STS-121 Press Kit 
STS-121 Press Kit 
May 2006 CONTENTS i

CONTENTS 

Section Page

STS-121 MISSION OVERVIEW: CONTINUING ON-ORBIT TESTING AND 

STATION MAINTENANCE......................................................................................................... 1

STS-121 TIMELINE OVERVIEW ............................................................................................... 5

MISSION OBJECTIVES ............................................................................................................ 9

LAUNCH AND LANDING ........................................................................................................... 11

LAUNCH............................................................................................................................................... 11

ABORT-TO-ORBIT (ATO)...................................................................................................................... 11

TRANSATLANTIC ABORT LANDING (TAL) ............................................................................................. 1 1

RETURN-TO-LAUNCH-SITE (RTLS)....................................................................................................... 11

LANDING ............................................................................................................................................. 11

ABORT ONCE AROUND (AOA)............................................................................................................... 11

MISSION PROFILE................................................................................................................... 12

STS-121 DISCOVERY CREW ................................................................................................... 13

KEY MISSION PERSONNEL ...................................................................................................... 18

RENDEZVOUS AND DOCKING .................................................................................................. 19

UNDOCKING, SEPARATION AND DEPARTURE ....................................................................................... 22

SPACEWALKS ......................................................................................................................... 23

EVA 1................................................................................................................................................... 23

EVA 2 .................................................................................................................................................. 29

EVA 3 (TENTATIVE) ............................................................................................................................. 30

PAYLOAD OVERVIEW .............................................................................................................. 34

EXPERIMENTS ......................................................................................................................... 44

DETAILED SUPPLEMENTARY OBJECTIVES (DSO) ................................................................................. 44

DETAILED TEST OBJECTIVES (DTO)..................................................................................................... 47

SHUTTLE (SORTIE) EXPERIMENTS ....................................................................................................... 50

EXPERIMENTS DELIVERED TO ISS ....................................................................................................... 51
May 2006 CONTENTS ii

Section Page

FUNGAL PATHOGENESIS, TUMORIGENESIS AND EFFECTS OF HOST IMMUNITY IN SPACE (FIT).......... 52

ANALYSIS OF A NOVEL SENSORY MECHANISM IN ROOT PHOTOTROPISM (TROPI).............................. 53

SPACE SHUTTLE SAFETY ENHANCEMENTS ............................................................................. 54

OVERVIEW........................................................................................................................................... 54

PREPARING THE EXTERNAL TANK RETURN TO FLIGHT EXTERNAL TANK, ET-119 .................................. 55

ENHANCED SHUTTLE-BASED CAMERA VIEWS...................................................................................... 59

IN-FLIGHT INSPECTION AND REPAIR .................................................................................................. 66

IMAGERY AND DATA COLLECTION FOR SPACE SHUTTLE LAUNCH AND LANDING ................................ 72 

TILE REPAIR ABLATOR DISPENSER (T-RAD) .......................................................................... 82

CONTINGENCY SHUTTLE CREW SUPPORT (CSCS) ................................................................ 83

SHUTTLE REFERENCE DATA .................................................................................................... 85

ACRONYMS AND ABBREVIATIONS ......................................................................................... 98

MEDIA ASSISTANCE ............................................................................................................... 115

PUBLIC AFFAIRS CONTACTS .................................................................................................. 116
May 2006 CONTENTS iii

FIGURES 

Figure Page

DISCOVERY CREW ..................................................................................................................................... 1

FULL VIEW OF INTERNATIONAL SPACE STATION ....................................................................................... 2

STEVE LINDSEY.......................................................................................................................................... 2

DISCOVERY UNDERSIDE VIEW................................................................................................................... 3

ASTRONAUT MICHAEL E. FOSSUM ............................................................................................................. 3

RAFFAELLO IN THE AFT BAY OF DISCOVERY............................................................................................... 4

OBSS INSPECTION OF DISCOVERY’S NOSE CAP HEAT SHIELD................................................................... 5

INSTALLATION OF LEONARDO WITH CANADARM2 ..................................................................................... 7

DISCOVERY UNDOCKING FROM ISS WITH THE OBSS IN THE HAND-OFF POSITION ................................... 7

STS-121 DISCOVERY CREW ....................................................................................................................... 13

STS-121 PATCH ......................................................................................................................................... 14

COMMANDER STEVEN LINDSEY.................................................................................................................. 14

PILOT MARK KELLY .................................................................................................................................... 14

MIKE FOSSUM ........................................................................................................................................... 15

LISA NOWAK.............................................................................................................................................. 15

STEPHANIE WILSON .................................................................................................................................. 16

PIERS SELLERS.......................................................................................................................................... 16

THOMAS REITER ........................................................................................................................................ 16

LÉOPOLD EYHARTS .................................................................................................................................... 17

STS-121 AT ANGLE..................................................................................................................................... 19

RPM START (800 MM LENS) ..................................................................................................................... 19

SHUTTLE BELLY-UP (400 MM LENS) .......................................................................................................... 19

ZVEZDA SERVICE MODULE ......................................................................................................................... 20

RENDEZVOUS APPROACH PROFILE............................................................................................................. 20

APPROACH PROFILE .................................................................................................................................. 21

IMAGERY OF DISCOVERY UPPER SURFACE USING 400 AND 800 MM DIGITAL CAMERA LENSES............... 21

IMAGERY OF DISCOVERY BELLY USING 400 AND 800 MM DIGITAL CAMERA LENSES ............................... 21

IUA WITH TUS CABLE ROUTED THROUGH MECHANISM ............................................................................. 24

ASTRONAUT PIERS J. SELLERS PARTICIPATES IN A SIMULATION ............................................................. 24

ENGINEERING MODEL OF THE APFR AND LOAD CELL CONFIGURATION ....................................................... 25

ROBOTIC ARM CLIMB POSITION ............................................................................................................... 26

FIRST POSITION OF THE ROBOTIC ARM .................................................................................................... 26
May 2006 CONTENTS iv

Figure Page

SECOND POSITION OF THE ROBOTIC ARM................................................................................................. 27

INTERMEDIATE POSITION OF THE ROBOTIC ARM ...................................................................................... 2 7

THIRD POSITION OF THE ROBOTIC ARM.................................................................................................... 28

FINAL POSITION OF THE ROBOTIC ARM..................................................................................................... 29

ENGINEERING IMAGERY OF THE S0 TRUSS SEGMENT BEFORE LAUNCH ..................................................... 30

SELLERS AND FOSSUM PRACTICE HAND OVER OF TUS-RA DURING SIMULATED SPACEWALK ................... 30

SELLERS AND FOSSUM PRACTICE REPLACING TUS DURING SIMULATED SPACEWALK .............................. 30

INFRARED CAMERA SIMULATION HARDWARE A ........................................................................................ 31

CONFIGURATION OF THE SAMPLES IN THE DTO PALLET............................................................................. 31

RCC REPAIR TOOLS TO BE USED DURING THE TEST .................................................................................. 32

DISCOVERY PAYLOAD DIAGRAM................................................................................................................ 34

LEONARDO IS LOWERED TOWARD THE CARGO ELEMENT WORK STAND ..................................................... 35

CANADARM2 GRASPS THE RAFFAELLO ...................................................................................................... 36

TECHNICIANS INSPECT THE MINUS EIGHTY LAB FREEZER FOR ISS........................................................... 38

ESA ASTRONAUT REINHOLD EWALD INSERTS AN EXPERIMENT CONTAINER INTO THE EMCS 

ENGINEERING MODEL................................................................................................................................. 40

PLANT CULTIVATION CHAMBER INSIDE EXPERIMENT CONTAINER ............................................................ 40

THE PERCUTANEOUS ELECTRICAL MUSCLE STIMULATOR .......................................................................... 41

EXTERNAL ACTIVE THERMAL CONTROL SYSTEM PUMP MODULE................................................................ 41

PAL RAMPS................................................................................................................................................ 55

EXTERNAL TANK WITH PAL RAMPS REMOVED ........................................................................................... 56

ICE/FROST RAMPS .................................................................................................................................... 57

CURRENT ICE/FROST RAMP ...................................................................................................................... 58

BIPOD INSTALLATION................................................................................................................................ 58

CAMERAS ON THE SPACE SHUTTLE BOOSTERS, EXTERNAL TANK AND ORBITER ........................................ 59

SHUTTLE ORBITER-BASED PHOTOGRAPHY FOR STS-121 ASCENT.............................................................. 60

EXTERNAL TANK CAMERA OVERVIEW ........................................................................................................ 61

SRB-MOUNTED CAMERAS.......................................................................................................................... 62

ET RING CAMERA HOUSING INSTALLED ..................................................................................................... 62

FORWARD SKIRT AFT-POINTING CAMERA PROTOTYPE HOUSING.............................................................. 62

CAMERA CONFIGURATION ......................................................................................................................... 63

RIGHT-HAND UMBILICAL WELL.................................................................................................................. 63

DIGITAL UMBILICAL STILL CAMERA SYSTEM ............................................................................................ 64

EVA FLASH MECHANICAL DESIGN .............................................................................................................. 65
May 2006 CONTENTS v

Figure Page

ORBITER BOOM SENSOR SYSTEM INSTALLED ON STARBOARD SILL .......................................................... 66

INSPECTION SENSORS .............................................................................................................................. 68

LCS, ITVC CAMERA, LDRI, AND PAN/TILT UNIT ......................................................................................... 68

ITVC, LCS, AND LDRI IMAGES.................................................................................................................... 70

CAMERA TYPES AND LOCATIONS............................................................................................................... 72

SHORT-RANGE TRACKING CAMERA ........................................................................................................... 73

LONG-RANGE TRACKER.............................................................................................................................. 73

KINETO TRACKING MOUNT TRACKER ........................................................................................................ 74

MLP DECK.................................................................................................................................................. 75

PAD PERIMETER ........................................................................................................................................ 75

SHORT-RANGE CAMERA CONFIGURATION ................................................................................................. 75

MEDIUM-RANGE CAMERA CONFIGURATION............................................................................................... 76

LONG-RANGE CAMERA CONFIGURATION.................................................................................................... 76

WB-57 AIRCRAFT ...................................................................................................................................... 77

SRB SEPARATION ...................................................................................................................................... 77

C-BAND RADAR ......................................................................................................................................... 78

X-BAND RADAR.......................................................................................................................................... 79

WING LEADING EDGE IMPACT DETECTION SYSTEM ................................................................................... 81

WING LEADING EDGE IMPACT DETECTION SYSTEM ................................................................................... 82

WING LEADING EDGE IMPACT DETECTION SYSTEM ................................................................................... 82

TILE REPAIR ABLATOR DISPENSER (T-RAD) .............................................................................................. 83 

T-RAD DELIVERY SYSTEM .......................................................................................................................... 83 

May 2006 OVERVIEW 1 

Discovery Crew

STS-121 MISSION OVERVIEW: 

CONTINUING ON-ORBIT TESTING 

AND STATION MAINTENANCE

(5 April 2006) — These seven astronauts take a break from training to pose for the STS‐121

crew portrait. From the left are astronauts Stephanie D. Wilson, Michael E. Fossum, both

mission specialists; Steven W. Lindsey, commander; Piers J. Sellers, mission specialist;

Mark E. Kelly, pilot; European Space Agency (ESA) astronaut Thomas Reiter of Germany;

and Lisa M. Nowak, both mission specialists. The crew members are attired in training

versions of their shuttle launch and entry suit.

The crew of Space Shuttle Discovery will

continue to test new equipment and procedures

that increase the safety of space shuttles during

the STS‐121 mission. The flight to the

International Space Station (ISS) also will

deliver critical supplies and cargo to the

complex for repair and future expansion of the

outpost.

The focus of the mission is to carry on analysis

of safety improvements that debuted on the
May 2006 OVERVIEW 2 

first Return to Flight mission, STS‐114, and

build upon those tests. This mission will

continue testing the External Tank designs and

processes that minimize potentially damaging

debris during launch, ground and flight camera

systems to observe the shuttle environment

during launch and on orbit, and techniques for

in‐flight inspection and repair of the shuttle’s

Thermal Protection System (TPS), or heat

shield.

Two spacewalks are planned. They are

devoted to maintenance of the space station

and additional testing of heat shield inspection

and repair materials, tools and techniques.

During the flight, mission managers expect to

evaluate the high probability of shuttle

consumables supporting an extra day for the

mission. If an extra day is available, the crew

and flight control team are training for a third

spacewalk that focuses on reinforced

carbon‐carbon (RCC) inspection and repair.

Full View of International Space Station

Backdropped by the Earth below,

this full view of the International Space

Station was photographed by an

STS‐114 crew member onboard the

Space Shuttle Discovery

Discovery will be docked to the International

Space Station for the majority of the mission.

STS‐121 is designated Utilization and Logistics

Flight‐1.1 (ULF‐1.1) in the space station

assembly sequence. The mission was added to

the sequence as an additional mission to

complete Return to Flight on‐orbit testing

before resuming major assembly of the space

station. The mission’s objectives for the station

will be maintenance work and the delivery of

equipment, supplies, experiments and spare

parts in support of operations and future

station assembly missions.

Discovery will deliver a third crew member to

live aboard the station. It will be the first time a

three‐person crew resides on station for a long

duration since the Expedition 6 crew returned

to Earth May 4, 2003, in Kazakhstan. Without

the space shuttle to ferry equipment to the

station after the Columbia accident, only two

people could be supported onboard until the

necessary provisions were in place. To help

deliver tons of supplies, Discovery will carry an

Italian‐built pressurized cargo container called

Leonardo, in its cargo bay.

Steve Lindsey
May 2006 OVERVIEW 3 

Discovery Underside View

Commanding the STS‐121 mission aboard the

Space Shuttle Discovery is Steve Lindsey, an

Air Force colonel. Joining him will be Pilot

Mark Kelly, a Navy commander, and mission

specialists Michael Fossum (Fŏs‐sŭm),

Stephanie Wilson, Piers (Peers) Sellers and

Navy Cmdr. Lisa Nowak (Nō‐wăc). European

Space Agency (ESA) astronaut Thomas (Toe‐

mahsʹ) Reiter (Rĭt‐ŭr) will ride to space with

the shuttle crew and remain on the station,

joining the Expedition 13 mission already in

progress. Reiter is the first ESA long‐duration

space station crew member and will remain on

board for six to seven months to work with the

Expedition 13 and Expedition 14 crews under a

contract between ESA and the Russian Federal

Space Agency, Roscosmos.

Expedition 13 Commander Pavel Vinogradov

and Flight Engineer Jeffrey Williams have been

aboard the station since arriving on a Russian

Soyuz spacecraft on April 1. The station crew

members will help with the transfer of supplies

to and from the cargo carrier Leonardo and

lend their expertise in airlock and robotic

system operations.

The mission’s top priority is to inspect all of the

reinforced carbon‐carbon heat protection

material on Discovery’s wing leading edge

panels and to downlink the data for evaluation

on the ground. Second on the list of priorities is

inspecting all of the shuttle’s silicon‐based tiles.

The on‐orbit inspections will be carried out

using a variety of methods, including umbilical

well and hand‐held photography and video of

the external tank after it is jettisoned. En route

to the station the day after launch, the crew will

use a 50‐foot‐long Orbiter Boom Sensor System

(OBSS) tipped with two types of lasers and a

high‐resolution television camera to inspect key

areas of the wings for any sign of damage that

may have occurred during launch. This boom

nearly doubles the length of the robotic

capability of the shuttle crane. There are

additional inspections using this equipment

scheduled the day before and the day of

undocking from the space station.

An inspection conducted by the station crew

will focus on the underside of Discovery at a

distance of 600 feet before docking. The shuttle

will be carefully rotated under command of

Lindsey through a back‐flip allowing the

station crew to train cameras on the shuttle as it

approaches. This maneuver, the rendezvous

pitch maneuver (RPM), was first performed

during the STS‐114 mission.

Astronaut Michael E. Fossum

Astronaut Michael E. Fossum, STS‐121

mission specialist, participates in a spacesuit

fit check in the Space Station Airlock Test

Article (SSATA) in the Crew Systems

Laboratory at the Johnson Space Center.
May 2006 OVERVIEW 4 

Two 61⁄2 hour spacewalks are scheduled for

Sellers and Fossum on the fifth and seventh

days of the mission. If an additional day is

available, a third spacewalk will be scheduled

on the ninth day.

For the first spacewalk, the crew members will

use the 50‐foot robotic arm inspection boom as

a potential work platform for hard‐to‐reach

repair sites on the bottom of the orbiter. They

also will begin maintenance of the station’s

mobile transporter (MT) by safing or replacing

a cable cutter on one side of the unit to allow

the robotic system to be translated in support of

the second spacewalk.

During the second spacewalk, on the other side

of the MT, the crew will replace a reel assembly

and the detached cable that was inadvertently

cut and swap out the cable cutter with a

disabled unit. The crew also will install a spare

pump for the thermal control system on the

outside of the station’s Quest airlock for future

use. The replacement cable reel and pump

module will be delivered on a carrier in

Discovery’s cargo bay.

If an extra day is available, the third spacewalk

will include tasks to test techniques for using an

infrared camera for inspecting and materials for

repairing the RCC segments that protect the

orbiter’s nose cone and wing leading edges.

STS‐121 is scheduled to launch during a

planning window extending July 1 to 19.

Discovery will launch from Launch Pad 39B at

Kennedy Space Center, Fla., and rendezvous

with the International Space Station on flight

day 3.

The Leonardo cargo carrier housed in

Discovery’s payload bay will be berthed to the

Raffaello in the Aft Bay of Discovery

The Multi‐Purpose Logistics Module

Raffaello stands out in the aft bay of

Discovery during the STS‐114 mission

space station Unity module’s Earth‐facing port

on flight day 4. This will be the fourth trip to

the station for Leonardo, the first of three such

Italian‐built cargo carriers to be put into service.

Leonardo flew to space for the first time aboard

Discovery during STS‐102 in February 2001.

Included in Leonardo’s cargo is the

Minus Eighty Laboratory Freezer for ISS

(MELFI) that will store extremely cold research

samples, the European Modular Cultivation

System for biological science experiments and

the oxygen generation system (OGS) that will

be activated by a station crew later to

supplement oxygen supplies onboard and a

new cycle ergometer for the station crew.

Equipment and supplies no longer needed on

the station will be moved to Leonardo before it

is unberthed on flight day 10 and put back into

Discovery’s cargo bay for return to Earth.

Undocking is set for flight day 11. Discovery’s

crew will make final preparations for the return

home on flight day 12, with landing at the

Kennedy Space Center’s Shuttle Landing

Facility on flight day 13.
May 2006 TIMELINE 5

STS-121 TIMELINE OVERVIEW 

(IF ONLY TWO SPACEWALKS ARE 

CONDUCTED) 

FLIGHT DAY 1: 

• Launch

• Payload Bay Door Opening

• Ku‐Band Antenna Deployment

• Shuttle Robot Arm Power Up

• External Tank Handheld Video and Wing

Leading Edge Sensor Data Downlink

FLIGHT DAY 2: 

• Shuttle Robot Arm Checkout

• Shuttle Robot Arm Grapple of Orbiter

Boom Sensor System (OBSS)

• Inspection of Shuttle Thermal Protection

System and Wing Leading Edge reinforced

carbon‐carbon (RCC)

• Spacesuit Checkout

• Orbiter Docking System Outer Ring

Extension

• Airlock Preparations

• Rendezvous Tool Checkout

FLIGHT DAY 3: 

• Rendezvous Operations

• Terminal Initiation Engine Firing

• Rendezvous Pitch Maneuver and ISS Digital

Photography of Discovery

OBSS Inspection of Discovery’s Nose Cap Heat Shield

Artist’s rendering of the OBSS inspection of

Discovery’s nose cap heat shield.

• Docking to the International Space Station

• Hatch Opening and Welcoming by

Expedition 13 Crew

• Thomas Reiter Soyuz Seatliner Transfer and

Installation (becomes part of Expedition 13

crew)

• Recharge Oxygen Orifice Bypass Assembly

(ROOBA) Leak Check and Checkout

• Station Robot Arm Grapple of OBSS and

Handoff to Shuttle Robot Arm

FLIGHT DAY 4: 

• Station Robot Arm Grapple of Leonardo

Multi‐Purpose Logistics Module (MPLM)

and Installation on Unity Module

• Station Robotic Arm Walkoff from Destiny

Laboratory to Mobile Base System

• OBSS Survey of Shuttle Reinforced Carbon‐

Carbon

• MPLM Ingress and Start of Cargo Transfers
May 2006 TIMELINE 6

Installation of Leonardo with Canadarm2

Artist’s rendering of the installation of

Leonardo with Canadarm2.

FLIGHT DAY 5: 

• EVA 1 (Zenith Integrated Umbilical

Assembly Replacement on Mobile

Transporter; Orbiter Boom Sensor System

Loads Evaluation)

• Cargo Transfers Continue

FLIGHT DAY 6: 

• Cargo Transfers Continue

• Joint Crew News Conference

FLIGHT DAY 7: 

• EVA 2 (Pump Module Transfer to External

Stowage Platform‐2; Trailing Umbilical

System Replacement on Mobile

Transporter)

• Station Robot Arm Walkoff from Mobile

Base System to Destiny Laboratory

• Cargo Transfers Continue

FLIGHT DAY 8: 

• Cargo Transfers Continue

FLIGHT DAY 9: 

• Crew Off‐Duty Period

FLIGHT DAY 10: 

• Final Cargo Transfers

• MPLM Egress and Deactivation

• Station Robot Arm Detachment of MPLM

from Unity for Berthing in Discovery

Payload Bay

• Station Robot Arm Grapple of OBSS from

Shuttle Robot Arm for Final Berthing

• Shuttle Robot Arm/OBSS Late Inspection of

Discovery’s Port Wing

FLIGHT DAY 11: 

• Final Farewells and Hatch Closing

• Undocking of Discovery from ISS

• Final Separation Maneuver

• Shuttle Robot Arm/OBSS Late Inspection of

Discovery’s Starboard Wing and Nose Cap

• Crew Off‐Duty Period

Discovery undocking fromPosition ISS with the OBSS in the Hand‐off

Artist’s rendering of Discovery undocking

from ISS with the OBSS in the  

hand‐off position.
May 2006 TIMELINE 7

FLIGHT DAY 12: 

• Flight Control System Checkout

• Reaction Control System Hot‐Fire Test

• Cabin Stowage

• Deorbit Timeline Review

• Ku‐Band Antenna Stowage

FLIGHT DAY 13: 

• Deorbit Preparations

• Payload Bay Door Closing

• Deorbit Burn

• KSC Landing

(IF THREE SPACEWALKS ARE 

CONDUCTED) 

Flight days 1 ‐ 7 would remain the same, but

activities on the following days would change.

FLIGHT DAY 8: 

• Cargo Transfers Continue

• Crew Off‐Duty Period

FLIGHT DAY 9: 

• EVA 3 (RCC Crack Repair Technique

Demonstration)

FLIGHT DAY 10: 

• Cargo Transfers Continue

• Crew Off‐Duty Period

FLIGHT DAY 11: 

• Final Cargo Transfers

• MPLM Egress and Deactivation

• Station Robot Arm Detachment of MPLM

from Unity for Berthing in Discovery

Payload Bay

• Station Robot Arm Grapple of OBSS from

Shuttle Robot Arm for Final Berthing

• Shuttle Robot Arm/OBSS Late Inspection of

Discovery’s Port Wing

FLIGHT DAY 12: 

• Final Farewells and Hatch Closing

• Undocking of Discovery from ISS

• Final Separation Maneuver

• Shuttle Robot Arm/OBSS Late Inspection of

Discovery’s Starboard Wing and Nose Cap

FLIGHT DAY 13: 

• Flight Control System Checkout

• Reaction Control System Hot‐Fire Test

• Cabin Stowage

• Deorbit Timeline Review

• Ku‐Band Antenna Stowage

FLIGHT DAY 14: 

• Deorbit Preparations

• Payload Bay Door Closing

• Deorbit Burn

• KSC Landing

May 2006 MISSION OBJECTIVES 8

MISSION OBJECTIVES 

Objectives for the STS‐121 Space Shuttle

mission include (in order of priority):

• Perform orbiter reinforced carbon‐carbon

(RCC) inspection using the Orbiter Boom

and Sensor System (OBSS) attached to the

Shuttle Remote Manipulator System (SRMS)

and downlink the OBSS sensors data to the

ground for evaluation.

• Perform orbiter tile inspection using ISS

imagery during the Rendezvous Pitch

Maneuver (RPM).

• Perform orbiter RCC inspection of the wing

leading edge of both wings and nose cap

prior to deorbit and landing to detect

micrometeoroid orbital debris (MMOD)

damage and downlink the sensor data to

the ground for evaluation.

• Transfer mandatory quantities of water

from the shuttle to the station.

• Augment Expedition 13 crew, transfer

mandatory crew augmentation cargo and

perform mandatory tasks consisting of

individual equipment liner kit, or Soyuz

seatliner (IELK), and Sokol suit checkout.

• Remove and replace the failed trailing

umbilical system (TUS)‐reel assembly (RA)

and interface umbilical assembly (IUA) on

the station with the new TUS‐RA and IUA.  

Return the failed TUS‐RA on the integrated

cargo carrier (ICC) and return the failed

IUA on the middeck.

• Berth Multi‐Purpose Logistics Module

(MPLM) to Unity Node 1.  Activate and

check out MPLM.

• Perform Detailed Test Objective (DTO) 849 ‐ 

OBSS/SRMS loads characterization with

extravehicular activity (EVA) crew

members during an EVA (see ʺSpacewalkʺ 

and ʺDetailed Supplementary Objectives

and Detailed Test Objectivesʺ sections for

details).

• Perform DTO 850 ‐ water spray boiler

cooling with water/ propylene glycol

monomethyl ether (PGME) mixture.

• Transfer critical cargo which includes items

to ensure crew and vehicle safety, items that

are required to support flight and stage

objectives, samples and data collection

items for return, hardware for return and

refurbishment, and increment science

objectives and last flight opportunity items

before implementation.

• Perform seven hours of crew handover for

augmented crew member.

• Return MPLM to orbiter payload bay.

• Remove the pump module (PM) with fixed

grapple bar (FGB) installed from the ICC

and install on the external stowage

platform 2 (ESP2).

• Transfer and install the oxygen generation

system (OGS).

• Transfer and install the Minus Eighty

Degrees Laboratory Freezer (MELFI).

• Transfer and install the starboard common

cabin air assembly (CCAA) heat exchanger.

• Perform recharge oxygen orifice bypass

assembly (ROOBA) checkout.
May 2006 MISSION OBJECTIVES 9

• Disassemble and exchange cycle ergometer

with vibration isolation system (CEVIS).

• Transfer required nitrogen from the orbiter

to the station Quest Airlock high pressure

gas tank (HGPT).

• Perform Station Development Test

Objective (SDTO) 12004‐U, shuttle booster

fan bypass.

• Transfer remaining cargo.

• Remove and replace the Microgravity

Science Glovebox (MSG) front window.

• Swap ISS and orbiter printer.

• Transfer oxygen from the orbiter to the

station Quest Airlock HGPT, if required.

• Perform daily ISS payload status checks, as

required.

• Reboost ISS with the orbiter to no more than

186.7 nautical miles, or 214.9 statute miles,

average orbital altitude, if propulsive

consumables are available.

• Perform middeck sortie payload activities.

