld laser-ranging device. Ochoa will operate a 

laptop computer program that gives position and guidance information regarding the 

rendezvous. 

Bloomfield will stop Atlantis a little more than 300 feet directly ahead of the station with the 

cargo bay facing it. There he will begin slowly moving directly toward the station's shuttle 

docking port – moving at about a tenth of a mile per hour. 

A view from the shuttle’s aft flight deck showing the Orbiter Docking System. 

Using a view from a camera mounted in the center of Atlantis’ docking mechanism as a key 

alignment aid, Bloomfield will center the docking ports of the two spacecraft. When the 

docking mechanisms are 30 feet apart, he will stop Atlantis for a few minutes to check their 

alignment. 

For Atlantis’ docking, Bloomfield will move the shuttle at about a tenth of a foot per second 

toward the station, keeping the docking mechanisms aligned to within a three-inch 

tolerance. When the two spacecraft make contact, preliminary latches will automatically 

engage, attaching them to one another. 

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Just after docking, Bloomfield will deactivate the shuttle's steering jets to reduce the forces 

acting at the 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, Mission Specialists Jerry 

Ross and Ellen Ochoa will secure the docking mechanism, sending commands for Atlantis’ 

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

A picture from the Russian segment of the International Space Station (ISS) 

captured this rare scene during STS-108 that shows portions of three separate 

space vehicles linked together. The Soyuz spacecraft partially obstructs the view 

of the recently docked Space Shuttle Endeavour. 

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Undocking, Separation and Flyaround 

Once Atlantis is ready to undock, Ross will send a command to release the docking 

mechanism. The initial separation will be provided by springs that will gently push the 

shuttle away from the station. Atlantis’ steering jets will be deactivated during this initial 

separation. 

Once the docking mechanism’s springs have pushed Atlantis to a distance of about two 

feet and the docking devices are clear of one another, Frick will turn the steering jets back 

on and fire them to begin very slowly moving away. From the aft flight deck, Frick will 

manually fly Atlantis in a tight corridor as he separates from the ISS. 

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

90-minute flyaround of the station, circling it 11⁄4 times. Atlantis will move directly over the 

station, then behind it, underneath it, and back in front of the ISS, where the flyaround 

began. The last quarter-circle brings the shuttle directly above the station. 

There Frick will fire Atlantis’s jets to move away from the station. 

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EVA 

Spacewalks 

Four spacewalks are scheduled for the STS-110 flight of Atlantis. Each will last about 61⁄2 

hours, and each focuses on installation of the S0 (S-Zero) Truss on the U.S. laboratory 

Destiny of the International Space Station. 

 

Astronauts Steve Smith, left, and Rex Walheim, suit up to practice their 

spacewalks. 

Astronauts Steve Smith and Rex Walheim will do the first spacewalk, on flight day four, and 

the third, on flight day seven. They will be Smith’s sixth and seventh, and Walheim’s first 

and second spacewalks. Smith is designated EV1 (for Extravehicular crewmember) and 

will wear a spacesuit marked with solid red stripes. Walheim, EV2, will wear a solid white 

spacesuit. 

20
STS-110

Jerry Ross, left, and Lee Morin check out their EMUs. 

The second spacewalk, on flight day six, and the fourth, on flight day nine, are to be done 

by astronauts Jerry Ross and Lee Morin. Ross will be making his eighth and ninth 

spacewalks, Morin his first and second. Ross, EV3, will wear the suit with broken red 

stripes and Morin, EV4, will have a suit marked by diagonally broken red stripes. 

Ellen Ochoa practices for her duties in the Johnson Space Center Virtual Reality 

Lab. 

For the first, second and fourth spacewalks, Atlantis crewmember Ellen Ochoa will move to 

the station’s Destiny laboratory to operate Canadarm2, the station’s robotic arm, to work 

with the spacewalking astronauts. For installation of the S0 Truss, Expedition 4 astronaut 

Dan Bursch will assist her in station arm operation. On spacewalks one and two, 

Commander Michael Bloomfield and pilot Stephen Frick will use the shuttle’s robotic arm 

cameras to take video of the spacewalkers. They also will use the shuttle arm to support 

the third and fourth spacewalks. 

21
STS-110

Each EV crewmember also will serve as Intravehicular (IV) crewmember during one 

spacewalk while two other astronauts are outside. The IV crewmember helps 

spacewalkers by serving as a source of information and suggestions, and helping them 

stay on their timeline. 

While Smith and Walheim are making the first spacewalk, Ross will be the IV crewmember, 

and while they are doing the third, Morin will provide IV support. During the second 

spacewalk, by Ross and Morin, Smith and Walheim will be the IV astronauts, and during 

the fourth spacewalk, Walheim will perform IV tasks. 

Expedition Four ISS astronauts Dan Bursch (left) and Carl Walz in the Quest 

Airlock before a February 20th spacewalk. 

All four spacewalks will originate from the station’s U.S. Joint Airlock Quest, and for all four 

the ISS Exercise EVA (Extravehicular Activity or spacewalk) Protocol will be used. 

Designed to purge nitrogen from the body, the protocol involves breathing pure oxygen 

while exercising vigorously. It eliminates the need to spend many hours at reduced cabin 

pressure. The protocol was first used during STS-104 during the first spacewalk from the 

Joint Airlock installed earlier during that mission. 

22
STS-110

Spacewalk 1 

Before the first spacewalk, the 43.3-foot, 27,830-pound S0 truss segment is installed on the 

Lab Cradle Assembly, a mounting device atop the U.S. laboratory Destiny, using the 

station’s Canadarm2. Once in place, the crew inside will command the capture latch to 

close. This is done to make the truss stable enough for attitude control and the small loads 

the spacewalkers will induce. 

The S0 truss, seen from below, during processing at the Kennedy Space Center. 

23
STS-110

After leaving the airlock, Smith and Walheim will spend about 45 minutes setting up 

equipment and tools. 

Their first task will be releasing starboard and port forward Module-to-Truss Structure 

(MTS) strut clamshell fasteners. Using a standard EVA power tool, they will undo a total of 

eight bolts, four on each side, beginning on the starboard side. Then they will release four 

launch restraint bolts, two on each side, from footplates. 

That allows the V-shaped structures to rotate downward. Smith and Walheim will install 

four bolts through each footplate, securing the structures to the lab. Then each clamshell 

fastener will be tightened to rigidize the struts. 

By releasing two bolts, Smith will deploy the Aft Lab Avionics Tray, which contains power, 

data and fluid umbilicals that will be connected to the lab, node and Z1. He will mate the 

avionics connectors only (not the fluid connectors) to the lab and Z1. He will pause from 

that task periodically to help Walheim, who is simultaneously installing and mating the Lab 

Forward Avionics Umbilicals on the starboard and then port side. If there is time during this 

spacewalk, Smith will remove the port drag link and enter the truss to install two Circuit 

Interrupt Devices (circuit breakers). That done, he again will team up with Walheim to 

install the Zenith Trailing Umbilical System Cable. 

About 5 hours and 50 minutes into the spacewalk, Smith and Walheim will begin their 

standard cleanup and then return to the airlock. 

Spacewalk 2 

After leaving the airlock and standard setup activities, the first task of Ross and Morin 

during their flight day six spacewalk is to install the aft MTS struts, first the starboard and 

then the port. The aft strut groups are tripods, with three adjustable struts meeting at a 

common footplate that attaches to the lab structure. Ross and Morin will work together to 

deploy the struts, with Morin on Canadarm2 near S0 and Ross at the lab receiving the 

“point” of the tripod. 

Each strut has two clamshell fasteners that must be released (for a total of 12 fasteners), 

and each strut group has five launch restraint bolts that must be released. Six bolts attach 

each aft MTS strut group to the lab’s aft endcone and five bolts attach each strut group to 

S0. This task is somewhat more difficult than other tasks because of the size of the strut 

groups and the specialized procedure required to torque down the bolts. Then each 

clamshell fastener will be tightened to rigidize the struts. 

24
STS-110

The S0 truss is loaded into its transport canister at Kennedy Space Center. 

With the completion of the strut attachments, S0 is attached rigidly to the ISS, and is able to 

support its design loads, including the solar arrays that will be on the ends of the truss at 

assembly complete. 

Ross, later joined by Morin, moves on to remove and stow drag links, large metal rods used 

to support the S0 truss during launch. They will be stowed on the truss’ exterior. Ross will 

also remove a thermal cover from the truss and bring it into the airlock. 

Next both Ross and Morin move on to mate the Trailing Umbilical System 2 nadir cable to 

the Mobile Transporter. Launched on the S0 Truss, the Mobile Transporter will serve as an 

installation point for Canadarm2’s Mobile Servicing System (MSS) Base System, to be 

launched later this year on STS-111. 

Finally, the spacewalkers remove the truss’ keel pin assemblies. Like the drag links, they 

will be attached to the truss for long-term stowage. 

Spacewalk 3 

The first task of the third spacewalk, on flight day seven, after Smith and Walheim leave the 

airlock and complete setup, is release of the Lab Cradle Claw atop Destiny by Walheim and 

the installation of the J300 Panel Connectors by Smith. 

The claw initially held the S0 truss to Destiny’s Lab Cradle Assembly. 

25
STS-110

The J300 Connectors and subsequent reconfiguration of the J400 Power Data and Grapple 

Fixture (PDGF) Connectors by Smith will route power, data, and video through the S0 truss 

for later operation of Canadarm2 from the MSS Base System after STS-111. 

If the installation of the Circuit Interrupt Devices was not completed during the first 

spacewalk, Walheim will install them during this spacewalk. 

Smith and Walheim will then turn their attention to the Mobile Transporter, spending about 

45 minutes releasing its many launch restraints and removing a small thermal cover from a 

radiator on the Mobile Transporter. Then they will continue work on the J400 

reconfiguration for another hour and a half. 

After transferring tools from the shuttle to the station’s exterior and transferring other tools 

on the station exterior, the spacewalkers will depress three sensors on the starboard side 

of S0 to test them for future mating of the S1 truss. The last task of the spacewalk is to 

install the Airlock Spur. The spur is a beam almost 14 feet long and fitted with handrails. 

The spur will help spacewalkers move more efficiently from the Quest airlock to the forward 

side of the S0 Truss and the Destiny laboratory. 

Spacewalk 4 

Tasks of the flight’s final spacewalk, on flight day nine, begin with release of Lab Cradle 

Assembly guide cones, used to guide the S0 Truss onto the assembly, by Morin and 

installation by Ross of a light on the Unity node to help future spacewalkers and robotics 

operators. 

Those tasks complete, both spacewalkers will spend the next 30 minutes partially 

assembling a portable work platform, which will aid future spacewalkers in maintenance 

activities. They will depress three sensors on the port side of the S0 truss to test them for 

future installation operations of the P1 truss segment. Ross will then install a second light 

on Destiny. 

While Ross does the 45-minute light installation, Morin will deploy the Extravehicular 

Charged Particle Directional Spectrometer. That instrument measures and characterizes 

the radiation environment outside the station for documenting crew exposure. It also can 

provide almost instant information on exposure rates during unexpected radiation events. 

Morin's next task is to deploy the Node 1 Swing Arm. Only the beam will be deployed on 

this mission. Its three umbilical connectors from the S0 truss aft to the Unity Node’s 

endcone will be deployed on a later flight. After the beam is deployed, the crew’s outfitting 

of the S0 truss is complete. Ross, meanwhile, is using that hour to install Mobile 

Transporter Energy Absorbers, port and starboard, to provide a barrier and attach point 

between the Mobile Transporter and future hand-propelled carts that will be used by 

spacewalkers. 

26
STS-110

Other tasks on this spacewalk include installation of handrails on the S0 truss, removal of a 

thermal blanket from S0, and tool relocations in preparation for the next flight’s 

spacewalkers. Additionally, Morin will be performing a checkout of a Trace Gas Analyzer 

that is designed to detect minute amounts of gas in the environment of space. 

The final hour and 20 minutes before cleaning up and entering the airlock will be spent in 

extensive photo documentation and doing any get-ahead tasks. 

