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Updated April 7, 2000

ATLANTIS

VISITS

INTERNATIONAL SPACE STATION

STS-101
STS-101 Table of Contents

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

Mission Index ..............................................................................................................................5

Crew................................................................................................................................................8

Orbiter Upgrades ...................................................................................................................... 11

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

EVAs

STS-101 EVA ................................................................................................................................. 16

Payloads

BioTube Precursor Experiment ......................................................................................................... 20

HTD 1403 Micro Wireless Instrumentation System (Micro WIS)

 HEDS Technology Demonstration .................................................................................................. 23

Integrated Cargo Carrier ................................................................................................................... 25

Logistics & Hardware Transfer .......................................................................................................... 27

Mission to America's Remarkable Schools ........................................................................................ 32

Space Experiment Module 6 ............................................................................................................. 34

SPACEHAB .................................................................................................................................... 38

Experiments 

Biotechnology Ambient Generic (PCG-BAG) ...................................................................................... 42

Commercial Protein Crystal Growth ................................................................................................... 44

Gene Transfer Experiment using ASTROCULTURETM Glove Box (ASC-GB) ......................................... 46

DTO/DSO/RME

DTO 493 Monitoring Latent Virus Reactivation and Shedding in Astronauts ........................................... 48

DTO 498 Space Flight and Immune Function ..................................................................................... 49

DTO 623 Cabin Air Monitoring ........................................................................................................... 50

DTO 805 Crosswind Landing Performance ......................................................................................... 51

DTO 700-21 SIGI Orbital Attitude Readiness ...................................................................................... 52

DTO 700-14 Single-String Global Positioning System ......................................................................... 53

DTO 847 Solid-State Star Tracker Size Limitations ............................................................................. 54
Shuttle Reference and Data 

Shuttle Abort Modes ........................................................................................................................ 55

Space Shuttle External Tank ............................................................................................................ 60

Space Shuttle Rendezvous Maneuvers .............................................................................................. 63

Space Shuttle Solid Rocket Boosters ................................................................................................ 64

Space Shuttle Super-Lightweight Tank (SLWT) .................................................................................. 72

Media Assistance ....................................................................................................................73

Contacts ....................................................................................................................................75
STS-101

Mission Overview

The development of the International Space Station (ISS) will continue 

during NASA's second shuttle flight of the year when Atlantis is launched on 

the STS-101 mission, the 98th flight in Shuttle program history.

Outfitted with a new "glass cockpit" and other state-of-the-art upgrades to 

key systems, Atlantis is scheduled to be launched from Complex 39-A at the 

Kennedy Space Center approximately 4:15 P.M. EDT April 24 at the start of 

a window of no longer than 10 minutes in duration. The precise launch time 

and duration of the launch opportunity will be narrowed within a week before 

the start of the mission to provide the best time for Atlantis to begin its twoday chase to catch up to the ISS. Atlantis last flew in space in support of the 

STS-86 mission in 1997. On STS-101, Atlantis will fly as the most updated 

Space Shuttle ever, with more than 100 new modifications incorporated 

during a 10-month period at Boeing's Palmdale, California Shuttle factory in 

1998.

Seven astronauts, led by veteran Commander Jim Halsell (Col., USAF), will 

link up to the international outpost two days after launch and will spend six 

days docked to the ISS, four of which will be spent refurbishing and 

replacing components in both the Zarya and Unity modules. Two crew 

members will perform a six and a half hour space walk the day after docking 

to install a Russian "Strela" cargo boom on the outside of Zarya, as well as 

replace a faulty radio antenna associated with the early communications 

system on Unity and perform several other tasks in advance of space walks 

on future station assembly missions.

Halsell, who is making his fifth flight into space and third as a Commander, 

will be joined by veteran Pilot Scott Horowitz (Lt. Col., USAF), who is making 

his third flight. 

Mission Specialists include Dr. Mary Ellen Weber, making her second flight, 

Jeff Williams (Lt. Col., USA), making his first trip into space, Jim Voss (Col., 

USA, ret.), embarking on his fourth flight, Susan Helms (Col., USAF), 

making her fourth flight, and veteran Russian cosmonaut Yuri Usachev, who 

is making his third flight into space and who has logged 376 days in space 

and six space walks during two previous missions aboard the Mir Space 

Station. Usachev and fellow cosmonaut Yuri Onufrienko hosted astronaut 

Shannon Lucid during Usachev's second flight on the Mir. Lucid went on to 

set a U.S. single spaceflight endurance mark of 188 days on that mission.

1
Usachev, Voss and Helms will return to the ISS next year as the second 

crew to live and work aboard the station. Permanent occupancy of the ISS is 

scheduled to begin in the fall by the Expedition One crew, William Shepherd, 

Yuri Gidzenko and Sergei Krikalev, who will be launched on a Russian 

Soyuz rocket from the Baikonur Cosmodrome in Kazakhstan.

Williams and Voss are the two space walkers during Atlantis' planned 10-

day flight. Williams, who has no previous space walk experience, will carry 

the designation of EV 1 during the planned excursion outside Atlantis and 

will wear the suit marked with red stripes on the elbows and the knees. Voss 

will be designated EV 2 and will wear the pure white suit. He conducted one 

previous space walk during the STS-69 mission in 1995 lasting almost 

seven hours.

The STS-101 mission originally was designed to follow the launch of the 

Zvezda Service Module as the flight to outfit the Russian component as the 

early living quarters for crews aboard the ISS. When Zvezda's launch was 

delayed, Shuttle and Station managers agreed to fly Atlantis on two 

separate flights to the station this year, STS-101 to conduct maintenance 

and logistics work aboard the ISS in advance of Zvezda's arrival, and STS106, to unload supplies onto Zvezda from both the Shuttle and a Russian 

Progress resupply vehicle. STS-106 is scheduled for launch in August, 

about five weeks after Zvezda's planned July launch on a Proton rocket from 

Baikonur.

The top priority of the docked phase of the mission is to replace four of six 

800-ampere power-producing batteries in Zarya which are no longer 

operable, and its associated electronics for proper current regulation.

Zarya will receive additional new equipment including four cooling fans, 

three fire extinguishers, 10 smoke detectors and an on-board computer. A 

suspect radio frequency power distribution box (RFPDB) in Unity used as 

part of the early S-band communications system will be replaced during the 

time Atlantis is linked to the new international facility.

The crew plans to transfer almost one ton of equipment from a double 

Spacehab module housed at the rear of Atlantis' cargo bay into Zarya and 

Unity for use by the Expedition One crew later this year. Those logistical 

items include personal clothing and hygiene gear, medical and exercise 

equipment, computer equipment and printers, hardware for the eventual 

setup and activation of the station's Ku-band communications system and a 

centerline camera for Unity's common berthing mechanisms to which other 

ISS components will be mated. Four large bags of water will also be brought 

from Atlantis into the ISS for later use.

2
The cost for all of the hardware and logistical supplies being carried to the 

Station is approximately $1.5 million. Slightly more than $1.3 million of that 

total cost will be assumed by Russia for new or replacement Russian 

hardware, while the portion for new and or replacement U.S. hardware is

$162,000. 

The next mission to expand the capacity of the International Space Station, 

will be the launch of the Zvezda Service Module in mid-July.

Adjustments to the official near term assembly sequence were agreed to by 

the International Partners and participants at a recent Space Station Control 

Board meeting. Representatives included the United States, Russia, 

Canada, Japan, the European Space Agency, Italy and Brazil.

The following is the updated near term assembly sequence through August 

2001 with the no-earlier-than target launch dates. The complete assembly 

sequence can be viewed on NASA's Human Spaceflight Website at: 

http://spaceflight.nasa.gov/station/assembly/flights/chron.html

International Space Station Assembly Sequence March 2000 Update

3
Date Flight Launch Vehicle Element(s)

Nov 20, 1998 1A/R Russian Proton 'Zarya' Control Module

Dec 3, 1998 2A Space Shuttle 

(STS-88)

'Unity' Connecting Module

May 27, 1999 2A.1 Space Shuttle 

(STS-96)

Spacehab - Logistics Flight

April 13, 2000 2A.2A Space Shuttle 

(STS-101)

Spacehab - Maintenance Flt.

July 8-14, 2000 1R Russian Proton 'Zvezda' service module

Aug 19, 2000 2A.2B Space Shuttle 

(STS-106)

Spacehab - Logistics Flight

Sept 21, 2000 3A Space Shuttle 

(STS-92)

Integrated Truss Structure

(ITS) Z1; Pressurized Mating Adapter3; Control Moment

Gyros (CMGs)

Oct 30, 2000 2R Russian Soyuz Expedition 1 Crew launch

Nov 30, 2000 4A Space Shuttle 

(STS-97)

Integrated Truss Structure(P6)

Photovoltaic Module;Radiators

Jan 18, 2001 5A Space Shuttle 

(STS-98)

'Destiny' laboratory module

Feb 9, 2001 4R Russian Soyuz Docking Compartment

Feb 15, 2001 5A.1 Space Shuttle 

(STS-102)

'Leonardo' Multi-Purpose Logistics 

Module (MPLM)

Apr 19, 2001 6A Space Shuttle 

(STS-100)

'Rafaello' MPLM

Station Remote Manipulator System

Apr 30, 2001 2S Russian Soyuz Soyuz spacecraft swap

May 17, 2001 7A Space Shuttle 

(STS-104)

Airlock

June 21, 2001 7A.1 Space Shuttle 

(STS-105)

'Donatello' MPLM

Aug 23, 2001 UF-1 Space Shuttle 

(STS-109)

First utilization flight

If all goes as planned, Atlantis will conclude its mission at approximately 

12:50 P.M. EDT on May 4 with a touchdown at the Shuttle Landing Facility 

at the Kennedy Space Center.

Updated: 04/06/2000

4
STS-101

Atlantis OV104

Launch: Monday, April 24, 2000 

 4:15 PM (eastern time)

Mission Objectives

A categorical priority system is used to guide the ordering of key operations 

tasks and places the highest value on ensuring crew safety. The priorities 

for STS-101/2A.2a are:

1. ISS ingress/safety 

- Take air samples

- Monitor carbon dioxide

- Deploy portable, personal fans

- Measure air flow

- Rework/modify ISS ducting

- Replace air filters

- Replace Zarya fire extinguishers, smoke detectors

2. Critical replacements/repairs/spares

- Replace four suspect batteries on Zarya

- Replaced failed or suspect electronics for Zarya's batteries

- Replace Radio Telemetry System memory unit

- Replace port early communications antenna

- Replace Radio Frequency Power Distribution Box

- Clear Space Vision System target 

3. Incremental assembly/upgrades

- Complete assembly of Strela crane

- Install additional exterior handrails

- Set up center-line camera cable

- Install "Komparus" cable inserts

- Reseat the U.S. crane

4. Assembly parts & equipment

- Transfer U.S. hardware 

- Transfer Russian hardware

- Provide EVA tools

- Supply IVA kit 
5. Pre-position/stow equipment & provisions for future missions

6. Resupply

- Water and water transfer, stowage equipment

- Docking mechanism accessory kit

- Film and video tape for documentation

- Office supplies

- Personal items

7. Crew health maintenance

- Exercise equipment

- Medical support supplies

- Formaldehyde monitor kit

- Passive dosimetry system

8. Detailed test objectives

- Monitor cabin air

- SOAR

Options

If there is sufficient shuttle propellant following Atlantis' undocking from the 

ISS, a flyaround inspection will be performed prior to the Shuttle's final 

separation maneuver.