• Perform ram burn observation (RAMBO)

payload operations.

• Perform Maui Analysis of

Upper‐Atmospheric Injections (MAUI)

payload operations.

• Perform an imagery survey of the ISS

exterior during an orbiter flyaround after

undocking, if propulsive consumables are

available.

• Perform U.S. operating segment

(USOS)/Russian segment (RS) payload

research operations tasks.

• Perform DTO 852, SRMS On‐orbit loads,

heavy payloads.

• Perform station development test objective

(SDTO) 13005‐U, ISS structural life

validation and extension for orbiter reboost,

integrated wireless instrumentation system

(IWIS) only if crew time is available.

• Perform station development test objective

(SDTO) 13005‐U, ISS structural life

validation and extension for orbiter

undocking, integrated wireless

instrumentation system (IWIS) only if crew

time is available.

• Perform ISS‐approved EVA get‐ahead tasks.
May 2006 LAUNCH & LANDING 10

LAUNCH AND LANDING 

LAUNCH 

As with all previous space shuttle launches,

Discovery on STS‐121 will have several modes

available that could be used to abort the ascent

if needed due to engine failures or other

systems problems.  Shuttle launch abort

philosophy aims toward safe recovery of the

flight crew and intact recovery of the orbiter

and its payload.  Abort modes include:

ABORT-TO-ORBIT (ATO) 

Partial loss of main engine thrust late enough to

permit reaching a minimal 105 by 85 nautical

mile orbit with orbital maneuvering system

engines.

TRANSATLANTIC ABORT LANDING 

(TAL) 

Loss of one or more main engines midway

through powered flight would force a landing

at either Zaragoza, Spain; Moron, Spain; or

Istres, France. For launch to proceed, weather

conditions must be acceptable at one of these

TAL sites.

RETURN-TO-LAUNCH-SITE (RTLS) 

Early shutdown of one or more engines, and

without enough energy to reach Zaragoza,

would result in a pitch around and thrust back

toward KSC until within gliding distance of the

Shuttle Landing Facility.  For launch to

proceed, weather conditions must be forecast to

be acceptable for a possible RTLS landing at

KSC about 20 minutes after liftoff.

LANDING 

The primary landing site for Discovery on

STS‐121 is the Shuttle Landing Facility at

Kennedy Space Center.  Alternate landing sites

that could be used if needed due to weather

conditions or systems failures are at Edwards

Air Force Base, Calif., and White Sands Space

Harbor, N.M.

ABORT ONCE AROUND (AOA) 

An AOA is selected if the vehicle cannot

achieve a viable orbit or will not have enough

propellant to perform a deorbit burn, but has

enough energy to circle the Earth once and land

about 90 minutes after liftoff.

May 2006 MISSION PROFILE 11

MISSION PROFILE 

CREW 

Commander: Steve Lindsey

Pilot: Mark Kelly

Mission Specialist 1: Mike Fossum

Mission Specialist 2: Lisa Nowak

Mission Specialist 3: Stephanie Wilson

Mission Specialist 4: Piers Sellers

Mission Specialist 5: Thomas Reiter

LAUNCH 

Orbiter: Discovery (OV‐103)

Launch Site: Kennedy Space Center

Launch Pad 39B

Launch Date: No earlier than July 1,

2006

Launch Time: 3:49 p.m. EDT (Preferred

in‐plane launch time for

7/1)

Launch Window: 5 minutes

Altitude: 122 nautical miles

(140 Statute Miles)

Orbital insertion; 185 NM

(212 SM) rendezvous

Inclination: 51.6 degrees

Duration: 11 days 19 hours

12 minutes

VEHICLE DATA 

Shuttle Liftoff Weight: 4,523,850

pounds

Orbiter/Payload Liftoff Weight: 266,962

pounds

Orbiter/Payload Landing Weight: 225,741

pounds

Software Version: OI‐30

Space Shuttle Main Engines: 

SSME 1: 2045

SSME 2: 2051

SSME 3: 2056

External Tank: ET‐119

SRB Set: BI‐126

RSRM Set: 93

SHUTTLE ABORTS 

Abort Landing Sites 

RTLS: Kennedy Space Center Shuttle

Landing Facility

TAL: Primary – Zaragoza; alternates

Moron and Istres

AOA: Primary – Kennedy Space Center

Shuttle Landing Facility; alternate

White Sands Space Harbor

Landing 

Landing Date: No earlier than July 13,

2006

Landing Time: 10:46 a.m. EDT

Primary landing Site: Kennedy Space Center

Shuttle Landing Facility

PAYLOADS 

Multi‐Purpose Logistics Module (MPLM)

Integrated Cargo Carrier (ICC)

Lightweight Multi‐Purpose Experiment

Structure Carrier (LMC)

May 2006 CREW 12

STS-121 DISCOVERY CREW 

The STS‐121 crew was first named in December

2003 after the flight was added to the space

shuttle schedule to help accommodate the

growing list of requirements originally

assigned to the first Return to Flight mission,

STS‐114.  The initial crew included Commander

Steven W. Lindsey, an Air Force colonel,  Pilot

Mark E. Kelly, a Navy commander, and mission

specialists Carlos I. Noriega  and Michael E.

Fossum.

Noriega was replaced by Piers J. Sellers in July

2004 because of a temporary medical condition.

Mission specialists Lisa M. Nowak, a Navy

commander, and Stephanie D. Wilson were

added to the flight in November 2004.

The mission was declared a crew rotation flight

when NASA determined returning to a three‐

person crew aboard the International Space

Station would be possible following the first

two shuttle supply missions.  Thomas Reiter

was added to the flight in July 2005.

Short biographical sketches of the crew follow

with detailed background available at:

http://www.jsc.nasa.gov/Bios/ and

http://www.esa.int/esaHS/astronauts.html

STS‐121 Discovery Crew
May 2006 CREW 13

STS‐121 Patch

The STS‐121 patch depicts the space shuttle

docked with the International Space Station in

the foreground, overlaying the astronaut

symbol with three gold columns and a gold

star.  The ISS is shown in the configuration

that it will be in during the STS‐121 mission.  

The background shows the nighttime Earth

with a dawn breaking over the horizon.

Commander Steven Lindsey is a veteran of

three spaceflights and a second‐time

commander who has overall responsibility for

the on‐orbit execution of the mission, orbiter

systems operations, and flight operations

including landing the orbiter.  In addition, he

will fly the shuttle in a procedure called the

rendezvous pitch maneuver while Discovery is

600 feet below the station before docking to

enable the ISS crew to photograph the orbiterʹs

heat shield.  He will then dock Discovery to the

station.  He will also be heavily involved in

inspections of Discovery’s heat shield and

transferring cargo to and from the shuttle.

Commander Steven Lindsey

Commander Steven Lindsey

Pilot Mark Kelly is flying for the second time

and will be responsible for systems operations

and assisting in the rendezvous and docking to

the International Space Station.  He will also

serve as the intravehicular activity crew

member helping to suit up and choreograph

spacewalkers Piers Sellers and Michael Fossum

during their spacewalks.  In addition, he will be

heavily involved in inspections of Discovery’s

heat shield and transferring cargo to and from

the shuttle.  He will undock Discovery from the

station at the end of the mission.

Pilot Mark Kelly

Pilot Mark Kelly
May 2006 CREW 14

Mission Specialist 1 (MS1) Michael Fossum will

make his first venture into space.  Fossum will

perform two to three spacewalks, as EV2 with

his colleague Piers Sellers, to test shuttle heat

shield inspection and repair techniques.  

Testing will include evaluating the robotic

boom extension as a work platform and testing

repair materials and hardware for damaged

shuttle heat shield components.  He will also

continue International Space Station assembly

by replacing failed hardware and installing

spare parts on the outside of the complex.  

Fossum will also assist with inspections of

Discovery’s heat shield.  Fossum will be seated

on the flight deck for launch and the middeck

for landing.

Mike Fossum

Mike Fossum

Mission Specialist 2 (MS2) is astronaut Lisa

Nowak, making her first flight into space.  She

will serve as the flight engineer on STS‐121,

adding a third set of eyes on orbiter systems for

the commander and the pilot on the flight deck

during launch and landing.  As a robotic arm

operator, she will maneuver her crewmates and

hardware during the two to three spacewalks

using the shuttle arm on the first and the station

arm for the second and third spacewalks.  She

will also perform heat shield inspections with

the orbiter boom sensor system and use the

station robotic arm to handoff the boom to the

shuttle arm.  During the rendezvous, docking

and undocking, she will manage computers,

lasers, cameras, and the orbiter docking system.

Lisa Nowak

Lisa Nowak

Mission Specialist 3 (MS3) is astronaut

Stephanie Wilson.  She is making her first flight

into space.  She will serve as the overall lead for

transferring supplies from the shuttleʹs cargo

module to the station.  She also will serve as a

robotic arm operator, using the space station

robotic arm to install the Leonardo cargo

module onto the station and to handoff the

boom to the shuttle arm, and use the orbiter

boom sensor system to inspect Discovery’s heat

shield.  Prior to the spacewalks, she will assist

with suit‐up of the spacewalkers.  During the

rendezvous, docking and undocking, she will

manage the hand‐held laser and the orbiter

docking system.  Wilson will be seated on the

middeck for launch and the flight deck for

landing.
May 2006 CREW 15

Stephanie Wilson

Stephanie Wilson

Mission Specialist 4 (MS4) is astronaut Piers

Sellers, a veteran of one spaceflight.  His main

objective is to lead and perform two to three

spacewalks, as EV1 along with his

spacewalking colleague, Michael Fossum.  

During the spacewalks, they will test shuttle

heat shield inspection and repair techniques.  

Testing will include evaluation of the robotic

boom extension as a work platform and testing

of repair materials and hardware for damaged

heat shield components.  He will also continue

International Space Station assembly by

replacing failed hardware and installing spare

parts on the outside of the complex.  Sellers will

be seated on the middeck for launch and

landing.

Piers Sellers

Piers Sellers

International Space Station Flight Engineer

Thomas Reiter (FE2), representing the

European Space Agency (ESA), is flying to the

space station aboard Discovery.  He will lead

the transfer of supplies from the shuttleʹs cargo

module to the space station during the

spacewalks and he will assist with suit‐up prior

to the spacewalks.  He is conducting his second

long‐duration spaceflight mission.  He spent

179 days in space in 1995‐1996 on a mission to

the Russian Mir space station during which he

conducted two spacewalks and about 40

European scientific experiments.  Reiter is the

first ESA astronaut to live aboard the

International Space Station for a long‐term

mission.  Reiter will work on the station as part

of an agreement between the Russian Federal

Space Agency and ESA.  Reiter will be on the

middeck for launch and remain on the space

station until the STS‐116 space shuttle, or a

Soyuz, mission.

Thomas Reiter

Thomas Reiter
May 2006 CREW 16

ESA astronaut Léopold Eyharts is serving as

Reiter’s backup for the long‐duration space

station mission and would be conducting his

second spaceflight if needed.  His previous

mission in 1998 was aboard the Russian Mir

space station during which he performed

various French experiments in the area of

medical research, neuroscience, biology, fluid

physics and technology.

Léopold Eyharts

Léopold Eyharts

May 2006 KEY PERSONNEL 17

KEY MISSION PERSONNEL 

KEY CONSOLE POSITIONS FOR STS-121 

Flt. Director CAPCOM PAO

Ascent Steve Stich Steve Frick

Rick Sturckow (Wx)

Rob Navias

Orbit 1 (Lead) Tony Ceccacci Rick Mastracchio Kylie Clem (Lead)

Orbit 2 Norm Knight Lee Archambault Kelly Humphries  

Planning Paul Dye Steve Swanson John Ira Petty

Nicole Cloutier

Lemasters

Entry Steve Stich Steve Frick

Rick Sturckow (Wx)

Kelly Humphries

ISS Orbit 1 Annette Hasbrook Megan McArthur n/a

ISS Orbit 2 (Lead) Rick LaBrode Julie Payette n/a

ISS Orbit 3 Matt Abbott Thadd Bowers n/a

Mission Control,

Korolev, Russia

Cathy Koerner n/a n/a

    

JSC PAO Representative at KSC for Launch – Kyle Herring

KSC Launch Commentator – Bruce Buckingham

KSC Launch Director – Mike Leinbach

NASA Launch Test Director – Jeff Spaulding

May 2006 RENDEZVOUS & DOCKING 18

RENDEZVOUS AND DOCKING 

Discovery’s approach to the International Space

Station during the STS‐121 rendezvous and

docking process will include a tricky maneuver

first demonstrated on STS‐114.  The orbiter will

be commanded to conduct a back flip, enabling

station crew members to take digital images of

the shuttle’s heat shield.

STS‐121 at Angle

With Commander Steve Lindsey at the controls,

Discovery will perform the 360‐degree pitch‐

around maneuver with the orbiter about 600

feet below the station.  The flip will take about

nine minutes to complete, offering Expedition

13 Commander Pavel Vinogradov and Flight

Engineer Jeffrey Williams time to photograph

tile surface imagery of Discovery.

The photos will then be downlinked through

the station’s Ku‐band communications system

for analysis by systems engineers and mission

managers.

The photos will be taken out of windows 6 and

7 in the Zvezda service module with Kodak

DCS 760 digital cameras and 400mm and

800mm lenses.  The imagery during the

rendezvous pitch maneuver (RPM) is among

several inspection procedures instituted after

the Columbia accident designed to detect and

determine the extent of any damage the

orbiter’s protective tiles and reinforced carbon‐

carbon surfaces might have sustained.

The sequence of events that brings Discovery to

its docking with the station begins with the

precisely timed launch of the shuttle, placing

the orbiter on the correct trajectory and course

for its two‐day chase to arrive at the station.  

During the first two days of the mission,

periodic engine firings will gradually bring

Discovery to a point about 91⁄2 miles behind the

station, the starting point for a final approach.

1. 2.

1. 800 mm lens RPM Start (800 mm lens)

2. 400 mm lens Shuttle Belly‐up (400 mm lens)
May 2006 RENDEZVOUS & DOCKING 19

About 21⁄2 hours before the scheduled docking

time on flight day 3, Discovery will reach that

point, about 50,000 feet behind the ISS.  There,

Discovery’s jets will be fired in a terminal

initiation (TI) burn to begin the final phase of

the rendezvous.  Discovery will close the final

miles to the station during the next orbit.

As Discovery moves closer to the station, the

shuttle’s rendezvous radar system and

trajectory control sensor (TCS) will begin

tracking the complex, and providing range and

closing rate information to the crew.  During

the final approach, Discovery will execute

several small mid‐course corrections at regular

intervals with its steering jets.  That will place

Discovery at a point about 1,000 feet directly

below the station where Lindsey will take over

the manual flying of the shuttle up the R‐Bar, or

radial vector toward the complex, the

imaginary line drawn between the station and

the Earth.

Zvezda Service Module

Station crew members will use Earth‐facing

windows in the Zvezda Service Module to

take photographs during the Rendezvous

Pitch Maneuver.

Rendezvous Approach Profile

Space Shuttle Rendezvous Maneuvers

OMS-1 (Orbit insertion) - Rarely used ascent 

burn.

OMS-2 (Orbit insertion) - Typically used to 

circularize the initial orbit following ascent, 

completing orbital insertion. For ground-up 

rendezvous flights, also considered a 

rendezvous phasing burn.

NC (Rendezvous phasing) - Performed to hit a 

range relative to the target at a future time.

NH (Rendezvous height adjust) - Performed 

to hit a delta-height relative to the target at a 

future time.

NPC (Rendezvous plane change) - Performed 

to remove planar errors relative to the target at 

a future time.

NCC (Rendezvous corrective combination) -

First on-board targeted burn in the rendezvous 

sequence. Using star tracker data, it is 

performed to remove phasing and height errors 

relative to the target at Ti.

Ti (Rendezvous terminal intercept) - Second 

on-board targeted burn in the rendezvous 

sequence. Using primarily rendezvous radar 

data, it places the orbiter on a trajectory to 

intercept the target in one orbit.

MC-1, MC-2, MC-3, MC-4 (Rendezvous 

midcourse burns) - These on-board targeted 

burns use star tracker and rendezvous radar 

data to correct the post-Ti trajectory in 

preparation for the final, manual proximity 

operations phase.

Rendezvous Approach Profile
May 2006 RENDEZVOUS & DOCKING 20

He will slow Discovery’s approach and fly to a

point about 600 feet directly below the station,

and if required, wait for the proper lighting

conditions.  The rendezvous is designed to

optimize lighting for inspection imagery as well

as crew visibility for critical rendezvous events.

Approach Profile

On verbal cue from Pilot Mark Kelly to alert the

station crew, Lindsey will command Discovery

to begin a nose‐forward, three‐quarter of a

degree per second rotational back flip.  At RPM

start, the ISS crew will begin of series of

photographs for inspection.  The sequence of

photography mapping provides optimization

of the lighting conditions.

Both the 400 and 800 mm digital camera lenses

will be used to photograph the required

surfaces of the orbiter.  The 400 mm lens

provides up to 3 inch resolution and the 800 can

provide up to 1 inch resolution as well as detect

gap filler protrusions of greater than .25 inch.  

The imagery includes the upper surfaces of the

shuttle as well as Discovery’s belly, nose

landing gear door seals, the main landing gear

door seals and the elevon cove with 1 inch

analytical resolution.  Since the STS‐114

mission, additional zones were added for the

800 mm lens to focus on the gap fillers on

Discovery’s belly when the orbiter is at 145 and

230 degree angles during the flip.  There should

be enough time for two sets of pictures.

Imagery of Discovery Digital Upper Camera SurfaceLenses Using 400 and 800 mm

bottomside_800mm.cnv

NOTE

1. indicates

critical focus

point.

2. Sequence is

~16 shots;

repeat

sequence, as

time allows.

bottomside_800mm.cnv

NOTE

1. indicates

critical focus

point.

2. Sequence is

~16 shots;

repeat

sequence, as

time allows.

Imagery of DiscoveryCamera Belly Using Lenses400 and 800 mm Digital

When Discovery completes its rotation, it will

return to an orientation with its payload bay

facing the station.

Lindsey will then move Discovery to a position

about 400 feet in front of the station along the

V‐Bar, or the velocity vector, the direction of

travel for both spacecraft.  Kelly will provide

Lindsey with navigation information as he

slowly inches the shuttle toward the docking

port at the forward end of the station’s Destiny

Laboratory.

Mission specialists Lisa Nowak and Stephanie

Wilson also will play key roles in the

rendezvous.  They will operate laptop

computers processing the navigational data, the

laser range systems and Discovery’s docking

mechanism.
May 2006 RENDEZVOUS & DOCKING 21

Using a view from a camera mounted in the

center of Discovery’s docking mechanism as a

key alignment aid, Lindsey will precisely align

the docking ports of the two spacecraft.  He will

fly to a point where the docking mechanisms

are 30 feet apart and pause to check the

alignment.

For Discovery’s docking, Lindsey will maintain

the shuttleʹs speed relative to the station at

about one‐tenth of a foot per second (while both

Discovery and the station are traveling at about

17,500 mph), and keep the docking mechanisms

aligned to within a tolerance of three inches.  

When Discovery makes contact with the

station, preliminary latches will automatically

attach the two spacecraft.  Immediately after

Discovery docks, the shuttleʹs steering jets will

be deactivated to reduce the forces acting at the

docking interface.  Shock‐absorber‐like springs

in the docking mechanism will dampen any

relative motion between the shuttle and the

station.

Once that motion between the spacecraft has

been stopped, Wilson will secure the docking

mechanism, sending commands for Discovery’s

docking ring to retract and to close a final set of

latches between the two vehicles.

UNDOCKING, SEPARATION AND 

DEPARTURE 

Additional inspections of Discovery’s heat

shield are scheduled on flight day 10, the day

before undocking, and flight day 11

immediately following undocking.  Therefore,

the orbiter will undock with the shuttle robotic

arm and OBBS deployed.  The OBSS will then

be stowed in Discovery’s payload bay after the

inspections are completed.

Once Discovery is ready to undock, Wilson will

send a command to release the docking

mechanism.  At initial separation of the

spacecraft, springs in the docking mechanism

will push the shuttle away from the station.  

Discovery’s steering jets will be shut off to

avoid any inadvertent firings during the initial

separation.

Once Discovery is about two feet from the

station, with the docking devices clear of one

another, Kelly will turn the steering jets back on

and fire them to very slowly move away.  From

the aft flight deck, Kelly will manually control

Discovery within a tight corridor as the orbiter

separates from the station, essentially the

reverse of the task performed by Lindsey just

before Discovery docked.

Discovery will continue away to a distance of

about 450 feet, where Kelly will initiate the first

of two separation burns to fly the shuttle above

the station.  A full flyaround of the station is

not planned to conserve time for further

inspections of Discoveryʹs heat shield.  Once

directly above the station, Kelly will fire

Discoveryʹs jets to leave the station area.  

Discovery will station keep at a distance of 40

nautical miles from ISS until the late inspection

imagery is reviewed and the Mission

Management Team clears the orbiter for

landing.  This position allows Discovery the

opportunity to redock to the station if needed.
May 2006 SPACEWALKS 22

SPACEWALKS 

The STS‐121 and Expedition 13 crews will work

together to accomplish two spacewalks.  They

will focus on shuttle thermal protection system

repair techniques and space station assembly

and repair tasks.

A third spacewalk also will be conducted if

mission managers determine the shuttle has

enough consumables for an extra day for the

mission.  The third spacewalk would include

tests of techniques for inspecting and repairing

the orbiter’s heat shield, the reinforced

carbon‐carbon (RCC) segments that protect the

orbiter’s nose cone and wing leading edges.

Each of the spacewalks by Piers Sellers and

Mike Fossum will last 61⁄2 hours.  They will be

conducted from the station’s Quest airlock on

flight days 5 and 7.  The third spacewalk would

be on flight day 9.  They would be the 20th, 21st

and 22nd Quest‐based EVAs in support of

space station assembly.

These will be the first spacewalks for Fossum.  

Sellers conducted three previous spacewalks on

the STS‐112 shuttle mission to station in

October 2002, during which he helped install

the starboard one (S1) truss segment.

Sellers will be designated EV1 and will wear

the spacesuit with red stripes.  Fossum will be

designated EV2 and will wear no stripes on his

spacesuit.  Discovery Pilot Mark Kelly will be

the intravehicular activity (IVA) crew member,

offering advice and coordinating spacewalk

activities from inside the complex.

Mission Specialists Lisa Nowak and Stephanie

Wilson will maneuver their crewmates and

hardware during the three spacewalks using

the shuttle arm on the first and the station arm

for the second and third spacewalks.

Expedition 13 crew members Jeffrey Williams

and Thomas Reiter will help with the

spacewalks.  During preparations for the first

spacewalk, Williams will join Kelly and Wilson

in the Quest Airlock to help with spacewalk

preparations.  Reiter will assist with

preparations for the third spacewalk.

Before each spacewalk, Sellers and Fossum will

prepare by exercising on the station’s bicycle

ergometer.  Designed to purge nitrogen from

the blood, the procedure involves breathing

pure oxygen while exercising vigorously.  It

prevents the spacewalkers from getting painful

decompression sickness, or the bends, during

the spacewalk.

EVA 1 

During the first spacewalk, the crew members

will test the 50‐foot robotic arm boom

extension, usually used for remote shuttle

thermal protection system (TPS) inspections, as

a potential work platform for hard‐to‐reach

repair sites on the bottom of the orbiter for

detailed test objective (DTO) 849.  They will

also begin maintenance of the station’s mobile

transporter (MT) by safing or replacing a cable

cutter and routing a cable on the MT to allow it

to be moved before the second spacewalk.
May 2006 SPACEWALKS 23

The cable cutter, called an interface umbilical

assembly (IUA), is on the top, or zenith side of

the MT.  A duplicate device on the Earth‐facing,

or nadir side, of the MT inadvertently cut the

nadir cable in December 2005.

IUA with TUS Cable Routed through Mechanism

Engineering photo of the IUA with the TUS

cable routed through mechanism before

launch and installation on ISS.

The crew will first work on keeping the zenith

IUA from activating in the future by either

installing a device to block the cutter from the

cable or remove the IUA and replace it with a

new unit launched on Discovery.  The

Expedition 12 crew had tried to safe the zenith

IUA during a spacewalk in March by installing

a safing bolt, but the bolt could not be inserted.  

To prevent the cable from being inadvertently

cut, that crew removed it from the IUA until the

STS‐121 crew could work on it.  Sellers and

Fossum will re‐route the Trailing Umbilical

System (TUS) cable through the IUA, once it is

configured safely, to allow the MT to be moved

from worksite 4 (WS4) to worksite 5 (WS5 on

the station’s truss) in advance of EVA 2.

The next objective of the spacewalk, is to test

the new robotic boom as an orbiter tile

inspection or repair work platform.

Astronaut Piers J. Sellers Participates in a Simulation

Astronaut Piers J. Sellers, wearing a training

version of the extravehicular mobility unit

spacesuit, participates in a simulation.  He is

anchored on the end of the training version of

the space shuttle remote manipulator system

(RMS) robotic arm in the Space Vehicle

Mockup Facility at Johnson Space Center.  

Lora Bailey (right), manager, JSC engineering

tile repair, assisted Sellers.  Astronaut Michael

E. Fossum (center), mission specialist, also

participated in the test.

For the test, first Sellers and then both crew

members, will work on the end of the boom.  

They will simulate repair‐related movements in

at least three different OBSS positions.  Sensors

installed on the OBSS and imagery from

various cameras will provide post‐flight

information to engineers that will help them

evaluate the stability of the boom.

Much of the test will be dedicated to setting up

tools and the OBSS for the movements and then

reconfiguring at the end.  The movements of

the spacewalkers for the tests in the three arm

positions are scheduled to take about

30 minutes each.  The spacewalkers will

provide comments about each movement,

while the sensors in the load cell record

quantitative data for review following the

mission.
May 2006 SPACEWALKS 24

After leaving the Quest airlock, Sellers and

Fossum will first safe the zenith IUA as

described above.  Then they will move to the

pressurized mating adapter (PMA) 1 to retrieve

an articulating portable foot restraint (APFR)

with a tool stanchion (TS).  Next they will work

their way down to Discovery’s payload bay,

hand‐over‐hand to setup for the test.  Once in

the payload bay, Sellers will temporarily place

the APFR/TS on the integrated cargo carrier

(ICC) and Fossum will configure it.

Sellers will then continue set up by deploying a

sensor, called a load cell or instrumented

worksite interface fixture (IWIF), which he will

install later on the OBSS.  Commander Steve

Lindsey will use a laptop computer inside

Discovery, with an RF antenna installed, to

activate the sensor.

Nowak and Wilson will then move the shuttle’s

robotic arm so that the end of the OBSS/SRMS

hovers above the starboard sill of the payload

bay.  There, Sellers will install several safety

tethers onto the OBSS.  Nowak and Wilson will

then move the tip of the OBSS to just above the

starboard sill of the payload bay.

Sellers will install the activated load cell and a

portable foot restraint attachment device

(PAD).  Since this will be the first time that

crew members interact directly with the OBSS,  

Engineering Model of the APFR and Load Cell Configuration

Engineering model of the Articulating

Portable Foot Restraint (APFR)  

and load cell configuration.