27
STS-110

Payloads 

Payload Overview 

As the 13th space shuttle mission in support of the assembly of the International Space 

Station, STS-110 is responsible for the integration of the 8A launch package with the ISS. 

This package includes the S0 truss segment and the Mobile Transporter (MT). 

The S0 segment will be structurally attached to the U.S. Lab Module and will be the center 

section of the station’s truss assembly. Fluid, power and data umbilicals are also attached 

to the S0 segment for connecting the truss-bases distributed systems with the pressurized 

modules. The S0 segment provides Extravehicular Activity (EVA) Airlock Spur and 

electrical power control and distribution; guidance, navigation and control; telemetry, 

command and control; video signal switching and passive and active thermal control. 

This drawing highlights the S0 truss and Mobile Transporter elements that will be 

added to the ISS on STS-110/8A. 

28
STS-110

The MT provides the truss translation capability for the Mobile Servicing System (MSS) as 

well as the structural, power, data and video link between the Integrated Truss Structure 

Mobile Remote Servicer. It will provide the rail system for eventual movement of the 

station’s robotic arm across the station’s football-field-long truss. 

The Airlock Spur will be deployed between the S0 segment and the Airlock to provide a 

path for EVA crewmembers to move from the Airlock to the truss segment. 

In addition, five powered payloads are to be transferred to/from the shuttle middeck and the 

station. The five transfers are the Biomass Production System (to be taken up to the 

station—see “Experiments”), Biotechnology Refrigerator-2 [to be taken up and down—the 

crew will transfer the contents of the BTR on the ISS to the one on the shuttle to return the 

Cellular Biotechnology Operations Support System (CBOSS) and the yet-to-be-taken 

Advanced Astroculture (ADVASC) samples], Commercial Generic Bioprocessing Apparatus 

(to be taken up to the station only), Commercial Protein Crystal Growth—High Density (to 

be taken up to the ISS) and Protein Crystal Growth—Single Locker Thermal Enclosure 

System (two PCG-STES lockers are to be returned aboard the shuttle during STS-110). 

Data products and samples for other experiments also are scheduled to be returned aboard 

the shuttle including Renal Stone samples, Experiment of Physics of Colloids in Space 

(EXPPCS) data hard drives and additional ADVASC air and water samples. 

29
STS-110

Central Integrated Truss Structure (S0 Truss) 

The first major element of the International Space Station’s enormous backbone will bring 

more power supplies and data handling capabilities when it is installed during the STS-110 

space shuttle mission. 

The Starboard 0 (S-Zero or S0) truss segment will be delivered to the orbiting outpost on 

STS-110 (ISS Assembly Flight 8A). Boeing Human Space Flight & Exploration in 

Huntington Beach, Calif., built the truss and company operations in Florida prepared it for 

launch. Human Space Flight & Exploration is part of Space & Communications, a business 

unit of The Boeing Company, NASA’s prime contractor on the space station. 

The S0 truss is lowered into its transport canister at the Kennedy Space Center. 

Power and data cables and the thermal control system that provides heating and cooling 

wind through the 44-foot by 15-foot, 27,000-pound truss segment to carry energy and 

information to and from the station’s extremities where solar panels collect electrical energy 

used to power experiments, computers, life support systems and other services. 

30
STS-110

Video cameras, attached to the structure, monitor assembly operations and other activities 

on the station. Other instruments provide the data that astronauts and ground controllers 

use to maintain the station’s position and orient the solar panels. 

The S0 truss segment will provide the structural backbone for the power generation 

subsystem of the ISS electrical power system; it also will provide power conversion and 

routing capabilities to downstream loads. 

The Integrated Truss Segment (ITS) S0 provides the capability to attach the four 

Photovoltaic Module truss segments to increase the ISS power production capacity. The S0 

truss is launched with a complement of pre-integrated hardware to increase ISS 

functionality including the Mobile Transporter (MT), the Trailing Umbilical System (TUS), 

the Portable Work Platform, four Global Positioning System (GPS) antennas, two rate 

gyros, an Extravehicular Charged Particle Detection System (EVCPDS), and umbilicals for 

U.S. on-orbit elements. Mission 8A also delivers four Main Bus Switching Units (MBSUs), 

two Circuit Interrupt Devices, three Crew and Equipment Translation Aid (CETA) lights and 

the Airlock Spur. 

The S0 is the center segment of 11 integrated trusses that provide the foundation for 

station subsystem hardware installation, utility distribution, power generation, heat rejection 

and external payload accommodations. The S0 truss acts as the junction from which 

external utilities are routed to the pressurized modules by means of EVA-deployed 

umbilicals. These utilities include power, data, video and Active Thermal Control System 

ammonia. The S0 truss provides a mounting point for electronic equipment such as the 

MBSUs, four of the DC-to-DC Converter Units (DDCUs), and four Secondary Power 

Distribution Assemblies. As mentioned, also mounted on S0 are the space station’s four 

GPS antennas and two Rate Gyros. 

The aft face of S0 is occupied by a 21-foot radiator panel, which radiates heat transported 

from S0 electronics boxes by a system of internal heat pipes. The forward facing rails of the 

S0 truss and the other truss assemblies form a track upon which the MT will move up and 

down the length of the station truss. Housed within the S0 truss structure are the MT TUS 

cable reels, which feed out and reel in electrical cable to the MT as it travels along the 

truss. 

The S0 truss will connect to its neighboring truss segments (S1 and P1) by means of the 

Segment-to-Segment Attachment System, which consists of a remotely operated capture 

latch and four motorized bolt assemblies. Structural attachment to the U.S. lab is 

accomplished through the Module-to-Truss Structure, which consists of 10 EVA-deployed 

telescoping struts. 

The S0 structure has an elongated hexagonal cross section with five bays arrayed along 

the long axis. Although S0 has a large complement of pre-integrated equipment on its 

structure, the frame is open enough to allow EVA operations within the spaces of the bays. 

The numbered faces of S0 make identification of worksites easier for EVA crews translating 

around the truss segment. These faces are numbered sequentially counterclockwise from 

the forward nadir face to the aft nadir face. 

31
STS-110

Astronauts are scheduled to make four spacewalks during the 11-day mission to install the 

truss. It will be installed onto the U.S. laboratory Destiny using the Module-to-Truss 

Segment Attach System (MTSAS), which consists of an active capture claw assembly on 

the Lab Cradle Assembly (LCA) and a capture bar on the passive MTSAS installed on the 

S0 nadir. 

Module-to-Truss Segment Attach System 

The MTSAS includes the MT struts and the LCA. The LCA provides a soft capture 

capability for mating the truss structure to the U.S. Lab as well as an adequate structural 

interface to allow attitude control and maneuvers after mating is complete. This allows 

freeing the SSRMS for other operations and would allow the orbiter to undock, if required, 

in a contingency situation. The MT struts are flown pre-integrated on S0 and must be 

deployed and attached to the U.S. Lab by EVA crewmembers. Once installed, the LCA 

capture latch is released. The struts will provide all of the structural support for not only S0 

but also for the completed integrated truss at assembly complete post-mission 20A. 

Lab Cradle Assembly 

The LCA is composed of an active half, consisting of a capture claw and alignment 

mechanisms, and a passive half (integrated into ITS S0), consisting of additional alignment 

mechanisms and a rigid capture bar. During mating of S0 to the LCA, the capture claw will 

engage the bar on the S0 passive half, drawing the truss segment down to the LCA 

interface for a semi-rigid structural hold. 

Umbilical Trays 

S0 is outfitted with four umbilical trays (two fluid, two power and data), which will provide 

thermal, communications, and electrical interfaces with other elements. The port and 

starboard forward umbilical trays are launched on the forward starboard face. 

Extravehicular Charged Particle Detection System 

The EVCPDS measures and characterizes the radiation environment on the ISS for 

documenting crew exposure for medical records, long-term risk assessment and for mapping 

the radiation levels within the ISS for dose management. The EVCPDS also provides near 

real-time data to confirm exposure rates during an off-nominal radiation event and it will 

provide data for improving environmental and transport computer models. Finally, the 

EVCPDS is used in conjunction with the Tissue Equivalent Proportional Counter and 

radiation dosimeters to characterize the primary and secondary radiation field inside the ISS. 

S0 Command and Data/Communication and Tracking 

The S0 truss is outfitted with two Enhanced Space Station Multiplexer/ Demultiplexers or 

ESSMDMs. These provide control capability for each of the S0 Remote Power Distribution 

Assemblies and associated Remote Power Control Modules. The ESSMDMs are identical 

in hardware design and functionality, controlling S0 equipment. 

32
STS-110

Mobile Bus Switching Units 

The Mobile Bus Switching Units or MBSUs perform power routing functions over electrical 

power buses within the ISS. The S0 truss is outfitted with four MBSUs located on Faces 0 

and 2, Bays 1, 2 and 3. 

Each MBSU accepts power input from two power channels and distributes power to module 

internal and truss external DDCUs. This power distribution is performed using internal 

Remote Bus Isolation (RBI) switches, which may be remotely commanded to provide or 

remove power from downstream loads. Each MBSU has an internal power supply with 

redundant power feeds off the channel inputs and control power provided by a single RBI 

on the paired MBSU. Each MBSU has two groups of six RBIs, which are each fed by a 

main power RBI from one of the channel inputs of the MBSU. Of these 23 RBIs, eight are 

allocated to provide power to downstream DDCUs. Power is supplied to the output RBIs by 

separate power feed switches internal to the Orbital Replacement Unit (ORU). 

Global Positioning System Antennas 

Four GPS antenna assemblies have been preinstalled on the exterior of the S0 truss. The 

GPS system on the ISS is required to prove a state vector with an accuracy of 3,000 feet 

(915 m) in position for a single position measurement and with an error of less than 50,000 

feet (15.24 km) during 24 hours of propagation. 

Rate Gyro Assemblies 

The Rate Gyro Assemblies (RGAs) provide a method for the ISS Guidance and Navigation 

Control subsystem to perform state vector determination independent of the U.S. GPS. 

Two RGAs have been preinstalled on the aft port side of the S0 truss segment at the 

junction between Face 4 and the aft port transition face. The RGAs are composed of three 

ring laser gyros that determine changes in motion by measuring changes in the frequency 

of a reference laser beam using the Doppler effect. One ring laser gyro is assigned to 

measure motion in each of the three coordinate axes, with redundancy coming from the 

second unit in the set. 

S0 Thermal Control System 

Active hardware on S0 will be cooled through the use of the coldplates. The primary 

equipment on STS-110 that will use coldplates will be the DDCUs, but the MBSUs also are 

outfitted with coldplates and will be used once the units are activated. Coldplates function 

by running a working coolant (ammonia, for external hardware) between heat exchanger 

tubes beneath the ORU and a remotely located radiator. 

The heat pipe radiator will provide a system for heat rejection for several of the S0 ORUs. 

The pipes are pre-routed on S0 and require no activation per their design. 

33
STS-110

Airlock Spur 

The Airlock Spur is a structural beam outfitted with multiple EVA handrails to facilitate 

translation from the Joint Airlock to the forward side of S0 and the Lab module. It measures 

166.9 inches in overall length from the S0 pin fitting to the airlock bolts interface. Ten 

handrails (seven long, three short) are installed on two faces of the beam to provide 

handholds for crew translation. The Airlock Spur will be launched preinstalled on the 

starboard aft side of S0 with a hinge pin joint attachment to S0 and will be bolted to the 

airlock on orbit. 

Crew and Equipment Translation Aids Lights 

The CETA lights are halogen light assemblies mounted on boom assemblies and rated for 

exterior use. During the mission, two CETA lights are to aid in EVA crew activities. The first 

CETA light is installed on Destiny while the second is installed on the Node zenith near the 

aft endcone. 

Future Elements 

As part of Phase 3, two more truss segments, Port 1 (P1) and Starboard 1 (S1), are 

scheduled to be launched this year and will be attached to S0 by space-walking astronauts. 

Both were built and prepared for launch by Boeing Human Space Flight and Exploration. 

The other segments that comprise Phase 3 are P3, S3, P4, S4, P5, S5, P6 and S6. Future 

shuttle missions are required to transport the remaining Phase 3 truss elements. 