Crew

Commander: James D. Halsell

Pilot: Scott J. Horowitz

Mission Specialist 1: Mary Ellen Weber

Mission Specialist 2: Jeffrey N. Williams

Mission Specialist 3: James S. Voss

Mission Specialist 4: Susan J. Helms

Mission Specialist 5: Yuri V. Usachev

Launch

Orbiter: Atlantis OV104

Launch Site: Kennedy Space Center Launch Pad 39A

Launch Window: 5 minutes

Altitude: 173 Nautical Miles

Inclination: 51.6 Degrees

Duration: 9 Days 20 Hrs. 36 Min.
Vehicle Data

Shuttle Liftoff Weight: 4519492 lbs.

Orbiter/Payload Liftoff Weight: 262565 lbs.

Orbiter/Payload Landing Weight: 224504 lbs.

Payload Weights

ICC 3,700 pounds

MARS 270 lb

Software Version: OI-27

Space Shuttle Main Engines

SSME 1: 2043 SSME 2: 2054 SSME 3: 2049

External Tank: ET-102

SRB Set: BI-100/RSRM-74

Shuttle Aborts

Abort Landing Sites

 RTLS: Kennedy Space Center Shuttle Landing Facility

 TAL: Zaragoza

 AOA: Edwards Air Force Base, California

Landing

Landing Date: 05/04/00

Landing Time: 12:50 PM (eastern time)

Primary Landing Site: Kennedy Space Center Shuttle Landing Facility

Payloads

Cargo Bay

BioTube Precursor Experiment

SPACEHAB

Integrated Cargo Carrier

Mission to America's Remarkable Schools

Space Experiment Module 6

In-Cabin

HTD 1403 Micro Wireless Instrumentation System (Micro WIS) HEDS Technology 

Demonstration
STS-101

Crew Profile Menu 

Commander: James D. Halsell

Jim Halsell (Col., USAF) is Commander for STS-101. Halsell will be 

responsible for overall mission success and safety during STS-101, 

as well as the rendezvous and docking of Atlantis to the 

 International Space Station.

Halsell, 43, is making his fifth flight into space, having previously 

 flown as Pilot on STS-65 in 1994 and STS-74 in 1995 and as 

Commander of STS-83 and 94 in 1997. 

Ascent Seating: Flight Deck - Port Forward

Entry Seating: Flight Deck - Port Forward

Pilot: Scott J. Horowitz

Scott Horowitz (Lt. Col., USAF) is Pilot for STS-101. 

Horowitz will be the intravehicular crew member during the space walk 

by Jeff Williams and Jim Voss during the flight, responsible for the 

choreography of the 6 1⁄2 hour excursion outside Atlantis. 

Horowitz will also help in the replacement of some of the equipment in 

the Unity module on the ISS and the inspection and installation of 

other systems in the Zarya module.

Horowitz, 43, is making his third flight into space after serving as Pilot on STS-75 in 1996 

and STS-82 in 1997.

Ascent Seating: Flight Deck - Starboard Forward

Entry Seating: Flight Deck - Starboard Forward

IV1

Mission Specialist 1: Mary Ellen Weber

Dr. Mary Ellen Weber, 37, is Mission Specialist 1 during the STS-101 

mission. 

Weber will be responsible for the transfer of logistics items from 

Atlantis to the International Space Station during the flight and will 

operate the Shuttle's robot arm during the space walk by Jeff Williams 

and Jim Voss. 

Weber will ride upstairs on Atlantis' flight deck for both launch and landing and will be 

responsible for Spacehab systems for the cargo carrier housed in Atlantis' payload bay.

Weber previously flew on the STS-70 mission in 1995.

Ascent Seating: Flight Deck - Starboard Aft

Entry Seating: Flight Deck - Starboard Aft

RMS

8
Mission Specialist 2: Jeffrey N. Williams

Jeff Williams (Lt. Col., USA) will serve as Atlantis' flight engineer 

 during STS-101, which will be his first flight into space. 

Williams, 42, who will be designated Mission Specialist 2, will be the 

lead space walker (EV 1) during the excursion he and Jim Voss will 

conduct to work on the International Space Station. He will wear the 

suit with the red stripes on the arms and knees of his space suit.

During the docked phase of the flight, Williams will transfer batteries 

and other electronics equipment into the Zarya module for installation as well as other 

logistics items.

Ascent Seating: Flight Deck - Center Aft

Entry Seating: Flight Deck - Center Aft

EV1

Mission Specialist 3: James S. Voss

Jim Voss (Col., USA, ret.) will make his fourth flight into space as 

Mission Specialist 3 during STS-101. He is also a member of the 

Expedition Two crew, which will be launched in 2001 for a three to four 

month stay aboard the International Space Station. 

Voss, who conducted one space walk on STS-69, will join Jeff Williams 

as EV 2 for the 6 1⁄2 hour space walk during STS-101 to work on the 

International Space Station. He will wear the pure white space suit.

Voss will also be responsible for air quality measures inside the ISS during docked 

operations and the replacement of equipment inside the Unity module. He will ride 

downstairs in Atlantis' middeck during launch and landing.

Voss, 51, previously flew on STS-44 in 1991, STS-53 in 1992 and STS-69 in 1995.

Ascent Seating: Mid Deck - Port

Entry Seating: Mid Deck - Port

EV2

Mission Specialist 4: Susan J. Helms

Susan Helms (Lt. Col., USAF), will make her fourth flight into space 

 as Mission Specialist 4 during STS-101. 

Helms, 42, is also a member of the Expedition Two crew, which will 

be launched in 2001 for a 3-4 month stay aboard the International 

Space Station. During STS-101, Helms will help conduct the 

replacement of a battery and associated electronic equipment in the 

Zarya module and will replace and inspect other equipment in both 

Zarya and the Unity module. 

She will ride downstairs in Atlantis' middeck during launch and landing.

Ascent Seating: Mid Deck - Center

Entry Seating: Mid Deck - Center

9
Updated: 03/27/2000

Mission Specialist 5: Yuri V. Usachev

Yuri Usachev, 42, will serve as Mission Specialist 5 during STS-101. 

The veteran Russian cosmonaut has spent 376 days in space and 

 has conducted six space walks during two long duration missions 

aboard the Mir Space Station. 

Usachev will serve as the Commander of the Expedition Two crew 

 along with Jim Voss and Susan Helms, which is scheduled for launch 

in 2001 for a 3-4 month stay on the International Space Station. 

On STS-101, Usachev will be responsible for the replacement of a battery and associated 

electronic equipment in the Zarya module and will help replace and inspect other equipment 

in both Zarya and the Unity module. Usachev will join Helms and Voss downstairs in Atlantis' 

middeck for both launch and landing.

Ascent Seating: Mid Deck - Starboard

Entry Seating: Mid Deck - Starboard

10
STS-101

Shuttle Reference and Data

Orbiter Upgrades

The 21st Century Space Shuttle: New Improvements

The space shuttle has undergone significant changes. From the inside out, 

thousands of advances in technology and enhanced designs have been 

incorporated into the shuttle since it was first launched. The result is a safer, 

more powerful and more efficient spacecraft. When the shuttle Atlantis 

launches on STS-101, it will be the most up-to-date space shuttle ever. 

From a new "glass cockpit" to main engines estimated to be three times 

safer, Atlantis is a far different vehicle from the one that first flew in 1985.

This year also will see the 100th space shuttle launch in history, a milestone 

for a spacecraft that has taken over 600 passengers and three million 

pounds of cargo to orbit. The shuttle fleet has spent almost two and a half 

years in space. But even the most-traveled shuttles remain young in the 

lifespan for which they were built. NASA is preparing for the possibility of 

flying the space shuttle for at least another decade, and future 

improvements are geared toward a goal of doubling shuttle safety by the 

year 2005.

The New "Glass Cockpit"

For the first time, on mission STS-101, 11 new full-color, flat-panel display 

screens in Atlantis's cockpit will replace 32 gauges and electromechanical 

displays and four cathode-ray tube displays. This new "glass cockpit," 

technically labeled the Multifunction Electronic Display Subsystem (MEDS), 

is 75 pounds lighter and uses less power than before; and its color displays 

facilitate pilot recognition of key functions. The new cockpit will be installed 

in all shuttles by 2002, setting the stage for the next cockpit improvement 

planned for 2005: a "smart cockpit" that reduces pilot workload during critical 

periods. 

On STS-101, Atlantis will fly with more than 100 new modifications 

incorporated during a 10-month period at Boeing's Palmdale, Calif., facility 

in 1998. The airlock was relocated to the payload bay to prepare for 

International Space Station assembly flights; the communications system 

was updated; several weight reduction measures were installed; 

enhancements were made to add protection to the cooling system; and the 

crew cabin floor was strengthened. The shuttle Columbia is at the Palmdale 

factory this year receiving many of the same upgrades, including installation 

of the new "glass cockpit."

11
Future Shuttle Upgrades: Cutting Risk in Half by 2005

Enhancements now under development could double the shuttle's safety by 

2005. New sensors and computer power in the main engines will "see" 

trouble coming a split second before it can do harm, allowing a safe engine 

shutdown. A new engine nozzle will eliminate the need for hundreds of 

welds and potential leaks. Electric generators for the shuttle's hydraulics will 

replace the highly volatile rocket fuel that now powers the system. And a 

next-generation "smart cockpit" will reduce the pilot's workload in an 

emergency, allowing the crew to better focus on critical tasks. Other 

improvements will make steering systems for the solid rocket boosters more 

reliable, make the manufacturing of solid propellant safer and increase the 

strength of external fuel tank welds.

"Smart Cockpit"--The new "glass cockpit" that will be initiated when Atlantis 

launches on STS-101 is the precursor of the "smart cockpit" planned for 

2005. The enhanced displays of the "smart cockpit" will not fly the shuttle, 

but they will do much of the deductive reasoning required for a pilot to 

respond to a problem. By simplifying the pilot's job, this "smart cockpit" will 

allow astronauts to better focus on critical tasks in an emergency.

Better Main Engines--The space shuttle's main engines operate at greater 

extremes of temperature and pressure than any other machine. Since 1981, 

three overhauls of the original design have more than tripled estimates of 

their safety. Now, a fourth major overhaul will make them even safer by 

2005. Planned improvements include a high-tech optical and vibration 

sensor system and computing power in the engines that detects trouble in 

advance. This advanced health monitoring system has sensors that will 

detect and track an almost microscopic flaw in an engine's performance in a 

split second, allowing the engine to be safely shut down before the situation 

can grow out of control. Also, the engine's main combustion chamber will be 

enlarged to reduce the pressures on internal components without reducing 

the thrust; and a new, simplified engine nozzle design will eliminate 

hundreds of welds--over 500 feet of them--and potential leaks.