Fossum will be on hand to physically stabilize

the OBSS any time Sellers is performing setup

and cleanup activities with it.  Next, Sellers and

Fossum will work together to move the

APFR/TS onto the top of the load cell now on

the tip of the OBSS.  Sellers will extend the TS

and ingress the APFR.

With setup complete, Nowak and Wilson will

maneuver the robotic boom into the first test

position, with Sellers riding at the end of the

OBSS.  Fossum will stay in the payload bay and

take digital photos during the first test.
May 2006 SPACEWALKS 25

Robotic Arm Climb Position

Graphics show the position where Sellers and later Fossum can climb on to the robotic arm.

For the first position, the end of the boom is

about 14 feet from the payload bay, directly

above the position where Sellers got on the

boom.  Once the boom is in place, Sellers will

perform several movements to simulate real

inspection or repair actions.  The positions will

simulate movement of a crew member on the

tip of the boom during translation to, and while

inspecting a potential damage site on the

bottom of the orbiter.  They include Sellers

simulating taking photographs, laying back

slightly to retrieve a tool behind him, reaching

for equipment in front of him, and making

positional changes to the APFR and TS.

Due to the addition of the zenith IUA tasks to

this EVA, time for the OBSS tests could be

reduced.  If the IUA task is completed faster

than estimated, the arm will be moved into a

second boom position for the tests.  If there is

not enough time, the arm will be moved

directly to the payload bay sill for Fossum to

attach to the boom and move directly into the

third evaluation position.

First Position of the Robotic Arm

Graphics show the first position of the robotic arm for the test.
May 2006 SPACEWALKS 26

Second Position of the Robotic Arm

Graphics show the second position of the robotic arm for the test.

The second position, where Sellers will perform

additional movements, has the end of the OBSS

extending about 27 feet to the port and aft of

Discovery’s payload bay.  This position has the

SRMS joints in a slightly “weaker”

configuration which should result in larger

OBSS deflections.  Sellers will go through three

sets of movements similar to the movements at

the first test position.  Fossum will reposition

himself in the payload bay to watch and

document the second round of tests.

Once the tests in the first position are complete,

and if time allows, Nowak and Wilson will

move the OBSS back to above the sill of the

payload bay where Fossum will be waiting.  

There, Sellers will move off the APFR so

Fossum can get on.  Then Sellers will hang onto

the TS and both will tether themselves in place.  

Nowak and Wilson will then move the OBSS

into an intermediate position and then the third

test position.

Intermediate Position of the Robotic Arm

Graphics show the intermediate position of the robotic arm for the test.
May 2006 SPACEWALKS 27

Third Position of the Robotic Arm

Graphics show the third position of the robotic arm for the test.

In the third position the end of the OBSS is

16 feet in front of the station’s P1 truss segment.  

The configuration of the SRMS joints provides a

similar “weakness” to those of position 2.  The

main difference is that both crew members are

now on the tip of the OBSS.  During the

position 3 evaluations, Fossum will make

gestures similar to what Sellers did at the first

two positions with Sellers now also on the

boom.  Both crew members will move

simultaneously for some of the test.

Once the movements at the third test position

are complete, Nowak and Wilson will move the

end of the OBSS with both Fossum and Sellers

toward the station’s P1 truss segment for the

final set of tests.  At this test position Fossum

will simulate repair movements on the P1 truss

structure.  The P1 truss was selected to

represent a TPS damage location somewhere on

the orbiter that would need repair.  This specific

location was chosen because of the SRMS joints

that are necessary to reach it.  Once again, the

joints provide a “weak” configuration that

allows for larger OBSS tip deflections.  The data

resulting from using a “weaker” configuration

is expected to provide the best information in

order to gauge the capability of performing a

real repair from the OBSS.  The movements

performed by Fossum will simulate applying

tile repair material with an emittance wash

applicator (EWA), drilling on an RCC panel,

and using a spatula with repair material on an

RCC panel.

Once the testing is done in the final OBSS

position, Nowak and Wilson will move the arm

so the spacewalkers can egress onto Discovery’s

payload bay sill.  With Fossum’s assistance,

Sellers will cleanup the end of the OBSS by

removing the APFR/TS, load cell, PAD and

safety tethers.  The equipment will be taken

back to the airlock with the spacewalkers.  Once

the OBSS is reconfigured, the arm will be

moved higher above the payload bay out of the

way.

With the testing complete, Sellers and Fossum

will work their way, hand‐over‐hand, back up

to the space station.  They will replace the

APFR/TS they used onto the PMA 1 and reenter

the Quest airlock.
May 2006 SPACEWALKS 28

Final Position of the Robotic Arm

Graphics show the final position of the robotic arm for the test.

EVA 2 

The second EVA will consist of installing the

thermal control system’s spare pump module

and replacing the nadir Trailing Umbilical

System – Reel Assembly (TUS‐RA).  The TUS

provides power, data and video to the MT.  

During EVA 1, the crew re‐routed the zenith

TUS cable thru the zenith IUA to allow the TUS

to be moved from position WS4 to WS5.  Before

EVA 2, the MT must be moved from WS4 to

WS5 because its current position makes it

difficult for the crew to change out the nadir

TUS‐RA.

At the start of EVA 2, both crew members will

translate down to the payload bay and prepare

the pump module for transfer.  The first activity

will be for Fossum and Sellers to take the fixed

grapple bar (FGB) from the underside of the

ICC and install it onto the pump module.  The

FGB will allow Nowak and Wilson to latch onto

the pump module with the station’s robotic arm

and move it to the worksite at the external

stowage platform 2 (ESP2) for installation.  

Once the FGB is installed, the crew will release

the pump module from the ICC and lift it up to

present it to the robotic arm.

During the arm’s maneuver, Sellers and

Fossum will begin preparation for removing

and replacing the TUS‐RA.  First, they will

prepare the payload bay by relocating some

APFRs and opening the TUS multi‐layer

insulation (MLI) cover.  Then, they will

translate to the starboard zero (S0) truss

segment, located above the Destiny Lab.  

Fossum will prepare the old TUS‐RA for

removal by releasing electrical connectors and

bolts, while Sellers changes out the nadir IUA

in preparation for routing the new TUS cable.

Once complete, they will both translate to ESP2

to install the pump module.  Nowak and

Wilson will present the pump module with the

robotic arm.  Once Sellers and Fossum have a

hold, the arm will release it and move away so

the pump module can be set on ESP2 and

bolted in place.
May 2006 SPACEWALKS 29

Engineering Imagery of the S0 Truss Segment Before Launch

Engineering imagery of the S0 truss  

segment before launch shows the  

original TUS‐RA installed inside.

Next, Fossum will configure the robotic arm

with an APFR and, along with Sellers, release

and remove the old TUS from S0.  Fossum, now

mounted on the robotic arm, will be

maneuvered down to the payload bay.  Because

this maneuver will take some time, Sellers will

translate to the payload bay and finish

preparation tasks for removal of the new

TUS‐RA.  Once both are ready, Sellers will get

into an APFR on the ICC and Fossum will hand

Sellers the old TUS‐RA.  Fossum will then

maneuver to the new TUS‐RA, remove it from

its launch location and return to Sellers to swap

the 330‐pound TUS‐RAs.

Sellers and FossumSimulated Practice Hand Spacewalk Over of TUS‐RA during

Sellers and Fossum practice handing over  

the TUS‐RA during a simulated spacewalk  

in the Neutral Buoyancy Lab.

Fossum will hand Sellers the new TUS‐RA—

Sellers will have a one in each hand—and then

Sellers will hand Fossum the old TUS‐RA.  

Fossum will put the old reel assembly on the

carrier and retrieve the new one from Sellers.  

Fossum, who is still on the end of the robotic

arm, will take the new TUS‐RA and begin to

maneuver up to S0 to install it.  Sellers will

complete installation of the old TUS onto its

stowage location with the flight support

equipment, and then translate back up to S0.  

Together they will install the new TUS‐RA into

S0 and route the new cable to the nadir IUA.  

With the EVA complete, there will be both a

zenith and nadir TUS, assuring redundancy for

operation of the Mobile Transporter.

Sellers and Fossum PracticeSpacewalk Replacing TUS during Simulated

Sellers and Fossum practice replacing the  

TUS during a simulated spacewalk in  

the Neutral Buoyancy Lab.

EVA 3 (TENTATIVE) 

Once mission managers determine the shuttle

consumables can support an extra day for the

mission, the third spacewalk will be performed.  

It will include tasks that aim to test techniques

for repairing and inspecting the RCC segments

that protect the orbiter’s nose cone and wing

leading edges.

After leaving Quest, Sellers and Fossum will

setup tools on the end of the station’s robotic
May 2006 SPACEWALKS 30

arm, Canadarm2.  Sellers will install an APFR

on the end of Canadarm2.  Fossum will hand

him supplies and tools to attach, including a

CRM bag and an Infrared camera.

Sellers will use the infrared (IR) camera as part

of DTO 851 to take about 20 seconds of IR video

of RCC panels on Discovery’s wing leading

edge while being transported on the end of

Canadarm2 to Discovery’s payload bay.

The FLIR Systems ThermaCAM S60 Infrared

Camera is being assessed as a way to inspect

RCC for damage on‐orbit.  Depending on how

far away the crew member is, the camera’s field

of view can cover 52 inches, or about two RCC

panels, to 83 feet, the entire wing leading edge

at a time.  The camera can record temperature

variances from minus 400‐degrees Celsius to

1,200‐degrees Celsius.  The video is recorded at

a 0.6 Hz frame rate and is saved on internal

memory and then transferred to a memory

card.

Infrared camera simulation hardware a

Infrared camera simulation hardware

Meanwhile, Fossum will travel hand‐over‐hand

to the cargo bay and begin setting up the

worksite.  The two will work side‐by‐side to

test repair techniques on a pallet of

pre‐damaged RCC samples.  The pallet includes

twelve RCC samples.  Eight have various sized

cracks and/or gouges, two are blank slates or

“palettes” to be used during repairs of the other

samples, and two are pre‐damaged samples to

be imaged with the IR camera.  There are more

samples for the crew members to work with

than what is required or expected to be

completed.  The pallet is located in the aft

portion of Discovery’s cargo bay.

Configuration of the Samples in the DTO Pallet

Artist’s rendering shows the configuration  

of the samples in the DTO pallet.

Fossum will setup another APFR to position

himself next to the pallet and open the pallet’s

lid.  Once in the cargo bay, Sellers will get off

the robotic arm to attach the CRM bag to the

inside of the pallet’s lid and then get back on

the arm to begin the repair work.

The RCC crack repair tasks for DTO 848 involve

using a pre‐ceramic polymer sealant

impregnated with carbon‐silicon carbide

powder, together known as NOAX (short for

non‐oxide adhesive experimental).  The NOAX

material is temperature sensitive and the ideal

condition for the repairs is when the samples

are between 100 and 35 degrees Fahrenheit,

with the temperature decreasing.

Therefore the crew members are scheduled to

work on the crack repairs with the NOAX

material during night portions of their orbit,

beginning the repair just after orbital sunset.  
May 2006 SPACEWALKS 31

The choreography of the spacewalk is planned

to optimize two to three day/night passes for

crack repair tasks.  There is about 21⁄2 hours

allotted for the repair technique testing.  When

the crew leaves the airlock, Mission Control

Houston will begin assessing the lighting

conditions and use temperature readings of the

RCC sample taken by the crew to determine

how to proceed with the tasks.

Due to the intricacies of each DTO’s

requirements, the flight control team will

closely monitor the spacewalk to prioritize the

order of the tasks real‐time.  DTO 848 has an

overall higher priority than DTO 851 and

within each DTO tasks are prioritized

individually.

EVA 3 DTO priorities:

1. Two of four RCC crack repair impact

damage samples (DTO 848)

2. IR camera wing leading edge imaging

(DTO 851)

3. IR camera specific RCC damaged sample

imaging (DTO 851)

4. The remaining two RCC crack repair impact

damage samples (DTO 848)

5. All remaining RCC repair samples

(DTO 848)

Once setup for the spacewalk is complete, if the

temperature readings are acceptable, the crew

will begin repairing a cracked or gouged RCC

sample.

For the tests, Fossum will assist Sellers as he

uses a space‐hardened caulk gun to dispense

the NOAX material.  Using one of three manual

caulk guns in the crack repair kit, he will

dispense the material directly onto the sample.  

He will then use one of many spatulas, similar

to a putty knife, to work the crack repair

material into the pre‐damaged RCC sample

mounted in the DTO pallet.  Additional layers

will then be added to the repair by first

extruding the material onto the nearby RCC

palettes.  He will then use the spatula to

manipulate the material onto the sample being

repaired.

RCC Repair Tools to be Used during the Test

Engineering models show the various RCC

repair tools the crew will use during the test.

NASA materials experts have estimated that

cracks or coating damage as small as 2 inches

long and .02 of an inch wide in some locations

on the shuttle’s wing leading edge could result

in catastrophic damage to that wing.  The crack

filling method is designed to fix the type of

damage most likely to be caused by small

pieces of foam coming off the redesigned

external tank.  NOAX can be used at any RCC

location, and does not require any physical

modification of the RCC before affecting a

repair.  It is expected to repair cracks or coating

losses up to four inches long, but cannot be

used to repair large holes.

The spacewalk crew members have had

extensive training and experience with the RCC

repair methods and the behavior of NOAX at

vacuum as well as at various thermal extremes.  

Since the behavior and working life of NOAX is
May 2006 SPACEWALKS 32

temperature dependent, the crew will be in the

best posture to determine if an RCC repair is

“complete” or if additional work needs to be

performed to the repair sample. “Completion”

of an RCC repair sample will be determined by

the spacewalkers, rather than the ground

control team.

Once the first repair is complete, the crew

members will move on to working with the

next cracked sample, using the same

techniques.

Sellers and Fossum will continue repairing the

remaining cracked samples with the NOAX

material as time permits.  If at least the two

highest priority RCC impact damage samples

have been repaired, there is an additional task

for DTO 851 for the crew to complete.  It

involves taking about 60 seconds of video with

the IR camera of two damaged RCC samples on

the pallet.  Sellers will use the IR camera to

record a temperature gradient throughout each

RCC sample itself.  As with the actual RCC

repair tasks, it is preferred that the temperature

is dropping.  Therefore, the best imaging will

occur by Sellers starting the imaging during

direct sunlight and then about 10 seconds later

he will shade the samples to provide the

desired temperature gradient.

About five hours into the spacewalk, the crew

members to begin cleaning up the worksite and

preparing to end the spacewalk.  Both crew

members will inspect each other’s suits for

repair material residue.  Sellers will get off the

robotic arm so Fossum can ride it back to the

Quest Airlock.  Before getting on the arm

Fossum will gather the repair material bag and

other tools for Sellers to attach to the robotic

arm.  Both crew members will close the sample

pallet lid.  Then while being transported back to

Quest, Fossum will use the IR camera to take

about 20 seconds of video of Discovery’s wing

leading edges again.  Meanwhile, Sellers will

move hand‐over‐hand back to Quest.  Once at

the airlock, Fossum will get off the robotic arm

and stow the APFR.  Both crew members will

then enter the airlock.

May 2006 PAYLOAD OVERVIEW 33

PAYLOAD OVERVIEW 

Space Shuttle Discovery will carry a variety of

payloads.  The flight will carry 28,120 pounds

of equipment and supplies in its cargo bay to

the International Space Station.  Additional

items will be carried on the space shuttle

mid‐deck, which include supplies, food, water

and clothing for the crew.

The cargo bay is 60 feet long and 15 feet in

diameter, and can carry the cargo equivalent to

the size of a school bus.  Under the Space Flight

Operations Contract with United Space

Alliance, Boeing performs the form, fit and

function of any cargo that goes into the payload

bay.  The addition of the 50‐foot boom and its

suite of sensors called the orbiter boom sensor

system are considered to be part of the orbiter

and are not considered part of the payload

weight listed above.  The OBSS is used to

conduct inspections of the space shuttle’s

thermal protection system (TPS).

MULTI-PURPOSE LOGISTICS MODULE 

(MPLM) “LEONARDO” 

The Leonardo MPLM acts as a moving van for

the International Space Station, ferrying

scientific experiments and crew supplies to and

from the orbiting laboratory.

On this mission, Leonardo will be mounted in

the space shuttleʹs payload bay for launch and

remain there until after docking.  Once the

shuttle is docked to the station, the ISS robotic

arm will be used to remove Leonardo from the

payload bay and berth it to a Boeing‐built

common berthing mechanism on the nadir side

of the station’s Unity Module.  During its

berthed period to the station, individual

components as well as racks will be transferred

to the station.

Discovery Payload Diagram
May 2006 PAYLOAD OVERVIEW 34

Leonardo is Lowered toward the Cargo Element Work Stand

Workers stand by in the Space Station

Processing Facility at NASA’s Kennedy  

Space Center, as the Multi‐Purpose  

Logistics Module Leonardo is lowered  

toward the Cargo Element Work Stand.

Leonardo will carry five resupply stowage

platforms (RSPs), three resupply stowage racks

(RSRs), one EXPRESS (EXpedite the PRocessing

of Experiments to the Space Station)

transportation rack (ETR), the European

modular cultivation system (EMCS), an oxygen

generation system (OGS) rack and the MELFI.  

The OGS, RSRs and ETR are U.S.‐built while

the MELFI is provided to NASA by the

European Space Agency (ESA) as part of the

Columbus orbital facility launch barter

agreement.

Utility Logistics Flight (ULF) 1.1 is primarily an

ISS crew augmentation mission (a third crew

member will arrive on this flight), with the

MPLM ferrying more than 5,000 pounds of

cargo, a majority of which is food, clothing and

crew consumables.  The MPLM will have 153

cargo transfer bags (can hold about 1.6 cubic

feet per each rectangular‐shaped suitcase) to

bring supplies into the station.  The CTBs are

installed in lockers in RSRs in the MPLM and

are removed individually by the crew and then

stored in the station.

The MPLM will carry two new research

facilities; MELFI and EMCS.  MELFI is a

dedicated rack sized facility while EMCS will

be located within EXPRESS Rack No. 2.  These

two facilities will be installed in the

Boeing‐built Destiny laboratory.

The EXPRESS rack is a standardized payload

rack system that transports, stores and supports

experiments aboard the ISS.  EXPRESS stands

for EXpedite the PRocessing of Experiments to

the space station, reflecting the fact this system

was developed specifically to maximize the

stationʹs research capabilities.  With its

standardized hardware interfaces and

streamlined approach, the EXPRESS rack

enables quick, simple integration of multiple

payloads aboard the ISS.

The MELFI, which weighs 1,617 pounds, will

provide current and future ISS crews with a

critical lab freezer capability for maintaining

scientific samples and experiments and will

ultimately provide greater capability for

utilization, life sciences and research.

The EMCS, a 1⁄2 EXPRESS rack that weighs

655 pounds, is a large incubator that provides

control over atmosphere, lighting and humidity

of growth chambers.  The first planned

experiment will use the chamber to study plant

growth.
May 2006 PAYLOAD OVERVIEW 35

The MPLM will also transport the 1,465 pound

OGS rack that uses water to generate breathable

oxygen for crew members.  The life‐support

system is considered a test initiative for future

long‐duration missions to the moon and Mars.  

The system ‐ which was designed and tested by

engineers from Marshall Space Flight Center

and from Hamilton Sundstrand Space Systems

International in Windsor Locks, Conn. – will

replace oxygen lost during experiments and

airlock depressurization and can provide up to

20 pounds of oxygen daily ‐ enough to support

six station crew members ‐ although it is

initially planned to produce about 12 pounds

daily.

The MPLM will also carry a new cycle

ergometer with vibration isolation and

stabilization (CEVIS).  CEVIS will give

expedition crews on station better aerobic and

cardiovascular conditioning through cycling

activities.  In addition, the MPLM will carry a

common cabin air assembly heat exchanger

(CCAA HX) used to cool cabin air and maintain

a good cabin temperature; it will replace the

one currently on orbit.

Used equipment and a small amount of trash

will be transferred to Leonardo from the ISS for

return to Earth.  The Leonardo logistics module

will then be detached from the station and

positioned back into the shuttleʹs cargo bay for

the trip home.  When in the cargo bay,

Leonardo is independent of the shuttle cabin,

and there is no passageway for shuttle crew

members to travel from the shuttle cabin to the

module.  The total weight of Leonardo for

STS‐121 with the cargo, platforms and racks is

just less than 21,000 pounds for launch and a

little over 17,900 pounds for landing.

Canadarm2 Grasps the Raffaello

The Canadarm2 grasps the Italian‐built

MPLM Raffaello to place it back in

Discoveryʹs cargo bay during STS‐114.   

The Earth forms the background.

History/Background 

Leonardo, built by the Italian Space Agency, is

the first of three such pressurized modules that

serve as the station’s ʺmoving vans,ʺ carrying

laboratory racks filled with equipment,

experiments and supplies to and from the ISS

aboard the space shuttle.

Construction of the Leonardo module was the

responsibility of Altec in Turin, Italy, which is a

subsidiary of Alenia Aerospazio.  Leonardo

was delivered to Kennedy Space Center from

Italy in August 1998 by a special Beluga cargo

aircraft.  The cylindrical module is about

6.4 meters (21 feet) long and 4.6 meters (15 feet)

in diameter.  It weighs about 9,500 pounds

(almost 4.5 metric tons).  It can carry up to

10 metric tons of cargo packed into 16 standard

space station equipment racks.

Although built in Italy, Leonardo and two

additional MPLMs are owned by the U.S.  They

were provided in exchange for Italian access to

U.S. research time on the station.  The

unpiloted, reusable logistics module functions

as a cargo carrier and a space station module

when it is flown.  To function as an attached
May 2006 PAYLOAD OVERVIEW 36

station module as well as cargo transport,

Leonardo contains components that provide

some life support, fire detection and

suppression, electrical distribution and

computer functions.  Eventually, the modules

might also carry refrigerator freezers for

transporting experiment samples and food to

and from the station.

Leonardo first flew to the space station aboard

Discovery on STS‐102/5A.1 in March 2001.  It

flew again aboard Discovery on STS‐105/7A.1

in August 2001 and aboard Endeavour on

STS‐111/UF2 in June 2002.  Aboard Discovery,

STS‐121 will be its fourth flight.

OXYGEN GENERATION SYSTEM (OGS) 

The MPLM will transport the 1,465‐pound OGS

rack to the International Space Station.  The

system uses water to generate breathable

oxygen for six crew members.  The system –

which was designed and tested by engineers

from NASA’s Marshall Space Flight Center in

Huntsville, Ala., and from Hamilton

Sundstrand Space Systems International in

Windsor Locks, Conn. – also will replace small

amounts of oxygen lost during experiments and

airlock depressurization.

In January 2006, the OGS was shipped from the

Marshall Space Flight Center to the Kennedy

Space Center, Fla., where it was installed in the

MPLM in preparation for its launch on board

Discovery.

The oxygen generation system is one of two

primary components in the stationʹs

regenerative environmental control and life

support system.  The other component, the

water recovery system, is planned for shipment

to Kennedy Space Center in early 2007, once

testing and design modifications are complete.

Delivering this hardware to the space station is

a major step toward achieving the full potential

of the complex.  Once complete, the

regenerative life support system will sustain

additional crew members who can conduct

more scientific research.  It also will provide

experience in operating and sustaining a life

support system similar to that necessary for

future human spaceflight missions farther from

Earth.

Once activated, the oxygen generation system

will be capable of providing up to 20 pounds of

oxygen daily.  During normal operations, it will

provide 12 pounds daily, enough to support six

crew members.  The system will tap into the

space stationʹs water supply and split the liquid

into hydrogen and oxygen molecules.  The

hydrogen will be vented to space, and the

oxygen will be vented into the space station

atmosphere.  The system is designed to operate

with little monitoring.

The water recovery system provides clean

water by recycling waste water and urine.  The

recycled water must meet purity standards

before it is used to support crew, payload and

spacewalk activities.  The oxygen generation

and water recovery systems will be packaged

into three refrigerator‐sized racks for

installation in the stationʹs Destiny lab module.

The oxygen generation and water recovery

systems both represent a substantial leap from

the technology used in earlier eras of space

travel.  The life support systems on the

Mercury, Gemini and Apollo spacecraft in the

1960s were designed to be used once and

discarded.  Oxygen for breathing was provided

from high‐pressure or cryogenic storage tanks.  

Carbon dioxide was removed from the air by

lithium hydroxide in replaceable canisters.  

Contaminants in the air were removed by

replaceable filters and activated charcoal
May 2006 PAYLOAD OVERVIEW 37

integrated with the lithium hydroxide canisters.  

Water for the Mercury and Gemini missions

was stored in tanks, while fuel cells on the

Apollo spacecraft produced electricity and

provided water as a byproduct.  Urine and

waste‐water were collected and stored or

vented overboard.  Today, the station relies on

a combination of expendable and regenerative

life support technologies in Destiny and the

Russian Zvezda Service Module.

As we continue to explore the solar system,

advancing life‐support technology will remain

a focus.  On future deep space missions,

resupply of oxygen and water will not be

possible, due to the distances involved.  It will

not be feasible to take along all the water and

air needed, due to the volume and mass of

consumables required for a voyage of months

or years.  Regenerative life support hardware

which can generate and recycle the life

sustaining elements required by human

travelers is essential for long duration trips into

space.

MINUS EIGHTY LABORATORY FREEZER 

FOR ISS (MELFI) 

The MELFI, which weighs 1,609 pounds, will

also be flying to the space station on the STS‐

121 mission.  It is a rack‐size facility which will

provide the space station with refrigerated

volume for storage and fast freezing of life

science and biological samples.  It will also

ensure the safe transportation of conditioned

specimens to and from the station by flying in

fully powered mode in the MPLM.  MELFI was

designed for an operational lifetime of 10 years,

with each continuous mission lasting up to

24 months.  MELFI has also been qualified for

15 launches.

Technicians Inspect the Minus Eighty Lab Freezer for ISS

Technicians inspect the Minus Eighty  

Lab Freezer for ISS (MELFI) at NASA’s

Kennedy Space Center.

ESA astronaut Thomas Reiter will be involved

in commissioning activities when it arrives at

the space station and will also use the facility

for storage of samples from the physiology

experiments CARD and Immuno.  The samples

can be stowed in four compartments (dewars),

whose temperature can be independently

controlled at different levels (‐112, ‐15, 39° F).  

Each dewar is a cylindrical vacuum‐insulated

container, having an internal volume of about

75 liters, divided internally in four sectors.  

Each sector hosts one tray, which can be

extracted without disturbing the samples in the

other three.  MELFI provides standard
May 2006 PAYLOAD OVERVIEW 38

accommodation hardware for the insertion of

samples of different shapes and sizes.

The MELFI cooling system has been the subject

of a very intense technology development

program.  In particular, the sophisticated

cooling machine, which is able to provide the

required temperatures while using very limited

power (less than 1 kW in the worst case).  It is

mounted within a complex enclosure, called the

cold box, in order to minimize any thermal loss

and contamination of the cooling fluid.  The

cold box contains in addition two heat

exchangers, consisting of a total of 10 km of

piping.

The cooling machine is designed to be an

orbital replacement unit.  It can be dismounted

from the cold box with the help of dedicated

tools, in less than eight hours, allowing the

preservation of specimen even in case of

machine failures.  In order to improve the

reliability and availability of the freezer, the

present launch configuration includes a spare

electronic unit and a spare cooling machine.  