34
STS-110

Mobile Transporter 

Just as trains carried supplies to the Old West frontier, the Mobile Transporter (MT) will 

become the first railroad in space on the International Space Station (ISS) during 

STS-110/8A. 

The Mobile Transporter provides mobility for the Mobile Servicing System 

operations along the truss segments and the solar power module rails. 

The 1,950-pound structure will travel along the rails of the Integrated Truss Structure (ITS) 

and, together with the Mobile Base System, will provide the work platform for the Canadianbuilt mechanical arm (also known as the Space Station Remote Manipulator System or 

Canadarm2). Strong and powerful, the high-strength aluminum transporter provides the 

mobility to relocate the Canadarm2 to 10 pre-designated space station worksites and helps 

deploy segments of the ITS with its payload capacity of 46,100 pounds. The MT will lock 

itself down to the rails to move the massive payloads. 

35
STS-110

The Roller Suspension Unit provides vertical and horizontal restraints for the MT. 

Built for performance, the transporter measures 108 inches long, 103 inches wide and 38 

inches high. It travels on a three-point suspension system: the Linear Drive Unit, which 

drives and supports the MT, and the two Roller Suspension Units, which provide additional 

support as the MT travels down the ITS rails. 

During the mission, the MT will undergo a series of diagnostic tests after power and data is 

connected and launch restraints are removed. Three translations of the S0 truss, the first 

major element of the enormous ISS backbone that will be installed during STS-110, will be 

performed as the camera mounted on the shuttle’s Canadarm2 records the runs with 

speeds of 1.0, 0.4 and 0.1 inches per second. 

The Load Transfer Unit attaches the MT to the truss at worksites for the Mobile 

Remote Servicer. 

36
STS-110

The transporter will perform translations and sequential latching and unlatching at different 

points along the S0 Truss, testing its different functions. This is all done in preparation for 

the arrival of the Mobile Base System, which together with the Canadarm2, will help 

assemble the remainder of the integrated truss segment. 

During STS-111/UF-2, the Mobile Base System will be installed onto the MT to complete 

the Mobile Servicing System, eventually giving Canadarm2 the capacity to move from the 

U.S. lab Destiny and travel the length of the ITS. 

The MT is controlled by complex software. About 20 different motors are directed to run the 

transporter from one point to another, latch it down to the integrated truss segment for 

construction and plug itself into the power source, the Umbilical Mechanism Assembly port. 

The Trailing Umbilical System provides data, power and video to the MT and the 

Mobile Servicing System. 

This represents the first time that a software-controlled movable robot has ever been used 

on an orbiting vehicle. MT software controls the movement and thermal control of the 

integrated system. These functions are safety-critical hazardous functions that are essential 

to the assembly and operation of the International Space Station. 

The MT system has been preinstalled on the forward face (Face 1) of S0, including the 

Trailing Umbilical System and rails required to allow the unit to move along the truss. 

The MT was built in California and furnished by Boeing, the prime contractor for station 

construction. It is driven by dual electric motors that generate only a few hundredths of one 

horsepower. It moves along the rails attached to the station truss at speeds varying from 

one-tenth of an inch to one inch per second. 

37
STS-110

The MT will be able to stop at the 10 pre-designated worksites on the line where it can be 

locked down with a 7,000-pound grip to hold it in place so the robotic arm may safely 

maneuver cargo. Magnetic sensors locate iron strips in the aluminum rails to indicate when 

the MT has reached a stop. 

Although it can be driven from either on board the station or from the ground, the engineers 

for NASA’s space railroad will normally reside in Mission Control, Houston, often driving the 

train from thousands of miles away and hundreds of miles below. 

For more on the MT hardware and software, see the Appendix. 

38
STS-110

Experiments 

Science Payloads 

On this mission, Atlantis will deliver science experiments to the International Space Station 

and many station experiments will return aboard the shuttle. 

The Enhanced Gaseous Nitrogen Dewar will make its fourth trip to the space station. This 

low-cost facility enables scientists to grow hundreds of crystals at once and study optimum 

crystal growth conditions. On past missions, more than 430 teachers and students have 

sent samples to the space station as part of a NASA-sponsored education activity. 

For this flight, the Dewar will be filled with approximately 150 samples loaded by teachers 

and students from Alabama, California, Florida, Indiana, Illinois, Michigan, Ohio, Texas and 

West Virginia, and hundreds of samples loaded by scientists at the University of California, 

Irvine. In May, the Space Shuttle Endeavour will return the samples to Earth, where 

scientists can study the crystals’ structures to learn about the biochemistry of animals and 

plants. This experiment is sponsored by NASA’s Biotechnology Program at the Marshall 

Center. 

Two experiments sponsored by NASA’s Space Product Development Program at the 

Marshall Center are making their second trips to the orbiting laboratory. These experiments 

are sponsored by two of NASA’s 17 Commercial Space Centers, which are located across 

the country and designed to help companies carry out space research. 

The Commercial Generic Bioprocessing Apparatus will study bacterial fermentation that 

could improve the production of antibiotics for treating cancer. This experiment is 

sponsored by BioServe Space Technologies in Boulder, Colo. – a NASA Commercial 

Space Center working with Bristol-Myers Squibb Pharmaceutical Research Institute in 

Wallingford, Conn. 

The Commercial Protein Crystal Growth-High Density experiment will grow crystals from 

more than a thousand different biological samples. This experiment is sponsored by the 

Center for Biophysical Sciences and Engineering at the University of Alabama at 

Birmingham. More than 50 major industrial companies work with this Commercial Space 

Center to study how biological crystals can be grown and then used to design new 

pharmaceutical products. Both these biological crystal samples and the antibiotic samples 

will be returned in May on Endeavour. 

Also going up on STS-110 will be the first samples to be processed in the Zeolite Crystal 

Growth Furnace, which was delivered on an earlier flight and is also sponsored by a 

Commercial Space Center – the Center for Advanced Microgravity Materials Processing at 

Northeastern University in Boston. Zeolites are the backbone of the chemical processes 

industry, and virtually all the world’s gasoline is produced or upgraded using zeolites. The 

petroleum industry is interested in growing improved zeolites in space to reduce chemical 

processing costs. The first set of samples will be returned to Earth in May, and another set 

will be delivered for processing inside the furnace, which will remain on the station. 

39
STS-110

It will be the first space station flight for the Biomass Production System and 

Photosynthesis Experiment and System Testing Operation – a new experiment that will 

help scientists at NASA’s Ames Research Center in Moffett Field, Calif., develop a 

dedicated plant research facility for the station. Researchers will grow wheat and Brassica 

during the next month. The plants and new hardware will be returned on Endeavour in May. 

Several experiments and samples will come back on Atlantis in April. These include plants, 

biological crystals and cell cultures. All are sponsored by NASA’s Office of Biological and 

Physical Research in Washington.

The following chart shows the various payloads during Expedition Four—which are 

pre/post, which are going up/coming down on 110, and which will be operated during the 

8A stage: 

Expedition 4 Research Program Overview

Cre w Ea rth Obs

Ea rthKAM

ARIS -ICE

MISSE

Educa tiona l O utre a ch

BPS/PESTO

ADF

Sub re gio na l Bone

Inte ra ctio ns

H-Re fle x

Xenon1

PuFF

Renal Stone

EVARM

PCG-EGN

MAMS

SAMS

EXPPCS

PCG-S TES -09/10

CBOSS

ADV AS C-GC-02

CBTM

CGBA-03

CP CG-H-02/03

 

ZC G

UF1 UF2 8A

Office of 

Space Flight

Fundamental 

Biology

Human Life 

Sciences

Microgravity 

Research

Space Products 

Development

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ARIS -ICE

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BPS/PESTO

ADF

Sub re gio na l Bone

Inte ra ctio ns

H-Re fle x

Xenon1

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Renal Stone

EVARM

PCG-EGN

MAMS

SAMS

EXPPCS

PCG-S TES -09/10

CBOSS

ADV AS C-GC-02

CBTM

CGBA-03

CP CG-H-02/03

 

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UF1 UF2 8A

Office of 

Space Flight

Fundamental 

Biology

Human Life 

Sciences

Microgravity 

Research

Space Products 

Development

{

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{

40
STS-110

ADVANCED ASTROCULTURE (ADVASC) 

Principal Investigators: Tad Theno and Eric Brunsell, chief program scientists for Space 

Explorers Inc., and Dr. Weijia Zhou, Wisconsin Center for Space Automation and Robotics 

(WCSAR), University of Wisconsin-Madison 

Co-Principal Investigator: Dr. Bratislav Stankovic, WCSAR 

Overview 

The first ADVANCED ASTROCULTURETM plant growth unit was used successfully to grow 

plants during Expedition Two. These plants were returned to investigators on Earth on the 

STS-104 space shuttle mission in July 2001. 

During their stay on the International Space Station during Expedition 2, the plants went 

through seed germination, plant growth and development, seed formation, and seed 

maturation -- completing an entire lifecycle. Of the 91 Arabidopsis seeds that were 

launched, about 90 percent germinated in space; and about 70 percent of the seeds grew 

to produce siliques that contained mature seeds. An average of 24 siliques per plant were 

produced, each containing an average of 36 seeds. The majority of siliques were rated as 

mature, while the others were moderately mature. 

ADVANCED ASTROCULTURE provides a completely enclosed, environmentally 

controlled plant growth chamber. It requires no power during shuttle ascent and descent. 

Before the flight, scientists plant seeds in a root tray using a dry rooting material called 

Arcillite, a type of crushed clay. The seed tray is then attached to the ADVANCED 

ASTROCULTURE growth chamber. Reservoirs in the growth unit are loaded with water 

and nutrient solutions that plants need to live while aboard the ISS. 

The equipment is configured as two single middeck lockers that insert separately into a 

space station EXPRESS Rack. One locker contains the support systems. The other 

contains the plant growth chamber and ancillary hardware. This arrangement allows the 

support system to remain on board, while the shuttle transports plant growth units to and 

from the station with different experiments. 

For the Expedition Four experiment, the payload was modified. A hatch was added so the 

crew can remove plant tissue while the plants are growing on board the station. The plant 

samples have been stored in tissue fixation tubes, designed by NASA’s Kennedy Space 

Center. Then, they were placed inside the station’s Biotechnology Refrigerator. The plant 

tissues’ RNA genetic information has been preserved to allow scientists and the 

commercial partner to study microgravity impact on plants’ gene expression levels after the 

plants are returned to Earth. 

The objectives of the Expedition Four ADVANCED ASTROCULTURE experiments are 

(1) to validate plant life support technologies used in the ADVASC payload; (2) to produce 

the second generation of seeds in space from the first generation produced during 

Expedition Two; and (3) to conduct a gene expression analysis to determine whether 

microgravity may alter plant gene expression levels. 

41
STS-110

Cellular Biotechnology Operations Support System (CBOSS) 

Principal Investigators: Jeanne L. Becker, Ph.D., University of South Florida, Tampa; 

Timothy G. Hammond, M.B., B.S., Tulane University Medical Center, New Orleans; J. 

Milburn Jessup, M.D., University of Texas Health Science Center, San Antonio, Texas; 

Peter I. Lelkes, Ph.D., Drexel University, Philadelphia, Pa. 

Program Manager: Dr. Neal Pellis, Manager, Cellular Biotechnology Program Office,

NASA Johnson Space Center 

Project Manager: Melody Anderson, Cellular Biotechnology Program Office, NASA 

Johnson Space Center 

Payload Experiment Developer: Fred R. Williams, Life Sciences Systems and Services, 

Wyle Labs, Inc. 

Overview 

The objective of the Cellular Biotechnology Operations Support System (CBOSS) is to 

provide a controlled environment for the cultivation of cells into healthy, three-dimensional 

tissues that retain the form and function of natural, living tissue. CBOSS will enable 

investigations on normal and cancerous mammalian cells, including ovarian and colon 

cancer cells, neural precursor and human renal cells. The system is comprised of the 

Biotechnology Specimen Temperature Controller, the Biotechnology Refrigerator, the Gas 

Supply Module and the Biotechnology Cell Science Stowage. The crew will periodically 

record scientific data, add fresh media to the tissue culture modules and process samples 

for return to Earth. The crew also will perform preventative maintenance. 