Safer Hydraulic Power--Aside from the main engines and solid rocket 

boosters, the single highest risk shuttle subsystems are the auxiliary power 

units, generators that power the hydraulic systems. Today, these generators 

use a highly volatile and toxic rocket fuel. But recent advances in battery 

and electrical power technology--much of which was developed by the 

automotive industry--will replace that system by 2005, eliminating many 

hazards not only in flight but also on the ground. Electric motors, powered 

by a bank of lightweight batteries, will be developed to power the shuttle's 

hydraulic system, providing greater reliability for astronauts in flight and a 

safer workplace for ground crews.

Solid Rocket Boosters and External Tank Upgrades--Future improvements 

for the solid rocket boosters include a redesign of several valves, filters and 

seals in the steering system to enhance their reliability as well as studies of 

12
the potential for an electrical system to power the booster hydraulics. In 

addition, changes in the solid rocket propellant manufacturing process will 

make the workplace safer for shuttle technicians. For the external tank, a 

new friction-stir welding technique will produce stronger and more durable 

welds throughout the structure.

Major Space Shuttle Improvements: A Brief History

April 1983, STS-6: A Lighter Fuel Tank--A redesigned lightweight external 

tank, 10,000 pounds lighter than the original design, flew on STS-6 in 1983, 

increasing the shuttle's cargo capacity by the same amount. In 1998, a 

super-lightweight external tank flew on STS-91, further reducing the tank's 

weight by 7,500 pounds and again increasing the shuttle's cargo capacity by 

the same amount. The super- lightweight tank is made of a Lockheed 

Martin-developed aluminum-lithium alloy that is not only lighter but also 30 

percent stronger than the previous tank design.

September 1988, STS-26: Return to Flight--When Discovery returned the 

shuttle fleet to space following the Challenger accident, more than 200 

safety improvements and modifications had been made. They included a 

major redesign of the solid rockets boosters, the addition of a crew escape 

and bailout system, stronger landing gear, more powerful flight control 

computers, updated inertial navigation equipment and several updated 

avionics units.

May 1992, STS-49: Endeavour's Maiden Voyage--Endeavour's first flight in 

1992 was the debut of many shuttle improvements, including a drag chute to 

assist braking during landing, improved nosewheel steering, lighter and 

more reliable hydraulic power units, and updates to a variety of avionics 

equipment.

June 1992, STS-50: Extended-Duration Flights--Columbia was the first 

shuttle to be modified for allow long-duration flights and flew the first such 

mission in 1992. The modifications included an improved toilet, a 

regenerative system to remove carbon dioxide from the air, connections for 

a pallet of additional hydrogen and oxygen tanks to be mounted in the cargo 

bay, and extra stowage room in the crew cabin.

June 1995, STS-71: International Space Station Assembly--The first 

shuttle/Mir docking mission featured new shuttle changes that allowed it to 

dock with the Russian space station and prepare for assembly of the 

International Space Station. For the shuttle to dock with Mir and ISS, the 

airlock had to be moved from inside the cabin to the cargo bay on all orbiters 

except Columbia. Weight was also reduced through lightweight lockers, 

seats and other cabin equipment. Those changes, coupled with the superlightweight external tank and performance improvements, increased the 

shuttle's cargo capacity by 16,000 pounds since 1992.

13
July 1995, STS-70: Space Shuttle Main Engines--Three major redesigns 

have more than tripled estimates of shuttle main engine safety. The first 

redesign (called the Block I engine), first flown in 1995, included changes to 

strengthen the oxygen turbopump and engine powerhead. The second 

overhaul, called the Block IIA engine, included a larger throat in main 

combustion chamber and first flew on STS-89 in January 1998. The third 

redesign, called the Block II engine, includes a stronger fuel turbopump and 

will fly for the first time in 2000. A fourth major overhaul is now planned to fly 

by 2005. Called the Block III engine, it will include further improvement of 

the combustion chamber and a simplified nozzle design.

Today's Space Shuttle--Since 1992, not only has the cargo capacity of the 

shuttle increased by 8 tons, the annual cost of operating the shuttle has 

decreased by 40 percent. Improvements in the main engines and other 

systems have reduced the estimated risks during launch by over 80 percent. 

And the number of all actual problems experienced by the shuttle in flight 

has decreased by 70 percent. Although they have flown for almost 20 years, 

the space shuttle orbiters have used only about a quarter of the lifetime for 

which they was designed. Discovery, which has flown the most missions, 

has completed 27 trips to space out of the 100 flights that all the shuttles 

were originally designed to complete.

Updated: 04/06/2000

14
STS-101

Flight Day Summary 

DATE TIME (EST) DAY MET EVENT

04/24/00 4:14:50 PM 0 000/00:00:00 Launch

04/26/00 9:08:30 AM 3 001/16:53:40 ISS Docking

04/27/00 7:49:50 AM 4 002/15:35:00 EVA 1 Begins

04/28/00 6:14:50 AM 5 003/14:00:00 ISS Ingress Begins

04/29/00 4:44:50 AM 4 004/12:30:00 Reboost Begins

05/01/00 9:29:50 AM 8 006/17:15:00 ISS Egress Begins

05/02/00 3:59:19 AM 9 007/11:44:29 ISS Undock

05/04/00 11:46:25 AM 11 009/19:31:35 Deorbit Tig

05/04/00 12:50:50 PM 11 009/20:36:00 KSC Landing

Updated: 04/05/2000

15
STS-101

EVAs

STS-101 EVA

Overview

Mission Specialists James Voss and Jeffrey N. Williams will emerge from 

Space Shuttle Atlantis on Flight Day 4 of the second logistics mission to the 

International Space Station and make the last planned equipment changes 

prior to the arrival of the ISS's third element, Russia's Service Module 

Zvezda.

During the planned 6 1/2 hour space walk, they will complete the assembly 

of a Russian crane, test the integrity of a U.S. crane, replace a faulty 

communications antenna, install handrails, set up a camera cable and thus 

make ready for Zvezda's launch scheduled between July 8-14.

Mission Specialist Mary Ellen Weber will assist the two astronauts in 

maneuvering around the ISS as she operates the shuttle's robotic arm from 

inside Atlantis.

When Voss and Williams step from Atlantis' airlock, their first job will be to 

set up the foot restraints, tethers and other gear essential for safely 

executing activities in space. Then they can go to work.

First they will head to a workstation fixture on pressurized mating adapter 

(PMA) -1, the passageway connecting U.S. module Unity and Russian-built 

control module Zarya. The objects of their attention will be the fixture itself 

and a small, 209-pound U.S. space-walker-operated crane. Mission 

Specialists Tamara E. Jernigan and Daniel T. Barry placed it there during 

the first logistics mission (May 27-June 6, 1999: STS-96/2A.1). 

16
Astronaut Tamara E. Jernigan totes part of Russian-built Strela ("Arrow") 

crane during first logistics mission STS-96/2A.1

The crane is not mounted to the fixture as tightly as expected. Although it 

poses no hazard to ISS components, Voss and Williams will inspect it and 

its fixture to ensure that neither is damaged or otherwise compromised. 

They will attempt to secure the crane in its housing, or relocate it to another, 

identical housing elsewhere on Zarya.

The two mission specialists will return to the airlock to get the spare Early 

Communications antenna and pick up a grapple fixture for the Russian 

crane Strela. From there they will go to the SPACEHAB Integrated Cargo 

Carrier (ICC) in the shuttle's cargo bay and obtain the rest of the 

components and tools required to complete assembly of Strela, begun by 

Jernigan and Barry on STS-96.

Finishing the assembly job will require about 100 different actions, steps and 

processes from the time Voss and Williams arrive at the ICC to get the 

crane's 45-ft telescoping boom to the completion of its assembly at its 

workstation on PMA-2. Strela, which is an updated version of the crane used 

on Mir, will be moved to Zarya during the August logistics mission, STS106/2A.2b. 

Next, Voss and Williams will replace an Early Communications (ECOMM) 

System antenna mounted on the port side of the common berthing 

mechanism at Unity's forward end-cone. It is one of two used for crew 

videoconferences, command activities and telemetry backup. The job of 

swapping out the device is relatively straightforward. It essentially involves 

disconnecting four cable connectors, releasing the antenna from its mount, 

17
disconnecting four cable connectors, releasing the antenna from its mount, 

installing and reconnecting the new antenna, and checking its alignment.

Only two more tasks remain to be completed: installation of the centerline 

camera cable and attachment of eight handrails on Unity. The equipment is 

in a bag Jernigan and Barry left behind for Voss and Williams. Williams will 

retrieve the bag, then move to the connecting module's starboard side to 

meet Voss and give him the cable. 

Handrails assist space-walking Astronauts in safely maneuvering around 

Unity

Installation of the cable will simply require that Voss secure it with wire ties 

to handrails already attached to Unity. Williams at the same time will use a 

power tool to securely bolt the new handrails to the module's forward, midand aft sections. When those tasks are completed, the EVA mission will be 

accomplished.

18
EVA Phase Elapsed Timeline for STS-101 EVA

Time Event

0:00 Airlock Egress

0:15 EVA Sortie Setup

0:45 OTD Activities

1:30 EVA Sortie Setup continued

1:45 Strela Install

3:45 Early Comm Antenna

4:45 Node Handrail Install - Centerline Camera Cable

5:15 EVA Sortie Cleanup

6:15 Airlock Ingress

6:30 Repress - End of EVA

Updated: 04/04/2000

19
STS-101

Payloads

BioTube Precursor Experiment

Payload Bay

Prime: Principal Investigator: David Cox

Backup:

Overview

The BioTube Precursor Experiment will test newly developed technologies 

involved in the BioTube Magnetic Field Apparatus, a device for growing 

seeds in microgravity that will be flown on STS-107. This precursor 

experiment, which occupies half of a locker in the middeck of Atlantis, will 

evaluate the MFA's water delivery system and seed germination substrates.

In plant growth experiments, a wicking material, such as germination paper, 

is sometimes used as a liquid distributor and temporary reservoir for 

germinating seeds. For the precursor experiment, wicking materials other 

than the standard germination paper will be tested for their ability to absorb, 

distribute, and retain water in microgravity without pooling around the seeds. 

The flight will also demonstrate seedling growth as a function of temperature 

in the limited volume of the sealed growth chambers. 

The payload consists of 24 seed cassettes housed in three Magnetic Field 

Chambers (MFCs), three syringe/tube mechanisms to deliver water, and 

three passive temperature-recording devices. The MFCs will be used on the 

BioTube MFA payload to expose plant materials to a magnetic field. For the 

precursor flight, aluminum blanks will be flown instead of magnets, so the 

precursor experiment will have no magnetic field.