The cooling fluid is high‐purity nitrogen.  All

the lines and components through which the

nitrogen flows are double walled, with high

vacuum and multi‐layer insulation in between

the two walls.  This allows maintaining the

selected temperature for up to eight hours even

without power.

The present launch configuration of MELFI

includes the MELFI On‐Orbit Commissioning

Experiment (MOOCE), also developed by ESA.  

This will be carried out few weeks after

installation to monitor the thermal behavior of

one of the compartments.  MELFI will be

immediately used to store samples processed

in, e.g., the human research facility.

Upon arrival to the space station, MELFI will be

transferred to the U.S. Destiny Laboratory and

will be ready to start its service life.

MELFI was developed by the ESA in the frame

of international barter agreements.  Two flight

units have been supplied to NASA and one the

Japan Aerospace Exploration Agency (JAXA).  

In addition, ESA has delivered to NASA

ground units for training and experiments

preparation and will provide the necessary

spares and sustaining engineering to maintain

MELFI for up to 10 years of operations.

EADS‐ ASTRIUM (France) led the Industrial

Team including L’Air Liquide (France), LINDE

(Germany), Kayser‐Threde (Germany) and

ETEL (Switzerland).

EUROPEAN MODULAR CULTIVATION 

SYSTEM (EMCS) 

The EMCS, a 1⁄2 Express Rack that weighs

655 pounds, is a large incubator that provides

control over atmosphere, lighting and humidity

of growth chambers.  The first planned

experiment will use the chamber to study plant

growth.

It is an ESA experiment facility dedicated to

biological experiments, with several

experiments already planned dealing primarily

with the effects of gravity on plant cells, roots

and physiology.  These types of experiments

will help to provide new knowledge about

growth processes in plants and have the

potential for making improvements in food

production techniques on Earth and in space.  

This will hold benefits for astronauts on

longer‐term missions such as an expedition to

Mars as part of ESA’s Aurora program.  

Experiments with insects or amphibia and

studies with cell and tissue cultures are

foreseen in the EMCS as well.  The ESA

astronaut will be involved in the

accommodation of the EMCS in an Express

Rack in the Destiny.
May 2006 PAYLOAD OVERVIEW 39

ESAContainer Astronautinto Reinhold the EMCS EwaldEngineering Inserts an Experiment Model

ESA astronaut Reinhold Ewald inserts  

an experiment container into the  

EMCS Engineering Model.

The EMCS consists of a gas tight incubator

where the humidity and composition of the air,

temperature, light, water supply and a number

of other parameters will be closely monitored

and controlled.  It contains two centrifuges,

each one with space for four experiment

containers.  Each experiment container has an

internal volume of 60 x 60 x 160 mm with a

transparent cover.  White light or infrared LED

illumination is available for each single

container.  Video cameras are available for

experiment observation.  Each centrifuge can be

programmed individually to provide from

0.001g up to 2g in weightlessness.

Video, data and command lines will allow

experiment control by the station crew and

from the ground.

During flight, equivalent ground control

experiments may be performed inside

dedicated experiment reference models, one

located at the Norwegian User Support and

Operations Center in Trondheim, Norway, the

other at the NASA Ames Research Center in

California.  The flight unit also provides the

potential for 1g control experiments on board

the space station.

Plant Cultivation Chamber Inside Experiment Container

Plant Cultivation Chamber inside experiment

container as part of experiment reference

model hardware.

The first experiments to take place within the

EMCS include molecular and physiological

analyses of a type of cress (Arabidopsis), and

the short‐ and long‐term effects of

weightlessness on the development of rotifers

and nematodes.

The scientific utilization of the EMCS will be

carried out in co‐operation with the NASA

Ames Research Center.  EMCS is developed

under ESA contract by an industrial team led

by the company EADS Space Transportation

(Friedrichshafen, Germany).  Although it is

provided as part of a barter agreement with the

United States, European access is also possible.
May 2006 PAYLOAD OVERVIEW 40

PERCUTANEOUS ELECTRICAL MUSCLE 

STIMULATOR (PEMS) 

The PEMS will be flying to the space station on

the STS‐121 shuttle mission.  It will be checked

out by the ESA astronaut as part of his

scheduled activities.

PEMS is a self‐contained device, the purpose

of which is to deliver electrical stimulation to

non‐thoracic muscle groups of the human test

subject, thereby creating contractile responses

from the muscles.  Its main purpose is to

support human neuromuscular research.  The

device can provide either single pulse or pulse

trains with two selectable pulse widths and

variable amplitudes.

The Percutaneous Electrical Muscle Stimulator

The Percutaneous Electrical  

Muscle Stimulator.

PEMS is portable, and designed to be used in

conjunction with other physiological

instruments, in particular the Muscle Atrophy

Research and Exercise System (MARES).  PEMS

will be checked out and commissioned in the

U.S. laboratory.  Eventually PEMS should be

used together with the MARES in the European

Columbus laboratory after it arrives at the

space station.

The PEMS was developed by the Swiss

company Syderal.  This is a second generation

of the PEMS device, the first generation PEMS

having flown on the space shuttle in 1996.

INTEGRATED CARGO CARRIER (ICC) 

A second item carried in the payload bay is

called the Integrated Cargo Carrier (ICC),

which will be located immediately forward of

the MPLM.  The ICC is a cross‐bay platform

used to carry items in the payload bay.

This platform will contain orbital replacement

units (ORU) for the space station and payload

grapple bars.  The ORU items include an

external active thermal control system pump

module for the station’s cooling system and a

trailing umbilical system reel assembly

(TUS‐RA).

External Active Thermal Control System Pump Module

EXTERNAL ACTIVE THERMAL CONTROL 

SYSTEM (EATCS) PUMP MODULE 

The EATCS is the space station cooling system

that radiates the heat generated on the complex

into space.  The pump modules circulate liquid

ammonia at a constant rate to a network of cold

plates and heat exchangers located on the

external trusses and U.S. segment modules,

respectively.  There are two pump modules on

the station, one located on the S1 truss and the

other on the P1 truss.
May 2006 PAYLOAD OVERVIEW 41

The pump module delivered on STS‐121 will be

transferred from the ICC and stowed on the

External Stowage Platform 2 (ESP‐2) during the

second spacewalk.  It is required for assembly

operations scheduled on shuttle mission

STS‐116 or 12A.1 in station assembly terms.

TRAILING UMBILICAL SYSTEM – REEL 

ASSEMBLY (TUS-RA) AND INTERFACE 

UMBILICAL ASSEMBLY (IUA) 

The mobile transporter is a cart‐like device that

moves up and down rails along the

International Space Station integrated truss

serving as a mobile base for the Canadian

robotic arm.  Its power, video and data go

through a set of redundant cables that are part

TUS.  The TUS reel assembly (TUS‐RA) is

basically a large spool much like a garden hose

reel that pays out cable when the MT moves

away and rolls it back up as the MT returns to

the center of the truss.  Each TUS is equipped

with a blade cutter device that can remotely

sever the cable in the event it becomes tangled

so the MT can continue to operate using the

other umbilical.  The mobile transporter is used

for assembly of large elements of the station.  It

must be locked down at various work sites

before the robotic arm can move anything.  

When it is locked down, power is provided to

the Canadian‐built arm and several

components on top of the mobile base station

and it is much more structurally secure.  NASA

flight rules require both TUS cables to be intact

before translating anything attached to the

transporter.

On Dec. 16, the TUS cable No. 1 was cut by the

electro‐mechanical TUS disconnect actuator

(TDA), which is located inside a device called

the interface umbilical assembly (IUA).  

Engineers believe there was a hardware failure

of the spring actuated TDA, but cannot confirm

it until it is returned for further analysis.  Once

the actuator deploys with about 960 pounds of

force, it cannot be retracted and the IUA must

be replaced since the cable path is blocked.  The

TUS‐RA has to be replaced too whenever the

cable is cut since it is too complex to repair on

orbit.  The two IUAs, which are mounted on the

mobile transporter, measure 20 by 18 inches

and weigh about 28 pounds each.  The

replacement IUA will be carried in the mid‐

deck of the space shuttle while the TUS‐RA will

be carried in the shuttle’s payload bay.  The

TUS‐RA is located on the starboard edge of the

S0 truss and measures 5’ x 5’ x 2.5’ and weighs

334 pounds.  The TUS‐RA cable is about

.25 inches thick and 1.6 inches wide and has

about 158 feet of usable length on the reel

assembly.

If the mobile transporter ever gets stuck

between stations, procedures have always

allowed for an astronaut to remove a hung

cable using a spacewalk; cutting the cable was

always a last option.  The cable cutter design

dates back to the Space Station Freedom days

when it was envisioned that large propulsive

elements, with potentially explosive hydrazine,

were expected to be translated on the mobile

transporter.  In those days, there was not

enough time to complete a spacewalk before

the situation would have become dangerous

(hydrazine becomes explosive once it freezes),

so the cable cutter was placed on station.  

Today, the station design does not have those

explosive dangers so station managers are

evaluating the need for the cable cutters.  For

now, a spacewalk would be conducted to

remove the cable in the future if the MT ever

gets hung up.  Cutting the cable renders the

TUS‐RA unusable on orbit.  Since the cause of

the TDA failure is not known, NASA and

Boeing have worked out a procedure to install a

cable blade blocker, a clamp‐like device that

prevents the cutter blade from moving.
May 2006 PAYLOAD OVERVIEW 42

On the first spacewalk during STS‐121, the crew

will carry a new IUA without the TDA and a

cable blade blocker.  When they arrive at the

zenith IUA, the astronauts will look at it and if

it has not fired, they will install the cable blade

blocker.  The first spacewalk will focus on the

zenith IUA to place it in a configuration using

the blocker that allows the mobile transporter

to translate.  If they are successful, then the

astronauts will not have to remove the IUA and

can install the IUA on the nadir side, which

fired on Dec. 16.

If the blade blocker cannot be installed, then the

astronaut will remove the zenith IUA that has

not been fired yet and will install the brand

new one in its place, then connect the TUS

cable.  The mobile transporter can translate

using only one cable.  The astronauts will bring

the IUA inside and sometime between the first

and second spacewalks, they will fix the zenith

IUA by removing the TUS Disconnect Actuator.  

To remove the TDA, astronauts will remove six

bolts and power and data connectors.

Between the first and second spacewalks, the

mobile transporter will have to be moved from

work site 4 to 5 to allow access to remove the

TUS‐RA.  The mobile transporter is in a

position that makes its extremely difficult to

pull out the TUS‐RA, so the goal of the first

spacewalk is to make the mobile transporter

operational again using one cable.

On the second spacewalk, the astronauts will

go out with the IUA and replace the TUS‐RA

and then the IUA.  The replacement TUS‐RA

will be located on the ICC towards the front of

the orbiter payload bay.  The TUS‐RA will be

positioned by the shuttle’s robotic arm.  

TUS‐RA is about 30 feet from the IUA.  The

EVA will consist of first installing the TUS‐RA

and then dragging the cable out of the reel and

connecting it to the IUA.  The oven‐sized

TUS‐RA requires no bolts for installation and

there is a spring loaded handle that snaps into

place.  The TUS‐RA has two pins that slide and

rotate about 100 degrees to secure it in place

and a third point that latches it in like a tripod.  

The TUS cable is then snaked along the truss,

with the astronauts working their way toward

the nadir IUA, which will be replaced.  

Following both spacewalks, there will be no

functional TDAs on either IUA.  A TUS‐RA and

IUA will be brought back and refurbished as

spares.

LIGHTWEIGHT MULTIPUPROSE 

EXPERIMENT SUPPORT STRUCTURE 

CARRIER (LMC) 

A third item carried in the payload bay is called

the LMC.  The LMC will carry a large box with

a lid, a DTO, that astronauts will open up

during a tentatively planned spacewalk to

conduct several tile and RCC panel repair

experiments while on orbit.  The experiment

will check the proof of concept of tile and RCC

panel inspection and repair methods.  The LMC

is a cross‐the‐bay carrier.  The LMC will weigh

2,103 pounds.
May 2006 EXPERIMENTS 43

EXPERIMENTS 

Detailed Supplementary Objectives (DSOs) are

space and life science investigations.  Their

purpose is to:

• Determine the extent of physiological

deconditioning—loss of physical fitness—

resulting from spaceflight

• Test countermeasures to those changes

• Characterize the environment of the space

shuttle and/or space station relative to crew

health

Detailed Test Objectives (DTOs) are aimed at

testing, evaluating or documenting space

shuttle systems or hardware, or proposed

improvements to the space shuttle or space

station hardware, systems and operations.

Such experiments assigned to STS‐121 are listed

below.

DETAILED SUPPLEMENTARY 

OBJECTIVES (DSO) 

DSO 490B BIOAVAILABILITY AND 

PERFORMANCE EFFECTS OF PROMETHAZINE 

DURING SPACEFLIGHT (PROTOCOL B) 

Promethazine (PMZ) is the anti‐motion sickness

medication (otherwise referred to as

Phenergen®), used to treat space motion

sickness (SMS) during shuttle missions.  The

possible side effects associated with this

medication include dizziness, drowsiness,

sedation and impaired psychomotor

performance, which could affect crew

performance of mission operations.  Early

reports from crew members indicate the central

nervous system side effects of PMZ are absent

or greatly reduced in microgravity.  Because the

body’s reaction to drugs and the extent and rate

the medication is absorbed in microgravity may

be different than on Earth, it could significantly

alter drug effectiveness as well as severity of

side effects for a given dosage.  Therefore, it is

important to evaluate how PMZ is absorbed, its

effects on performance, and its side effects and

effectiveness to determine the optimal dosage

and route of administration in‐flight.  PMZ also

affects sleep patterns.  During the mission, the

crew will wear a device known as an Actiwatch

to record sleep and wake data.  The crew will

complete a Sleep Logbook each morning for

analysis postflight.

DSO 493 MONITORING LATENT VIRUS 

REACTIVATION AND SHEDDING IN 

ASTRONAUTS 

Latent viruses are important sources of human

disease and inhabit more than 90% of the

world’s adult population.  These viruses will be

carried by the astronauts into space, and they

pose an important health risk especially during

long‐duration missions.  Herpes viruses are the

best known examples of latent viruses, and

there are eight known human herpes viruses.  

First experiences with these viruses may result

in an acute illness (e.g., chickenpox), and as the

symptoms subside, the virus establishes a

life‐long relationship with its human host.  You

may go for long periods with no further

symptoms.  However, several factors, such as

stress, may decrease the immune system

resulting in an “awakening” of the latent herpes

virus.  These reactivated viruses may result in

no symptoms or may produce significant illness

(e.g., shingles).  This study investigates the
May 2006 EXPERIMENTS 44

effects of spaceflight (before, during and after)

on the reactivation and shedding of latent

viruses in body fluids such as saliva, urine, and

blood.  Subjects will provide specimens of these

fluids for analysis of viruses and substances

that allow us to determine if any latent viruses

have been reawakened.  These include

substances produced by the immune system, or

by active virus, or by stress.  If findings from

these studies indicate increased risk of latent

viral infections during long space mission,

countermeasures will be developed and

evaluated for efficacy.  Stress intervention and

management would be a likely countermeasure

candidate; several pharmaceuticals are also

available and effective.

DSO 498 SPACEFLIGHT AND IMMUNE 

FUNCTION (PRE/POST FLIGHT ONLY) 

Astronauts face an increasing risk of

contracting infectious diseases as they work

and live for longer periods in the crowded

conditions and closed environments of

spacecraft such as the International Space

Station.  The effect of spaceflight on the human

immune system, which plays a pivotal role in

warding off infections, is not fully understood.  

Understanding the changes in immune function

caused by exposure to microgravity will allow

researchers to develop countermeasures to

minimize the risk of infection.

The objective of this DSO is to characterize the

effects of spaceflight on cells which play an

important role in maintaining an effective

defense against infectious agents.  The study’s

premise is that the space environment alters the

essential functions of these elements of human

immune response and stressors associated with

spaceflight.

Researchers will conduct a functional analysis

of neutrophils and monocytes from blood and

urine samples taken from astronauts before and

after the flight.  They will assess the subjectsʹ 

pre‐ and postflight production of cytotoxic cells

and cytokine.

This study will complement previous and

continuing immunology studies of astronautsʹ 

adaptation to space.

DSO 499 EYE MOVEMENTS AND MOTION 

PERCEPTION INDUCED BY OFF-VERTICAL 

AXIS ROTATION (OVAR) AT SMALL ANGLES 

OF TILT AFTER SPACEFLIGHT (PRE/POST 

FLIGHT ONLY) 

Sensorimotor adaptation to weightlessness

during orbital flight leads to perceptual and

motor coordination problems upon return to

Earth.  Researchers hypothesize that there are

adaptive changes in how the central nervous

system processes gravitational tilt information

for the vestibular (otolith) system.  Eye

movements and perceptual responses during

constant velocity off‐vertical axis rotation will

reflect changes in otolith function as crew

members readapt to Earthʹs gravity.  The

purpose of this study is to examine changes in

spatial neural processing of gravitational tilt

information following adaptation to

microgravity.  Postflight oculomotor and

perceptual responses during off‐vertical axis

rotation will be compared with preflight

baselines to track recovery time.

DSO 500 SPACEFLIGHT INDUCED 

REACTIVATION OF LATENT EPSTEIN-BARR 

VIRUS (PRE/POST FLIGHT ONLY) 

DSO 500 will study the effects of spaceflight

T‐cell mediated immunity, especially

Epstein‐Barr virus (EBV) and reactivation of

latent EBV infections.  This study will address

the mechanisms of the decreased immune

function from spaceflight and characterize the

replication of latent viruses.  Specifically, this

study will determine the magnitude of immuno
May 2006 EXPERIMENTS 45

suppression as a result of spaceflight by

analyzing stress hormones.  Blood and urine

samples are used to analyze the latent viruses.

The successful completion of this study will

provide new information on the mechanisms

involved in spaceflight‐induced EBV

reactivation.  Correlating the viral reactivation

data with the immunological findings will

expand the knowledge on the role of the

immune system and reactivation of latent

viruses in humans during spaceflight.

DSO 634 SLEEP-WAKE ACTIGRAPHY AND 

LIGHT EXPOSURE DURING SPACEFLIGHT 

Spaceflight results in disruption of sleep on

short duration missions.  The disruption is

associated with inappropriately timed light—

one dawn and one dusk happen during each

90‐minute orbit—or exposure to light that is not

intense enough.  The success and effectiveness

of manned spaceflight depends on the ability of

crew members to maintain a high level of

cognitive performance and vigilance while

operating and monitoring sophisticated

instrumentation.  Astronauts, however,

commonly experience sleep disruption,

together with misalignment of circadian phase

during spaceflight.  Both of these conditions are

associated with insomnia and associated

impairment of alertness and cognitive

performance.  Relatively little is known of the

prevalence or cause of spaceflight‐induced

insomnia in short duration missions.  This

experiment will use state‐of‐the‐art ambulatory

technology, an Actiwatch worn on the wrist, to

monitor sleep‐wake activity and light exposure

patterns obtained in‐flight.  The crew members

will also use sleep logs in the morning to

document perceived quality of sleep.  These

data should help us better understand the

effects of spaceflight on sleep as well as aid in

the development of effective countermeasures

for both short and long‐duration spaceflight.

DSO 635 SPATIAL REORIENTATION 

FOLLOWING SPACEFLIGHT (PRE/POST 

FLIGHT ONLY) 

Spatial orientation is altered during and after

spaceflight by a shift of central inner

processing—from a gravitational

frame‐of‐reference to an internal, head‐centered

frame‐of‐reference—that occurs during

adaptation to microgravity and is reversed

during the first few days after return to Earth.  

A previous observation suggested conflicting

sensory stimuli caused by an unusual motion

environment.  This causes a disrupted spatial

orientation and balance control in a returning

crew member by triggering a shift in central

vestibular (inner ear) processing.  The short arm

centrifuge and posture platform are used to

collect the neurovestibular data.   The findings

of the current investigation are expected to

demonstrate the degree to which challenging

motion environments may affect how a crew

member adapts after the flight.  These findings

could lead to a better understanding of safe

postflight activities and could help designers

better understand the characteristics needed for

an artificial gravity countermeasure on long

duration space station or exploration missions.
May 2006 EXPERIMENTS 46

DSO 637 CHROMOSOMAL ABERRATIONS IN 

BLOOD LYMPHOCYTES OF ASTRONAUTS 

(PRE/POST FLIGHT ONLY) 

During spaceflight, crew members are

constantly exposed to solar and galactic

radiation such as electrons, protons, heavy

particles, single particles of high energy (HZE).  

They are also exposed to secondary radiation

created by interactions of primary radiations

with nuclei of spacecraft shielding material or

the human body.  The radiation dosage of each

type depends largely on the altitude and

inclination of the spacecraft’s orbit,

effectiveness of the shielding and solar activity

during the mission.

Previous studies documented severe damage

from single particles of high energy (HZE

particles) passing through biological material.  

Therefore, it can be assumed that despite of

their rarity, HZE particles represent a

considerable risk for humans in space.  The

specific effects of HZE particles in humans are

not well documented.  This investigation

studies chromosomal deviations in human

blood lymphocytes to assess the potential of

ionizing radiation.  Blood will be drawn before

and immediately after spaceflight.  The whole

blood will be processed to stimulate the

lymphocytes to undergo mitosis.  After

48 hours, the cells will be stained and prepared

for microscopic analysis.  A comparison

between pre‐ and postflight will be made.  

Because some of the crew members take anti‐

oxidant vitamins, the data will be correlated

with intake information to determine if that

affects the results.  The data from the study

should lead to better radiation protection for

crew members.

DETAILED TEST OBJECTIVES (DTO) 

DTO 702 MADS PCMU TO SSR TELEMETRY 

The objective of the DTO is to demonstrate if

the modified Modular Auxiliary Data System

(MADS) Pulse Code Modulation Unit (PCMU)

hardware using a new solid state recorder (SSR)

and low‐pass filter can provide telemetry for

orbiter vehicle data that was recorded on

MADS PCMU during the ascent phase and

downlink the recorded data during the on‐orbit

phase of flight.  The ground processing

systems, primarily the Mission Control Center

front end processor (FEP) were modified to

receive the downlinked telemetry and process

the data in real time and will be operated

during the flight test.

DTO 805 CROSSWIND LANDING 

PERFORMANCE (IF OPPORTUNITY) 

The purpose of this DTO is to demonstrate the

capability to perform a manually controlled

landing in the presence of a crosswind.  The

testing is done in two steps.

1. Pre‐launch:  Ensure planning will allow

selection of a runway with Microwave

Scanning Beam Landing System support,

which is a set of dual transmitters located

beside the runway providing precision

navigation vertically, horizontally and

longitudinally with respect to the runway.  

This precision navigation subsystem helps

provide a higher probability of a more

precise landing with a crosswind of 10 to

15 knots as late in the flight as possible.

2. Entry:  This test requires that the crew

perform a manually controlled landing in

the presence of a 90‐degree crosswind

component of 10 to 15 knots steady state.
May 2006 EXPERIMENTS 47

During a crosswind landing, the drag chute will

be deployed after nose gear touchdown when

the vehicle is stable and tracking the runway

centerline.

DTO 848 ORBITER THERMAL PROTECTION 

SYSTEM (TPS) REPAIR TECHNIQUES 

Reinforced carbon carbon (RCC) samples will

be flown in a thermal protection system sample

box located on the upper surface of the LMC

(lightweight mission peculiar equipment

support structure carrier).  If consumables

allow an extra day and a third spacewalk, the

crew will perform setup activities on the

SSRMS (space station remote manipulator

system) and the payload bay to allow them to

perform RCC sample repairs.  The samples

within the box provide the crew with the

capability to perform RCC crack repairs using a

material called NOAX or Non‐Oxide Adhesive

eXperimental.  An applicator similar to a

caulking gun will be used to insert the material

into the crack.  The NOAX will come out of the

applicator gun looking like thick, dark‐

chocolate pudding.  The crew will then use a

trowel to apply the material, layering it, over

the damaged area.  The objective is to

thoroughly fill the cracks creating a smooth

surface and to gather information about how

the material responds in zero‐G.  The samples

repaired by the crew will be returned for

ground testing.

NOAX combines a pre‐ceramic polymer sealant

and carbon‐silicon carbide powder.  It was

developed to survive very high temperatures,

such as those experienced during re‐entry of

the shuttle.

DTO 849 OBSS SRMS LOADS 

CHARACTERIZATION WITH EVA CREW 

MEMBERS 

For this DTO, STS‐121 EVA crew members

Sellers and Fossum will conduct a spacewalk

on the OBSS boom attached to the SRMS.  The

OBSS boom/SRMS system as an EVA platform

is a contingency vehicle inspection capability

for current shuttle flights (if OBSS sensors fail)

and will be used as the vehicle repair platform

starting with ISS flight 10A (delivery of

Node 2).  The stability of this platform is unlike

any EVA platform used on‐orbit to date.  The

purpose of this DTO is to characterize the

motion of the boom under inspection and

repair‐like actions, to verify the inspection

capability and to understand the requirements

for operational constraints, boom modifications,

and/or supplemental hardware that will be

required to perform a vehicle repair.  The DTO

will also help to validate ground simulators

that have been developed to train crews and

provide engineering data for certification of

repair hardware and operations.

The DTO is planned to include several different

combinations of crew member configurations,

simulated tasks, SRMS positions and APFR

positions to gather information on as many

variables as possible.  The DTO builds from a

more stable configuration (stiffer SRMS

position with a single crew member) with more

benign operations to less stable configurations

(less stiff SRMS positions with two crew

members) with more aggressive operations.  

The DTO incorporates special test hardware

(Instrumented WIF or IWIF) specifically

designed to gather loads and acceleration data

at the crew members foot restraint during the

DTO.  The IWIF uses a load cell and wireless

data recorders to gather the DTO data.
May 2006 EXPERIMENTS 48

The types of crew actions that will be executed

during the DTO include camera operations, tool

hand‐offs, APFR reconfiguration, laying back

and leaning forward in the foot restraint,

ingressing and egressing the APFR and

simulated vehicle repair techniques required by

the current vehicle repair methods (scraping,

dabbing, drilling, installing overlays, etc.).  

Three different APFR positions and four SRMS

positions are used for the evaluations.  One

SRMS position will put the crew members near

ISS structure to simulate an actual vehicle

repair worksite.

DTO 850 WATER SPRAY BOILER COOLING 

WITH WATER/PGME ANTIFREEZE 

Water spray boilers, after spraying water,

freeze every time auxiliary power units are shut

down and remain frozen for unpredictable

amounts of time.  A solution is to replace water

as the cooling fluid in the water spray boiler

tank with an azeotropic mixture of 53 percent

water and 47 percent propylene glycol

monomethyl ether (PGME).  Tests done at

White Sands Test Facility in New Mexico show

that a water/PGME mixture is not likely to

freeze in the conditions seen on orbit.  A

water/PGME mixture turns to slush at about ‐40

degrees Fahrenheit and freezes at ‐54 degrees F.

The plan is to fill only water spray boiler No. 3

water tank with a water/PGME mixture.  The

primary objective is to confirm ground test

results for water spray boiler in the post‐ascent,

high‐vacuum, zero‐G environment.  A

secondary objective is to confirm coolant usage

is within predictions.

The pilot will perform the water spray boiler

cooling verification.