Background/Flight History 

The first cellular experiment flew aboard the space shuttle in the mid-1990s during STS-70 

and STS-85. Long-duration cellular biotechnology experiments also were conducted in the 

Biotechnology System Facility on the Russian space station Mir from 1996 through 1998. 

This experiment also flew on the space station during Expedition 3. 

Benefits 

Bioreactor cell growth in microgravity permits cultivation of in vitro tissue cultures of size 

and quantity not possible on Earth. Such a capability provides unprecedented 

opportunities for breakthrough research in human diseases, including various types of 

cancer, diabetes, heart disease and AIDS. 

More information on NASA biotechnology research and other Expedition Four experiments 

is available at: 

http://microgravity.msfc.nasa.gov

http://scipoc.msfc.nasa.gov

42
STS-110

Commercial Generic Bioprocessing Apparatus (CGBA) 

Principal Investigators: Dr. Louis Stodiek, BioServe Space Technologies, University of 

Colorado, Boulder, and Dr. Raymond Lam, Bristol-Myers Squibb Pharmaceutical Research 

Institute, Wallingford, Conn. 

Project Manager: Cooperative agreement managed by John West, Office of Space 

Product Development, NASA Marshall Space Flight Center, Huntsville, Ala., and technical 

management by BioServe at the University of Colorado, Boulder 

Overview 

The goal of the research conducted in the Commercial Generic Bioprocessing Apparatus 

(CGBA) payload is to develop commercial uses of the unique microgravity environment for 

the field of life sciences. The CGBA hardware is able to support many standard biological 

laboratory techniques that have been adapted to operate in space. The experiments are 

designed to further our understanding of how gravity influences various biophysical and 

biochemical actions. Applications of this knowledge are geared toward creating or 

improving various biologically derived products, as well as enhancing the processes used 

to create them. 

History/Background 

The CGBA is a commercial payload sponsored by NASA’s Space Product Development 

Program at the Marshall Space Flight Center. BioServe Space Technologies builds and 

manages the apparatus. BioServe is a NASA Commercial Space Center jointly located 

within the Aerospace Engineering Sciences Department at the University of Colorado in 

Boulder and the Division of Biology at Kansas State University in Manhattan. Bristol-Myers 

Squibb Pharmaceutical Research Institute in Wallingford, Conn., is BioServe’s sponsoring 

commercial partner for this research. Since 1991, BioServe has flown payloads in space on 

16 shuttle flights, two Mir flights and during Expedition 2 and Expedition 4. 

Benefits 

Gaining a better understanding of what is causing the stimulated production of antibiotics in 

space is helping scientists to design experiments that attempt to mimic this increase in 

productivity on Earth. These experimental techniques may lead to the development of 

methods for improving production efficiency in terrestrial pharmaceutical processing 

facilities. 

Additional information on CGBA can be found at: 

http://www.colorado.edu/engineering/BioServe/

43
STS-110

Physics of Colloids in Space (PCS) 

Principal Investigator: Prof. David Weitz, Harvard University, Cambridge, Mass. 

Co-Investigator: Prof. Peter Pusey, University of Edinburgh, Edinburgh, UK 

Project Manager: Michael Doherty, NASA Glenn Research Center, Cleveland, OH 

Overview 

A colloid is a system of fine particles suspended in a fluid. Paint, milk and ink are some 

common examples. Though these products are routinely produced and used, scientists still 

have much to learn about the underlying properties of colloidal systems. Understanding 

their properties may allow scientists to manipulate the physical structures of colloids -- a 

process called “colloidal engineering” -- for the manufacture of new materials and products. 

The PCS experiment began during Expedition Two with International Space Station 

Mission 6A (STS-100, April 2001) and is to conclude with the return of the samples on 

Flight UF-2. It gathers data on the basic physical properties of colloids by studying three 

different colloid sample types. This experiment represents the first in-depth study of the 

growth and properties of colloidal superlattices -- formed from mixtures of different-sized 

colloidal particles -- performed in a microgravity environment. Scientists hope to better 

understand how colloid structures grow and behave with the long-term goal of learning how 

to control their growth to create new materials. 

The experiment will focus on the growth and behavior of three different classes of colloid 

mixtures of tiny manmade particles of either polymethyl methacrylate or silica or 

polystyrene; these will include samples of binary colloidal crystal alloys, samples of colloidpolymer mixtures and samples of colloidal gels. Binary colloidal crystal alloys are 

dispersions of two different size particles in a stabilizing fluid. Colloid-polymer mixtures are 

solutions of mono-disperse particles mixed with a polymer in a stabilizing fluid, where the 

phase behavior -- solid, liquid and gas -- is controlled by the concentration of the polymer. 

Colloidal gels include aqueous solutions of particles, in this case aggregated on-orbit with a 

salt solution, to form fractal structures. The structure, stability and equilibrium properties of 

all the samples, as well as their structure, dynamics and mechanical properties, are being 

studied. 

History/Background 

The first generation experiments by these investigators in microgravity were glovebox 

experiments with binary colloidal crystal alloys and colloid-polymer mixtures, flown on the 

Russian space station Mir and on the STS-95 mission in October 1998. 

44
STS-110

Protein Crystal Growth— Single-locker Thermal Enclosure System 

(PCG-STES) Housing the Protein Crystallization Apparatus for 

Microgravity (PCAM) 

Principal Investigators: Dr. Daniel Carter and Dr. Craig Kundrot, New Century 

Pharmaceuticals, Huntsville, Ala. 

Project Manager: Todd Holloway, NASA's Marshall Space Flight Center, Huntsville, Ala. 

Overview 

The STES is an incubator/refrigerator module that can house different devices for growing 

biological crystals in microgravity. Each STES unit houses six Protein Crystallization 

Apparatuses for Microgravity (PCAM), which are designed to grow the actual crystals. The 

fundamental goal for growing biological macromolecular crystals is to determine their 

structure and the biological processes in which they are involved. Scientists select 

macromolecules, crystallize them, and analyze the atomic details to determine the threedimensional atomic structure of the macromolecule. Understanding these structures may 

impact the studies of medicine, agriculture, the environment and other biosciences. 

Background/Flight History 

The STES hardware has previously flown on six shuttle missions (STS-63, 67, 73, 83, 85, 

95) and during Expedition 2 and Expedition 4. 

Benefits 

Structural biological experiments conducted in the PCG-STES will enable the more 

accurate mapping of the three-dimensional structure of macromolecules. Once the 

structure of a particular macromolecule is known, it may become much easier to determine 

how these compounds function. Every chemical reaction essential to life depends on the 

function of these compounds. 

Additional information on the STES and biological crystal growth is available at: 

http://crystal.nasa.gov/

http://www.microgravity.nasa.gov/

http://www.ssl.msfc.nasa.gov/msl1/images/pcambig.jpg

45
STS-110

Renal Stone Risk During Space Flight: Assessment and 

Countermeasure Validation 

Principal Investigator: Dr. Peggy A. Whitson, Johnson Space Center, Houston 

Project Manager: Michelle Kamman, Johnson Space Center, Houston

Overview 

Exposure to microgravity results in a number of physiological changes in the human body, 

including alterations in kidney function, fluid redistribution, bone loss and muscle atrophy. 

Previous data have shown that human exposure to microgravity increases the risk of 

kidney stone development during and immediately after space flight. Potassium citrate, a 

proven Earth-based therapy to minimize calcium-containing kidney stone development, is 

being tested as a countermeasure to reduce the risk of kidney stone formation. This study 

also will assess the kidney stone-forming potential in humans based on mission duration, 

and determine how long after space flight the increased risk exists. 

Benefits 

The formation of kidney stones could have severe health consequences for ISS 

crewmembers and negatively impact the success of a mission. This study will provide a 

better understanding of the risk factors associated with kidney stone development both 

during and after a space flight, as well as test the effectiveness of potassium citrate as a 

countermeasure to reduce this risk. Understanding how the disease may form in otherwise 

healthy crewmembers under varying environmental conditions also may provide insight into 

kidney stone-forming diseases on Earth. 

46
STS-110

Commercial Protein Crystal Growth–High Density (CPCG-H) 

Missions: Expedition 4, ISS Mission 8A, STS-110 for March 21, 2002; experiment will 

continue through Mission UF-2, STS-111 for May 2, 2002 

Experiment Location on ISS: U.S. Lab EXPRESS Rack 4 

Principal Investigator: Dr. Lawrence DeLucas, Director, Center for Biophysical Sciences 

and Engineering, University of Alabama at Birmingham 

Project Manager: John West, NASA Space Product Development Program, Marshall 

Space Flight Center, Huntsville, Ala. 

Overview 

The word protein is coined from the Greek proteios, or "primary." Proteins are the primary 

building blocks of all life, and how they react with other biochemical compounds in living 

organisms determines many things, including if a creature will be healthy or become ill. 

First discovered in 1838, proteins are recognized as the predominant ingredients of cells. 

Understanding this hidden world is intensely interesting and important to scientists and 

physicians. 

Each protein has a particular chemical structure, which means it has a favored “shape.” 

Researchers still lack detailed knowledge about the structures of many proteins. If they can 

determine the shape, or shapes, of a protein, they can learn how it works. Once this is 

understood, researchers can then find a way to help or hinder a given protein, and they may 

be able to develop new treatments that target specific human, animal and plant diseases. 

One of the most widely used methods of studying protein structures is protein 

crystallography. Proteins can be made to crystallize in much the same way sugar crystals 

can be formed from sugar water to make rock candy. Scientists then use X-rays to 

determine the three-dimensional molecular structures of proteins. 

The structures of many important proteins remain a mystery simply because researchers are 

unable to obtain crystals that have the quality or size required for X-ray crystallographic 

studies. NASA 's Protein Crystal Growth (PCG) program has been developed to learn how 

protein crystals grow in space and how to optimize the growth process, while producing 

large, high-quality crystals of selected proteins. The near-zero microgravity conditions inside 

an orbiting spacecraft allow crystals to grow in a more regular and perfect form because of 

the effects of convection and sedimentation are dampened relative to the 1-g laboratory. 

The Commercial Protein Crystal Growth – High Density (CPCG-H) experiments, developed 

by the Center for Biophysical Sciences and Engineering at the University of Alabama at 

Birmingham, will launch on space shuttle flight STS-110, scheduled for launch in April 2002 

as part of ISS mission 8A, and be transferred to the International Space Station. 

Researchers hope that these experiments will provide large, well-ordered protein crystals of 

several different proteins for X-ray analysis that will lead to the development of new drugs. 

The experiment is scheduled to return to Earth on board the shuttle STS-111 mission. 

47
STS-110

Experiment Summary 

The Commercial Protein Crystal Growth-H experiment consists of 1,008 individual 

experiments contained in a High-Density Protein Crystal Growth Assembly. This assembly 

is then stored in the Commercial Refrigerator Incubator Module (CRIM) at 22 degrees 

Celsius (72 degrees Fahrenheit). 

The space station crew will install the CRIM into a locker in the Space Station EXPRESS 

Rack 4 in the U.S. Lab, activate the crystal growth experiments and conduct daily status 

checks. These daily checks consist of checking temperature readings and cleaning the air 

filter. When the payload is scheduled to return to Earth, the crew will deactivate the 

experiments and return the module. 

The protein crystals will be grown using a process known as vapor diffusion. Each 

experiment chamber consists of a small chamber that holds the protein crystal solution and 

a reservoir chamber that holds the precipitating agent solution. A small droplet of protein 

solution is mixed with a small amount of precipitating agent solution and placed in the 

protein chamber. 

During activation, the protein chamber is rotated so it is in vapor contact with the reservoir. 

Water molecules migrate from the protein droplet through the vapor space into the more 

concentrated reservoir. As the volume of the protein droplet decreases, the concentration 

of protein increases and protein crystals form. As the experiment continues, the crystals 

grow larger. 

Once back on Earth, the crystals will be studied using a process called X-ray diffraction. 