Twice during the flight, a crew member will turn cranks on the three syringes 

to deliver water to the seed cassettes. The first watering will occur 30 to 36 

hours before landing, the second 12 to 20 hours before landing. 

20
21
History/Background

When seeds are grown in the microgravity of space, the surface tension of 

water can cause excess water to pool on the surface of the seeds, which 

blocks oxygen transport around the seed. If the barrier forms before the 

seeds germinate, they will die. 

Benefits

This investigation will enable researchers to develop devices for 

successfully growing plants in space to supply oxygen and food on longduration space flights.

Updated: 04/06/2000

22
STS-101

Payloads

HTD 1403 Micro Wireless Instrumentation System (Micro WIS) 

HEDS Technology Demonstration

In-Cabin

Prime:

Backup:

Overview

HTD1403 will demonstrate the operational utility and functionality of the 

micro WIS on orbit, initially in the crew cabin of the Shuttle orbiter and then 

on the International Space Station. 

The micro WIS consists of autonomous, tiny sensors for data acquisition. 

Two versions have been developed-a sensor/transmitter and a 

sensor/recorder. This HTD is designed to demonstrate the micro WIS 

transmitter and recorder. 

The micro WIS sensor/recorder was first flown on STS-96 as part of the 

Integrated Vehicle Health Monitoring payload. This DTO will document 

requirements for the micro WIS sensor/recorder when it is not part of the 

IVHM.

One of the objectives of this HTD is to obtain meaningful real-time 

measurements for use in the orbiter's environmental control and life support 

system (ECLSS) operations. The micro WIS sensor/transmitter's 

simultaneous real-time measurements of air cabin temperatures in many 

interior compartments of the orbiter will help ECLSS operations personnel 

address issues encountered on STS-88 and early International Space 

Station flights. Currently, only one temperature reading in the aft flight deck 

of the orbiter is available for adjusting model predictions for real-time 

environments. 

Micro WIS will also reduce the time it takes the crew to obtain on-orbit 

temperature measurements and will increase the capability to monitor 

temperatures over long periods. On busy Space Station assembly flights, 

the distances traveled and the time required to make the measurements can 

be prohibitive. 

23
Micro WIS data will also be used to validate cabin air temperature models 

that are used for critical predictions of the dew point on early ISS missions, 

where orbiter cabin air exerts a significant influence on the entire station 

volume. Although the physical configuration of orbiter cabin air ducting has 

been changed significantly, the sensors have remained the same and some 

temperature data has never been available.

History/Background

In the past, space missions have been limited by the penalties associated 

with weight and integration costs. However, breakthroughs in the 

miniaturization of very low power radio transceivers have led to the 

introduction of a 1-inch-diameter micro wireless instrumentation system that 

can send temperature measurements to a laptop computer for five months.

Benefits

This breakthrough in miniaturization means significant cost, weight, and 

power savings for current and future space vehicles and ground test 

facilities and should revolutionize system design of future spacecraft. The 

micro WIS on-orbit demonstration should also increase the flexibility, 

reliability, and maintainability of data acquisition systems for spacecraft and 

lead to a reduction in vehicle turnaround time and increased reliability by 

eliminating cable connectors and by providing near-real-time reconfigurable 

data paths.

Updated: 04/06/2000

24
STS-101

Payloads

Integrated Cargo Carrier

Payload Bay

3,700 pounds lbs.

Prime:

Backup:

Overview

Astronauts use the SPACEHAB Integrated Cargo Carrier to accommodate 

and support the transfer of exterior cargo from the shuttle orbiter to the 

International Space Station and from the station to work sites on the truss 

assemblies. 

The ICC provides sufficient surface area in the orbiter cargo bay to carry 

approximately 8,000 pounds of cargo, which would otherwise have to be 

carried in the shuttle's cabin.

The ICC is an unpressurized flatbed pallet and keel yoke assembly housed 

in the orbiter's payload bay. Constructed of aluminum, it is 8 feet long, 15 

feet wide and 10 inches thick, and is capable of carrying cargo on both faces 

of the pallet, both on top and below. There are no active interfaces (thermal, 

electrical or data) to the shuttle. 

On Mission STS-101, the ICC will carry three cargoes: parts of the Russian 

Strela crane, the Space Integrated Global Positioning System/Inertial 

Navigation System (SIGI) Orbital Attitude Readiness (SOAR) payload, and 

the SPACEHAB-Oceaneering Space System (SHOSS) box. 

Strela is a Russian crane that will be mounted on the Zarya module to 

transport orbital replacement units and serve as a translational aid for 

extravehicular crew members on the Russian segment of the station. The 

Strela grapple fixture adapter and base were installed on STS-96; STS-101 

will deliver the boom, ring and extension to complete the crane assembly.

SOAR is designed to be space station's primary global positioning source 

and the crew return vehicle's primary navigation source. (DTO 700-21 

describes the SOAR test on STS-101 to demonstrate that SIGI can 

determine GPS attitude in space.)

25
The SHOSS is a trunk mounted on the ICC that can carry up to 400 pounds 

of tools and flight equipment. On STS-101, it will contain space-walking tools 

and logistics items to be transferred and stowed in the U.S. Unity module for 

use in future missions.

History/Background

This is the second flight of the Integrated Cargo Carrier. It last flew on STS96.

Related Links: http://spartans.gsfc.nasa.gov/

Updated: 04/06/2000

26
STS-101

Payloads

Logistics & Hardware Transfer

Prime:

Backup:

Overview

More than 3,000 pounds of hardware and supplies will accompany the 

Space Shuttle Atlantis when it begins its journey to the International Space 

Station to make final preparations for the planned addition of Russia's 

Service Module Zvezda this summer. 

Atlantis will carry the tonnage in its mid-deck lockers and cargo bay. In 

addition, biotechnology and microgravity experiments will be housed in the 

crew compartment and the cargo bay's Space Experiment Module (SEM). 

The shuttle is expected to dock to the ISS on Flight Day 3 or 4, depending 

on the day of launch. 

27
Mission Specialists will be preparing to move some 3,000 pounds of 

equipment and supplies from the shuttle into the ISS. One of the first tasks 

will be to test ISS air quality and to improve air circulation with the 

installation of new filters in the Zarya module before addressing power 

system issues in the Russian component.

First logistics mission astronauts Julie Payette (left) and Ellen Ochoa 

transfer supplies from shuttle Discovery to ISS.

The astronauts will open the hatch to the ISS on Flight Day 5 or 6 and will 

begin to collect air quality samples in Unity and Zarya for comparison with a 

sample from Atlantis. They also will measure air-circulation velocity and 

monitor carbon dioxide levels. Upon completion of those tasks, the crew 

members will break out their tools and rework some of the air ducts in Zarya 

to improve airflow. They will re-route some ducts, strengthen others, add 

new acoustic mufflers where required, and they'll swap out the contaminant 

filter in Zarya and the charcoal filter in Unity. 

Once they determine that there has been a sufficient improvement 

in air circulation, the crew members will turn their attention to maintenance 

issues and cargo transfers.

Battery Change-Out

Problems with performance of at least one of Zarya's six "800A" storage 

batteries last summer during routine, ground-commanded battery 

maintenance led to a decision in August to take the battery off line from the 

ISS power system. The batteries collect energy during the daytime portion of 

the Station's orbit and provide power at night. 

28
Battery current converter, left, and 800 A-1 battery with which the crew will 

replace failed units on Zarya during STS-101/2A.2a.

Battery No. 1 was tested a number of times during the following weeks and, 

in September, was removed from service with no plans for its attempted reuse. The Station can run on as few as three of the batteries with no 

significant impact on operations. 

Battery No. 2 failed to discharge properly following routine maintenance in 

mid-November. It was taken off line and subsequently found to have failed 

altogether due to a problem with a voltage current regulator, which operates 

the charging and discharging function of the unit. Battery No. 1 was brought 

back on line in early December and operated normally at first. But after a 

week and a half, it once again began to discharge improperly and its use 

was discontinued except during short periods when necessary. In early 

March, it was discharged and taken off line for good until Atlantis' flight.

A problem that occurred in March during cycling of battery No. 3 led mission 

controllers in Moscow to disconnect the unit. They subsequently 

reconnected it and it appears to be operating normally, but the problem may 

have damaged it. Battery No. 5 is operational but is showing signs of 

degradation. Batteries 4 and 6 continue to operate normally. 

Atlantis' crew will replace the four suspect, 163-pound batteries -Nos. 1, 2, 3 

and 5 - as well as three of their 34-pound current converters and two of their 

10-pound current converter controllers. 

Komparus cables will provide additional control capabilities in Zarya.

29
The crew will complete the day's repair and replacement chores with the 

replacement in Zarya of one of the four Radio Telemetry System memory 

units, which has exceeded its design life. They will also install new 

"Komparus" command system cable inserts. The inserts enhance the 

capability of Zaryaís computer to control the ISS command and 

measurement system flight equipment. 

Other Maintenance Items

Three fire extinguishers in Zarya have reached the end of their design life. 

The crew will replace them, as well as 10 smoke detectors and four cooling 

fans. In Unity, they will replace the Radio Frequency Power Distribution Box 

implicated in the loss of a return link for the Early S-Band Communications 

System. 

New fire extinguishers for Russian control module Zarya will replace three 

that are approaching the end of their service lives.

Cargo Transfer

The transfer of equipment and supplies between the shuttle and station will 

be managed by Weber and Williams. They will initiate the transfer process 

on Flight Day 5 or 6 and will continue through Flight Day 8 or 9. 

As was the case with the first logistics flight last May, some of the cargo will 

be stowed aboard the ISS for use on future missions through STS-97/4A. 

30
Among the supplies and equipment will be devices to remove humidity from 

the atmosphere, a cycle ergometer for the first Expedition, or resident, crew, 

four portable fan assemblies for STS-92/3A, and the Pressurized Mating 

Adapter (PMA)-3 duct extension kit for STS-97/4A.

Pressurized Mating Adapter (PMA)-3 before completion

Some of the cargo to be transferred will consist of everyday household items 

such as trash bags, can openers, sewing kits, bungee cords, note pads, 

tools and two dictionaries in both English-to-Russian and Russian-to-English 

language. Other items include:

US Hardware Transfer

- ISS crew health-care system elements

- Intra-vehicular activity seal kits

- Early space communications hardware

- IMAX camera

- Space walk equipment

- Printer and accessories

- Zarya enclosures (space-saving storage units)

- Treadmill assembly; resistance exercise system

- Common Berthing Mechanism Centerline Camera

Russian Hardware Transfer

- 800A Batteries

- Battery electronics

- Strela space-crane parts

- Radio telemetry unit 

Updated: 04/06/2000

31
STS-101

Payloads 

Mission to America's Remarkable Schools

Payload Bay

270 lb lbs.