DTO 851 EVA INFRARED (IR) CAMERA 

The criteria for assessing the extent and severity

of wing leading edge (WLE) reinforced

carbon‐carbon (RCC) damage includes cracks,

coating loss, and sub‐surface separation.  The

orbiter boom sensor system (OBSS) and EVA

digital camera are both capable of detecting

certain cracks and coating loss.  However,

neither of those systems is capable of detecting

RCC subsurface separation, or delamination.  

Infrared (IR) thermography—recording an

image of heat—is the most promising

technology for detecting RCC subsurface

delamination while on orbit.

If consumables allow an extra day and third

spacewalk, as time allows, the crew is to

retrieve the infrared camera and record video

clips of the RCC.  The objective is to video the

orbiter wing leading edge (WLE) during both

day and night passes.  This is to be done from a

distance that allows multiple WLE RCC panels

to be recorded at the same time.  The second

priority is recording specific RCC samples

located within the thermal protection system

sample box.  The two samples are 6 inch by 6

inch and were purposely damaged on the

backside prior to flight.  The crew will begin

recording the samples while in direct sunlight

and then shade the samples a few seconds.  

This will allow the camera to record the heat

flux of the samples, providing information

about damage.

DTO 852 SRMS ON-ORBIT LOADS, HEAVY 

PAYLOADS 

The objective of the DTO is to characterize the

loads—the weight and force exerted on a

structure—that are induced into the SRMS

during “non‐typical” loaded SRMS operations

and to correlate these SRMS loads to math

models. “Non‐typical” operations are

operations that fall outside the current
May 2006 EXPERIMENTS 49

historical operational information.  This

includes operations such as heavy payload

maneuvering and interaction with a vehicle’s

motion control system, payloads that don’t

meet current SRMS requirements or new

operational techniques like EVA worksite

stabilization at the end of the grappled OBSS.  

This loads data will be used by the NASA to

validate current analytical tools to actual flight

information versus simulation to simulation

comparisons that are being worked today.  This

is important information as NASA prepares to

provide a stable worksite for crew members to

repair the orbiter’s thermal protection system.

SDTO 12004-4 SHUTTLE BOOSTER FAN 

BYPASS

This Station Development Test Objective

(SDTO) will optimize cryogenic oxygen savings

by operating the booster fan differently within

the context of the flight rules and expenditure

of other resources (crew time, LiOH, etc.).

Shuttle on‐orbit cryogenic oxygen margin can

be increased on space station missions if the

shuttle booster fan (also known as the airlock

fan) is bypassed post docking.  While docked,

sufficient space station/shuttle air circulation

will be achieved through the use of the U.S.

Laboratory Forward Intermodule Ventilation

(USL IMV) fan so that carbon dioxide levels on

both the station and shuttle can be controlled

during the day by the station.  Nominally,

while the shuttle is docked to the station, active

ventilation has included use of the shuttle

booster fan and the station IMV fan. During the

overnight period, additional remediation may

be required to control carbon dioxide levels in

the shuttle.  The crew may be instructed to

install LiOH on the middeck to supplement the

carbon dioxide removal provided by the

station, or reconfigure the duct and turn on the

booster fan.

SDTO 13005-U ISS STRUCTURAL LIFE 

VALIDATION AND EXTENSION 

The International Space Station structure has a

15‐year life requirement.  The overall objective

is to guarantee safety of the station structure

and crew.  Specific objectives are to accurately

determine structural life usage, to expand

station operations and to increase the life of the

structure.  Structural life estimates are based on

worst case loading conditions using finite

element models of structures and forcing

function estimations.  It is desirable to reduce

this conservatism through post‐flight

reconstructions using correlated models,

validated forcing functions, measured station

response data and actual on‐orbit loading

conditions.  This reconstruction requires actual

or educated estimates of input (forcing

function) and actual output (on‐orbit sensor

measurements) of the station response.  

Measurement of the force input (i.e., thruster

firing sequences, video of crew activity) and

station response will aid reconstruction of

station loads and structural life usage over the

life of the station, thus allowing life extension of

the structure.

SHUTTLE (SORTIE) EXPERIMENTS 

Fungal Pathogenesis, Tumorigenesis, and

Effects of Host Immunity in Space (FIT)

studies the susceptibility to fungal infection,

progression of radiation‐induced tumors and

changes in immune function in sensitized

Drosophila, or fruit fly, lines.

Effect of Spaceflight on Microbial Gene

Expression and Virulence (Microbe) will

investigate the effects of the spaceflight

environment on the infectiousness of three

model microbial pathogens identified during

previous spaceflight missions as potential

threats to crew health.
May 2006 EXPERIMENTS 50

Maui Analysis of Upper Atmospheric

Injections (MAUI) observes the exhaust plume

of the space shuttle from the ground, leading to

an assessment of spacecraft plume interactions

with the upper atmosphere.

Ram Burn Observations (RAMBO) is a

Department of Defense experiment that

observes Shuttle Orbital Maneuvering System

engine burns by satellite for the purpose of

improving plume models.  Understanding the

spacecraft engine plume flow could be

significant to the safe arrival and departure of

spacecraft on current and future exploration

missions.

EXPERIMENTS DELIVERED TO ISS 

Passive Observatories for Experimental

Microbial Systems (POEMS) will evaluate the

effect of stress in the space environment on the

generation of genetic variation in model

microbial cells.  POEMS will provide important

information to help evaluate risks to humans

flying in space to further understand bacterial

infections that may occur during long‐duration

space missions.

Analysis of a Novel Sensory Mechanism in

Root Phototropism (Tropi) will observe the

growth and collect samples of plants sprouted

from seeds.  By analyzing the samples at a

molecular level, researchers gain insight on

what genes are responsible for successful plant

growth in microgravity.
May 2006 EXPERIMENTS 51

FUNGAL PATHOGENESIS, TUMORIGENESIS AND EFFECTS OF 

HOST IMMUNITY IN SPACE (FIT) 

Principal Investigator(s):  Sharmila Bhattacharya, Ph.D., Ames Research Center, Moffett Field, Calif.,

and Deborah Kimbrell, Ph.D., University of California Davis, Davis, Calif.

Payload Developer(s):  Ames Research Center

Increment(s) Assigned:  13

Research Summary

This study will investigate the susceptibility to

fungal infection, progression of radiation‐

induced tumors, and changes in immune

function in sensitized Drosophila (fruit fly) lines.

• This experiment will study the growth of

cancerous and benign tumors in sensitized

genetic lines (breeds) of Drosophila

melanogaster (fruit flies) that show an

increase in the incidence of tumor

formation.  The effect of radiation exposure

will be coupled to this study.

• In addition, samples of a fungal pathogen

that infects flies will be exposed to radiation

and the space environment.  Space‐flown

samples will be used post‐flight to infect

Drosophila on the ground and assess

changes in the pathogen.

• These studies will provide more

information on the interaction between

elements of the space environment (space

radiation, microgravity) and immune

function and tumor growth.

Research Operations

This experiment requires the crew to monitor

the cassette for temperature stability.  

Researchers will analyze changes in blood cell,

hematopoietic organ (lymph gland) and fat

body (liver) morphology from postflight

samples.

Flight History/Background

The STS‐121 mission will be the first flight for

this experiment.

Web Site

For more information on FIT, visit:

http://exploration,nasa.gov/progams/ 

station/list.html 
May 2006 EXPERIMENTS 52

 ANALYSIS OF A NOVEL SENSORY MECHANISM IN ROOT PHOTOTROPISM (TROPI) 

Principal Investigator:  John Kiss, Ph.D., Miami University, Oxford, Ohio

Payload Developer:  Ames Research Center, Moffett Field, Calif.

Increment(s) Assigned:  13

Research Summary

Plants sprouted from seeds will be videotaped

and samples collected to be analyzed at a

molecular level to determine what genes are

responsible for successful plant growth in

microgravity.  Insights gained from Tropi can

lead to sustainable agriculture for future long‐

term space missions.

The primary objectives of Tropi are:

• To understand the mechanisms by which

plant roots respond to varying levels of

both light and gravity.

• To determine how plants organize multiple

sensory inputs, like light and gravity.

• To gain insight into how plants grow in

space to help create sustainable life support

systems for long‐term space travel.

Research Description

Tropi consists of dry Arabidopsis thaliana (thale

cress) seeds stored in small seed cassettes.  

Arabidopsis thaliana is a rapidly growing,

flowering plant in the mustard family.

The seed cassettes will be flown inside the

European Modular Cultivation System (EMCS).  

The seeds will remain dry and at ambient

temperature until hydrated by an automated

system of the EMCS.  At specified times during

the experiment, the plants will be stimulated by

different light spectrums and by different

gravity gradients.  The only work required by

the crew is to replace videotapes and harvest

the plants when they are grown.  Once the

plants are harvested, they will be stored in the

Minus Eighty Degree Laboratory Freezer for

ISS (MELFI) until their return to Earth.

Web Site

For more information on Tropi, visit:

http://exploration.nasa.gov/programs/ 

station/list.html 
May 2006 SPACE SHUTTLE SAFETY ENHANCEMENTS OVERVIEW 53

SPACE SHUTTLE SAFETY ENHANCEMENTS OVERVIEW 

SPACE SHUTTLE DISCOVERY – STS-121/ULF1.1 

OVERVIEW 

SETTING THE STAGE FOR RESUMPTION 

OF ASSEMBLY 

Space Shuttle Discovery is set to resume service

to the International Space Station with launch

targeted for July 1 during a window extending

through July 19.  It is a test flight and the

second in a series to validate improvements

through a structured test program put in place

following the Columbia accident in 2003.

While the Return to Flight mission last July

completed all mission objectives by resupplying

the station and restoring full capability to its

attitude control system, during launch a piece

of foam was shed from the external tank which

clearly was unacceptable for continued

operations.

The Space Shuttle Program determined the

foam area of concern could safely be removed

based on preliminary engineering analysis and

testing continues to verify the computer

analysis.  While the analysis continues, work

proceeded on shuttle components in order to be

ready to launch as soon as the analysis of

completed testing proves it is safe to do so.

Removal of the nearly 40 pounds of foam

required extensive work to prove the overall

structural integrity of the shuttle system

(orbiter, boosters and external tank) prior to

flight.  The foam “ramps,” as they are known,

were put in place early in the shuttle program

because they alleviated the need for this type of

analysis and testing via technology that—at the

time—did not exist.

Now that supercomputers and advances in

technology are available, it is possible to prove

the tank structure is more robust to handle any

loads that would be experienced during the

early minutes of launch.

So Discovery and its seven‐member crew is

poised once again to return to the International

Space Station for a supply mission and to

restore the station’s crew to three, which last

was supported in early 2003.

The stage will then be set to resume assembly of

the ISS with Atlantis in August/September

leading toward completing the construction

and addition of international partner

laboratories and components.

As with every flight remaining before the

shuttle is retired at the end of 2010, Discovery’s

mission is more than a single flight.

That in turn provides another major

stepping‐stone to the long range planning in

the form of the Vision for Space Exploration

announced in January 2004.

NASA has committed itself to excellence in all

aspects of its programs by strengthening its

culture and improving technical capabilities.

May 2006 RECOGNIZING & ELIMINATING DEBRIS SOURCES 54

PREPARING THE EXTERNAL TANK 

RETURN TO FLIGHT EXTERNAL TANK, ET-119 

About six hours before Space Shuttle

Discovery’s launch, the bright orange

15‐story‐tall fuel tank is loaded with

535,000 gallons of liquid hydrogen and oxygen.  

Just before liftoff, these super cold liquids are

mixed and burned by the shuttle’s three main

engines, which gulp it at a rate equal to

emptying the average size backyard swimming

pool in 20 seconds.

The external tank’s aluminum skin is a

tenth‐of‐an‐inch thick in most places and is

covered with polyurethane‐like foam averaging

an inch thick, which insulates the propellants,

prevents ice formation on its exterior, and

protects its skin from aerodynamic heat during

flight.  About 90 percent of the foam is applied

by automated systems, while the remainder is

applied manually.

PROTUBERANCE AIR LOAD 

(PAL) RAMPS 

ET‐119 is the first external tank to fly without

Protuberance Air Load Ramps—manually

sprayed wedge‐shaped layers of foam along the

pressurization lines and cable tray on the side

of the tank.  They were designed as a safety

precaution to protect the tankʹs cable trays and

pressurization lines from air flow that could

potentially cause instability in these attached

components.  Previously, there were two PAL

ramps on each external tank.  One was near the

aft end of the liquid oxygen tank, just above the

intertank, and the other was below the

intertank, along the upper end of the liquid

hydrogen tank.  Both ramps extended about

5 feet into the intertank area.  The liquid oxygen

PAL Ramp was 13.7 feet long and the liquid

PAL Ramps

PAL ramps, manually sprayed wedge‐shaped

layers of foam along the tankʹs pressurization

lines and cable tray.

hydrogen PAL Ramp was 36.6 feet long.  The

weight of foam removed was 37 pounds total.

During the STS‐114 mission in July 2005, video

analysis indicated a piece of foam –

approximately 36 inches long at the longest

point and approximately 11 inches wide at its

widest point – was lost from the external tank.  

The location of the foam loss was

approximately 15 feet below the flange that

joins the intertank to the liquid hydrogen tank,

or approximately 20 feet from the top of the

liquid hydrogen PAL ramp.  The event

occurred at 127 seconds into the flight.  The

imagery review, as well as on‐orbit and post‐

flight inspections, indicated the debris did not

impact Discovery.

The external tank project has spent nearly three

years testing and analyzing the aerodynamics

of the cable trays and pressurization lines to

determine the need for the ramps.  Enhanced

structural dynamics math models were created
May 2006 RECOGNIZING & ELIMINATING DEBRIS SOURCES 55

to better define the characteristics of this area of

the tank and scaled models of the tank were

tested in wind tunnels at the Marshall Space

Flight Center in Huntsville, Ala.; NASA’s

Langley Research Center in Hampton, Va.;

NASA’s Glenn Research Center in Cleveland,

Ohio; and at the Canadian National Research

Council wind tunnel in Ottawa.  A full‐scale

model of this section of the tank also was tested

in a wind tunnel at the Arnold Engineering and

Development Center at Arnold Air Force Base,

Tenn.  Computational fluid dynamics work was

completed on full‐stack (tank, boosters and

orbiter) models to better determine the

aerodynamic flow in this area.

Following STS‐114, external tanks at NASAʹs

Kennedy Space Center, Florida, were returned

to the Michoud Assembly Facility outside New

Orleans for detailed inspection of these PAL

ramps as part of investigative work to

understand and identify the most likely root

cause of the foam loss.

Two teams were assigned to review foam

performance and determine the most likely root

causes.  One team, composed of NASA’s top

government and contractor experts on the

space shuttle external tank, investigated the

foam loss with the intent of determining root

cause.  Another team, chartered by the Space

Operations Mission Directorate at NASA

Headquarters in Washington, performed an

independent engineering assessment of work

required to resolve the foam loss issue.

Three redesign options were studied as

possibilities for future improvements to the

external tank.  These included removing the

PAL Ramp from the tank; modifying the PAL

ramp to a smaller configuration (mini‐ramp);

and installing a trailing edge fence on the back

side of the cable tray.  The no‐PAL Ramp

option was chosen because recent testing of

External Tank with PAL Ramps Removed

External tank with PAL ramps removed  

for the STS‐121 mission.

actual flight hardware demonstrated the

current cable tray design did not pose an

instability concern.

A detailed verification and validation plan

addressed the entire spectrum of changes

needed to remove the PAL ramp, including

foam elimination and impacts to the attached

hardware, including cable trays, pressurization

lines and support brackets.  Engineering

processes included detailed modeling of the

tank to validate any changes.  Additional tests

are planned to ensure that required design

safety factors have been maintained on all

components.

Rigorous analysis and testing is under way to

establish that the external tank can be flown

safely without the PAL ramps.  Testing to

verify aeroelastic, aerodynamic and

aerothermal loads was completed, indicating

that flying the tank without the PAL ramp did

not pose additional instability, pressure or

heating concerns.

Wind tunnel testing and computational fluid

dynamics testing, using computers to study

liquids and gases in motion, will verify that the

design environments provided to the External

Tank Project envelope the flight environment.
May 2006 RECOGNIZING & ELIMINATING DEBRIS SOURCES 56

ICE/FROST RAMPS 

The main propulsion system pressurization

lines and cable trays are attached along the

length of the tank at multiple locations by metal

support brackets.  These metal brackets are

protected from forming ice and frost during

tanking operations by foam protuberances

called ice/frost ramps.  There are 34 ice/frost

ramps on the tank, 12 on the liquid oxygen

tank, six on the intertank and 16 on the liquid

hydrogen tank.  The size of the ice/frost ramps

is dependent upon location.  The smaller ramps

on the liquid oxygen tank are roughly 1.5 feet

long by 1.5 feet wide by 5 inches high.  Each

weighs about 12 ounces.  The larger ramps on

the liquid hydrogen tank are roughly 2 feet

long by 2 feet wide by 1 foot high.  They weigh

approximately 1.7 pounds each.

Ascent/on‐orbit imagery from STS‐114

indicated foam loss from three liquid hydrogen

ice/frost ramps.  One piece of foam was

approximately 7 inches by 2 inches, in a

location approximately 15 feet from the top of

the liquid hydrogen PAL ramp.

Nondestructive evaluation techniques and

dissection activity on one tank in the inventory

(ET‐120) which had undergone several

pre‐flight sequences of cryogenic chill‐down

and pressurization to flight‐like levels revealed

cracks in ice/frost ramps.  During dissection of

one crack, a portion of the base foam was found

to have vertical and horizontal cracks which

separated into layers near the substrate, or base

aluminum skin of the tank.

Options to resolve the ice/frost ramp cracks are

being studied, including the possibility of

reshaping the ramps to reduce thermal stresses

in the foam and to reduce the amount of foam

used on each ramp.  Wind tunnel tests are

being conducted to verify the possibilities for

Ice/frost ramps

Ice/frost ramps are foam segments that protect

against ice and frost formation.  There are

34 ice/frost ramps on the tank.

any redesign.  The Space Shuttle Program

management made a decision in April 2006 to

fly the ice/frost ramps in their current

configuration.  The rationale for doing so was

based on several factors including the

performance of the ice/frost ramps on previous

flights.  Any design changes would need to be

thoroughly tested and certified before

modifying the tank.  To do otherwise could

result in more uncertainly instead of reducing

risk of the tank.

Small foam ramps, called ice/frost ramp

extensions, have been added to the ice/frost

ramp locations where the PAL ramps were

removed.  The new extensions were added to

make the geometry of these ice/frost ramps

consistent with other locations on the tank.

Testing and analysis continues for

modifications to the ice frost ramp.  New

cameras will allow better insight into the

current ramp performance, which will help in

the redesign effort.  Flying the current ice/frost

ramps limits the design changes on the tank,

which has already undergone a significant

redesign with the removal of the Protuberance

Air Load (PAL) ramp.
May 2006 RECOGNIZING & ELIMINATING DEBRIS SOURCES 57

Current Ice/Frost Ramp

Current Ice/Frost Ramp

BIPOD CLOSEOUT 

Ascent/on‐orbit imagery from STS‐114

documented a 7‐inch‐by‐8‐inch divot, or lump

of missing foam, near the tank’s left hand bipod

attachment fitting.  The bipod fittings use

electric heaters to prevent ice buildup—a

potential debris source—on bipod fittings.  The

bipod design requires cabling to operate the

heating system and includes eight circuits—

four for each bipod fitting— that run from the

external tank ground umbilical carrier plate to

the heaters which are under the fittings

themselves.  These fittings connect the external

tank to the orbiter through the shuttleʹs two

forward attachment struts.

Analysis indicates a probable cause of the divot

during the STS‐114 mission was cryoingestion,

where gases are pulled or ingested through leak

paths into regions under the foam at cryogenic

temperatures.  These gases condense into liquid

during tanking on the launch pad, and later

expand back into gases during ascent as the

tank structure warms.  This rapid expansion

can cause increases in pressure under the foam,

potentially causing divots to be liberated.  For

the bipod, the leak path for this gas could have

been through the heater or temperature sensor

wiring harness.  Another potential contributor

to the cryoingestion scenario is the voids found

in the material used to bond the wire harnesses

to the substrate.  These voids can act as

reservoirs for the liquid nitrogen ingested

through the harness.

To correct these problems, electrical harnesses

that service the bipod heaters and temperature

sensors were removed and replaced with

improved versions that are designed to reduce

the potential for nitrogen leakage from the

intertank through the cables into the cryogenic

region near the bipod fittings.  Void spaces

beneath the cables were eliminated by using an

improved bonding procedure to ensure

complete adhesive coverage.

Testing and analysis has confirmed this

modification will significantly improve the

performance of the foam in the bipod closeout

area.

Bipod Installation

INSTRUMENTATION 

External Tank ET‐119 has the same

development flight instrumentation (DFI) suite

as External Tank ET‐118, which is the fuel tank

designated for the STS‐115 mission.

Instrumentation, to make measurements during

flight, includes accelerometers in both the

liquid oxygen and liquid hydrogen cable trays.

Bipod Installation
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 58

ENHANCED SHUTTLE-BASED CAMERA VIEWS 

New and modified cameras on the space shuttle

solid rockets, external tank and on Discovery will

greatly increase the views available to verify that

there is no hazardous debris or damage during

ascent.

The cameras increase the capability to monitor

the ascent environment, including debris, and

verify the health of the shuttleʹs thermal

protection system and the redesigned portions of

the external tank.

Enhancements include reinstating previously

used digital cameras on the shuttle solid rocket

boosters; a video camera on the external tank; a

remote electronic still camera on the underside of

the shuttle to replace a previous film camera in

that location; and crew handheld digital

photography of the tank that can be processed

onboard the shuttle for transmission to the

ground.

Cameras on the Space Shuttle Boosters, External Tank and Orbiter

Cameras on the Space Shuttle Boosters, External Tank and Orbiter
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 59

Together, these steps are part of a project

known as the enhanced launch vehicle imaging

system (ELVIS).

The tank‐mounted camera provides

supplementary imaging to that gained through

in‐flight inspection with the orbiter boom and

sensor system.  Beginning with STS‐121,

additional cameras were added to the solid

rockets to provide better views of the wings

during ascent.

EXTERNAL TANK-MOUNTED CAMERA 

A television camera on the exterior of the

external tank located several feet above the

right bipod area in the liquid oxygen feedline

fairing housing is the same as used on space

shuttle mission STS‐114 in July 2005.

Shuttle Orbiter‐Based Photography for STS‐121 Ascent

Shuttle Orbiter‐Based Photography for STS‐121 Ascent
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 60

External Tank Camera Overview

External Tank Camera Overview

The camera is a Sony XC‐999 secured in a

modified, space‐hardened housing.  It is about

the size of two C batteries laid end‐to‐end and

is of a type commonly referred to as a ʺlipstickʺ 

camera.  The cameraʹs views will be transmitted

to the ground in real time via the ground

communications station at Merritt Island, Fla.,

during the shuttleʹs climb to orbit.

The transmission occurs through an electronics

package located within the central part

(intertank) of the external tank, which joins the

oxygen and hydrogen tanks.  The electronics

box houses batteries, a 10‐watt transmitter and

other equipment.  The signal is sent to the

ground via antennas located on the exterior

back side of the tank, almost directly opposite

the cameraʹs location.

The new tank camera is expected to remain in

the same configuration for all remaining

missions.

SOLID ROCKET BOOSTER CAMERAS 

Previously used cameras – one on the left solid

rocket and one on the right – provide views of

the intertank for STS‐121.  The cameras are

located just below the nose cone of each booster

and do not provide real‐time views during

launch.  Their imagery is recorded for playback

after their retrieval from the Atlantic Ocean.

Two additional cameras on each booster are at

the tank’s attach ring, about one‐quarter of the

way up each rocket.  Another camera has been

added to the forward skirt of each booster,
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 61

where each rocketʹs nose cone and main body

intersect.

The forward skirt cameras will look aft to

provide views of the shuttle wing leading

edges.  The tank attach ring cameras will look

forward to provide views of the wing and

fuselage underside tiles.  All cameras will

record imagery on the rockets for viewing after

they have been recovered.  They will not

provide real‐time television views during

launch.

SRB‐Mounted Cameras

SRB‐Mounted Cameras

ET Ring Camera Housing Installed

ET Ring Camera Housing Installed

  Forward Skirt Aft‐Pointing Camera Prototype Housing

Forward Skirt Aft‐Pointing Camera  

Prototype Housing
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 62

Camera Configuration

Camera Configuration

EXTERNAL TANK UMBILICAL WELL 

DIGITAL STILL CAMERA 

A 35mm still camera previously located in the

right umbilical well on the underside of the

orbiter has been replaced with a Kodak DCS760

digital still camera.  The new camera will take

digital images of the tank after it has separated

from the orbiter and feed them to a laptop

computer in the crew cabin.  The crew then will

downlink those images to Mission Control for

analysis early in the flight.

The left umbilical well will continue to have

two film cameras as has been flown on previous

missions to gather movie imagery for use in

analysis after it has been returned to Earth.

Right‐Hand Umbilical Well

Right‐Hand Umbilical Well
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 63

CREW HAND-HELD PHOTOGRAPHY 

The crewʹs procedures in photographing the

external tank after it has separated from the

orbiter have been modified to use a digital still

camera Kodak DCS760.  The hand‐held digital

camera has been flown on many past missions,

but never before has been used for imagery of

the tank after launch.  Previously, imagery of

the tank was taken by the crew using a

hand‐held film camera and saved for analysis

after the shuttleʹs return to Earth.

The hand‐held digital images of the tank will be

transferred to a laptop computer and then

transmitted to Mission Control early in the

mission for analysis.  Along with the

photography taken by the umbilical well digital

camera, the handheld digital images will assist

ground technicians in characterizing the

condition of the tank as it was jettisoned.  They

will assist in characterizing any foam loss and

verifying the flight operation of tank design

changes that have been made.

To photograph the tank, the orbiter will be

pitched over shortly after the tank has

separated to optimize its view from the

overhead cabin windows.  This maneuver will

be done a few minutes earlier to improve the

resolution of the imagery.

Digital Umbilical Still Camera System

Digital Umbilical Still Camera System
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 64

DIGITAL SPACEWALK CAMERA 

A new hand‐held digital camera for use by

spacewalkers outside the vehicle will be flown

on all flights.  Previously, cameras used by

spacewalkers outside the vehicle had been film

cameras.  The new extravehicular activity

(EVA) camera is a Kodak DCS760 camera, the

same camera used for digital imagery inside the

shuttle cabin, with some modifications made to

equip it for use in the vacuum and extreme

temperatures of space.  The modifications

included a change of lubricants for the camera

and a thermal protective covering.

A flash unit also is available for use.  The flash

has been modified to remain in an air‐tight

housing for use in the vacuum of space.

Digital images taken during a spacewalk are

stored in the memory of the camera and later

brought back inside the shuttle cabin.  Then,

they are fed into a laptop computer in the cabin

and transmitted to Mission Control.  The digital

EVA camera may be used to provide images of

an inflight repair performed during a mission,

to assist an EVA inspection of potential damage

or for other reasons.

EVA Flash Mechanical Design

EVA Flash Mechanical Design

May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 65

IN-FLIGHT INSPECTION AND REPAIR 

In addition to improved cameras on the ground

and on the space shuttle, Discovery’s astronauts

will conduct close‐up, in‐flight inspections with

cameras, lasers, and human eyes.