Scientists send a beam of X-rays through the crystal and measure how the atoms in the 

crystal scatter the X-rays. By studying the pattern made by the X-rays, scientists can map the 

locations of the different atoms, allowing them to create a 3-dimensional model of the protein. 

With this structural information, researchers determine how the protein functions and can 

design small molecules to aid or impede the protein’s function. This process, known as 

structure-based drug design, may lead to more effective drugs that target specific proteins. 

Background/Flight History 

Because of the enormous potential this research offers, the Center for Biophysical 

Sciences and Engineering (formerly the Center for Macromolecular Crystallography or 

CMC), a NASA-sponsored Commercial Space Center located at the University of Alabama 

at Birmingham, has more than 50 major industry and academic partners using the lowgravity environment of space to grow protein crystals for use in drug design.

Protein-crystal growth experiments began flying on the space shuttle in 1985. Today, more 

than 40 protein-crystal growth payloads have flown, producing diffraction-quality crystals of 

many proteins. The CPCG-H first flew aboard the ISS during Expedition 2, launching 

aboard STS-100 in April 2001 and returning aboard STS-105 in August 2001. The data 

derived from each crystal analyzed is leading researchers closer to understanding the 

structure and function of proteins. 

48
STS-110

Benefits 

NASA’s commercial research program attempts to use the materials or knowledge developed 

in space to develop or improve a commercial product or service on Earth. Commercial space 

research has the potential to create new or improved products, create jobs, give United 

States industry competitive advantages and improve the quality of life on Earth. 

Structural studies using microgravity-grown protein crystals may provide information that 

can be used in the development of new drugs. With the advent of genetic information from 

humans and many other species, the role proteins play in diseases and degenerative 

conditions is becoming more clear and the need for information about the structure of these 

proteins more critical. 

Experiments involving the crystallization of proteins and other biological macromolecules 

will be part of the ongoing research conducted aboard the International Space Station. The 

space station provides an ideal platform for growing crystals that require longer periods of 

microgravity than has been available on short-duration space shuttle flights. 

Benefits from protein growth experiments conducted in space have already been seen. 

Many of the crystallization experiments conducted on the space shuttle have yielded 

crystals that furthered structural biology projects. For example, microgravity crystallization 

experiments have been conducted with recombinant human insulin. These studies have 

yielded X-ray diffraction data that helped scientists to determine higher-resolution 

structures of insulin formulations. This structural information is valuable for ongoing 

research toward more effective treatment of diabetes. 

Other very successful microgravity crystallization experiments have provided enhanced 

X-ray diffraction data on a protein involved in the human immune system. These studies 

have contributed to the search for drugs to decrease inflammation problems associated 

with open-heart surgery. 

The crystallization of proteins in the low-gravity environment of Earth orbit has developed 

into a valuable and necessary tool for the science of macromolecular crystallography. 

Crystallization experiments conducted on the International Space Station involve not only 

human but also animal and plant proteins and promise to help answer key questions about 

the world around us. 

Additional Information/Photos 

More information on this experiment is available at: 

www.scipoc.msfc.nasa.gov www.spaceflight.nasa.gov

http://www.microgravity.nasa.gov http://www.spd.nasa.gov

http://spaceresearch.nasa.gov/ http://commercial.nasa.gov

http://www.cbse.uab.edu/ 

49
STS-110

Experiments 

Biomass Production System (BPS) and the Photosynthesis 

Experiment and System Testing Operation (PESTO) 

The Biomass Production System (BPS) is a test facility for a future International Space 

Station (ISS) plant habitat capable of supporting plant growth and botanical 

experimentation in microgravity for 90-day intervals or longer. The BPS will be delivered to 

the ISS during the STS-110 mission and then transferred to an ISS EXPRESS rack for inflight operations. 

On orbit, the BPS is designed to support the continued growth and development of plant 

specimens and to provide the capabilities necessary to perform scientific investigations. 

The BPS is one of several pieces of ISS hardware being developed by NASA’s Space 

Station Biological Research Project (SSBRP), located at NASA Ames Research Center in 

California’s Silicon Valley. Dr. Randall Berthold is the payload manager, and Kristina Lagel 

is project scientist for NASA Ames. 

The primary objective of the BPS is the Technology Validation Test (TVT), which is 

intended to evaluate hardware performance under orbital conditions in order to select 

subsystems ideal for design and development of a permanent plant research unit for the 

ISS. The BPS also will support the Photosynthesis Experiment and System Testing 

Operation (PESTO), a study of the effects of microgravity on photosynthesis and 

metabolism in wheat plants. Some of the results from this study will be used as part of the 

Technical Validation Test. 

Science samples will be returned to Earth from the ISS on the STS-111 space shuttle 

mission, currently scheduled for launch in May 2002. 

50
STS-110

Biomass Production System 

Hardware Overview 

The BPS is a powered, double middeck locker equivalent hardware system that includes 

four independent plant growth chambers, a nutrient delivery system, a 

temperature/humidity control system, airflow and atmospheric control systems, a video 

system and a data-processing system. Each plant growth chamber has a growing area of 

about 42 square inches (260 square centimeters) and a height of over 6 inches (15 

centimeters). The BPS was developed by Orbital Technologies Corp., Madison, Wis. 

Experiment Overview 

The BPS will support two sets of experiments. The primary objective is to conduct the 

Technical Validation Test (TVT), which will evaluate the ability of the BPS and its 

environmental control subsystems to support plant growth and development in 

microgravity. Researchers will study the health and growth of the plants, facility 

temperature and humidity controls, nutrient delivery, lighting, plant manipulation and 

sample retrieval, video and data acquisition, and performance of other operations and 

support systems. 

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STS-110

The TVT will use two types of plants. Chamber 4 will contain Brassica rapa, plants 

belonging to the mustard family. Brassica plants include such commonly grown vegetables 

as broccoli, cabbage, cauliflower, rutabaga and turnip. Brassica is a dicot – a plant with two 

cotyledons, or leaf-like structures, per seed -- and exhibits multiple developmental stages 

(growth, flowering and seedpod production) in a short time. The growth of Brassica rapa

seedlings will test the ability of the BPS to support the growth of a developmentally complex 

plant. Dr. Robert Morrow, Orbital Technologies Corp., Madison, Wis., is the principal 

investigator for the TVT. 

The TVT also will use Apogee wheat, a monocot plant with only one cotyledon, or leaf-like 

structure, per seed. Chamber 3 will contain wheat seedlings that will be four days old at 

launch. The wheat will be exposed to a variety of temperature and humidity levels in order 

to test the ability of the BPS to control temperature and humidity set points. In addition, 

water utilization and plant photosynthesis will be measured. Tissue will be harvested and 

frozen or fixed when the plants are 21 days old. Upon successful completion of the initial 

verification test, the chamber temperature and humidity will be maintained at a constant 

75.2 ̊ F (24 ̊ C) and 75 percent relative humidity to conduct a 21-day microgravity test, 

followed by a test to grow plants that will be 12 days old at landing. Plants grown during 

these last two growth periods will be part of the PESTO experiments. 

The second experiment set is the Photosynthesis Experiment and System Testing Operation 

(PESTO), which will study the growth, photosynthesis, gas exchange and metabolism of 

Apogee wheat in microgravity. Plants have the capability to remove carbon dioxide, generate 

oxygen, and purify water. This experiment will determine the ability of wheat seeds to 

germinate, develop and grow in microgravity conditions, measure the growth of the 

seedlings, and determine the effects of microgravity on photosynthesis and transpiration. The 

experiment will evaluate techniques for planting and watering seeds on orbit. Plants will be 

harvested in space and returned to Earth for detailed analysis. The PESTO principal 

investigator is Dr. Gary Stutte, Dynamac Corp., Kennedy Space Center, Fla. 

One of the PESTO experiments will compare the effect of microgravity on Apogee wheat 

plants of two different ages. Chamber 1 will include 32 plants 12 days old at the time of 

launch. These plants will be well developed and able to photosynthesize. Chamber 2 will 

hold a group of 32 plants eight days old at launch. These plants will have just developed a 

‘canopy’ capable of photosynthesis. Analyses of the plants’ photosynthetic development will 

be done three times during their development. Comparisons will be made with plants of the 

same age but developed under normal Earth gravity. 

Another component of the PESTO experiment will germinate seeds in microgravity, and 

then analyze the living plants once they are returned to Earth. The plants, which will be 

harvested on the ground, will be 12, 19 or 24 days old at landing. The in-flight water use 

and photosynthetic responses of these plants will be compared to post-flight analysis of the 

photosynthetic apparatus. In addition, tissue will be frozen and analyzed for carbohydrate 

partitioning and fixed for ultrastructural analysis of the development of the photosynthetic 

apparatus. 

52
STS-110

System Components 

Each of the BPS’s four plant growth chambers includes a root module connected to a 

removable chamber cover. Each chamber is independently controlled for temperature, 

humidity, lighting, atmospheric composition (CO2) and delivery of water. Each chamber also 

has its own video monitoring system. The BPS is programmed to capture still images from 

each chamber every two hours using this system, and recording equipment interfaced with 

the BPS front panel can be used to capture full-motion video footage. 

Background/Flight History 

Studies of the effects of microgravity on plant growth date back to the 1960s with the 

Biosatellite program and continued throughout the history of the Space Shuttle Program. 

With the addition of a stable, long-term plant research facility on the ISS, researchers will 

gain more reliable knowledge about the relationship between microgravity and plant 

growth. This research will allow the effects of microgravity on the potential of using plants to 

generate oxygen, remove carbon dioxide, and purify water on long-duration space missions 

to be evaluated under realistic conditions. This research will have direct application to 

future production of salad crops that the ISS crew could eat directly, such as radishes, 

lettuce or onions. 

Benefits 

The photosynthetic properties of plants are a critical component of plant-based atmospheric 

regeneration systems now under study for possible implementation in future long-duration 

space missions. Studies of photosynthesis in microgravity and determining its effects on 

atmosphere controls will enable NASA to make an informed decision about the feasibility 

and design of a self-sustaining biosphere. In such a facility, living plants will help maintain 

proper ship atmosphere, and reduce the air/water resupply costs associated with living and 

working in space. The technology used to maintain the environmental conditions necessary 

for plant growth also have the potential to improve environmental controls in the 

greenhouse and controlled-environment industries. 

The BPS studies are supported by NASA’s Office of Biological and Physical Research, 

which promotes basic and applied research to support human exploration of space and to 

take advantage of the space environment as a laboratory. More information is available at: 

http://spaceresearch.nasa.gov/

For more information about NASA’s Space Station Biological Research Project, visit: 

http://brp.arc.nasa.gov/

Details about the BPS and NASA Ames’ Expedition Four fundamental biology project are 

available at: 

http://lifesci.arc.nasa.gov/UF1

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STS-110

Other Expedition Four experiment information can be found at: 

http://microgravity.msfc.nasa.gov

http://scipoc.msfc.nasa.gov

54
STS-110

DSOs and DTOs 

Detailed Supplementary Objectives (DSOs) are space and life science investigations. Their 

purpose is to: 

• Determine the extent of physiological deconditioning resulting from spaceflight 

• Test countermeasures to those changes 

• Characterize the environment of the space shuttle and/or space station relative to 

crew health. 

Detailed Test Objectives (DTOs) are aimed at testing, evaluating or documenting space 

shuttle systems or hardware, or proposed improvements to the space shuttle or space 

station hardware, systems and operations. 

Such experiments aboard Atlantis are: 

DSO 493 

Monitoring Latent Virus Reactivation and Shedding in Astronauts 

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

saliva and urine will increase during space flight. 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 space flight. 

Space-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-

80 percent of all adults. Its classic manifestations are cold sores, pharyngitis and tonsillitis; 

and it is usually acquired through contact with the saliva, skin, or mucous membranes of an 

infected individual. However, many recurrences are asymptomatic, resulting in the 

shedding of the virus. 