Prime: Principal Investigator: Dennis Chamberland, KSC

Backup:

Overview

This life sciences payload, sponsored by the NASA's Kennedy Space 

Center (KSC), contains 20 experiments from schools across the United 

States. The projects include seeds of various types reflown from SEEDS I 

and II as well as regionally important seed varieties such as lettuce and 

spinach. In addition, some schools submitted cellular specimens like 

chlorella and e.Coli (from commercial high school scientific supply houses). 

Each experiment is placed in a 2-inch-diameter PVC tube inside a Complex 

Autonomous Payload (CAP)/Getaway Special (GAS) canister. The 

CAP/GAS is positioned in space shuttle cargo bay 13, port side, forward 

position. 

MARS is a passive payload that does not require any power or crew 

interaction. Experiments are self-contained, back-filled with dry nitrogen at 

one atmosphere before launch, and sealed throughout the mission.

History/Background

The Complex Autonomous Payload project grew out of the Getaway Special 

program as a means to fly designated canisters as shuttle secondary 

payloads sponsored by NASA. These CAP experiments offer an 

inexpensive means for educational institutions to experiment in space. The 

GAS program also provides inexpensive access to space for non-NASA 

experiments. The GAS program allows educational institutions to develop a 

payload that fits in the NASA standard 5-cubic-foot GAS canister. The 

payload control weight is 270 pounds--100 pounds for the experiment and 

170 pounds for the carrier. The Goddard Space Flight Center Wallops Island 

facility manages the GAS program.

The primary program objective is outreach to schools with an emphasis on 

NASA space life sciences, encouraging direct student participation in the 

space shuttle program. The program is managed by KSC and the NASA 

Space Life Sciences Outreach Program Intercenter Working Group.

Further information on the Getaway Special program, as well as other 

shuttle carrier programs managed by Goddard Space Flight Center, can be 

found at http://sspp.gsfc.nasa.gov.

32
Updated: 03/27/2000

Benefits

Encourages student participation and experimentation in space life 

sciences.

33
STS-101

Payloads

Space Experiment Module 6

Payload Bay

Prime:

Backup:

Overview

Ten passive experiments will fly on STS-101 as part of NASA's Space 

Experiment Module program, which is managed by the Goddard Space 

Flight Center's Wallops Flight Facility in Wallops Island, Va. The SEM 

program is an educational initiative to increase access to space for students 

in kindergarten through the university level. Since its first flight in 1995, SEM 

has allowed tens of thousands of students in the United States and other 

countries to fly their experiments in space. SEM-06 is a mixture of 

experiments from the United States and Argentina.

Idaho Tubers in Space: Shoshone-Bannock High School, Fort Hall, Idaho

Students will study the effect of space on Idaho tubers. The "Spuds in 

Space" experiment was developed by students from the Fort Hall Indian 

Reservation. 

Seeds/CREPLD II: Purdue University, West Lafayette, Indiana

This experiment will study the effects of the space environment on seeds 

and on programmable logic devices.

Effects of Microgravity on Samples/GADGET: Glenbrook High School, 

Northbrook, Illinois

Students will determine the effects of the space environment on different 

types and colors of paint. Secondary experiment samples from other Illinois 

schools consist of dried shrimp, sand, hair, and feathers.

Yeast in Space: Brock Bridge Elementary, Laurel, Maryland

Students will study the effects of microgravity and temperature on yeast.

Effects of Cosmic Radiation: Benfield Elementary, Severna Park, Maryland

Students will study the effects of the space environment (cosmic radiation 

and microgravity) on various items, such as film, seeds, bulbs, yeast, beans, 

and popcorn.

34
Effects of Space on Fluids and Seeds: Technical School No. 469, Rosario, 

Argentina

Students will investigate the effects of the space environment on seeds and 

liquids such as colored fluids, oil, and water.

GERMINAR-2: National University of Patagonia, Argentina

This experiment will study the effects of the space environment on bee glue 

and various seeds.

Seeds and Sea Monkeys in Space: Rosario National University, Argentina

This experiment will study the effects of the space environment on 

Patagonic seeds (trees), humus, and Artemias Salina (sea monkeys).

Electronics and Magnetic Recording Devices: Rosario National 

University/St. Hilda's School, Argentina

Students will study the effects of the space environment on electronics and 

magnetic chips such as those used in diskettes, CD ROMs, PC boards, and 

phone cards.

Cosmic Ray Detectors: Buenos Aires National School/Rosario National 

University, Argentina

This experiment will use thermoluminiscent detectors to study the effect of 

cosmic rays. 

 

35
SEM-06 uses a standard 5-cubic-foot Getaway Special (GAS) canister, 

mounted on an SSP/JSC-provided adapter beam in bay 13, port side, forward 

position in the orbiter payload bay. SEM-06 is passive: no batteries or power 

utilities are supplied by the orbiter.

NASA began the Space Experiment Module (SEM) program in 1995 as an 

offshoot of the Getaway Special program, managed by the Shuttle Small 

Payloads Project at Goddard Space Flight Center in Greenbelt, Md., and the 

Wallops Flight Facility, Wallops Island, Va. Since 1982, GAS canisters have 

flown on the shuttle, offering economic access to space to a broader array of 

experimenters, particularly students. But participation was still somewhat 

limited by the high-level engineering skills required to design GAS 

experiments. 

36
In 1995, the program directors started SEM to relieve students of the 

engineering burden and let them concentrate on creating their experiments. 

Since the module is equipped with electrical power, there is no need to 

engineer and build battery boxes, etc. Students of all ages can create, 

design, and build experiments with a little help from teachers or mentors. The 

experiments--which can be simple or complicated, active or passive--are 

placed in half-moon-shaped SEMs, ten of which are then stacked in a GAS 

canister.

This is the fourth flight of SEM.

More information about the Space Experiment Module program can be found 

at http://www.wff.nasa.gov/~sspp/sem.html.

Benefits

Economical and simplified access for space experimenters, especially 

students.

Interests young students in science and math.

Updated: 03/27/2000

37
STS-101

Payloads

SPACEHAB

Payload Bay

Prime:

Backup:

Overview

U.S. and Russian hardware for the International Space Station will be 

carried in the SPACEHAB logistics double module, a pressurized laboratory 

in the shuttle's cargo bay that is connected to the middeck area of the 

orbiter. The seven-member crew will transfer more than 2,700 pounds of 

U.S. supplies and more than 2,200 pounds of Russian supplies from the 

module to the Unity and Zarya modules of the ISS. 

The logistics include clothing and personal hygiene articles, health care 

supplies, exercise equipment, food, TV and movie equipment, a fire 

detection and suppression system, computers, and sensors. The hardware 

is stowed in SPACEHAB's numerous lockers and Soft Stowage bags and is 

mounted to the fronts of stowage racks and the module floor. 

In addition to the logistics and maintenance cargo, SPACEHAB is carrying a 

commercial payload, the Self-Standing Drawer--Morphological Transition 

and Model Substances.

Designed to augment the shuttle orbiter's middeck, the SPACEHAB double 

module has a total cargo capacity of up to 10,000 pounds and contains 

systems necessary to support astronauts, such as ventilation, lighting, and 

limited power. Crew access to SPACEHAB is through a tunnel system 

located between the orbiter middeck and the SPACEHAB module.

Generally, two crew members are required for SPACEHAB operations. The 

SPACEHAB environmental control system is designed to nominally 

accommodate two crew members on a continuous basis. Additional crew 

members can be accommodated for brief periods at the expense of reduced 

cabin air heat rejection capability. 

Microgravity Research Program

Working in partnership with the scientific community and commercial 

industry, NASA's Microgravity Research Program strives to increase 

understanding of the effects of gravity on biological, chemical, and physical 

systems. 

38
Using both space flight- and ground-based experiments, researchers 

throughout the nation, as well as international partners, are working together 

to benefit economic, social, and industrial aspects of life for the United 

States and the entire Earth. U.S. universities, designated by NASA as 

commercial space centers, share these space advancements with U.S. 

industry to create new commercial products, applications, and processes. 

Under the NASA Headquarters' Office of Life and Microgravity Sciences and 

Application, the Microgravity Research Program supports NASA's strategic 

plan in the Human Exploration and Development of Space Enterprise. 

Microgravity research has been performed by NASA for more than 25 years. 

The term microgravity means a state of very little gravity. The prefix micro 

comes from the Greek word mikros ("small"). In metric terms, the prefix 

means one part in a million (0.000001). 

Gravity dominates everything on Earth, from the way life has developed to 

the way materials interact. But aboard a spacecraft orbiting the Earth, the 

effects of gravity are barely felt. In this microgravity environment, scientists 

can conduct experiments that are all but impossible to perform on Earth. In 

this virtual absence of gravity as we know it, space flight gives scientists a 

unique opportunity to study the states of matter (solids, liquids, and gases) 

and the forces and processes that affect them. 

Marshall Space Flight Center in Huntsville, Ala., is the lead center for 

NASA's Microgravity Research Program. The program manages 

Microgravity Science and Applications Project Offices at the Lewis Research 

Center in Cleveland, Ohio, and the Jet Propulsion Laboratory in Pasadena, 

Calif., and project offices at Marshall. 

Under the project offices, the Microgravity Research Program is divided into 

nine major areas: five science disciplines, three research infrastructure 

programs, and the Space Products Development Office. 

The science disciplines include biotechnology, fluid physics, materials 

science, combustion science and fundamental physics. The infrastructure 

activities include acceleration measurement, advanced technology, and the 

Glovebox Flight Program. 

Marshall manages the Biotechnology Program and Material Science 

Program as well as the Glovebox Flight Program and the Space Products 

Development Office. Lewis Research Center manages the Fluid Physics, 

Combustion Science and Acceleration Measurement programs, while the 

Jet Propulsion Laboratory manages the Fundamental Physics and the 

Advanced Technology Development Program. As an element of the 

Biotechnology Program, Johnson Space Center manages bioreactor 

research in cell tissue growth. 

39
In addition to the U.S. and Russian hardware for the International Space 

Station carried within the SPACEHAB module, additional unpressurized 

equipment for transfer to the space station will be carried on the new 

SPACEHAB integrated cargo carrier. The ICC, a cross-bay carrier that can 

accommodate 6,000 pounds of cargo, will be carrying parts of the Russian 

cargo crane known as Strela, the SPACEHAB Oceaneering Space System 

box, and DTO 700-21.

History/Background

Early in the shuttle program, it became evident that the orbiter middeck is 

the best place to conduct crew-tended experiments in space. Each shuttle 

orbiter has 42 middeck lockers, but most are used to stow crew gear for a 

typical seven-day mission, leaving only seven or eight for scientific studies. 

But SPACEHAB, the first crew-tended commercial payload carrier, has 

initiated a new era of space experimentation. 

The basic SPACEHAB module, which takes up a quarter of the orbiter's 

payload bay, is like a second middeck. The 10-foot-long pressurized module 

adds 1,100 cubic feet of pressurized work space that can hold 61 lockers or 

experiment racks or a combination of the two. The lockers are sized and 

equipped like those in the shuttle middeck so that experiments can be 

moved from one location to the other. The lockers accommodate up to 60 

pounds of experiment hardware in about 2 cubic feet. A rack, which can be 

single or double, takes the space of ten lockers. Double racks are similar in 

size and design to those planned for the space station so that they can 

serve as test beds for future projects. A single rack can carry 655 pounds of 

hardware in 22.5 cubic feet. 