The primary tool for on‐orbit inspection will be a

50‐foot‐long space shuttle robotic arm extension

and associated sensors, known as the Orbiter

Boom Sensor System (OBSS).  While the shuttle’s

remote manipulator system (SRMS) is capable of

inspecting part of the thermal protection system

on its own, the OBSS is used to extend that reach

to all critical areas of the shuttle’s wing leading

edge and underside.

The OBSS was assembled by MD Robotics of

Brampton, Ontario, Canada, which

manufactures remote manipulator systems for

both the shuttle and the International Space

Station.  The OBSS combines two 20‐foot‐long

graphite epoxy cylinders originally

manufactured as shuttle arm replacement parts.  

At one end of the boom is a modified electrical

grapple fixture, and on the other end are the

imagery systems.

The two sections are joined by a rigid fixture,

which has an attached modified flight releasable

grapple fixture that will be used to hand the

boom from the station arm to the shuttle arm

during docked operation at the complex.  

Electrical and data cables run the length of the

boom, providing power for the sensors while

allowing imagery to be transferred through the

shuttle’s wiring system to laptop computers and

downlink systems in the crew cabin.

Orbiter Boom Sensor System Installed on Starboard Sill

Orbiter Boom Sensor System Installed on Starboard Sill
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 66

The imagery systems include a laser dynamic

range imager (LDRI), a laser camera system

(LCS) and an intensified television camera

(ITVC).  The LDRI and ITVC are attached to the

boom using a standard Pan Tilt Unit (PTU) for

pointing.  The LCS is hard‐mounted to the side

of the boom just behind the other two

instruments.

Manufactured by Sandia National Laboratories,

Albuquerque, N.M., the LDRI is comprised of

an infrared (not visible to the human eye) laser

illuminator and an infrared camera receiver.  

The LDRI can be used to provide either two‐ or

three‐dimensional video imagery data; the

two‐dimensional imagery may be seen by the

shuttle crew on orbit, but three‐dimensional

data will need to be processed on the ground

after being downlinked via the shuttle’s high‐

bandwidth Ku antenna system that transmits

the video through the Tracking and Data Relay

Satellite System (TDRSS).

The ITVC is the same low‐light,

black‐and‐white television camera used in the

space shuttle’s payload bay.  The two imagery

systems may not be used simultaneously.

The LCS, manufactured by Neptec of Ottawa,

Ontario, Canada, is a scanning laser range

finder developed for use aboard the Space

Shuttle.  The LCS can be used as a 3D camera or

to generate computer models of the scanned

objects, accurate to a few millimeters at

distances of up to 10 meters.  Unlike the LDRI,

the LCS data is not video, but instead are files

collected on a dedicated laptop.

For STS‐121, another digital camera has been

added to the boom’s sensor package.  This

Integrated Sensor Inspection System Digital

Camera (IDC) is packaged with the Laser

Camera System and offers high enough

resolution to see minute damage on the wing

leading edge panels.  It is designed to help

distinguish “brown spots” and gap fillers as

were seen during inspections on STS‐114 last

July.

The data is processed on the ground after being

downlinked through the orbital

communications adapter (OCA) ‐ a high‐speed

computer modem that uses the Shuttle’s Ku

antenna system to transmit the data through

the TDRSS.

Discovery is scheduled to rendezvous and dock

with the International Space Station on flight

day 3.  As the shuttle pursues the station on

flight day 2, the crew will conduct a thorough

inspection of Discovery’s wing leading edges

and nose cone using the OBSS.  Three crew

members will take turns, working in pairs, to

operate the shuttle’s robotic arm from the aft

flight deck, unberth the OBSS from its cradles

on the starboard side of the payload bay and

conduct the inspection.

Since the LDRI and LCS must remain within

10 feet of its target to ensure image quality and

because the arm and boom must not contact

any of the shuttle’s surfaces in the process, the

astronauts use a combination of automated and

manual arm operation modes.  The surveys are

done using automatic mode with the astronauts

monitoring its progress.  The astronauts will

use the manual arm operation mode to move

the OBSS from the end of one sequence to the

start of the next.
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 67

  Inspection Sensors

Inspection Sensors

LCS, ITVC Camera, LDRI, and Pan/Tilt Unit

• Neptec Laser Camera System (LCS)

• Triangulates 3D position with a small

diameter scanning laser beam

• Sandia Laser Dynamic Range Imager

(LDRI)

• Illuminates the FOV with modulated laser

light.  Images on a camera CCD are

processed to provide depth information.

• Designed & flown as an integrated package

with an ITVC and pan & tilt unit (PTU)
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 68

Mission planners expect the flight day 2 survey

of Discovery’s wing leading edges and nose cap

to take about seven hours to complete,

assuming a maximum scan rate of four meters

per minute (21⁄2 inches per second).  The scans

will be broken into 60‐ to 90‐minute blocks, or

sequences, corresponding with specific areas of

the shuttle’s thermal protection skin.  

Engineering experts on the ground will review

the data both in real time and after processing

on the ground to identify any areas that need

additional scrutiny.

Discovery’s robotic arm is expected to be used

without the boom on flight day 2 to conduct

video inspections of the upper tile surfaces

using the arm’s end effector camera.  The next

day, during the shuttle’s rendezvous with the

station, as Discovery reaches a point 600 feet

below the station, the crew will perform a

rendezvous pitch maneuver, a

three‐quarter‐foot per‐second backflip, so that

its underside faces the station.  The station crew

will use digital still cameras with 400 and 800

millimeter lenses and a detailed plan to

photographically map the shuttle’s underside

for about 90 seconds before it continues on to

docking.  The images will be sent to Earth for

inclusion in the collection of data that will be

used by the Mission Evaluation Room (MER)

and Mission Management Team (MMT) to

evaluate the condition of the thermal protection

system.  That data will be part of the

compilation of imagery to allow mission

managers to make decisions on how the

mission should proceed.

After docking and welcome ceremonies are

complete, shuttle and station crew members

will work together, lifting the OBSS out of the

cargo bay using the space station remote

manipulator system (SSRMS) and handing it to

the shuttle arm for use in additional surveys the

following day.  The station arm, also known as

Canadarm2, will be brought into play because

the geometry of the combined shuttle‐station

configuration results in obstructions that

prevent the shuttle arm from maneuvering the

OBSS out of its cargo bay cradles.  The flight

plan identifies flight day 4 as an additional day

for docked surveys, if required, using the OBSS,

either to complete parts of the survey that time

would not allow on flight day 2, or to

supplement the survey with “stop‐and‐stare”

scans of sites of potential interest.  Some of

Discovery’s crew will reserve time for these

detailed inspections for the last half of flight

day 4 while other crew members are making

preparations for the first spacewalk, which will,

among other things, test thermal protection

system inspection and repair capabilities.

Additional inspections of the orbiter wing

leading edges and nose cap prior to deorbit and

landing to detect Micrometeoroid Orbital

Debris (MMOD) damage has been made a high

priority by the Space Shuttle Program.  These

so‐called “late inspections” using the OBSS will

be conducted during STS‐121.  The survey of

the port wing will be conducted the day before

Discovery undocks from the space station.  The

starboard wing and nose cap will be inspected

immediately after undocking.  The sensor data

will be downlinked to the ground for

evaluation.

After the in‐flight data, images and personal

reports from the crew are relayed to the

ground, engineers and imagery experts will

process and integrate the information with that

recorded during launch and the climb to orbit.  

The Space Shuttle Program’s Systems

Engineering and Integration Office (SE&I) will

work closely with the MER to review and

evaluate the information and provide separate

damage assessments for tiles and the reinforced

carbon‐carbon panels of the wing leading edges

and nose cap.
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 69

THERMAL PROTECTION SYSTEM 

ON-ORBIT REPAIR TECHNIQUES 

Prevention is NASA’s first line of defense

against damage to the space shuttle’s thermal

protection system (TPS).  Minimizing cannot

eliminate all the threats to the shuttle’s tiles and

reinforced carbon‐carbon wing leading edge

panels.  Orbital debris (or space junk) and

micrometeoroids also are capable of causing

damage.

Experts from the TPS engineering, mission

operations and extravehicular activity

organizations at JSC, working in collaboration

with their counterparts at other NASA centers

and with contractors, identified the issues that

needed to be addressed, and devised means of

addressing them.  Preliminary criteria for

damage that must be repaired on orbit was

defined, identifying all critical areas that must

be reached for inspection, identifying candidate

on‐orbit repair materials capable of

withstanding the stress of entry, and design

initial tools and techniques that would allow

spacewalkers to repair critical damage to both

tiles and reinforced carbon‐carbon segments.

The TPS repair systems developed to date fall

into two basic categories, mechanical or

chemical.  Each type has advantages and

disadvantages.  Mechanical systems rely on

prefabricated materials and fasteners that

connect them to the shuttles’ existing protection

systems.  Chemical systems rely on materials

that are applied in a raw form and develop a

chemical adhesive bond when applied to the

existing protection systems; these must cure in

place before being subjected to re‐entry

conditions.  Mechanical installation methods

can be tested and validated on Earth, while

chemical methods require testing in space to

validate application techniques and material

hardening.

ITVC, LCS, and LDRI Images

• ITVC

• Good flexibility as a general survey tool

• Low resolution, inherent image defects

• Able to detect small defects under specific

conditions

• LCS

• Provides very detailed 3‐dimensional

information

• Shown to operate while translating

• LDRI

• Valuable performance as both a 2D & 3D

imager

• Picture shows an intensity image laid on

top of range image, although it appears

fuzzy to the untrained eye, it gives a wealth

of data
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 70

The crack repair option uses a pre‐ceramic

polymer sealant impregnated with

carbon‐silicon carbide powder, together known

as NOAX (short for Non‐Oxide Adhesive

eXperimental).  It is designed to fix the most

likely type of damage caused by small pieces of

foam coming off the external tank.  NOAX can

be used at any RCC location, and does not

require any physical modification of the RCC

before affecting a repair.  A selection of hand

tools similar to putty knives would be used to

work the material into the crack and to smooth

the surface of the repair.

ACCESS 

Access to damaged sites will be accomplished

through a variety of means, depending on

whether the shuttle is at the International Space

Station.

On station missions, techniques are being

developed that will allow robotic arm operators

to undock and reposition the shuttle for a

station‐based spacewalk repair.  Spacewalkers

would be positioned at the work site by the

station’s robotic arm using a portable

articulating foot restraint (PAFR).

For non‐station missions, access may be gained

through the use of the shuttle’s robotic arm or

the arm and its 50‐foot boom extension, which

is being tested on EVA 1 during STS‐121, or

through use of the shuttle aid for extravehicular

rescue (SAFER).  A variety of candidate work

platforms are in preliminary stages of

development and continue to be evaluated.

FUTURE WORK 

Several other repair concepts have been

proposed for both tile and RCC repair.  These

include flexible adhesive patches and small

area repair plugs for RCC, and hardening of the

existing tile system coating.  Researchers at a

variety of NASA centers and contractor

laboratories are continuing to develop these

approaches for possible future use.
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 71

IMAGERY AND DATA COLLECTION FOR 

SPACE SHUTTLE LAUNCH AND LANDING 

Documenting the space shuttle launches

includes a minimum of three different views

from ground sites as well as aircraft‐based

video.  These additional views and cameras

provide much higher fidelity footage for

assessing whether any debris came off the

external tank during the first two minutes of

flight when the vehicle encounters the highest

aerodynamic loads.  A total of 107 ground and

aircraft‐based cameras will document

Discovery’s launch and climb to orbit.

The ground camera ascent imagery system was

upgraded following the Columbia accident and

also will include ship and ground‐based radar

to compliment the strategically placed cameras.  

In place for launch will be upgraded cameras

and high definition television (HDTV) for quick

look analysis, and mirrored server capability to

more easily and quickly allow the sharing of

imagery between KSC, JSC, and Marshall.

GROUND-BASED IMAGING OF LAUNCH 

The three camera sites are designated one, two

and six.  Site one, northeast of the launch pad,

ensures a view of the underside of the right

wing as well as the area between the external

tank and the orbiter to track any debris during

its roll maneuver just after launch.  All sites

have two film and one HDTV video cameras.

The short‐range tracking cameras have 200mm

focal length lenses and are loaded with 400 feet

of film, running 100 frames per second.  In

addition to the film cameras around the launch

pads, there are 42 fixed cameras with 16mm

motion picture film.

TYPE NO. 

Infrared (IR) 2 

High Speed Digital Video (HSDV) 2 

70 mm 3 

High Definition (HDTV) 19 

National Television Standards 

Committee (NTSC) 20 

35 mm 29 

16 mm 32 

TOTAL 107 

LOCATION TYPE NO. 

Launch Pad 39B 16 mm 30 

(Launch platform & launch 

tower) 

Launch Pad Perimeter 16 mm 2 

35 mm 5 

Short Range Tracking Sites 

(3) HDTV 3 

 35 mm 6 

Medium Range Tracking 

Sites (6) 70 mm 1 

 NTSC 1 

HSDV 2 

35 mm 7 

HDTV 6 

Long Range Tracking Sites 

(11) 70 mm 2 

NTSC 4 

 HDTV 5 

 35 mm 11 

WB-57 Aircraft (2) Infrared 2 

 HDTV 2 

Operational Television 

(OTV) HDTV 3 

NTSC 9 

Public Affairs NTSC 6 

TOTAL 107

Camera Types and Locations
Short‐range Tracking Camera

May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 72

Medium‐range trackers are at six sites, three

along the coast and three near the Launch

Complex 39 area.  They provide three views for

triangulation, to better characterize any suspect

area.  These cameras have 800mm and greater

lenses, and can capture 100 frames per second.  

Three of the cameras have 400 feet of film and

two have 1,000 feet.  The additional tracking

cameras have 150‐inch lenses, with 1,000 feet of

film.  Five of six sites also have HDTV video

cameras.

Five long‐range trackers have existed north and

south of the pads, from Shiloh and Playalinda

to Cocoa Beach, ranging from 14 miles north to

20 miles south.  These additions will reach as

far north as Ponce de Leon Inlet, 38 miles from

the launch pads, and south to Pigor, 11 miles

from the pads.  One of the cameras previously

located at Patrick Air Force Base has been

converted to be transportable and moved north

of the pad.

All the cameras have 400‐inch focal length and

100 feet per second capability to provide more

data points to better track any debris.

Two of the cameras are part of the distant object

attitude measurement system (DOAMS),

located at Playalinda Beach and the Cocoa

Beach area.  A refurbished five‐meter focal

length telescope has been installed in the Cocoa

Beach location.  Each of these sites also will

have HDTV video cameras.

A unique feature of the tracking telescopes is a

robotic camera manned by a technician sitting

on top and manipulating a joystick to map the

shuttle’s track through the sky.

Long‐range Tracker
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 73

CAMERAS 

A variety of cameras and lenses are used to

support ascent imaging, including film and

digital cameras.

• 35mm film cameras are used at the pad and

on short, medium and long range camera

sites and provide the highest resolution

dictating they are the primary imagery to

meet the minimum size requirements for

debris identification during ascent.

• HDTV digital video cameras are co‐located

with many of the 35mm cameras and

provide quick look capability.  The digital

video data provides the ability to conduct

expedited post‐launch imagery processing

and review (quick look) before the film is

processed and distributed.

• National Television Standards Committee

(NTSC) – backup sites without HDTV.

• 70mm motion picture film cameras provide

“big sky” views.

• 16mm motion picture film cameras are used

on the Mobile Launch Platform and Fixed

Service Structure of the launch pad.

• Other cameras throughout the launch pad

perimeter and other locations provide

additional quick look views.

Cameras are either fixed or mounted on a

tracker.  A variety of trackers are used, the

predominant being a Kineto Tracking Mount

(KTM) tracker.  All of the trackers near the

launch pads are remotely controlled.  The

remaining trackers are remotely or manually

controlled on‐site.

Kineto Tracking Mount Tracker

Kineto Tracking Mount tracker
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 74

CAMERA LOCATIONS 

The ascent ground cameras provide imagery

from the launch platform and on the launch

tower itself, as well as from short, medium and

long‐range sites as mentioned above.

Twenty‐two 16mm cameras are on the Mobile

Launch Platform...

MLP Deck

...and eight 16mm cameras are on the launch

tower (Fixed Service Structure).

Pad Perimeter

The three short‐range camera sites are within

the pad perimeter approximately 422 to

432 yards from the launch pads and include

two 35mm cameras and an HDTV camera.  

These sites provide coverage during the early

phases of a launch to image individual portions

of the shuttle stack.  Once the vehicle clears the

launch tower, these cameras can capture larger

portions of the shuttle, but lose the ability to

image and track small debris.

Short‐range Camera Configuration

Eleven medium‐range sites are one to six miles

from the launch pads—seven used for Pad 39A

and six for Pad 39B.  The medium‐range sites

each have a 35mm camera while 10 of the 11

incorporate HDTV cameras.  Medium‐range  
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 75

Medium‐range Camera Configuration

cameras are used from the early phase of ascent

until the distance to the shuttle becomes too far

to identify and track debris.

Eleven long‐range sites are located 4 to almost

40 miles from the launch pads, and support

both pads.  All these sites have 35mm cameras,

and two have 70mm cameras.  Five of the

10 sites have HDTV cameras.  Long‐range

cameras are used during early phases of ascent

to identify and track debris and continue to be

used as long as the vehicle is visible.

Long‐range Camera Configuration

CAMERA RESOLUTION 

• Liftoff to 30 seconds:  Objects of 1 inch in

diameter or larger, 0.5 foot linear accuracy

of debris source and impact location

• 30 seconds to 60 seconds:  Objects of

3 inches in diameter or larger, 1 foot

linear accuracy of debris source and

impact location

• 60 seconds to 90 seconds:  Objects of

8 inches in diameter or larger, 3 foot

linear accuracy of debris source and

impact location

• 90 seconds to booster separation:  Objects of

15 inches in diameter or larger, 5 foot linear

accuracy of debris source and impact

location

CAMERA OPERATIONS PLAN 

All of the cameras are checked pre‐launch, and

then activated on launch day to capture the

ascent imagery.  After launch, the 70mm, 35mm

and 16mm films are collected and taken to a

central location at the Kennedy Space Center.  

Then they are flown to a processing facility to

be developed and copied for delivery to the

Johnson Space Center in Houston and the

Marshall Space Flight Center in Huntsville, Ala.  

The delivery occurs in two steps, one the day

after launch and the second two days after

launch.

The quick look video imagery—HDTV and

other formats—is collected and distributed

within the first few hours after launch and

provided to the image analysis facilities at

Kennedy, Johnson and Marshall via a mirrored

server available for review between one and

eight hours after launch.
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 76

About one hour after launch, the quick look

imagery consists primarily of views from the

short‐range cameras and is reviewed by all of

the imagery analysis teams.  Quick look

imagery consisting of HDTV imagery from the

medium and long‐range sites will be retrieved

and made available to the imagery analysis

teams and thermal protection system experts

approximately eight hours after launch.

ASCENT IMAGING FROM ABOVE 

NASA has implemented an aircraft‐based

imaging system using agency WB‐57 aircraft

based near the Johnson Space Center in

Houston.  The WB‐57 ascent video experiment

(WAVE) will be used again to provide ascent

and entry imagery to enable better observation

of the shuttle on days of heavier cloud cover

and areas obscured from ground cameras by

the launch exhaust plume.  WAVE was initiated

as a return to flight capability to develop the

technical and operational capabilities of

obtaining video of the shuttle during launch

from an aircraft, which will supplement ground

cameras to obtain three useful views.

WB‐57 Aircraft

WB‐57 Aircraft

WAVE includes a 32‐inch ball turret system

mounted on the nose of each WB‐57.  The turret

houses an optical bench providing installation

for both high definition television and infrared

cameras.  Optics consists of an 11‐inch

diameter, 4.2 meter fixed focal length lens.  The

system can be operated in both auto track and

manual modes from a command and control

system in the cockpit, which includes monitors

for all three cameras, switch panels and

joysticks.  All footage will be recorded on board

and returned for processing and evaluation

shortly after the shuttle launch.

The two imaging cameras are a HDTV color

camera (Panasonic AK‐HC900) and a near

infrared camera (Sensors Unlimited SU640SDV

1.7RT/RS‐170).  Both share a Celestron fixed

field‐of‐view telescopic lens.  In addition, a

National Television Standards Committee

(NTSC) color acquisition camera will be used

during ascent.

Two days before launch the two WB‐57s will fly

from Ellington Field in Houston to Patrick Air

Force Base in Florida.

Two and a half hours before launch, the aircraft

will take off from Patrick and enter a holding

pattern.  One will be positioned north and one

south of the shuttle’s flight path.  They will be

in communication with a WAVE Operations

Officer in the Range Operations Control Center

who in turn will be in communication with the

chairperson of the imagery team in the Launch

Control Center.

SRB Separation

SRB Separation

Twenty minutes before launch the aircraft will

enter their final circuit, and about five minutes

before launch will begin recording video.  The

WAVE requirement is for imagery acquisition

from 60 seconds after liftoff to 15 seconds after
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 77

booster separation.  However, plans are for the

aircraft to track the vehicle from liftoff through

main engine cutoff (MECO), 81⁄2 minutes later.  

The two aircraft should be about 23 miles

(37 kilometers) from the shuttle at booster

separation.

After launch, the aircraft will return to Patrick,

and the video will be taken to Kennedy.  There

it will be loaded on the mirrored servers about

eight hours later.

The WB‐57 aircraft operate under direction of

JSC.  They are the only two WB‐57s still flying.  

Identified as NASA 926 and NASA 928, the

high‐altitude weather aircraft can fly day and

night with a range of 2,500 miles.  Two crew

members in pressurized suits pilot the plane to

altitudes in excess of 60,000 feet.  They can

carry a payload of about 6,000 pounds.

RADAR TRACKING 

A new wideband and Doppler radar tracking

system has been implemented for adequate

detection of debris during launch and ascent.  

Three radars now will digitally record tracking

data of the shuttle from launch until signal is

lost with the primary timeframe of interest

being launch plus 60 seconds to launch plus

two minutes.

Data from each radar site will be stored on a

hard disk and backed up on CDs/DVDs, as will

be the boresight video used by the radar

operators to help track the vehicle.

The three radar systems that launch will be in

place for one C‐band and two Doppler X‐band

radar systems.

The Wideband Coherent C‐band Radar

provides high spatial resolution of debris

events, and can detect debris events within the  

C‐band Radar

The 50‐foot, C‐band radar located  

at the NDR‐1 site north of the  

Kennedy Space Center

Shuttle vehicle stack.  This radar—called the

Navy Midcourse Radar—formerly was located

at Roosevelt Roads Naval Station in Puerto

Rico.

The two Weibel Continuous Pulse Doppler

X‐band Radars provide velocity and differential

shuttle/debris motion information.  Correlation

of these two data sets over the three geometries

provided for the debris radar system optimizes

the insight and probability of detection for very

faint debris targets.  These radar systems will

be located on ships—one on a booster recovery

ship downrange of the launch site and the other

on a ship south of the ground track.

The radars are capable of resolving debris at or

greater than observed signal strength of minus

50 decibels per square meter (dBsm).  Shuttle

debris sources have been characterized as

typically falling within in the minus 30 dBsm to

minus 45 dBsm range.  The X‐band and the

C‐band radars were flight tested during the

launch of Discovery in July 2005 and for three

expendable rocket launches site from the NASA

Debris Radar (NDR‐1) intended to permanently

house the systems.
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 78

X‐band Radar

NASA X‐band radar on the fantail of

ʺFreedom Starʺ ‐ one of two solid  

rocket booster recovery ships

The radar data will be analyzed at the NDR‐1

site with the C‐band data being available in

near real‐time, while the X‐band data (screen

captures) will be sent from the ships via

satellite link to the site.  The southern ship is

expected back in port 6 hours after launch, and

the data will be transported immediately.

WING LEADING EDGE 

INSTRUMENTATION 

NASA chose to incorporate sensors along the

orbiter wing leading edges to compliment

thermal protection system inspection by

measuring, recording, and transmitting

acceleration data to a laptop computer on the

flight deck for early transmission to the Mission

Control Center.

The Wing Leading Edge Impact Detection

System (WLEIDS) is comprised of 88 sensors

embedded behind the protective reinforced

carbon carbon panels.  Sixty six acquire

acceleration data and 22 gather temperature

measurements during the shuttle’s launch

phase.  The temperature sensor data is used to

calibrate the impact sensors.

Battery‐powered sensor units inside the wing

will measure, record and transmit acceleration

and temperature data, along with battery

voltage to the laptop computer via a

combination of radio relays and cables.

Before launch, the sensor units are loaded with

command files that contain the Greenwich

Mean Time (GMT) of launch.  Shortly before

liftoff, the units start taking accelerometer data

at 20,000 samples per second per channel and

the launch vibrations cause the units to begin

storing the data in internal memory.  New for

STS‐121, the sensors will be activated preflight

to measure vibration from countdown

milestones such as auxiliary power unit

start‐up and the gimbal checks of the three

space shuttle main engines.  This data can be

used to verify the margin on the launch triggers

(settings used to initiate data collection when

WLEIDS senses liftoff) to avoid premature start

of data storage.  Temperature and battery

voltage data is stored every 15 seconds.

Ten minutes after launch—after the external

tank separates—continuous data collection will

stop.  Each sensor unit will process the data to

determine the peak acceleration forces that

particular sensor experienced during ascent.  

These summary data files, which are more

quickly downlinked to the ground than the

huge volume of raw data, will be screened to

determine whether any potential impact events

occurred.  Since STS‐114, the analysis team has

refined its procedures on how to standardize

and automate the analysis in order to produce

an ascent report as soon as 18–24 hours after

launch.

Any measured ascent impacts will be ranked in

order of importance for the focused inspection

(if required) based on the best measure of

impact energy.  Since this is only the second

flight of the WLEIDS, the data will not
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 79

necessarily relate to risk of damage, but will

continue to build the database required to

validate models in the future.

After processing the data, the system will enter

on‐orbit mode, meaning only six sensor units

(2 on each wing) will collect acceleration,

temperature and battery voltage.  The other

units will become idle.  The specific units in

each mode will rotate throughout the flight in

order to maximize the battery life of the

sensors.

About 11⁄2 hours after launch, the crew will

connect the wing leading edge system laptop to

the onboard computer network and the

software will begin to download data from each

sensor unit.  Commands are sent through the

laptop to the 44 sensor units and will download

acceleration, temperature and voltage data for

each sensor to designated folders on the laptop

and, new for STS‐121, the designated backup

laptop on the LAN.

A small amount of raw data from liftoff also

will be downloaded to be used as a baseline for

calculations on the ground.  Throughout the

remainder of the flight, the sensor units will be

commanded every six hours to download

G‐force peaks, time of occurrence, voltage and

temperature files.

As an STS‐121 detailed test objective, the wing

leading edge impact detection system will

investigate its on orbit monitoring capability for

micrometeroid debris (MMOD) detection as

long as battery life permits.  Future potential

software enhancements could increase the

on‐orbit battery life and the ability to detect

small MMOD impacts based on data collected

during this, and future flights.

As the data files are written to the laptop, they

will be extracted from the laptop via ground

control by operators in Mission Control and

placed on a server for access and evaluation by

experts.  The back‐up laptop will allow

WLEIDS operations to continue in case the

crew is not available to reset the primary laptop

in the event of a fault.