DSO 496 

Individual Susceptibility to Post-Space Flight Orthostatic Intolerance 

(Preflight and Postflight Only) 

The occurrence of postflight orthostatic hypotension in some, but not all astronauts is 

contributed to by preflight, gender-related differences in autonomic regulation of arterial 

pressure, and space flight-induced changes in autonomic function which precipitate 

orthostatic hypotension in predisposed individuals. This DSO will address this hypothesis 

by performing a flight-related study, designed to elucidate preflight and postflight 

differences in susceptible and non-susceptible astronauts. 

55
STS-110

DSO 498 

Space Flight and Immune Function 

(Preflight and Postflight Only) 

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 as the 

International Space Station. The effect of space flight 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 microgravity will enable researchers to develop 

countermeasures to minimize infection risk. DSO 498 will look at the effects of spaceflight 

on the neutrophils, monocytes and cytoxic cells, which play an important role in maintaining 

an effective defense against infectious agents. Scientists believe that space changes the 

way that these cells function. Researchers will analyze neutrophils and monocytes from 

astronaut blood samples before and after flight. They will also assess the subjects’ preflight 

and postflight production of cytotoxic cells and cytokine. This study will complement 

previous and continuing immunology studies of astronauts’ adaptation to space. 

DSO 500 

Space Flight-Induced Reactivation of Latent Epstein-Barr Virus 

(Preflight and Postflight Only) 

The effects of microgravity, along with associated physical and psychological stress, will 

decrease Epstein-Barr virus (EBV)-specific T-cell immunity and reactivate latent EBV in 

infected B-lymphocytes. DSO 500 will examine the mechanisms of space flight-induced 

alterations in human immune function and latent virus reactivation. Specifically, it will 

determine the magnitude of immunosuppression as a result of space flight by analyzing 

stress hormones, performing quantitative analysis of EBV replication using molecular and 

serological methods, and determining virus-specific T-cell immune function. 

DSO 503-S 

Test of Midodrine as a Counteractive Measure Against Postflight 

Orthostatic Hypotension 

(Preflight and Postflight Only) 

After space flight, astronauts returning to upright posture may experience the inability to 

maintain adequate arterial pressure and cerebral function (orthostatic or postural 

hypotension). This may result in lightheadedness or loss of consciousness during re-entry 

or egress. DSO 503-S will evaluate the efficacy of midodrine, a medicine commonly used to 

treat low blood pressure. It works by stimulating nerve endings in the blood pressure. The 

experiment will assess midodrine’s effectiveness in reducing the incidence and/or severity 

of orthostatic hypotension in returning astronauts. 

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DTO 263 

Shuttle Automatic Reboost Testing 

The purpose of this DTO is to validate the preflight estimate of the structural natural 

frequencies and damping, and thus the jet firing separation time. The structural natural 

frequencies can be measured using the shuttle IMU downlink data, and the jet firing 

separation time can be implemented by display inputs by the shuttle crew. This DTO is 

appropriate for shuttle flight to the ISS between availability of OI-28 reboost software and 

availability of the vernier jet reboost capability. This is the third of approximately four flights 

of DTO 263. 

DTO 264 

Space Station RMS Dynamic Model Validation 

(DTO of Opportunity) 

The purpose of DTO 264 is to assure stable shuttle control system performance, and 

acceptable loads on the space shuttle remote manipulator system (SSRMS) induced by the 

shuttle jet firings. During planned SSRMS handling of payloads, a brief pause is requested 

at a specific planned SSRMS geometric configuration in the operations preplanned 

trajectory. At this configuration, crew inputs to SSRMS motion will be commanded followed 

by an SSRMS brakes on command. This will be performed three times to excite two lateral 

bending modes and one torsion mode of the SSRMS. The SSRMS data system in the end 

effector will be active to measure the SSRMS transient load response. Two flights are 

chosen to assess SSRMS dynamic characteristics while attached to a light and a heavy 

payload. This is the last of two flights of this DTO. 

DTO 700-14 

Single-String Global Positioning System 

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

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

phases. It uses a modified military GPS receiver processor and the existing orbiter GPS 

antennas. GPS data may be downlinked during all mission phases. This is the 23rd flight for 

this DTO. 

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DTO 805 

Crosswind Landing Performance 

(DTO of Opportunity) 

DTO 805 is to demonstrate the capability to perform a manually controlled landing in 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 substation helps 

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

knots as late in the flight as possible. 

2. Entry: This test requires that the crew perform a manually controlled landing in a 90-

degree crosswind component of 10-15 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. This DTO has been on 70 flights. 

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Appendix 

Mobile Transporter 

The purpose of the Mobile Transporter (MT) is to provide the following: structural 

attachment between the Mobile Remote Servicer Base System (MBS)/Space Station 

Remote Manipulator System (SSRMS) and the truss rails (MT interfaces directly with 

MBS); utility interfaces between the United States Orbital Segment (USOS) and the 

MBS/SSRMS (when parked at one of the 10 truss worksites); and the translation force for 

the entire Mobile Servicing System (MSS) along the International Space Station main truss 

structure. 

The MT has a maximum velocity of 1 inch/sec (2.54 cm/sec) and the longest translation 

time from one end of the truss to the other (at Assembly Complete) is 50 minutes. The MT 

allows the MSS to accommodate payloads of up to 46,100 lbs (20,900 kg). The MT is 

controlled remotely (IVA) and requires no EVA support for execution of translation 

sequences. 

The MT will be launched on STS-110/8A integrated with the S0 truss segment. 

Mobile Transporter Hardware 

The MT provides the primary load path between the MBS/SSRMS and the Integrated Truss 

Structure (ITS) rails. It is constructed of machined, aluminum-alloy space frames, which are 

attached with permanent Hi-Lok fasteners. The primary structure supports a number of 

mounted Orbital Replacement Units (ORUs) and additional components. The hardware is 

described below: 

Trailing Umbilical System 

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Trailing Umbilical System (TUS)—The TUS provides all utility connections between the 

MT/MBS/SSRMS and the USOS. This includes all operational power during MT translation 

and SSRMS maneuvering (SSRMS receives no power during MT translation); a continuous 

command/control and telemetry data bus link; and video/sync and control lines for SSRMS 

video. These utilities connect the MT/MBS/SSRMS with the S0 truss and the rest of the 

USOS through the use of primary and redundant multi-conductor cables, which are reeled 

in and out along opposite sides of the ITS rails to follow the MT as it travels along the truss. 

The TUS is controlled by the MT software in conjunction with the concurrent MT translation 

sequence. Cable deployment rate can vary between 0-1 inch/sec to match the MT 

translation speed. 

TUS Reel Assemblies—There are two TUS reel assemblies housing the two TUS cables 

that are to be deployed as well as additional lengths of cable for the Concentric Cable 

Management System (CCMS). The CCMS provides a means of managing the cable as a 

single continuous length, eliminating the need for slip rings. The TUS reel assembly 

maintains tension in the cable as it is laid in cable guides along the truss rail. This is 

accomplished through the use of a spring-loaded control arm. Each TUS reel assembly 

housing also supports a Video Signal Converter (VSC) for the SSRMS video being routed. 

The TUS reel assemblies are mounted on the port end of ITS S0 Bay 1. The MT is 

nominally parked during periods of inactivity on the adjacent ITS S0 Bay 2. 

TUS Cable—The majority of the TUS cable is flat, 10 conductor design. Three central 

power wires are 12-gauge nickel-plated copper. Three video and two sync and control lines 

are 50-ohm, silver-plated copper PFM coaxial with 22-gauge center conductors. The two 

outer data conductors are 22-gauge, 75-ohm Twisted Shielded Pairs (TSP) of nickel-plated 

copper. The deployable portion of the TUS cable has additional beryllium copper stiffeners 

along its sides. At each end of the TUS cable, the flat cable transitions to a round, rope lay 

design, which is then broken out into three separate leads terminated by connectors 

(power, data, video). Maximum flat cable dimensions are 1.85 in. wide (1.60 in. without 

stiffeners) by .23 in thick. The TUS cable is considered to be an integral part of the reel 

assembly; thus a cable replacement on orbit, if required, may only be in the form of the 

entire reel assembly ORU. 

TUS Cable Guides—The TUS cable guides are located intermittently along the ISS main 

truss structure, mounted on both the nadir and zenith MT rails. The cable guides are 

passive devices that constrain the location of the TUS cable within a predetermined 

corridor as the MT travels along the truss. 

TUS Interface Umbilical Assembly (IUA)—There are two TUS IUAs mounted directly to 

the MT structure near the starboard-nadir and port-zenith corners. The IUAs provide for the 

attachment of the TUS cables to the MT and also for the insertion or removal of the TUS 

cable into or out of the TUS cable guides by means of a guide shoe as the MT translates. 

In addition, each IUA houses a TUS cable cutter assembly and an Impedance Matching 

Unit (IMU). The cable cutter assembly allows for remote disconnection of a TUS cable in a 

contingency situation. In the event of a reel assembly failure or a TUS cable jam, the cable 

cutter can be used to sever the TUS cable, which would allow the MT to safely reach the 

nearest worksite and receive power to prevent freezing hardware. The cut sequence is 

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manually initiated by the IVA MT operator and controlled via the MT software. Power is 

removed from the problem TUS and the cable cutter is powered by the opposite TUS. 

Umbilical Mechanism Assembly (UMA)—The UMA provides the capability to transfer 

USOS power to the MT at specific utility ports located along the main truss structure for 

stationary operation of the SSRMS. The UMA can only be connected to these ports when 

the MT is at one of the 10 MSS worksites. The UMA passes dual 6.0 kW 120V dc power 

feeds to the MBS, SSRMS and any attached payloads. A UMA is comprised of two halves. 

The active half, attached directly to the MT primary structure, contains primary and 

redundant mechanisms to physically drive its power connectors to mate with the fixed, 

passive UMA half, located on the main truss structure at each MSS worksite location. 

There are two active UMA halves on the nadir side of the MT, and each MSS worksite 

contains a pair of corresponding passive UMA halves. The active UMA half can be 

operated using an EVA manual override, if required. 

Remote Power Controller Module (RPCM)—The MT contains two RPCMs mounted on 

its zenith side for distributing USOS power to its various loads. Each RPCM receives 120 V 

dc power from a separate TUS via the TUS IUAs and distributes the power to the MT 

Electrical Power Consuming Equipment (EPCE) under control of MT software. S0 power 

allocation to the MT is 6 kW, which supplies all MT power-consuming components and the 

MT heater network. Power for the TUS reel assemblies is not included in this allocation. 

Load Transfer Unit 

Load Transfer Unit (LTU)—There are four LTUs—one mounted in each corner of the 

MT—for restraining the MSS at any of the various truss worksites. The four LTUs latch to 

hardened fittings at each worksite with holes on the ITS rails to provide a clamping force for 

distribution of the load between the MSS and the rails. 

Linear Drive Unit (LDU)—The LDU provides the MT translation drive force and supports 

the zenith side of the MT during translation. The LDU contains a friction brake system for 

use as a parking brake at the various worksites and as an emergency brake in the event of 

an LDU or MT system failure. 

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Roller Suspension Unit 

Roller Suspension Unit (RSU)—There are two RSUs mounted on the nadir side of the MT 

for restraint and support during MT translation along the truss rails. Each passive RSU 

interfaces to the nadir ITS rail through two sets of plastic wheels supported with springloaded compliance to allow the RSU to cross all rail joints. When the MT is parked at a 

worksite with latched LTUs, the RSUs are effectively suspended and are not part of the 

MSS load path. 

MT/CETA Energy Absorber—The MT contains two MT/Crew and Equipment Translation 

Aid (CETA) energy absorbers, located respectively on its port and starboard sides. These 

ORUs will provide latching and collision energy absorption between the MT and the two 

CETA carts, once they are delivered on Missions 9A and 11A, respectively. Both the port 

and starboard energy absorbers terminate with a passive coupler half that connects to an 

active coupler half on the port or starboard tongue of the respective CETA cart. The active 

coupler half contains the mechanism which allows capture, locking and release of the 

passive half. The coupler is EVA operated, and both energy absorbers will be installed on 

the MT during Mission 8A. 