A new double module, developed specifically for shuttle missions to Mir, will 

be used on STS-96. The double module, which can accommodate nearly 

10,000 pounds of cargo, was created by joining two single modules. 

The astronauts enter the module through a modified Spacelab tunnel 

adapter. SPACEHAB can accommodate two crew members on a continuous 

basis, but additional crew members can work in the module for brief periods. 

Power, command and data services, cooling, vacuum, and other utilities are 

supplied by orbiter crew cabin and payload bay resources. 

SPACEHAB was privately developed and is privately operated by 

SPACEHAB, Inc., of Arlington, Va. STS-101 is the 14th flight of 

SPACEHAB. 

40
Benefits

Using both space- and ground-based experiments, researchers throughout 

the nation, as well as international partners, are working together to develop 

economic, social, and industrial benefits for the United States and the entire 

Earth. U.S. universities, designated by NASA as commercial space centers, 

share these space advancements with U.S. industry to create new

commercial products, applications, and processes.

Updated: 04/06/2000

41
STS-101

Experiments

Biotechnology Ambient Generic (PCG-BAG)

Prime: Principal 

Investigator:

Dr. Daniel Carter of New Century 

Pharmaceuticals Inc., Huntsville, Ala.

Backup: Project 

Scientist:

Todd Holloway of NASA's Marshall 

Space Flight Center in Huntsville, Ala.

Overview

Objective:

The Protein Crystal Growth Biotechnology Ambient Generic payloads are 

designed to provide opportunities to grow high-quality protein crystals in 

microgravity. 

Researchers use these crystals to understand the molecular structure of the 

proteins. This information can be used to develop drugs that someday may 

battle the effects of aging, and treat cancer, rheumatoid arthritis, periodontal 

disease, influenza, septic shock, emphysema and AIDS.

History/Background

While many protein crystal growth microgravity experiments are conducted 

with stringent temperature controls and extensive participation by shuttle 

crew members, the Biotechnology Ambient Generic experiments require 

minimal crew support. 

The payloads are flown as stowage items in Atlantis's middeck, where they 

are subject to normal temperature conditions aboard the shuttle.

Shortly after lift-off, 504 individual experiments, stored in eight cylindrical 

containers, will be activated. Each experiment consists of two reservoirs 

separated by a flexible seal. When the seal is opened, the fluid in the protein 

drop will evaporate, starting the crystallization process. During the mission, 

this evaporation process will result in the growth of crystals that investigators 

can later study to determine the molecular structure of protein compounds.

42
Updated: 04/06/2000

43
STS-101

Experiments

Commercial Protein Crystal Growth

Prime: Principal 

Investigator:

Dr. Larry DeLucas, director of the 

Center for Biophysical Science and 

Engineering at the University of 

Alabama at Birmingham. 

Backup: Project 

Scientist:

Steve Lide of the Space Product 

Development Office at the Marshall 

Space Flight Center in Huntsville, Ala. 

Overview

Through protein crystallography, protein crystals are grown in the laboratory 

and examined to determine their three-dimensional structure. That 

information is used to develop new drugs targeting the protein's structure. 

But crystals grown in Earth's gravity frequently have defects that make such 

analysis difficult or impossible. Space-grown crystals often have fewer 

defects and are larger than their Earth-grown counterparts, making them 

easier to examine. 

The objective of the STS-101 protein crystal growth experiments is to grow 

crystals of human alpha interferon 2b--a protein pharmaceutical used 

against several afflictions, including human viral hepatitis B and C, 

melanoma, hairy cell leukemia, multiple myeloma and AIDS-related Kaposi's 

sarcoma. These alpha interferon samples will be crystallized under a range 

of conditions in sufficient size and quantity to assess the concentration and 

distribution of impurities. The protein is supplied by the Schering Plough 

Research Institute of Kenilworth, N.J. The experiments will be performed in 

the protein crystallization facility that stimulates crystal growth through 

changes in temperature. 

44
This Commercial Protein Crystal Growth experiment aboard STS-101 is 

sponsored by the Center for Biophysical Science and Engineering at the 

University of Alabama at Birmingham. The center is part of NASA's 

Commercial Space Center Program, which forms a bridge between NASA 

and private industry to develop methods for crystallizing large molecules in 

microgravity. 

By fostering such commercial projects aboard the space shuttle, NASA 

contributes to research that may lead to a new generation of drugs for 

treating diseases such as cancer, rheumatoid arthritis, periodontal disease, 

influenza, septic shock, emphysema and AIDS.

Updated: 04/06/2000

45
STS-101

Experiments

Gene Transfer Experiment using ASTROCULTURETM Glove Box 

(ASC-GB)

Prime: Principal 

Investigator:

Dr. Bratislav Stankovic,Wisconsin 

Center for Space Automation and 

Robotics, University of Wisconsin, 

Madison, Wis

Backup: Project 

Scientist:

Dr. Weijia Zhou, Wisconsin Center for 

Space Automation and Robotics, 

University of Wisconsin, Madison, Wis.

Overview

Objectives: The objective of the experiment is to evaluate a novel method 

for production of commercially important transgenic plant materials in 

microgravity using Agrobacterium tumefaciens. This transformation method, 

developed by the Wisconsin Center for Space Automation and Robotics and 

its industrial partner, was first tested during the STS-95 mission in October 

1998. That testing found increased transformation efficiency in comparison 

to the identical ground experiments. 

The gene transfer experiment to be conducted on the STS-101 mission is a 

cooperative venture between Producers' Natural Processing Corporation 

(PNP) and the Wisconsin Center for Space Automation and Robotics. PNP 

is a for-profit, privately owned company which: takes advantage of 

proprietary patented technologies in genetic transformation that will allow in 

planta production of proteins, enzymes, antibodies and vaccines; utilizes its 

relationship with prominent life science companies to deliver specific, 

identity-preserved crop attributes to the end user; and utilizes its new 

product development division and partners for the production of 

nutraceuticals, industrial enzymes, plant-based edible vaccines, and 

pharmaceutical intermediates.

Description: Crop production and utilization are undergoing significant 

modifications and improvements that emanate from adaptation of recently 

developed plant biotechnologies. One of these is the transfer of desirable 

genes from organisms to economically important crop species in a way that 

cannot be accomplished with traditional plant breeding techniques. These 

new technologies offer opportunities to improve crop species in various 

characteristics, as well as to use source materials for specific industrial 

applications, and hence, to convert plant materials that originally have no 

commercial values to plant materials that represent commercially important 

crop varieties. 

46
For the STS-101 mission, a sample size of 1,000 soybean seeds will be coincubated on orbit, with Agrobacterium tumefaciens containing the 

proprietary commercial gene and rs-GFP reporter gene that will be used for 

in vivo detection of transformation events that had occurred during the time 

the seeds were in microgravity. The results will be analyzed to determine the 

percentage of transient and stable transformation events, which will be 

compared with the results obtained during the STS-95 mission. During the 

STS-101 mission, the transformation procedures will be performed by the 

crew.

The ASTROCULTURETM flight experiment series is sponsored by the 

Space Product Development Program managed at the Marshall Space 

Flight Center in Huntsville, Ala. 

Updated: 04/06/2000

47
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Monitoring Latent Virus Reactivation and Shedding in Astronauts

DSO 493

Prime: Principal Investigator: Duane L. Pierson

Backup:

Overview

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-flight-induced alterations in the immune response become 

increasingly important on long missions, particularly the potential for 

reactivation and dissemination (shedding) of latent viruses. An example of a 

latent virus is Herpes Simplex Type 1 (HSV-1), which infects 70 to 80% of all 

adults. Its classic manifestations are cold sores, pharyngitis, and tonsillitis, 

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

membranes of an infected individual. However, many recurrences are 

asymptomatic, resulting in shedding of the virus. Twenty subjects have been 

studied for Epstein-Barr virus. Three additional viruses will be examined in 

an expanded subject group.

48
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Space Flight and Immune Function

DSO 498

Prime: Principal Investigator: Duane L. Pierson

Backup:

Overview

The objective of this DSO is to characterize the effects of space flight on 

neutrophils, monocytes, and cytotoxic cells, which play an important role in 

maintaining an effective defense against infectious agents. The premise of 

this study is that the space environment alters the essential functions of 

these elements of human immune response.

Researchers will conduct a funtional analysis of neutrophils and monocytes 

from blood samples taken from astronauts before and after the flight. They 

will also assess the subjects' pre- and postflight production of cytotoxic cells 

and cytokine.

This study will complement previous and continuing immunology studies of 

astronauts' adaptation to space.

History/Background

Astronauts face an increasing risk of contracting infectious diseases as they 

work and live for longer periods in the crowded conditions and closed 

environmnets of spacecraft such as the Russian Mir space station and the 

International Space Station. The effects 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 function caused by 

exposure to microgravity will allow researchers to develop countermeasures 

to minimize the risk of infection. 

49
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Cabin Air Monitoring

DTO 623

Prime:

Backup:

Overview

A solid sorbent sampler will continuously sample the orbiter's atmosphere 

throughout the flight for possible impurities due to outgassing and particulate 

matter. This is the 25th flight for this DTO.

50
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Crosswind Landing Performance

DTO 805

Prime:

Backup:

Overview

This DTO will continue to gather data to demonstrate the capability to 

perform a manually controlled landing with a 90-degree, 10- to 15-knot 

steady-state crosswind. This DTO can be performed regardless of landing 

site or vehicle mass properties. 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 manifested on 58 

previous flights.

51
STS-101

DTO/DSO/RMEs 

SIGI Orbital Attitude Readiness

DTO 700-21

Prime:

Backup:

Overview

The objective of DTO 700-21 is to demonstrate the operation of the space 

integrated Global Positioning System/inertial navigation system (SIGI) on 

orbit. The SIGI is intended to be the primary GPS source for the International 

Space Station (ISS) and the primary navigation source for the crew return 

vehicle (CRV). The ability of the SIGI to perform GPS attitude determination 

in space has not been demonstrated. Data from this DTO will be used to 

evaluate the SIGI design before it is used on the ISS or CRV.

The payload consists of the SIGI in a pressurized container on a GPS 

antenna mounting structure (GAMS). The SIGI has RF connections to four 

antenna assemblies, which are mounted on the corners of the GAMS. A 

payload and general support computer (PGSC) located in SPACEHAB is 

used for commanding and data storage. Data from two star trackers mounted 

on the GAMS will be collected by a separate PGSC inside SPACEHAB.

This is the first flight of DTO 700-21.