Based on the data evaluation of summary data,

additional raw data will be requested for each

potential impact or data event of interest.  Raw

data can also be requested based on findings

from telemetry or other imagery sources.  A

command will download the specific time

period needed for further evaluation.  Data

from each sensor unit is downloaded at a rate

equivalent to two minutes for 1⁄2 second of raw

data to the laptop, so a complete set of raw data

will not be downloaded to the laptop.

After landing, ground operations personnel at

Kennedy Space Center will download the

remaining raw data for archival and analysis.
Wing Leading Edge Impact Detection System

Wing Leading Edge Impact Detection System

May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 80
May 2006 IDENTIFYING & REPAIRING DAMAGE IN FLIGHT 81

Wing Leading Edge Impact Detection System

May 2006 Tile Repair Ablator Dispenser 82

TILE REPAIR ABLATOR DISPENSER (T-RAD) 

NASA engineers have designed the Tile Repair

Ablator Dispenser or T‐RAD as part of the

ongoing development of an in‐orbit repair

capability for the Space Shuttle.  Similar to a

caulk‐gun, the T‐RAD was designed to facilitate

the repair of tiles near the orbiter’s nose landing

gear door, its two main landing gear doors and

the external tank attachment doors.

Should tiles in those areas be damaged, an

Extra‐Vehicular Activity (EVA) crew member

will use T‐RAD to mix and extrude a two‐part

silicone‐based ablator material into the void in

the tile and then work it in smoothly.

The silicone‐based material, known as Shuttle

Tile Ablator‐54 (STA‐54), consists of a base

material and a catalyst.  Once mixed, it

resembles the consistency of cake‐frosting.  

However, the material cures to the texture of a

pencil eraser within 24 to 48 hours.  During

re‐entry, the STA‐54 dissipates heat by

charring, thus protecting the shuttle tiles.

Tile Repair Ablator Dispenser (T‐RAD)

The T‐RAD is comprised of a single, carbon

dioxide‐pressurized vessel separated into two

main sections.  Its mixing, delivery system

consists of a static mixer, a 3‐foot length of hose

and an applicator gun that controls the flow of

the extruding material.  The assembly weighs

55 pounds and is about the same size as a hand‐

held vacuum.

T‐RAD Delivery System

T‐RAD replaces the Cure‐In‐Place Ablative

Applicator (CIPAA) that flew on STS‐114.  The

more cumbersome CIPAA system consisted of

an EVA backpack with tanks that held the base

and catalyst components under pressure, and

paired hoses to transport the components to the

damaged area.  The applicator gun that CIPAA

used has been incorporated directly into the T‐

RAD design.

The T‐RAD will not be tested on the STS‐121

mission, it is being carried for contingency use

if, for some reason, the ISS safe‐haven option

were unavailable.  It also will be manifested on

space shuttle flights STS‐115 and STS‐116 for

contingency use.

May 2006 Contingency Shuttle Crew Support 83

CONTINGENCY SHUTTLE CREW SUPPORT (CSCS) 

NASA initiated a study to determine the

feasibility of rescuing a stranded space shuttle

crew at the International Space Station (ISS) in

the unlikely event damage would prevent the

safe re‐entry of the vehicle.  The ISS Program

conducted an extensive evaluation of the

station’s capability to provide provisions and

life support to a shuttle crew as part of an

agency self‐imposed contingency case that

would ensure a second shuttle was far enough

along in processing to be launched to rescue the

stranded crew.

This contingency shuttle crew support

(CSCS)—also known as safe haven—would be

used only as a last resort to return the crew of a

critically damaged shuttle.  In the unlikely

event all new safety measures were

unsuccessful, and a shuttle docked to the ISS is

deemed unsafe for return to Earth, NASA

would consider using CSCS to rescue the crew.

The ISS and Space Shuttle Programs have made

the necessary preparations for this option to be

available for the next two shuttle flights

(STS‐121 & STS‐115).  The Programs will

continue to evaluate the capability to enact

CSCS for future flights.

Those preparations include investigating ways

to appropriately build up critical systems and

consumables onboard the station.

The CSCS scenario allows the visiting crew of a

critically damaged shuttle to live onboard the

space station until a rescue shuttle can be

launched.  The crews would transfer all of the

consumables from the damaged shuttle to the

station.  Once the shuttle consumables are

depleted, the unmanned shuttle will be

remotely commanded to undock by Mission

Control in Houston and burn up in the Earth’s

atmosphere.

In the meantime, the next space shuttle in the

launch processing flow at the Kennedy Space

Center in Florida will become the rescue vehicle

and work will focus on it launching and

arriving at the station before consumables run

out.  The number of days the station can

support a stranded shuttle crew would be

determined, in part, by the consumables

already on board, plus what is brought up with

the shuttle.  The level of consumables onboard

the station, including food, water, oxygen and

spare parts, will be reviewed and provided up

until the day of the first shuttle launch to define

the CSCS capability for that particular mission.

NASA’s plan of crew support in a contingency

calls for a subset of the STS‐115 crew to support

STS‐121 and a subset of the STS‐116 crew to

support STS‐115.  The contingency flights are

designated STS‐300 and STS‐301, respectively.  

The crew members that would support a CSCS

case are:
May 2006 Contingency Shuttle Crew Support 84

STS‐300

Brent Jett, commander

Chris Ferguson, pilot and backup Remote

Manipulator System operator

Joe Tanner, mission specialist 1,

Extravehicular 1 and prime Remote

Manipulator System operator

Dan Burbank, mission specialist 2 and

Extravehicular 2

STS‐301

Mark Polansky, commander and prime Remote

Manipulator System operator

Bill Oefelein, pilot and backup Remote

Manipulator System operator

Bob Curbeam, mission specialist 1,

Extravehicular 1

Christer Fuglesang, mission specialist 2,

Extravehicular 2

The Soyuz spacecraft at the space station will

remain the emergency rescue vehicle for the ISS

Expedition crew.

Detailed biographies on the astronauts are

available at:  http://www.jsc.nasa.gov/Bios/
May 2006 SHUTTLE REFERENCE DATA 85

SHUTTLE REFERENCE DATA 

SHUTTLE ABORT MODES 

RSLS Aborts 

These occur when the on‐board shuttle

computers detect a problem and command a

halt in the launch sequence after taking over

from the ground launch sequencer and before

solid rocket booster ignition.

Ascent Aborts 

Selection of an ascent abort mode may become

necessary if there is a failure that affects vehicle

performance, such as the failure of a space

shuttle main engine or an orbital maneuvering

system.  Other failures requiring early

termination of a flight, such as a cabin leak,

might also require the selection of an abort

mode.  There are two basic types of ascent abort

modes for space shuttle missions:  intact aborts

and contingency aborts.  Intact aborts are

designed to provide a safe return of the orbiter

to a planned landing site.  Contingency aborts

are designed to permit flight crew survival

following more severe failures when an intact

abort is not possible.  A contingency abort

would generally result in a ditch operation.

Intact Aborts 

There are four types of intact aborts:  abort to

orbit (ATO), abort once around (AOA),

transoceanic abort landing (TAL) and return to

launch site (RTLS).

Return to Launch Site 

The RTLS abort mode is designed to allow the

return of the orbiter, crew and payload to the

launch site, Kennedy Space Center,

approximately 25 minutes after liftoff.

The RTLS profile is designed to accommodate

the loss of thrust from one space shuttle main

engine between liftoff 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 external

tank 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, about 3 minutes, 34 seconds into the

mission; whereas an RTLS chosen due to an

engine out at liftoff is selected at the earliest

time, about 2 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

toward 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
May 2006 SHUTTLE REFERENCE DATA 86

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 pitch‐down)

takes the mated vehicle to the required external

tank separation attitude and pitch rate.  After

main engine cutoff has been commanded, the

external tank separation sequence begins,

including a reaction control system translation

that ensures that the orbiter does not recontact

the external tank and that the orbiter has

achieved the necessary pitch attitude to begin

the glide phase of the RTLS.

After the reaction control system translation

maneuver has been completed, the glide phase

of the RTLS begins.  From then on, the RTLS is

handled similarly to a normal entry.

Transoceanic Abort Landing 

The TAL abort mode was developed to

improve the options available when a space

shuttle main engine fails after the last RTLS

opportunity but before the first time that an

AOA can be accomplished with only two space

shuttle main engines or when a major orbiter

system failure, for example, a large cabin

pressure leak or cooling system failure, occurs

after the last RTLS opportunity, making it

imperative to land as quickly as possible.

In a TAL abort, the vehicle continues on a

ballistic trajectory across the Atlantic Ocean to

land at a predetermined runway.  Landing

occurs about 45 minutes after launch.  The

landing site is selected near the nominal ascent

ground track of the orbiter 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.  The three

landing sites that have been identified for a due

east launch are Zaragoza, Spain; Moron, Spain;

and Istres, France.

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 vehicleʹs

landing weight.  TAL is handled like a nominal

entry.

Abort to Orbit 

An ATO is an abort mode used to boost the

orbiter to a safe orbital altitude when

performance has been lost and it is impossible

to reach the planned orbital altitude.  If a space

shuttle main engine fails in a region that results

in a main engine cutoff under speed, the
May 2006 SHUTTLE REFERENCE DATA 87

Mission Control Center will determine that an

abort mode is necessary and will inform the

crew.  The orbital maneuvering system engines

would be used to place the orbiter in a circular

orbit.

Abort Once Around 

The AOA abort mode is used in cases in which

vehicle performance has been lost to such an

extent that either it is impossible to achieve a

viable orbit or not enough orbital maneuvering

system propellant is available to accomplish the

orbital maneuvering system thrusting

maneuver to place the orbiter on orbit and the

deorbit thrusting maneuver.  In addition, an

AOA is used in cases in which a major systems

problem (cabin leak, loss of cooling) makes it

necessary to land quickly.  In the AOA abort

mode, one orbital maneuvering system

thrusting sequence is made to adjust the post‐

main engine cutoff orbit so a second orbital

maneuvering system thrusting sequence will

result in the vehicle deorbiting and landing at

the AOA landing site (White Sands, N.M.;

Edwards Air Force Base; or the Kennedy Space

Center).  Thus, an AOA results in the orbiter

circling the Earth once and landing about

90 minutes after liftoff.

After the deorbit thrusting sequence has been

executed, the flight crew flies to a landing at the

planned site much as it would for a nominal

entry.

Contingency Aborts 

Contingency aborts are caused by loss of more

than one main engine or failures in other

systems.  Loss of one main engine while

another is stuck at a low thrust setting may also

necessitate a contingency abort.  Such an abort

would maintain orbiter integrity for in‐flight

crew escape if a landing cannot be achieved at a

suitable landing field.

Contingency aborts due to system failures other

than those involving the main engines would

normally result in an intact recovery of vehicle

and crew.  Loss of more than one main engine

may, depending on engine failure times, result

in a safe runway landing.  However, in most

three‐engine‐out cases during ascent, the

orbiter would have to be ditched.  The inflight

crew escape system would be used before

ditching the orbiter.

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.

Mission Control Houston is prime for calling

these aborts because it has a more precise

knowledge of the orbiterʹs position than the

crew can obtain from on‐board 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 on‐

board methods, such as cue cards, dedicated

displays and display information, to determine

the abort region.

Which abort mode is selected depends on the

cause and timing of the failure causing the
May 2006 SHUTTLE REFERENCE DATA 88

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 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 about

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.

SHUTTLE ABORT HISTORY 

RSLS Abort History: 

(STS-41 D) June 26, 1984 

The countdown for the second launch attempt

for Discovery’s maiden flight ended at T‐4

seconds when the orbiter’s computers detected

a sluggish valve in main engine No. 3.The main

engine was replaced and Discovery was finally

launched on Aug. 30, 1984.

(STS-51 F) July 12, 1985 

The countdown for Challenger’s launch was

halted at T‐3 seconds when on‐board

computers detected a problem with a coolant

valve on main engine No. 2.  The valve was

replaced and Challenger was launched on

July 29, 1985.

(STS-55) March 22, 1993 

The countdown for Columbia’s launch was

halted by on‐board computers at T‐3 seconds

following a problem with purge pressure

readings in the oxidizer preburner on main

engine No. 2 Columbia’s three main engines

were replaced on the launch pad, and the flight

was rescheduled behind Discovery’s launch on

STS‐56.  Columbia finally launched on

April 26, 1993.

(STS-51) Aug. 12, 1993 

The countdown for Discovery’s third launch

attempt ended at the T‐3 second mark when

onboard computers detected the failure of one

of four sensors in main engine No. 2 which

monitor the flow of hydrogen fuel to the

engine.  All of Discovery’s main engines were

ordered replaced on the launch pad, delaying

the shuttle’s fourth launch attempt until

Sept. 12, 1993.

(STS-68) Aug. 18, 1994 

The countdown for Endeavour’s first launch

attempt ended 1.9 seconds before liftoff when

on‐board computers detected higher than

acceptable readings in one channel of a sensor

monitoring the discharge temperature of the

high pressure oxidizer turbopump in main

engine No. 3.  A test firing of the engine at the

Stennis Space Center in Mississippi on

September 2nd confirmed that a slight drift in a

fuel flow meter in the engine caused a slight

increase in the turbopump’s temperature.  The

test firing also confirmed a slightly slower start

for main engine No. 3 during the pad abort,

which could have contributed to the higher

temperatures.  After Endeavour was brought

back to the Vehicle Assembly Building to be

outfitted with three replacement engines,

NASA managers set Oct. 2 as the date for

Endeavour’s second launch attempt.

Abort to Orbit History: 

(STS-51 F) July 29, 1985 

After an RSLS abort on July 12, 1985,

Challenger was launched on July 29, 1985.  Five
May 2006 SHUTTLE REFERENCE DATA 89

minutes and 45 seconds after launch, a sensor

problem resulted in the shutdown of center

engine No. 1, resulting in a safe ʺabort to orbitʺ 

and successful completion of the mission.

SPACE SHUTTLE MAIN ENGINES 

Developed in the 1970s by NASAʹs Marshall

Space Flight Center in Huntsville, Ala., the

space shuttle main engine is the most advanced

liquid‐fueled rocket engine ever built.  Its main

features include variable thrust, high

performance, reusability, high redundancy and

a fully integrated engine controller.

The shuttle’s three main engines are mounted

on the orbiter aft fuselage in a triangular

pattern.  Spaced so that they are movable

during launch, the engines are used – in

conjunction with the solid rocket boosters – to

steer the shuttle vehicle.

Each of these powerful main engines is 14 feet

(4.2 meters) long, weighs about 7,000 pounds

(3,150 kilograms) and is 7.5 feet (2.25 meters) in

diameter at the end of its nozzle.

The engines operate for about 81⁄2  minutes

during liftoff and ascent—burning more than

500,000 gallons (1.9 million liters) of super‐cold

liquid hydrogen and liquid oxygen propellants

stored in the huge external tank attached to the

underside of the shuttle.  The engines shut

down just before the shuttle, traveling at about

17,000 mph (28,000 kilometers per hour),

reaches orbit.

The main engine operates at greater

temperature extremes than any mechanical

system in common use today.  The fuel,

liquefied hydrogen at ‐423 degrees Fahrenheit  

(‐253 degrees Celsius), is the second coldest

liquid on Earth.  When it and the liquid oxygen

are combusted, the temperature in the main

combustion chamber is 6,000 degrees

Fahrenheit (3,316 degrees Celsius), hotter than

the boiling point of iron.

The main engines use a staged combustion

cycle so that all propellants entering the engines

are used to produce thrust or power—more

efficiently than any previous rocket engine.  In

a staged combustion cycle, propellants are first

burned partially at high pressure and relatively

low temperature—then burned completely at

high temperature and pressure in the main

combustion chamber.  The rapid mixing of the

propellants under these conditions is so

complete that 99 percent of the fuel is burned.

At normal operating level, the engines generate

490,847 pounds of thrust (measured in a

vacuum).  Full power is 512,900 pounds of

thrust; minimum power is 316,100 pounds of

thrust.

The engine can be throttled by varying the

output of the pre‐burners, thus varying the

speed of the high‐pressure turbopumps and,

therefore, the flow of the propellant.

At about 26 seconds into launch, the main

engines are throttled down to 316,000 pounds

of thrust to keep the dynamic pressure on the

vehicle below a specified level—about

580 pounds per square foot or max q.  Then, the

engines are throttled back up to normal

operating level at about 60 seconds.  This

reduces stress on the vehicle.

The main engines are throttled down again at

about seven minutes, 40 seconds into the

mission to maintain three g’s – three times the

Earth’s gravitational pull – again reducing

stress on the crew and the vehicle.  This

acceleration level is about one‐third the

acceleration experienced on previous crewed

space vehicles.
May 2006 SHUTTLE REFERENCE DATA 90

About 10 seconds before main engine cutoff or

MECO, the cutoff sequence begins; about three

seconds later the main engines are commanded

to begin throttling at 10 percent thrust per

second to 65 percent thrust.  This is held for

about 6.7 seconds, and the engines are shut

down.

The engine performance has the highest thrust

for its weight of any engine yet developed.  In

fact, one space shuttle main engine generates

sufficient thrust to maintain the flight of 21⁄2

747 airplanes.

The space shuttle main engine is also the first

rocket engine to use a built‐in electronic digital

controller, or computer.  The controller will

accept commands from the orbiter for engine

start, change in throttle, shutdown, and

monitor engine operation.  In the event of a

failure, the controller automatically corrects the

problem or safely shuts down the engine.

NASA continues to increase the reliability and

safety of shuttle flights through a series of

enhancements to the space shuttle main

engines.  The engines were modified in 1988,

1995, 1998 and 2001.  Modifications include new

high‐pressure fuel and oxidizer turbopumps

that reduce maintenance and operating costs of

the engine, a two‐duct powerhead that reduces

pressure and turbulence in the engine, and a

single‐coil heat exchanger that lowers the

number of post flight inspections required.  

Another modification incorporates a large‐

throat main combustion chamber that improves

the engine’s reliability by reducing pressure

and temperature in the chamber.

After the orbiter lands, the engines are removed

and returned to a processing facility at

Kennedy Space Center, Fla., where they are

rechecked and readied for the next flight.  Some

components are returned to the main engine’s

prime contractor, Rocketdyne Propulsion &

Power unit of the Boeing Company, Canoga

Park, Calif., for regular maintenance.  The main

engines are designed to operate for

7.5 accumulated hours.

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 about

3,300,000 pounds at launch.  They are ignited

after the three space shuttle main enginesʹ 

thrust level is verified.  The two SRBs provide

71.4 percent of the thrust at liftoff and during

first‐stage ascent.  Seventy‐five seconds after

SRB separation, SRB apogee occurs at an

altitude of about 220,000 feet, or 35 nautical

miles (40 statute miles).  SRB impact occurs in

the ocean about 122 nautical miles (140 statute

miles) downrange.

The SRBs are the largest solid‐propellant

motors ever flown and the first designed for

reuse.  Each is 149.16 feet long and 12.17 feet in

diameter.

Each SRB weighs about 1,300,000 pounds at

launch.  The propellant for each solid rocket

motor weighs about 1,100,000 pounds.  The

inert weight of each SRB is about

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
May 2006 SHUTTLE REFERENCE DATA 91

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 liftoff.

During the downtime following the Challenger

accident, detailed structural analyses were

performed on critical structural elements of the

SRB.  Analyses were primarily focused in areas

where anomalies had been noted during

postflight inspection of recovered hardware.

One of the areas was the attach ring where the

SRBs are connected to the external tank.  Areas

of distress were noted in some of the fasteners

where the ring attaches to the SRB motor case.  

This situation was attributed to the high loads

encountered during water impact.  To correct

the situation and ensure higher strength

margins during ascent, the attach ring was

redesigned to encircle the motor case

completely (360 degrees).

Previously, the attach ring formed a C and

encircled the motor case 270 degrees.

Additionally, special structural tests were done

on the aft skirt.  During this test program, an

anomaly occurred in a critical weld between the

hold‐down post and skin of the skirt.  A

redesign was implemented to add

reinforcement brackets and fittings in the aft

ring of the skirt.

These two modifications added about

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

about a third 50 seconds after liftoff 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
May 2006 SHUTTLE REFERENCE DATA 92

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, a transition

piece between the nose cone and solid rocket

motor, and turns on the recovery aids.  The aft

assembly, mounted in the external tank/SRB

attach ring, connects with the forward assembly

and the orbiter avionics systems for SRB

ignition commands and nozzle thrust vector

control.  Each integrated electronic assembly

has a multiplexer/demultiplexer, which sends

or receives more than one message, signal or

unit of information on a single communication

channel.

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 ATK 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

(NSDs), 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 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
May 2006 SHUTTLE REFERENCE DATA 93

launcher platform.  They provide the ignition to

the hold‐down NSDs.  The launch processing

system monitors the SRB hold‐down PICs for

low voltage during the last 16 seconds before

launch.  PIC low voltage will initiate a launch

hold.

SRB Ignition 

SRB ignition can occur only when a manual

lock pin from each SRB safe and arm device has

been removed.  The ground crew removes the

pin during prelaunch activities.  At T minus

five minutes, the SRB safe and arm device is

rotated to the arm position.  The solid rocket

motor ignition commands are issued when the

three SSMEs are at or above 90 percent rated

thrust, no SSME fail and/or SRB ignition PIC

low voltage is indicated and there are no holds

from the LPS.

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 on‐board computers at T minus 6.6 seconds

(staggered start—engine three, engine two,

engine one—all about 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 liftoff 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 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 on‐board

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 on‐board master

timing unit, event timer and mission event

timers are started; the three SSMEs are at

100 percent; and the ground launch sequence is

terminated.

The solid rocket motor thrust profile is tailored

to reduce thrust during the maximum dynamic

pressure region.
May 2006 SHUTTLE REFERENCE DATA 94

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 generatorʹs 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 lineʹs.  Then all the

fuel is supplied to the fuel pump.

The APU turbine assembly provides

mechanical power to the APU gearbox.  The

gearbox drives the APU fuel pump, hydraulic

pump and lube oil pump.  The APU lube oil

pump lubricates the gearbox.  The turbine

exhaust of each APU flows over the exterior of

the gas generator, cooling it, and is then

directed overboard through an exhaust duct.

When the APU speed reaches 100 percent, the

APU primary control valve closes, and the APU

speed is controlled by the APU controller

electronics.  If the primary control valve logic

fails to the open state, the secondary control

valve assumes control of the APU at 112

percent speed.

Each HPU on an SRB is connected to both

servoactuators on that SRB.  One HPU serves as

the primary hydraulic source for the

servoactuator, and the other HPU serves as the

secondary hydraulics for the servoactuator.  

Each servoactuator has a switching valve that

allows the secondary hydraulics to power the

actuator if the primary hydraulic pressure
May 2006 SHUTTLE REFERENCE DATA 95

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 liftoff and ascent.  Commands

from the guidance system are transmitted to the

ATVC drivers, which transmit signals

proportional to the commands to each

servoactuator of the main engines and SRBs.  

Four independent flight control system

channels and four ATVC channels control six

main engine and four SRB ATVC drivers, with

each driver controlling one hydraulic port on

each main and SRB servoactuator.

Each SRB servoactuator consists of four

independent, two‐stage servovalves that

receive signals from the drivers.  Each

servovalve controls one power spool in each

actuator, which positions an actuator ram and

the nozzle to control the direction of thrust.

The four servovalves in each actuator provide a

force‐summed majority voting arrangement to

position the power spool.  With four identical

commands to the four servovalves, the actuator

force‐sum action prevents a single erroneous

command from affecting power ram motion.  If

the erroneous command persists for more than

a predetermined time, differential pressure

sensing activates a selector valve to isolate and

remove the defective servovalve hydraulic

pressure, permitting the remaining channels

and servovalves to control the actuator ram

spool.

Failure monitors are provided for each channel

to indicate which channel has been bypassed.  

An isolation valve on each channel provides the

capability of resetting a failed or bypassed

channel.

Each actuator ram is equipped with transducers

for position feedback to the thrust vector

control system.  Within each servoactuator ram

is a splashdown load relief assembly to cushion

the nozzle at water splashdown and prevent

damage to the nozzle flexible bearing.

SRB Rate Gyro Assemblies 

Each SRB contains two RGAs, with each RGA

containing one pitch and one yaw gyro.  These

provide an output proportional to angular rates

about the pitch and yaw axes to the orbiter

computers and guidance, navigation and

control system during first‐stage ascent flight in
May 2006 SHUTTLE REFERENCE DATA 96

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.

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.

SPACE SHUTTLE SUPER LIGHT WEIGHT 

TANK (SLWT) 

The super lightweight external tank (SLWT)

made its first shuttle flight June 2, 1998, on

mission STS‐91.  The SLWT is 7,500 pounds

lighter than the standard external tank.  The

lighter weight tank allows 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 shuttleʹs current tank.  

The tankʹs 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, by Lockheed Martin.
May 2006 SHUTTLE REFERENCE DATA 97

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 shuttleʹs three

main engines.