End Stop Unit (ESU)—The MT also contains two ESUs, located respectively on its port 

and starboard sides. The ESUs interact with MT stops built into the main truss structure to 

prevent the MT from running off the ITS rails in the emergency event of multiple failures 

during MT translation. Each ESU consists of a cylinder and piston and a crushable 

aluminum honeycomb core, which absorbs the energy of an impact so as not to damage 

the MT primary structure or violate the loads at the MT/MBS interface. The ESUs are OnOrbit Maintainable Items (OMI) with a replaceable crush core and are thus intended for 

emergency use only. 

Heaters—Thermal control of the various MT components is provided by a network of 

primary and redundant thermal resistive heaters. All MT heaters are passive, 

thermostatically controlled with no monitoring capability. The heaters are applied in pairs, 

and nominal operation has both heaters operating simultaneously. 

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Mobile Transporter Software 

The MT software controls all functions of the MT and TUS required for translation across 

the ITS and parking at any of the MSS worksites. The software provides for automated or 

manual translation and can automatically detect MT component failures and route the 

failure event data to the operator. 

The Amplifier Orbital Replacement Unit buffers and amplifies data signals 

between the Mobile Transporter and Trailing Umbilical System and between the 

Mobile Remote Servicer and Trailing Umbilical System. 

Software Modes 

The MT software modes are Idle, Standby, Translate and Manual. Idle mode is the default 

mode that results upon powering the external Multiplexer/Demultiplexer, where no data 

input or output occurs with the lower tier MT components. Idle mode also occurs when the 

MT is commanded to shutdown from Standby mode after successfully latching down the 

MT at the worksite. Translate mode is the automated commanding mode used by the MT 

operator to perform automated command, sequencing, and monitoring of MT translation. 

Upon completion or failure of an automated translation sequence between worksites, the 

MT software automatically transitions to Standby mode. Manual mode is the low level mode 

used by the MT operator to perform direct, low-level commands (e.g., manually command 

translation components after an MT sequence failure) or RPCM commands (e.g., to 

override the inhibit and cut the TUS cable after a cable jam or reel assembly failure). 

Manual mode can only be reached by operator command from Standby mode. 

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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.

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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). 

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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 

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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. 

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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. 

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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 

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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. 

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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. 

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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. 

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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. 

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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. 

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STS-110

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. 

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STS-110

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. 

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STS-110

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. 

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STS-110

Acronyms and Abbreviations 

A/L Airlock 

AA Antenna Assembly 

AAA Avionics Air Assembly 

ABC Audio Bus Couplers 

ACBM Active Common Berthing Mechanism 

ACH Assembly Console Handbook 

ACS Assembly Contingency System 

 Atmosphere Control and Supply 

 Attitude Control System 

ACSM Attitude Control System Moding 

ACU Arm Computer Unit 

AD Active Device 

AEA Antenna Electronics Assembly 

AFD Aft Flight Deck 

AOH Assembly Operations Handbook 

APAS Androgynous Peripheral Attachment System 

APCU Assembly Power Converter Unit 

APDS Androgynous Peripheral Docking System 

APFR Articulating Portable Foot Restraint 

APM Attached Pressurized Module 

APPCM Arm Pitch Plane Change Mode 

APS Automated Payload Switch 

AR Atmosphere Revitalization 

ARC Ames Research Center 

ARCU American-to-Russian Converter Unit 

ARR/DPTR Arrival/Departure 

ASCR Assured Safe Crew Return 

ASK Ames Stowage Kit 

ATA Ammonia Tank Assembly 

ATCS Active Thermal Control System 

ATU Audio Terminal Unit 

Audio Thermal Unit 

AUAI Assembly Contingency System / UHF Audio Interface 

AVU Artificial Vision Unit 

BBC Bolt Bus Controller 

BBS Bolt Back Switch 

BC Bus Controller 

BCDU Battery Charge/Discharge Unit 

BCU Bus Controller Unit 

BDU Backup Drive Unit 

BGA Beta Gimbal Assembly 

BIT Built-In Test 

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STS-110

BITE Built-In Test Equipment 

BMRRM Bearing Motor Roll Ring Module 

BMS Bristol-Myers Squibb 

BPS Biomass Production System 

BRS Backup Restraint System 

BSP Baseband Signal Processor 

C&C Command and Control 

C&DH Command and Data Handling 

C&M Control and Monitor 

C&T Communication and Tracking 

C&W Caution and Warning 

C/A-code Coarse/Acquisition-code 

C/L Crew Lock 

CA Control Attitude 

CAB Chamber Access Bay 

CAM Centrifuge Accommodations Module 

CAS Common Attach System 

CBC Common Booster Core 

CBM Common Berthing Mechanism 

CCAA Common Cabin Air Assembly 

CCD Cursor Control Device 

CCS Command and Control Software 

CCTV Closed-Circuit Television 

CDR Commander 

CDRA Carbon Dioxide Removal Assembly 

CDS Command and Data Software 

CETA Crew and Equipment Translation Aid 

CEU Control Electronics Unit 

CGBA Commercial Generic Bioprocessing Apparatus 

CHeCS Crew Health Care System 

CHX Condensing Heat Exchanger 

CI Configuration Item 

CID Circuit Interrupt Device 

CIOB Cargo Integration and Operations Branch 

CIR Cargo Integration Review 

CMB Common Berthing Mechanism 

CMG Control Moment Gyro 

COTS Commercial-Off-the-Shelf 

CO2 Carbon Dioxide (di-molecular) 

CPA Control Panel Assembly 

CPCG-H Commercial Protein Crystal Growth – High Density Protein Growth 

CRIM Commercial Refrigerator Incubator Module 

CRIM-M Commercial Refrigerator Incubator Module - Modified 

CRV Crew Return Vehicle 

CSA Computer Systems Architecture 

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STS-110

CSC Computer Software Component 

CSCI Computer Software Configuration Item 

CTB Crew Transfer Bag 

CTRS Conventional Terrestrial Reference System 

CVIU Common Video Interface Unit 

CVT Current Value Table 

CVV Carbon dioxide Vent/Valve 

CWC Contingency Water Collection 

DAIU Docked Audio Interface Unit 

DAP Double Adapter Plate 

DC Direct Current 

Docking Compartment 

DCAM Diffusion-controlled Crystallization Apparatus for Microgravity 

DCP Display and Control Panel 

DCSU Direct Current Switching Unit 

DDCU DC-to-DC Converter Unit 

DDCU-E DC-to-DC Converter Unit – External 

DMCU Docking Mechanism Control Unit 

DMS-R Data Management System-Russian 

DOF Degrees of Freedom 

DPA Digital Pre-Assembly 

DPS Data Processing System 

DSO Detailed Supplementary Objective 

DTO Detailed Test Objective 

DSM Docking and Stowage Module 

E/D Electrodynamics 

 Engage/Disengage 

E/L Equipment Lock 

E-Stop Emergency Stop 

EACP Extravehicular Audio Control Panel 

EAIU EMU Audio Interface Unit 

EAS Early Ammonia Servicer 

EATCS External Active Thermal Control System 

ECLSS Environmental Control and Life Support System 

ECU Electronics Control Unit 

EDDA EMU Don/Doff Assembly 

EE End Effector 

EEATCS Early External Active Thermal Control System 

EET Experiment Elapsed Time 

EETCS Early External Thermal Control System 

EF Exposed Facility 

EFGF Electrical Flight Grapple Fixture 

EIA Electrical Interface Assembly 

ELM Experimental Logistics Module 

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STS-110

EMU External Maneuvering Unit 

Extravehicular Mobility Unit 

EPG Electrical Power Group 

EPS Electrical Power System 

ERA Electrical Replaceable Assembly 

ES Escape System 

ESP External Stowage Platform 

ESSMDM Enhanced Space Station Multiplexer/Demultiplexer 

ETCS External Thermal Control System 

ETI Elapsed Time Indicator 

ETSD EVA Tool Storage Device 

EUE Experiment Unique Equipment 

EV Extravehicular 

EVA Extravehicular Activity 

EVCPDS Extravehicular Charged Particle Directional Spectrometer 

EVR Extravehicular Robotics 

EVSU External Video Switch Unit 

EVSWS Extravehicular Support Work Station 

EXPRESS Expediting the Process of Experiments to the Space Station 

EXT Experimental Terminal 

FC Firmware Controller 

FCC Flat Collector Circuit 

FCS Fluid Circulation System 

FCV Flow Control Valve 

FD Flight Day 

FDA Fault Detection and Annunciation 

FDIR Failure, Detection, Isolation, and Recovery 

FDS Fire Detection Suppression 

FGB Functional Cargo Block 

FPU Fluid Pumping Unit 

FRGF Flight Releasable Grapple Fixture 

FSEGF Flight Support Equipment Grapple Fixture 

FSS Fluid System Servicer 

FT Fault Tolerant 

GC Growth Cell 

GFE Government Furnished Equipment 

GLONASS Russian Global Navigation Satellite System 

GNC Guidance, Navigation, and Control 

GPC General Purpose Computer 

GPS Global Positioning System 

GUI Graphical User Interface 

HC Hand Controller 

HCU Headset Control Unit 

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STS-110

HCS Humidity Control System 

HDPCG High Density Protein Crystal Growth 

HDR High Data Rate 

HGA High Gain Antenna 

HEC Headset Extension Cable 

HEPA High Efficiency Particulate Air 

HGA High Gain Antenna 

HP Heat Pipe 

HPGT High Pressure Gas Tank 

HRDL High Rank Data Link 

HRFM High Rate Frame Multiplexer 

HRM High Rate Modem 

I/F Interface 

I/O Input/Output 

IAC Internal Audio Controller 

IAS Internal Audio System 

Internal Audio Subsystem 

ICC Integrated Cargo Carrier 

ICM Isothermal Containment Module 

ICS Intersatellite Communication System 

IDA Integrated Diode Assembly 

IEA Integrated Equipment Apparatus 

IFHX Interface Heat Exchanger 

IFM In-Flight Maintenance 

IMCA Integrated Motor Controller Assembly 

IMCS Integrated Mission Control System 

IMV Intermodule Ventilation 

INCO Instrumentation and Communication Officer 

INS Inertial Navigation System 

INT Integrated 

IOCU Input/Output Controller Unit 

IP International Partner 

IRU In-flight Refill Unit 

ISPR International Standard Payload Rack 

ISS International Space Station 

ISSSH International Space Station Systems Handbook 

ITCS Internal Thermal Control System 

ITS Integrated Truss Segment 

IUA Interface Umbilical Assembly 

IV Intravehicular 

IVA Intravehicular Activity 

IVCPDS Intravehicular Charged Particle Directional Spectrometer 

IVSU Internal Video Switch Unit 

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JEM Japanese Experiment Module 

JEU Joint Electronic Unit 

KBAR Knee-Brace Assembly Replacement 

KFT Kennedy Space Center Fixation Tube 

km Kilometer 

KSC Kennedy Space Center 

LA Lab Assembly 

Lab U.S. Laboratory Module 

LAB Lower Avionics Bay 

LAN Local Area Network 

LB Local Bus 

LCA Lab Cradle Assembly 

 Loop Crossover Assembly 

LCD Liquid Crystal Display 

LDA Launch Deployment Assembly 

LDR Low Data Rate 

LDU Linear Drive Unit 

LED Light Emitting Diode 

LEE Latching End Effector 

LFDP Load Fault Detect/Protect 

LGA Low Gain Antenna 

LLA Low-Level Analog 

LTA Launch to Activation 

LTL Low Temperature Loop 

LTU Load Transfer Unit 

LVLH Local Vertical/Local Horizontal 

m Meter 

MA Mechanical Assembly 

MAM Manual Augmented Mode 

MAX Maximum Time Estimate 

MBM Manual Berthing Mechanism 

MBS Mobile Base System 

 Mobile Remote Servicer Base System 

MBSU Main Bus Switching Unit 

MCA Major Constituent Analyzer 

MCC Mission Control Center 

MCC-H Mission Control Center-Houston 

MCC-M Mission Control Center-Moscow 

MCDS Multifunction Cathode Ray Tube Display System 

MCS Motion Control System 

MDL Middeck Locker 

MDM Multiplexer/Demultiplexer 

MELF Metal Electrical Face 

MER Mission Evaluation Room 

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METOX Metal Oxide 

MFCV Manual Flow Control Valve 

MILA Moding Indicator Light Assembly 

MLI Multilayer Insulation 

Mm Millimeter 

MM/OD Micrometeoroid/Orbital Debris 

MOD Mission Operations Directorate 

MPEV Manual Pressure Equalization Valve 

MPLM Minipressurized Logistics Module 

Multipurpose Logistics Module 

MPM/MRL Manipulator Positioning Mechanism/Manipulator Retention Latch 

ms millisecond 

MSD Mass Storage Device 

MSFC Marshall Space Flight Center 

MSS Mobile Servicing System 

MT Mobile Transporter 

MTL Moderate Temperature Loop 

MTS Mobile Tracking Station 

 Module-to-Truss Structure 

MTSAS Module-to-Truss Segment Attach System 

MUP Mission Unique Process 

MWA Maintenance Work Area 

N2 Nitrogen (di-molecular) 