52
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Single-String Global Positioning System

DTO 700-14

Prime:

Backup:

Overview

The purpose of this DTO is to evaluate the performance and operation of 

the Global Positioning System as a shuttle navigation aid during the ascent, 

on-orbit, entry and landing phases of the mission. A modified military GPS 

receiver processor and the orbiter's existing GPS antenna will be used for 

this evaluation.

This is the ninth flight for DTO 700-14. It was last flown on STS-96.

53
STS-101

Updated: 03/27/2000

DTO/DSO/RMEs 

Solid-State Star Tracker Size Limitations

DTO 847

Prime:

Backup:

Overview

The objective of this DTO is to characterize the performance of the orbiter's 

solid-state star tracker with a large, bright target-the International Space 

Station. Laboratory tests show that the SSST can track significantly larger 

and brighter objects that the orbiter's other star tracker-the image-dissecting 

tracker. It may be necessary to use the SSST to track the station during 

orbiter passes because the ISS will reach a size that could prohibit the use 

of the image-dissecting tracker under certain conditions very early in the 

assembly sequence.

At a minimum, the SSST should be verified to track the ISS accurately up to 

22.6 arcminutes, which is the largest size tested in the lab and the number 

that was used in analyzing potential problems that might be caused by the 

size of the ISS. If possible, the absolute upper limit to the size of an object 

that the SSST can track will be determined.

This DTO will be performed when the orbiter separates from the ISS but 

only if specific lighting conditions exist.

This is the second of three planned flights for this DTO.

54
STS-101

Shuttle Reference and Data 

Shuttle Abort Modes

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).

ABORT TO ORBIT (ATO)

The ATO mode is designed to allow the vehicle to achieve a temporary orbit 

that is lower than the nominal orbit. This mode requires less performance 

and allows time to evaluate problems and then choose either an early 

deorbit maneuver or an orbital maneuvering system thrusting maneuver to 

raise the orbit and continue the mission.

ABORT ONCE AROUND (AOA)

The AOA is designed to allow the vehicle to fly once around the Earth and 

make a normal entry and landing. This mode generally involves two orbital 

maneuvering system thrusting sequences, with the second sequence being 

a deorbit maneuver. The entry sequence would be similar to a normal entry.

TRANSOCEANIC ABORT LANDING (TAL)

The TAL mode is designed to permit an intact landing on the other side of 

the Atlantic Ocean. This mode results in a ballistic trajectory, which does not 

require an orbital maneuvering system maneuver.

55
RETURN TO LAUNCH SITE (RTLS)

The RTLS mode involves flying downrange to dissipate propellant and then 

turning around under power to return directly to a landing at or near the 

launch site.

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.

RETURN TO LAUNCH SITE OVERVIEW

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 

56
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).

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 pitch-down maneuver (called powered pitchdown) 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.

57
TRANSATLANTIC LANDING ABORT OVERVIEW

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 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 OVERVIEW

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 OVERVIEW

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 

58
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 ABORT OVERVIEW

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 in-flight crew 

escape system would be used before ditching the orbiter.

Updated: 03/27/2000

59
STS-101

Shuttle Reference and Data 

Space Shuttle External Tank

The external tank contains the liquid hydrogen fuel and liquid oxygen 

oxidizer and supplies them under pressure to the three space shuttle main 

engines in the orbiter during lift-off and ascent. When the SSMEs are shut 

down, the ET is jettisoned, enters the Earth's atmosphere, breaks up, and 

impacts in a remote ocean area. It is not recovered. 

The largest and heaviest (when loaded) element of the space shuttle, the 

ET has three major components: the forward liquid oxygen tank, an 

unpressurized intertank that contains most of the electrical components, and 

the aft liquid hydrogen tank. The ET is 153.8 feet long and has a diameter of 

27.6 feet. 

The ET is attached to the orbiter at one forward attachment point and two aft 

points. In the aft attachment area, there are also umbilicals that carry fluids, 

gases, electrical signals and electrical power between the tank and the 

orbiter. Electrical signals and controls between the orbiter and the two solid 

rocket boosters also are routed through those umbilicals. 

Liquid Oxygen Tank

The liquid oxygen tank is an aluminum monocoque structure composed of a 

fusion-welded assembly of preformed, chem-milled gores, panels, machined 

fittings and ring chords. It operates in a pressure range of 20 to 22 psig. The 

tank contains anti-slosh and anti-vortex provisions to minimize liquid 

residuals and damp fluid motion. The tank feeds into a 17-inch-diameter 

feed line that conveys the liquid oxygen through the intertank, then outside 

the ET to the aft right-hand ET/orbiter disconnect umbilical. The 17-inchdiameter feed line permits liquid oxygen to flow at approximately 2,787 

pounds per second with the SSMEs operating at 104 percent or permits a 

maximum flow of 17,592 gallons per minute. The liquid oxygen tank's 

double-wedge nose cone reduces drag and heating, contains the vehicle's 

ascent air data system (for nine tanks only) and serves as a lightning rod. 

The liquid oxygen tank's volume is 19,563 cubic feet. It is 331 inches in 

diameter, 592 inches long and weighs 12,000 pounds empty. 

Intertank

The intertank is a steel/aluminum semimonocoque cylindrical structure with 

flanges on each end for joining the liquid oxygen and liquid hydrogen tanks. 

The intertank houses ET instrumentation components and provides an 

umbilical plate that interfaces with the ground facility arm for purge gas 

supply, hazardous gas detection and hydrogen gas boiloff during ground 

operations. It consists of mechanically joined skin, stringers and machined 

60
panels of aluminum alloy. The intertank is vented during flight. The intertank 

contains the forward SRB/ET attach thrust beam and fittings that distribute 

the SRB loads to the liquid oxygen and liquid hydrogen tanks. The intertank 

is 270 inches long, 331 inches in diameter and weighs 12,100 pounds. 

Liquid Hydrogen Tank

The liquid hydrogen tank is an aluminum semimonocoque structure of 

fusion-welded barrel sections, five major ring frames, and forward and aft 

ellipsoidal domes. Its operating pressure range is 32 to 34 psia. The tank 

contains an anti-vortex baffle and siphon outlet to transmit the liquid 

hydrogen from the tank through a 17-inch line to the left aft umbilical. The 

liquid hydrogen feed line flow rate is 465 pounds per second with the 

SSMEs at 104 percent or a maximum flow of 47,365 gallons per minute. At 

the forward end of the liquid hydrogen tank is the ET/orbiter forward 

attachment pod strut, and at its aft end are the two ET/orbiter aft attachment 

ball fittings as well as the aft SRB/ET stabilizing strut attachments. The liquid 

hydrogen tank is 331 inches in diameter, 1,160 inches long, and has a 

volume of 53,518 cubic feet and a dry weight of 29,000 pounds. 

ET Thermal Protection System

The ET thermal protection system consists of sprayed-on foam insulation 

and premolded ablator materials. The system also includes the use of 

phenolic thermal insulators to preclude air liquefaction. Thermal isolators are 

required for liquid hydrogen tank attachments to preclude the liquefaction of 

air-exposed metallic attachments and to reduce heat flow into the liquid 

hydrogen. 

ET Hardware

Each propellant tank has a vent and relief valve at its forward end. This 

dual-function valve can be opened by ground support equipment for the vent 

function during prelaunch and can open during flight when the ullage (empty 

space) pressure of the liquid hydrogen tank reaches 38 psig or the ullage 

pressure of the liquid oxygen tank reaches 25 psig. 

The liquid oxygen tank contains a separate, pyrotechnically operated, 

propulsive tumble vent valve at its forward end. At separation, the liquid 

oxygen tumble vent valve is opened, providing impulse to assist in the 

separation maneuver and more positive control of the entry aerodynamics of 

the ET. 

There are eight propellant-depletion sensors, four each for fuel and oxidizer. 

The fuel-depletion sensors are located in the bottom of the fuel tank. The 

oxidizer sensors are mounted in the orbiter liquid oxygen feed line manifold 

downstream of the feed line disconnect. During SSME thrusting, the orbiter 

general-purpose computers constantly compute the instantaneous mass of 

the vehicle due to the usage of the propellants. Normally, main engine cutoff 

is based on a predetermined velocity; however, if any two of the fuel or 

61
The locations of the liquid oxygen sensors allow the maximum amount of 

oxidizer to be consumed in the engines, while allowing sufficient time to shut 

down the engines before the oxidizer pumps cavitate (run dry). In addition, 

1,100 pounds of liquid hydrogen are loaded over and above that required by 

the 6:1 oxidizer/fuel engine mixture ratio. This assures that MECO from the 

depletion sensors is fuel-rich; oxidizer-rich engine shutdowns can cause 

burning and severe erosion of engine components. 

Four pressure transducers located at the top of the liquid oxygen and liquid 

hydrogen tanks monitor the ullage pressures. 

Each of the two aft external tank umbilical plates mate with a corresponding 

plate on the orbiter. The plates help maintain alignment among the 

umbilicals. Physical strength at the umbilical plates is provided by bolting 

corresponding umbilical plates together. When the orbiter GPCs command 

external tank separation, the bolts are severed by pyrotechnic devices. 

The ET has five propellant umbilical valves that interface with orbiter 

umbilicals: two for the liquid oxygen tank and three for the liquid hydrogen 

tank. One of the liquid oxygen tank umbilical valves is for liquid oxygen, the 

other for gaseous oxygen. The liquid hydrogen tank umbilical has two valves 

for liquid and one for gas. The intermediate-diameter liquid hydrogen 

umbilical is a recirculation umbilical used only during the liquid hydrogen 

chill-down sequence during prelaunch. 

The ET also has two electrical umbilicals that carry electrical power from the 

orbiter to the tank and the two SRBs and provide information from the SRBs 

and ET to the orbiter. 

A swing-arm-mounted cap to the fixed service structure covers the oxygen 

tank vent on top of the ET during the countdown and is retracted about two 

minutes before lift-off. The cap siphons off oxygen vapor that threatens to 

form large ice on the ET, thus protecting the orbiter's thermal protection 

system during launch. 

ET Range Safety System

A range safety system provides for dispersing tank propellants if necessary. 

It includes a battery power source, a receiver/decoder, antennas and 

ordnance. 

Various parameters are monitored and displayed on the flight deck display 

and control panel and are transmitted to the ground. 

The contractor for the external tank is Martin Marietta Aero space, New 

Orleans, La. The tank is manufactured at Michoud, La. Motorola, Inc., 

Scottsdale, Ariz., is the contractor for range safety receivers. 

Updated: 03/27/2000

62
STS-101

Shuttle Reference and 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 onboard targeted burns use star tracker and rendezvous radar data to correct 

the post-Ti trajectory in preparation for the final, manual proximity operations 

phase

Updated: 03/29/2000

63
STS-101

Shuttle Reference and 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 (41 statute miles). SRB impact occurs in the ocean 

approximately 122 nautical miles (141 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, 

64
Additionally, special structural tests were performed on the aft skirt. During 

this test program, an anomaly occurred in a critical weld between the holddown 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 

65
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.

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 

66
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.

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 

67
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.

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.

68
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.

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.

69
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.

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.

70
The SRBs separate from the external tank within 30 milliseconds of the 

ordnance firing command.

The forward attachment point consists of a ball (SRB) and socket (ET) held 

together by one bolt. The bolt contains one NSD pressure cartridge at each 

end. The forward attachment point also carries the range safety system 

cross-strap wiring connecting each SRB RSS and the ET RSS with each 

other.

The aft attachment points consist of three separate struts: upper, diagonal 

and lower. Each strut contains one bolt with an NSD pressure cartridge at 

each end. The upper strut also carries the umbilical interface between its 

SRB and the external tank and on to the orbiter.

There are four booster separation motors on each end of each SRB. The 

BSMs separate the SRBs from the external tank. The solid rocket motors in 

each cluster of four are ignited by firing redundant NSD pressure cartridges 

into redundant confined detonating fuse manifolds.

The separation commands issued from the orbiter by the SRB separation 

sequence initiate the redundant NSD pressure cartridge in each bolt and 

ignite the BSMs to effect a clean separation.

Updated: 03/29/2000

71
STS-101

Shuttle Reference and Data 

Space Shuttle Super-Lightweight Tank (SLWT)

The super-lightweight external tank (SLWT)made its first shuttle flight June 

2, 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 percent 

stronger and 5 percent less dense. 

The SLWT, like the standard tank, is manufactured at Michoud Assembly, 

near New Orleans, Louisiana, by Lockheed Martin. 

The 154-foot-long external tank is the largest single component of the space 

shuttle. It stands taller than a 15-story building and has a diameter of about 

27 feet. The external tank holds over 530,000 gallons of liquid hydrogen and 

liquid oxygen in two separate tanks. The hydrogen (fuel) and liquid oxygen 

(oxidizer) are used as propellants for the shuttle's three main engines. 

Updated: 03/29/2000

72
STS-101

Media Assistance

NASA Television Transmission

NASA Television is available through the GE2 satellite system which is 

located on Transponder 9C, at 85 degrees west longitude, frequency 3880.0 

MHz, audio 6.8 MHz.

The schedule for television transmissions from the orbiter and for mission 

briefings will be available during the mission at Kennedy Space Center, FL; 

Marshall Space Flight Center, Huntsville, AL; Dryden Flight Research 

Center, Edwards, CA; Johnson Space Center, Houston, TX; and NASA 

Headquarters, Washington, DC. The television schedule will be updated to 

reflect changes dictated by mission operations.

Status Reports

Status reports on countdown and mission progress, on-orbit activities and 

landing operations will be produced by the appropriate NASA newscenter

Briefings

A mission press briefing schedule will be issued before launch. During the 

mission, status briefings by a flight director or mission operations 

representative and when appropriate, representatives from the payload 

team, will occur at least once each day. The updated NASA television 

schedule will indicate when mission briefings are planned.

Internet Information

Information is available through several sources on the Internet. The primary 

source for mission information is the NASA Shuttle 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://shuttle.nasa.gov

If that address is busy or unavailable, Shuttle Information is available 

through the Office of Space Flight Home Page:

http://www.hq.nasa.gov/osf/

73
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

Information on other current NASA activities is available through the 

Today@NASA page:

http://www.nasa.gov/today.html

The NASA TV schedule is available from the NTV Home Page:

http://www.nasa.gov/ntv

Status reports, TV schedules and other information also are available from 

the NASA headquarters FTP (File Transfer Protocol) server, 

ftp.hq.nasa.gov. Log in as anonymous and go to the directory /pub/pao. 

Users should log on with the user name "anonymous" (no quotes), then 

enter their E-mail address as the password. Within the /pub/pao directory 

there will be a "readme.txt" file explaining the directory structure:

* Pre-launch status reports (KSC): ftp.hq.nasa.gov/pub/pao/statrpt/ksc

* Mission status reports (KSC): ftp.hq.nasa.gov/pub/pao/statrpt/jsc

* Daily TV Schedules: ftp.hq.nasa.gov/pub/pao/statrpt/jsc/tvsked.

NASA Spacelink, a resource for educators, also provides mission 

information via the Internet. Spacelink may be accessed at the following 

address:

http://spacelink.nasa.gov

Access by Compuserve

Users with Compuserve accounts can access NASA press releases by 

typing "GO NASA" (no quotes) and making a selection from the categories 

offered.

Updated: 03/27/2000

74
STS-101

Media Contacts

NASA PAO CONTACTS

Dwayne Brown 202 358-1726

NASA Headquarters

Washington, DC

Space Shuttle/Space Station Policy

dwayne.brown@hq.nasa.gov

Eileen Hawley 281 483-5111

NASA, Johnson Space Center

Houston, TX

Astronauts/Mission Operations

eileen.hawley1@jsc.nasa.gov

Dan Beck 818 586-4572

Space Shuttle Main Engines

Canoga Park, CA

Boeing Rocketdyne

daniel.c.beck@boeing.com

Kari Kelley Allen 281-336-4844

The Boeing Company

Houston, TX

International Space Station

kari.k.allen@boeing.com

Jack King 321 861-4358

United Space Alliance

Kennedy Space Center, FL

Shuttle Processing

KingJW@usafoo.unitedspacealliance.com 

Beth Hill 714 372-4736

Boeing

Huntington Beach, CA

Space Shuttle

sara.b.hill@boeing.com

Alan Buis 714 372-4734

Boeing

Huntington Beach, CA

Space Shuttle

alan.d.buis@boeing.com

Updated: 04/07/2000
Table prepared by Richard W. Orloff, 02/2001 

SHUTTLE FLIGHTS AS OF MAY 2000 

97 TOTAL FLIGHTS OF THE SHUTTLE SYSTEM -- 72 SINCE RETURN TO FLIGHT 

STS-103 

12/19/99 - 12/27/99 

STS-93 

07/23/99 - 07/27/99 

STS-96 

05/27/99 - 06/06/99 

STS-90 

04/17/98 - 05/03/98 

STS-95 

10/29/98 - 11/07/98 

STS-87 

11/19/97 - 12/05/97 

STS-91 

06/02/09 - 06/12/98 

STS-94 

07/01/97 - 07/17/97 

STS-85 

08/07/97 - 08/19/97 

STS-83 

04/04/97 - 04/08/97 

STS-82 

02/11//97 - 02/21/97 

STS-80 

11/19/96 - 12/07/96 

STS-70 

07/13/95 - 07/22/95 

STS-78 

06/20/96 - 07/07/96 

STS-63 

02/03/95 - 02/11/95 

STS-86 

09/25/97 - 10/06/97 

STS-75 

02/22/96 - 03/09/96 

STS-64 

09/09/94 - 09/20/94 

STS-84 

05/15/97 - 05/24/97 

STS-73 

10/20/95 - 11/05/95 

STS-60 

02/03/94 - 02/11/94 

STS-81 

01/12/97 - 01/22/97 

STS-65 

07/08/94 - 07/23/94 

STS-51 

09/12/93 - 09/22/93 

STS-79 

09/16/96 - 09/26/96 

STS-62 

03/04/94 - 03/18/94 

STS-56 

04/08/83 - 04/17/93 

STS-76 

03/22/96 - 03/31/96 

STS-58 

10/18/93 - 11/01/93 

STS-53 

12/02/92 - 12/09/92 

STS-74 

11/12/95 - 11/20/95 

STS-55 

04/26/93 - 05/06/93 

STS-42 

01/22/92 - 01/30/92 

STS-71 

06/27/95 - 07/07/95 

STS-99 

02/11/00 - 02/22/00 

STS-52 

10/22/92 - 11/01/92 

STS-48 

09/12/91 - 09/18/91 

STS-66 

11/03/94 - 11/14/94 

STS-88 

12/04/98 - 12/15/98 

STS-50 

06/25/92 - 07/09/92 

STS-39 

04/28/91 - 05/06/91 

STS-46 

07/31/92 - 08/08/92 

STS-89 

01/22/98 - 01/31/98 

STS-40 

06/05/91 - 06/14/91 

STS-41 

10/06/90 - 10/10/90 

STS-45 

03/24/92 - 04/02/92 

STS-77 

05/19/96 - 05/29/96 

STS-35 

12/02/90 - 12/10/90 

STS-51L 

01/28/86 

STS-31 

04/24/90 - 04/29/90 

STS-44 

11/24/91 - 12/01/91 

STS-72 

01/11/96 - 11/20/96 

STS-32 

01/09/90 - 01/20/90 

STS-61A 

10/30/85 - 11/06/85 

STS-33 

11/22/89 - 11/27/89 

STS-43 

08/02/91 - 08/11/91 

STS-69 

09/07/95 - 09/18/95 

STS-28 

08/08/89 - 08/13/89 

STS-51F 

07/29/85 - 08/06/85 

STS-29 

03/13/89 - 03/18/89 

STS-37 

04/05/91 - 04/11/91 

STS-67 

03/02/95 - 03/18/95 

STS-61C 

01/12/86 - 01/18/86 

STS-51B 

04/29/85 - 05/06/85 

STS-26 

09/29/88 - 10/03/88 

STS-38 

11/15/90 - 11/20/90 

STS-68 

09/30/94 - 10/11/94 

STS-9 

11/28/83 - 12/08/83 

STS-41G 

10/05/84 - 10/13/84 

STS-51-I 

08/27/85 - 09/03/85 

STS-36 

02/28/90 - 03/04/90 

STS-59 

04/09/94 – 04/20/94 

STS-5 

11/11/82 - 11/16/82 

STS-41C 

04/06/84 - 04/13/84 

STS-51G 

06/17/85 - 06/24/85 

STS-34 

10/18/89 - 10/23/89 

STS-61 

12/02/93 - 12/13/93 

STS-4 

06/27/82 - 07/04/82 

STS-41B 

02/03/84 - 02/11/84 

STS-51D 

04/12/85 - 04/19/85 

STS-30 

05/04/89 - 05/08/89 

STS-57 

06/21/93 - 07/01/93 

STS-3 

03/22/82 - 03/30/82 

STS-8 

08/30/83 - 09/05/83 

STS-51C 

01/24/85 - 01/27/85 

STS-27 

12/02/88 - 12/06/88 

STS-54 

01/13/93 - 01/19/93 

STS-2 

11/12/81 - 11/14/81 

STS-7 

06/18/83 - 06/24/83 

STS-51A 

11/08/84 - 11/16/84 

STS-61B 

11/26/85 - 12/03/85 

STS-47 

09/12/92 - 09/20/92 

STS-1 

04/12/81 - 04/14/81 

STS-6 

04/04/83 - 04/09/83 

STS-41D 

08/30/84 - 09/05/84 

STS-51J 

10/03/85 - 10/07/85 

STS-49 

05/07/92 - 05/16/92 

 

OV-102 

Columbia 

(26 flights) 

OV-099 

Challenger 

(10 flights) 

OV-103 

Discovery 

(27 flights) 

OV-104 

Atlantis 

(20 flights) 

OV-105 

Endeavour 

(14 flights)