NASA National Aeronautics and Space Administration 

NCS NICMOS Cooling System 

 Node Control Software 

NDS Nutrient Delivery System 

NGTC Next Generation Thermal Carrier 

NIV Nitrogen Isolation Valve 

NTA Nitrogen Tank Assembly 

O2 Oxygen (di-molecular) 

OCA Orbital Communications Adapter 

OCAD Operational Control Agreement Document 

OCJM Operator Commanded Joint Position Mode 

OCPM Operator Commanded Point of Reference Mode 

OCS Operations and Control Software 

ODIN Onboard Data Interfaces and Networks 

ODS Orbiter Docking System 

OIU Orbiter Interface Unit 

OIV Oxygen Isolation Valve 

OPP Orbiter Space Vision System Patch Panel 

OPS Operations 

ORBITEC Orbital Technologies Corporation 

ORCA Oxygen Recharge Compressor Assembly 

ORU Orbital Replacement Unit 

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STS-110

OSE Orbital Support Equipment 

OSO Operations Support Officer 

OSVS Orbiter Space Vision System 

OSVU Orbiter Space Vision Unit 

OTD Orbital Replacement Unit Transfer Device 

P&S Pointing and Support 

P/L Payload 

P-Code Precision Code 

PB Power Bus 

PBA Portable Breathing Apparatus 

PC Personal Computer 

PCA Pressure Control Assembly 

PCAM Protein Crystallization Apparatus for Microgravity 

PCG Protein Crystal Growth 

PCG-STES Protein Crystal Growth, Single-locker Thermal Enclosure System 

PCMCIA Personal Computer Memory Card International Adapter 

PCMMU Pulse Code Master Modulation Unit 

PCN Page Change Notice 

PCP Pressure Control Panel 

PCR Portable Computer Receptacle 

PCS Portable Computer System 

PD Physical Device 

PDGF Power and Data Grapple Fixture 

PDI Payload Data Interface 

PDIP Payload Data Interface Panel 

PDRS Payload Deployment and Retrieval System 

PEHG Payload Ethernet Hub Gateway 

PESTO Photosynthesis Experiment and System Testing and Operations 

PFCS Pump and Flow Control Subassembly 

PFE Portable Fire Extinguisher 

PGSC Payload General Support Computer 

PGT Pistol Grip Tool 

PIHPC Permanent International Human Presence Capability 

PJAM Pre-stored Joint Position Autosequence Mode 

PL Payload 

PLB Payload Bay 

PLS Primary Landing Site 

PMA Pressurized Mating Adapter 

PMCU Power Management Controller Unit 

PMP Payload Mounting Payload 

POR Point of Reference 

 Point of Resolution 

POST Power On Self-Test 

PPA Pump Package Assembly 

PPAM Pre-stored Point of Reference Autosequence Mode 

PPRV Positive Pressure Relief Valve 

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STS-110

PRD Payload Retention Device 

PRLA Payload Retention Latch Assembly 

PS Power Supply 

PSP Payload Signal Processor 

PSRP Payload Safety Review Panel 

PTCS Passive Thermal Control System 

PTT Push-To-Talk 

PTU Pan/Tilt Unit 

PV Photovoltaic 

PVCU Photovoltaic Control Unit 

PVM Photovoltaic Module 

PVRGF Photovoltaic Radiator Grapple Fixture 

PWP Portable Work Platform 

PWR Portable Water Reservoir 

QD Quick Disconnect 

R&R Remove and Replace 

R/P Receiver/Processor 

RACU Russian-to-American Conversion Unit 

RAIU Russian Audio Interface Unit 

RAM Random Access Memory 

RAMV Rheostat Air Mix Valve 

RBI Remote Bus Isolation 

RCU Remote Control Unit 

RF Radio Frequency 

RFCA Rack Flow Control Assembly 

RFG Radio Frequency Group 

RGA Rate Gyro Assembly 

RHC Rotational Hand Controller 

RHX Regenerative Heat Exchanger 

RIC Rack Interface Controller 

RJAM Prestored Joint Position Autosequence Mode 

RM Research Module 

RMS Remote Manipulator System 

ROS Russian Orbital Segment 

RPC Remote Power Controller 

RPCM Remote Power Control Module 

RPDA Remote Power Distribution Assembly 

RS Russian Segment 

RSA Russian Space Agency 

RSP Resupply Stowage Platform 

RSR Resupply Stowage Rack 

RSU Roller Suspension Unit 

RT Remote Terminal 

RTL Ready to Latch 

RU Rigid Umbilical 

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RWS Robotic Workstation 

S0 Starboard Zero 

SA Solar Array 

SABB Solar Array Blanket Box 

SASA S-band Antenna Support Assembly 

SAW Solar Array Wing 

SCA Switchgear Controller Assembly 

SCU Service and Cooling Umbilical 

Sync and Control Unit 

 Signal Conditioning Unit 

SD Smoke Detector 

SDMS Structural Dynamics Measurement System 

SDO Solenoid Driver Input 

SDS Sample Delivery System 

SFA Sunfinder Assembly 

SFCA System Flow Control Assembly 

SGANT Space-to-Ground Antenna 

SHOSS SpaceHab Oceaneering Space System 

SIGI Space Integrated Global Positioning System/Inertial Navigation System 

SJRM Single Joint Rate Mode 

SLP Spacelab Pallet 

SM Service Module 

SMCC Shuttle Mission Control Center 

SMTC Service Module Terminal Computer 

SOC State of Charge 

SPCE Servicing Performance and Checkout Equipment 

SPEC Specified 

SPD Serial Parallel Digital 

SPDA Secondary Power Distribution Assembly 

SPDC Secondary Power Distribution Control 

SPDM Special Purpose Dexterous Manipulator 

SPP Science Power Platform 

SRMS Shuttle Remote Manipulator System 

SSAS Segment-to-Segment Attachment System 

SSBRP Space Station Biological Research Project 

SSC Station Support Computer 

 Subsystem Computer 

SSMDM Space Station Multiplexer/Demultiplexer 

SSOR Space-to-Space Orbiter Radio 

SSP Space Shuttle Program 

 Standard Switch Panel 

SSRMS Space Station Remote Manipulator System 

SSSR Space-to-Space Station Radio 

SSU Sequential Shunt Unit 

SVS Synthetic Vision System 

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TA Thruster Assist 

TC Terminal Computer 

TCS Thermal Control System 

TCCS Trace Contaminant Control Subassembly 

TCCV Temperature Control and Check Valve 

TD Translation Drive 

TDRS Tracking and Data Relay Satellite 

TDRSS Tracking and Data Relay Satellite System 

TEPC Tissue Equivalent Proportional Counter 

THC Translational Hand Controller 

Temperature and Humidity Control 

THOR Thermal Operations and Resources 

TORU Teleoperator Control Mode 

TRC Transmitter Receiver Controller 

TRRJ Thermal Radiator Rotary Joint 

TSA Tool Storage Assembly 

TUS Trailing Umbilical System 

TV Television 

TVIS Treadmill Vibration Isolation and Stabilization 

UAB Upper Avionics Bay 

UB User Bus 

UDG User Data Generation 

UDM Universal Docking Module 

UF Utilization Flight 

UHF Ultra High Frequency 

UIA Umbilical Interface Assembly 

UIP Utility Interface Panel 

ULC Unpressurized Logistic Carrier 

ULCAS Unpressurized Logistic Carrier Attach System 

UMA Umbilical Mechanism Assembly 

UOP Utility Outlet Panel 

URL Uniform Resource Locator 

USA United Space Alliance 

USOS United States On-Orbit Segment 

USS United States Segment 

VAJ Vacuum Access Jumper 

VBSP Video Baseband Signal Processor 

VDA-2 Vapor Diffusion Apparatus – Second Generation 

VDS Video Distribution System 

VDU Video Distribution Unit 

VES Vacuum Exhaust System 

VGS Video Graphics Software 

VPMP Vented Payload Mounting Panel 

VRCS Vernier Reaction Control System 

VRCV Vent/Relief Control Valve 

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VRIV Vent/Relief Isolation Valve 

VRS Vacuum Resource System 

VRV Vent/Relief Valve 

VSC Video Signal Controller 

VSU Video Switch Unit 

VSW Video Switch 

VTR Video Tape Recorder 

WHS Workstation Host Software 

WRM Water Recovery and Management 

WS Water Separator 

WVA Water Vent Assembly 

WVS Wireless Video System 

XCF X-ray Crystallography Facility 

ZSR Zero-g Stowage Rack 

RUSSIAN Acronyms and Abbreviations 

АСА-Г Active/Hybrid Docking Assembly 

АСП-Б Passive Docking Assembly 

АСПП Androgynous Peripheral Docking System (APDS) 

ГА Pressurized Adapter 

ПГО Instrumentation Cargo Compartment 

ПГО1 Instrument Module 1 

ПГО2 Instrument Module 2 

ПГО3 Instrument Module 3 

ПрК Transfer Tunnel 

ПхО Transfer Compartment 

РО Working Compartment 

 

TOPY Teleoperator Control Mode 

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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, Fla.; Marshall Space Flight Center, 

Huntsville, Ala.; Dryden Flight Research Center, Edwards, Calif.; Johnson Space Center, 

Houston, Texas; 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 news center. 

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

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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. 

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Media Contacts 

Dwayne Brown 

NASA Headquarters 

Washington 

Dwayne.brown@hq.nasa.gov

Space Shuttle/Space Station Policy 

202-358-1726 

Debbie Rahn 

NASA Headquarters 

Washington 

Debbie.rahn@hq.nasa.gov

International Partners 

202-358-1638 

Donald Savage 

NASA Headquarters 

Washington 

donald.savage@hq.nasa.gov

Space Science Policy, Budget 

202-358-1727 

Eileen Hawley 

Johnson Space Center 

Houston 

Eileen.hawley1@jsc.nasa.gov

Astronauts/Mission Operations 

281-483-5111 

George Diller 

Kennedy Space Center 

Kennedy Space Center, Fla. 

George.Diller-1@ksc.nasa.gov

Space Shuttle Launch Operations 

321-867-2468 

Bruce Buckingham 

Kennedy Space Center 

Kennedy Space Center, Fla. 

Bruce.Buckingham-1@kmail.ksc.nasa.gov

Launch Operations 

321-867-2468 

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Kari Kelley Allen 

The Boeing Company 

Houston 

Kari.k.allen@boeing.com

International Space Station 

281-226-4844 

Glen Golightly 

The Boeing Company 

Huntington Beach, Calif. 

Robert.g.golightly@boeing.com 

Space Shuttle 

714-372-4742 

Dan Beck 

Boeing Rocketdyne 

Canoga Park, Calif. 

Daniel.c.beck@boeing.com

Space Shuttle Main Engines 

818-586-4572 

Jack King 

United Space Alliance 

Kennedy Space Center, Fla. 

KingJW@usafoo.unitedspacealliance.com

Shuttle Processing 

321-861-4358 

Dave Drachlis 

Marshall Space Flight Center 

Huntsville, Ala. 

Dave.Drachlis@msfc.nasa.gov

Space Shuttle 

256-544-0034 

94