May 2006 Acronyms/Abbreviations 98

ACRONYMS AND ABBREVIATIONS 

AA Antenna Assembly

AAA Avionics Air Assembly

AAC Aft Access Closure

ABC Audio Bus Coupler

ABOLT Acquire Bolt

AC Assembly Complete

ACBM Active CBM

ACC Aft Cargo Carrier

ACO Assembly and Checkout Officer

ACS Atmosphere Control System

Attitude Control System

ACSM ACS Moding

ACU Arm Computer Unit

AD Active Device

Attachment Device

ADF Air Diffuser

AEA Antenna Electronics Assembly

AESD Airlock External Stowage Devices

AFD Aft Flight Deck

AGB Adjustable Grapple Bar

AIO Analog Input/Output

AO Atomic Oxygen

AOA Abort Once Around

AOH Assembly Operations Handbook

AOP Assembly Ops

APAS Androgynous Peripheral Attachment System

APCU Assembly Power Converter Unit

APDS Androgynous Peripheral Docking System

APFR Articulating Portable Foot Restraint

APM Attached Pressurized Module

APPCM Arm Pitch Plane Change Mode

APS Automated Payload Switch

Auxiliary Power Supply

AR Atmosphere Revitalization

ARCU American‐to‐Russian Converter Units

ARIS Active Rack Isolation System

ARS Air Revitalization System

ASCR Assured Safe Crew Return

ASDA Area Smoke Detector Assembly
May 2006 Acronyms/Abbreviations 99

ASL Atmosphere Sampling Line

ATA Ammonia Tank Assembly

ATCS Active Thermal Control System

ATU Audio Terminal Unit

AUAI Assemble Contingency System/UHF Audio Interface

AVU Artificial Vision Unit

AVV Accumulator Vent Valve

B/U Backup

BBC Backup Control Unit

BC Bus Controller

BCDU Battery Charge/Discharge Unit

BCU Backup Control Unit Bus Controller Unit

BDU Backup Drive Unit

BG Beta Gimbal

BGA Beta Gimbal Assembly

BGDTS Beta Gimbal Deployment Transition Structure

BGHS Beta Gimbal Housing Subassembly

BIT Built‐In Test

BITE Built‐In Test Equipment

BMRRM Bearing Motor and Roll Ring Module

BPSMU Battery‐Powered Speaker Mike Unit

BRS Bottom Right Side

BSP Baseband Signal Processor

C&C Command and Control

C&DH Command and Data Handling

C&M Control and Monitor

C&T Command and Telemetry

Communications and Tracking

C&W Caution and Warning

C/L Crew Lock

CA Control Attitude

CAS Common Attach System

CB Control Bus

CBC‐D2 Cross Bay Carrier—Deployable, Second Flight

CBC‐ND Cross Bay Carrier—Nondeployable

CBM Common Berthing Mechanism

CCAA Common Cabin Air Assembly

CCD Cursor Control Device

CCMS Concentric Cable Management System

CCS Command and Communications Center

CCTV Closed‐Circuit Television

CDDT Common Display Development Team
May 2006 Acronyms/Abbreviations 100

CDR Commander

CDRA Carbon Dioxide Removal Assembly

CDRS Carbon Dioxide Removal System

CDS Command and Data Software

CE Cargo Element

CETA Crew and Equipment Transportation Aid

CEU Control Electronics Unit

CFA Circulation Fan Assembly

CHeCS Crew Health Care System

CHX Condensing Heat Exchanger

CIPA Cure‐In‐Place Ablator

CLA Camera and Light Assembly

CMG Control Moment Gyroscope

CMG‐TA Control Moment Gyroscope‐Thruster Assist

COAS Crew Optical Alignment Sight

COR Communication Outage Recorder

COTS Commercial‐Off‐The‐Shelf

CP Cold Plate

CR Change Request

CRPCM Canadian RPCM

CRT Cathode Ray Tube

CSA Canadian Space Agency

Computer Systems Architecture

CSC Computer Software Component

CSCI Computer Software Configuration Item

CTB Cargo Transfer Bag

CTBE Cargo Transfer Bag Equivalents

CTVC Color Television Camera

CVIU Common Video Interface Unit

CVT Current Value Table

CVV Carbon Dioxide Vent Valve

CWC Contingency Water Collection

DA Depressurization Assembly

DAIU Docked Audio Interface Unit

DAK Double‐Aluminized Kapton

DAP Digital Autopilot

DC Direct Current

DC‐1 Docking Compartment‐1

DCAM Diffusion Controlled Apparatus for Microgravity

DCP Display and Control Panel

DCSU Direct Current Switching Unit

DDCU DC‐to‐DC Converter Unit

DDCU‐E Digital Current‐to‐Direct Current/Converter Unit External
May 2006 Acronyms/Abbreviations 101

DDCU‐I Internal DDCU

DDCU‐HP Digital Current‐to‐Direct Current/Converter Unit‐Heat Pipe

DIO Discreet Input/Output

DMCS Docking Mechanism Control System

DMCU Docking Mechanism Control Unit

DMS‐R Data Management System‐Russian

DOF Degrees Of Freedom

DPA Digital Preassembly

DPS Data Processing System

DSAT Desaturation

DSO Detailed Supplementary Objectives

DTO Development Test Objective

E/L Equipment Lock

EA Electrical Assembly

EACP Extravehicular Audio Control Panel

EAIU EMU Audio Interface Unit

EATCS External Active Thermal Control System

ECLSS Environmental Control and Life Support System

ECS Environmental Control System

ECU Electronics Control Unit

ED Extended‐height Deployable

EDDA External Maneuvering Unit Don/Doff Assembly

EEATCS Early External Active Thermal Control System

EELS Emergency Egress Lighting System

EETCS Early External Thermal Control System

EFGF Electrical Flight‐releasable Grapple Fixture

EIA Electrical Interface Assembly

ELH Electrical Harness

ELM‐ES Experiment Logistics Module‐Exposed Section

ELPS Emergency Lighting Power Supply

ELS Emergency Lighting Strip

EMCS European Modular Cultivation System

EMU Extravehicular Mobility Unit

EXPRESS memory Unit

EOM‐1 End of Mission Minus 1

EPCE Electrical Power Consuming Equipment

EPS Electrical Power System

ER Express Rack

ESA European Space Agency

External Sampling Adapter

ESP External Stowage Platform

ESPAD ESp‐2 Attachment Device

ESSMDM Enhanced Space Station Multiplexer/Demultiplexer
May 2006 Acronyms/Abbreviations 102

ESU End Stop Unit

ETI Elapsed Time Indicator

ETR Express Transportation Rack

ETSD Extravehicular Tool Storage Device

EU Electronics Unit

EV Extravehicular

EVA Extravehicular Activity

EV‐CPDS Extravehicular‐Charged Particle Directional Spectrometer

EVR Extravehicular Robotics

EVSU External Video Switching Unit

EXPRESS EXpedite the PRocess of Experiments to the Space Station

EXT Experimental Terminal

External

FAWG Flight Assignments Working Group

FC Firmware Controller

FCB Functional Cargo Block

FCC Flat Controller Circuit

FCT Flight Control Team

FCV Flow Control Valve

FD Flight Day

FDA Fault Detection and Annunciation

FDI Failure Detection and isolation

FDIR Failure, Detection, Isolation and Recovery

FDS Fire Detection and Suppression

FEPS Front‐End Processor System

FET Field Effect Transistor

FGB Fixed Grapple Bar

Functional Cargo Block

FHRC Flex Hose Rotary Coupler

FOR Flight Operations Review

FPMU Floating Potential Measurement Unit

FPP Floating Point Potential

FPU Fluid Pumping Unit

FQDC Fluid Quick Disconnect Coupling

FR Flight Rule

FRAM Flight Releasable Attachment Mechanism

FRD Flight Requirements Document

FRGF Flight Releasable Grapple Fixture

FSE Flight Support Equipment

FWCI Firmware Configuration Item

FWD Forward

GAS Get Away Special
May 2006 Acronyms/Abbreviations 103

GFE Government‐Furnished Equipment

GFI Ground Fault Interrupter

GJOP Generic Joint Operations Panel

GLA General Lighting Assembly

General Luminare Assembly

GLONASS Global Navigation Satellite System

GMT Greenwich Mean Time

GNC Guidance and Navigation Computer

Guidance, Navigation, and Control

GPC General Purpose Computer

GPS Global Positioning System

GSE Ground Support Equipment

GUI Graphical User Interface

HAB Habitat Module

HC Hand Controller

HCA Hollow Cathode Assembly

HCI Human Computer Interface

HCOR High‐Rate Communications Outage Recorder

HCU Heater Control Unit

HDPCG High Density Protein Crystal Growth

HDR High Data Rate

HEPA High Efficiency Particulate Unit

HGA High Gain Antenna

Hollow Cathode Assembly

HHL Handheld Lidar

HLA High Level Analog

HPGT High Pressure Gas Tank

HRF Human Research Facility

HRFM High Rate Frame Multiplexer

HRM High Rate Modem

HX Heat Exchanger

I/F Interface

I/O Input/Output

IAC Internal Audio Controller

IAS Internal Audio System

IATCS Internal Active Thermal Control System

IBA Integrated Boom Assembly

ICC Integrated Cargo Carrier

ID Identification

IDA Integrated Diode Assembly

IDRD Increment Definition Requirements Document

IDS Integrated Documentation System
May 2006 Acronyms/Abbreviations 104

IEA Integrated Equipment Assembly

IELK Individual Equipment Liner Kit

IFHX Interface Heat Exchanger

IFM In‐flight Maintenance

IGA Inner Gimbal Assembly

IMCA Integrated Motor Control Assembly

IMCS Integrated Mission Control System

IMS Inventory Management System

IMU Impedance Matching Unit

IMV Intermodule Ventilation  

INCO Instrumentation Communications Officer

INT Internal

IOC Input/Output Controller

IOCU Input/Output Controller Unit

IP International Partner

IRU In‐Flight Refill Unit

ISA Internal Sampling Adapter

ISIS International Subrack Interface Standard

ISO Inventory and Stowage Officer

ISOV Intermodule Ventilation Shut‐Off Valve

ISPR International Standard Payload Rack

ISS International Space Station

ISSSH International Space Station Systems Handbook

ISSIS International Space Station Interface Standard

ISSPO International Space Station Program Office

ITCS Internal Thermal Control System

ITS Integrated Truss Segment

ITVC Intensified Television Camera

IUA Interface Umbilical Assembly

IVA Intravehicular Activity

IVSU Internal Video Switch Unit

JEU Joint Electronic Unit

JEUS Joint Expedited Undocking and Separation

JSC Johnson Space Center K‐BAR Knee‐Brace Assembly Replacement

km kilometer

KSC Kennedy Space Center

KYA Keel Yoke Assembly

LA Launch Aft

Lab Laboratory Module

LAN Local Area Network
May 2006 Acronyms/Abbreviations 105

LaRC Langley Research Center

LAT Latch

LB Local Bus

LB‐RWS RWS Local Bus

LCA Lab Cradle Assembly

Loop Crossover Assembly

LCC Laser Camera Controller

LCD Liquid Crystal Display

LCH Laser Camera Head

LCP Lower Connector Panel

LCS Laser Camera System

LDI Local Data Interface

LDR Low Data Rate

LDRI Laser Dynamic Range Imager

LDU Linear Drive Unit

LED Light Emitting Diode

LEE Latching End Effector

LEU LEE Electronic Unit

LFDP Load Fault Detection Protection

LGA Low Gain Antenna

LIS Laser Interface Software

LLA Low Level Analog

LMC Lightweight Multipurpose Carrier

LRU Line Replaceable Unit

LT Low Temperature

LTA Launch To Activation

LTL Low Temperature Loop

LTU Load Transfer Unit

LVLH Local Vertical Local Horizontal

MA Mechanical Assembly

MAM Manual Augmented Role

MBE Metal Bellows Expander

MBS Manual Berthing System

MBSU Main Bus Switching Unit

MC Midcourse Correction

MCA Major Constituent Analyzer

MCAS MBS Common Attach System

MCC Mission Control Center

MCC‐H Mission Control Center‐Houston

MCC‐M Mission Control Center‐Moscow

MCDS Multifunction CRT Display System

MCOR Medium‐Rate Communications Recorder

MCS Motion Control System
May 2006 Acronyms/Abbreviations 106

MCU Control Software

MCU MBS Computer Unit

MDA Motor Drive Assembly

MDL Middeck Locker

Mission Data Lead

MDM Multiplexer/Demultiplexer

MDPS Meteoroid and Debris Protection System

MEEP Mir Environmental Effects Payload

MELFI Minus Eighty‐degree Laboratory Freezer for ISS

MER Mission Evaluation Room

MET Mission Elapsed Time

METOX Metal Oxide

MFCV Manual Flow Control Valve

MHS MCU Host Software

MILA Mode Indicating Light Assembly

MIM Multi‐Increment Manifest

MIP Mission Integration Plan

MISSE Materials ISS Experiment

MLI Multi‐Layer Insulation

mm millimeter

MM/OD Micrometeoroid/Orbital Debris

MOD Mission Operations Directorate

MPES Multipurpose Experiment Structure

MPEV Manual Pressure Equalization Valve

MPLM Multipurpose Logistics Module

MPM Manipulator Positioning Mechanism

MRL Manipulator Retention Latch

MSD Mass Storage Device

MSFC Marshall Space Flight Center

MSG Microgravity Science Glovebox

MSS Mobile Servicing System

MT Mobile Transporter

Moderate Temperature

MTCL MT Capture Latch

MTL Moderate Temperature Loop

MTS Module‐to‐Truss Segment

MTSAS Module‐to‐Truss Segment Attachment System

MTWsN Move to Worksite Number

N/A Not Applicable

N/R Not Required

NASA National Aeronautics and Space Administration

NC Nominal Corrective

NCC Nominal Corrective Combination
May 2006 Acronyms/Abbreviations 107

NCG Non Condensable Gas

NCS Node Control Software

NET No Earlier Than

NIA Nitrogen Interface Assembly

NIV Nitrogen Introduction Valve

NLP Narrow‐sweep Langmuir Probe

NPRA Negative Pressure Relief Assembly

NPRV Negative Pressure Relief Valve

NTA Nitrogen Tank Assembly

NTSC National Television Standards Committee

O.D. Outer Diameter

OBSS Orbiter Boom Sensor System

OCA Orbital Communications Adapter

OCAD Operational Control Agreement Document

OCJM Operator Commander Joint Position Mode

OCPM Operator‐Commanded POR Mode

OCS Operations and Control Software

ODA Orbiter Disconnect Assembly

ODM Orbiter Arm Drive Mechanism

ODS Orbiter Docking System

OIU Orbiter Interface Unit

OIV Oxygen Isolation Valve

OMI On‐Orbit Maintainable Item

OMS Orbital Maneuvering System

OPP OSVS Patch Panel

Ops Operations

OPS LAN Operations Local Area Network

ORBT Optimized RBar Targeting Technique

ORCA Oxygen Recharge Compressor Assembly

ORU Orbital Replacement Unit

OTD ORU Transfer Device

OSE Orbiter Support Equipment

OSO Operations Support Officer

OSVS Orbiter Space Vision System

OSVU Orbiter Space Vision Unit

OV Orbiter Vehicle

P&S Pointing and Support

P/L Payload

PAD PFR Attachment Device

PAS Payload Attach System

PBA Portable Breathing Apparatus

PC Personal Computer
May 2006 Acronyms/Abbreviations 108

PCA Pressure Control Assembly

PCAM Protein Crystallization Apparatus for Microgravity

PCBM Passive Cargo Berthing Mechanism

PCC Power Converter Controller

PCG‐STES Protein Crystal Growth‐Single Thermal Enclosure System

PCM Phase Change Material

PCMCIA Personal Computer Memory Card International Adapter

PCMMU Pulse Code Master Modulation Unit

P‐code Precision code

PCP Pressure Control Panel

PCVP Pump and Control Valve Package

PCR Portable Computer Receptacle

PCS Portable Computer System

PCT Post‐Contact Thrusting

PCU Plasma Connector Unit

PCVP Pump and Control Valve Package

PD Physical Device

PDA Payload Disconnect Assembly

PDB Power Distribution Box

PDGF Power and Data Grapple Fixture

PDI Payload Data Interface

PDIP Payload Data Interface Panel

PDRS Payload Deployment and Retrieval System

PDU Power Drive Unit

PEC Passive Experiment Container

Payload Experiment Carrier

PEHB Payload Ethernet Hub Bridge

PEHG Payload Ethernet Hub Gateway

PEV Pressure Equalization Valve

PFCS Pump Flow Control Subassembly

PFE Portable Fire Extinguisher

PFM Pulse Frequency Modulation

PFME Pore Formation and Mobility Experiment

PFR Portable Foot Restraint

PG Product Group

PGBA Plant Generic Bioprocessing Apparatus

PGSC Portable General Support Computer

PGT Pistol Grip Tool

PHALCON Power, Heating, Articulation, Lighting, and Control Officer

PIP Plasma Impedance Probe

PJAM Pre‐stored Joint Position Autosequence Mode

PLB Payload Bay

PLBD Payload Bay Doors
May 2006 Acronyms/Abbreviations 109

PM Pump Module

PMA Pressurized Mating Adapter

PMCU Power Management Control Unit

PMP Payload Mounting Panel

PNOM Procedural Nomenclature

POA Payload/ORU Accommodation

POC Point of Contact

POEMS Passive Observatories for Experimental Microbial Systems

POR Point of Reference

POST Power On Self‐Test

PPA Pump Package Assembly

PPAM Pre‐stored POR Autosequence Mode

PPL Pre‐Positioned Load

PPRA Positive Pressure Relief Assembly

PPRV Positive Pressure Relief Valve

PRD Payload Retention Device

PRI Primary

PRLA Payload Retention Latch Assembly

Prox‐Ops Proximity Operations

PSP Payload Signal Processor  

PTCS Passive Thermal Control System

Positive Thermal Control System

PTU Pan/Tilt Unit

PUI Program Unique Identifier

PV Photovoltaic

PVCA Photovoltaic Controller Application

PVCE Photovoltaic Controller Element

PVCU Photovoltaic Controller Unit

PVM Photovoltaic Module

PVR Photovoltaic Radiator

PVTCS Photovoltaic Thermal Control System

PWM Pulse Width Modulator

PWP Portable Work Platform

PWR Portable Water Reservoir

PYR Pitch Yaw Roll

QD Quick Disconnect

R/F Refrigerator/Freezer

R/P Receiver/Processor

R&MA Restraint and Mobility Aid

RAB Rack Attachment Block

RACU Russian‐to‐American Converter Unit

RAIU Russian Audio Interface Unit
May 2006 Acronyms/Abbreviations 110

RAM Random Access Memory

RAMV Rheostat Air Mix Valve

RBB Right Blanket Box

RBI Remote Bus Isolator

RBVM Radiator Beam Valve  

RCA Remote Control Amplifier

RCC Reinforced Carbon‐Carbon

RCS Reaction Control System

RF Radio Frequency

RFCA Rack Flow Control Assembly

RFG Radio Frequency Group

RGA Rate Gyro Assemblies

RHC Rotational Hand Controller

RHX Regenerative Heat Exchanger

RIC Rack Interface Controller

RJMC Rotary Joint Motor Controller

RMS Remote Manipulator System

ROBO Robotics

ROEU Remotely Operated Electrical Umbilical

ROFU Remote Operated Fluid Umbilical

ROOBA Recharge Oxygen Orifice Bypass Assembly

RPC Remote Power Controller

RPCM Remote Power Control Mechanism

Remote Power Controller Module

RPDA Remote Power Distribution Assembly

RPM Rbar Pitch‐over Maneuver

RPOP Rendezvous and Prox‐Ops Program

RS Russian Segment

RSP Resupply Stowage Platform

RSR Resupply Stowage Rack

RSTS Rack Standalone Temperature Sensor

RSU Roller Suspension Unit

RT Remote Terminal

RTL Ready to Latch

RTD Resistive Thermal Device

RWS Robotic Workstation

S/W Software

SA Solar Array

SAPA   Small Adapter Plate Assembly

SARJ Solar Alpha Rotary Joint

SASAS‐band Antenna Support Assembly

SAW Solar Array Wing

SCA Switchgear Controller Assembly
May 2006 Acronyms/Abbreviations 111

SCI Signal Conditioning Interface

SCMI Serial Command and Monitoring Interface

SCU Service and Cooling Umbilical

Sync and Control Unit

SD Smoke Detector

SDO Solenoid Driver Output

SDS Sample Delivery System

SELS SFOC Electronic Library System

SEM Shunt Electronics Module

SFA Small Fine Arm

SFCA System Flow Control Assembly

SGANT Space‐to‐Ground Antenna

SIGI Space Integrated Global Positioning System/Inertial Navigation System

SJRM Single Joint Rate Mode

SLDP SpaceLab Double Pallet

SLP SpaceLab Pallet

SM Service Module

SMCC Shuttle Mission Control Center

SOC State of Charge

SOV Shutoff Valve

SPCE Servicing Performance and Checkout Equipment

SPD Serial Parallel Digital

Spool Positioning Device

SPDA Secondary Power Distribution Assembly

SPDM Special Purpose Dexterous Manipulator

SPG Single‐Point Ground

SPM Solar Power Module

SRAM Static Random Access Memory

SRMS Shuttle Remote Manipulator System

SSAS Segment‐to‐Segment Attach System

SSBA Space Station Buffer Amplifier

SSC Station Support Computer

Subsystem Computer

SSMDM Space Station Multiplexer/Demultiplexer

SSOR Space‐to‐Space Orbiter Ratio

SSOV Sample Line Shutoff Valve

SSP Space Shuttle Program

Standard Switch Panel

SSPCM Solid State Power Control Module

SSRMS Space Station Remote Manipulator System

SSSR Space‐to‐Space Station Radio

SSU Sequential Shunt Unit

STCR Starboard Thermal Control Radiator
May 2006 Acronyms/Abbreviations 112

STES Single Thermal Enclosure System

STS Space Transportation System

SVS Space Vision System

SX Short Extension

TA Thruster Assist

Trunnion Angle

TBD To Be Determined

TC Terminal Computer

TCCS Trace Contaminant Control Subassembly

TCCV Temperature Control and Check Valve

TCS Thermal Control System

Trajectory Control System

TD Translation Drive

TDRS Tracking and Data Relay Satellite

TDRSS Tracking and Data Relay Satellite System

TEA Torque Equilibrium Attitude

TFL Telemetry Format Load

TFR Translation Foot Restraint

THA Thermal Housing Assembly

THC Temperature and Humidity Control

Translational Hand Controller

THOR Thermal Operations and Resources Officer

TI Terminal Phase Initiation

TIG Time of Ignition

TM Torque Motor

TORF Twice Orbital Rate Flyaround

TORU Teleoperator Control Mode

TORVA Twice Orbital Rate +Rbar to +Vbar Approach

TP Total Pressure

TPL Transfer Priority List

TPS Thermal Protection System

TRC Transmitter Receiver Controller

TRRJ Thermal Radiator Rotary Joint

TSA Toolbox Stowage Assembly

TTCR Trailing Thermal Control Radiator

TUS Trailing Umbilical System

TUS‐RA Trailing Umbilical System‐Reel Assembly

TVCIC Television Camera Interface Control

Television Camera Interface Converter

TVIS Treadmill Vibration Isolation System

TWMV Three‐Way Mixing Valve

UB User Bus
May 2006 Acronyms/Abbreviations 113

UCP Unpressurized Cargo Pallet

UDG User Data Generation

UHF Ultrahigh Frequency

UIA Umbilical Interface Assembly

UIL User/Utility Interface Language

UIP Utility Interface Panel

ULCAS Unpressurized Logistics Carrier Attach System

ULC‐ND Unpressurized Logistics Carrier—Non‐Deployable

ULF‐1.1 Utilization Logistics Flight 1.1

UMA Umbilical Mechanism Assembly

UOP Utility Outlet Panel

USA United Space Alliance

USL U.S. Laboratory

USOS United States On‐Orbit Segment

UTA Universal Trunnion Attachment

Utility Transfer Assembly

UTAS Universal Trunnion Attachment System  

VAJ Vacuum Access Jumper

VBSP   Video Baseband Signal Processor

VCSA Video Camera Support Assembly

VDA‐2 Vapor Diffusion Apparatus—Second Generation  

VDS Video Distribution System

VDU Video Distribution Unit

VES Vacuum Exhaust System

VGS Video Graphics Software

VMDS Valve Motor Drive Switch

VPMP Vented Payload Mounting Panel

VRCV Vent/Relief Control Valve

VRIV Vent/Relief Isolation Valve

VRS VES Resource System

VRV Vent/Relief Valve

VSC Video Signal Converter

VSSA Video Support Stanchion Assembly

Video System Support Assembly

WETA WVS External Transceiver Assembly

WHS Workstation Host Software

WIF Worksite Interface

WLE Wing Leading Edge

WLP Wide Langmuir Probe

WMV Water Modulating Valve

WORF Window Observational Research Facility

WOV Water ON/OFF Valve
May 2006 Acronyms/Abbreviations 114

WPP Water Pump Package

WRM Water Recovery Management

WS Water Separator

WV Work Volume

WVA Water Vent Assembly

WVS Wireless Video System

ZSR Zero‐g Stowage Rack

May 2006 MEDIA ASSISTANCE 115

MEDIA ASSISTANCE 

NASA TELEVISION TRANSMISSION 

NASA Television is carried on an MPEG‐2

digital signal accessed via satellite AMC‐6, at

72 degrees west longitude, transponder 17C,

4040 MHz, vertical polarization.  For those in

Alaska or Hawaii, NASA Television will be

seen on AMC‐7, at 137 degrees west longitude,

transponder 18C, at 4060 MHz, horizontal

polarization.  In both instances, a Digital Video

Broadcast (DVB)‐compliant Integrated Receiver

Decoder (IRD) (with modulation of QPSK/DBV,

data rate of 36.86 and FEC 3⁄4) will be needed for

reception.  The NASA Television schedule and

links to streaming video are available at:

http://www.nasa.gov/ntv 

NASA TVʹs digital conversion will require

members of the broadcast media to upgrade

with an ʹaddressableʹ Integrated Receiver

Decoder, or IRD, to participate in live news

events and interviews, press briefings and

receive NASAʹs Video File news feeds on a

dedicated Media Services channel.  NASA

mission coverage will air on a digital NASA

Public Services (ʺFree to Airʺ) channel, for

which only a basic IRD will be needed.

The schedule for television transmissions from

the orbiter and for mission briefings will be

available during the mission at Kennedy Space

Center, Fla.; Marshall Space Flight Center,

Huntsville, Ala.; Dryden Flight Research

Center, Edwards, Calif.; Johnson Space Center,

Houston; and NASA Headquarters,

Washington.  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 posted at:

http://www.nasa.gov/shuttle 

This site also contains information on the crew

and will be updated regularly with photos and

video clips throughout the flight.

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 Mission

Management Team members will occur every

day.  The updated NASA television schedule

will indicate when mission briefings are

planned.

Internet Information 

Information on other current NASA activities is

available at:

http://www.nasa.gov/home 

Resources for educators can be found at the

following address:

http://education.nasa.gov

May 2006 MEDIA CONTACTS 116

PUBLIC AFFAIRS CONTACTS 

HEADQUARTERS 

WASHINGTON, DC 

Allard Beutel

Public Affairs Specialist

Space Operations

202‐358‐4769

Katherine Trinidad

Public Affairs Specialist

Space Operations

202‐358‐3749

Joe Pally

Public Affairs Specialist

Space Operations

202‐358‐7239

Melissa Mathews

Public Affairs Specialist

International Partners

202‐358‐1272

JOHNSON SPACE CENTER 

HOUSTON, TEXAS 

James Hartsfield

News Chief

281‐483‐5111

Kyle Herring

Public Affairs Specialist

Space Shuttle Program Office

281‐483‐5111

Kylie Clem

Public Affairs Specialist

International Space Station

& Mission Operations

281‐483‐5111

Lynnette Madison

Public Affairs Specialist

Engineering

281‐483‐5111

Rob Navias

Program and Mission Operations Lead

281‐483‐5111

KENNEDY SPACE CENTER 

FLORIDA 

Bruce Buckingham

News Chief

321‐861‐2468

Jessica Rye

Public Affairs Specialist

Space Shuttle

321‐867‐2468

Tracy Young

Public Affairs Specialist

International Space Station

321‐867‐2468

MARSHALL SPACE FLIGHT CENTER 

HUNTSVILLE, ALABAMA 

Dom Amatore

Public Affairs Manager

256‐544‐0034

June Malone

Public Affairs Specialist

Space Shuttle Propulsion

256‐544‐0034
May 2006 MEDIA CONTACTS 117

STENNIS SPACE CENTER 

MISSISSIPPI 

Linda Theobald

Public Affairs Specialist

228‐688‐3249

Paul Foerman

News Chief

228‐688‐1880

Rebecca Strecker

Public Affairs Specialist

228‐688‐3346

AMES RESEARCH CENTER 

MOFFETT FIELD, CALIFORNIA 

Mike Mewhinney

News Chief

650‐604‐3937

Jonas Dino

Public Affairs Specialist

650‐604‐5612

DRYDEN FLIGHT RESEARCH CENTER 

CALIFORNIA 

Alan Brown

News Chief

661‐276‐2665

Leslie Williams

Public Affairs Specialist

661‐276‐3893

GLENN RESEARCH CENTER 

CLEVELAND, OHIO 

Lori Rachul

News Chief

216‐433‐8806

Katherine Martin

Public Affairs Specialist

216‐433‐2406

LANGLEY RESEARCH CENTER 

HAMPTON, VIRGINIA 

H. Keith Henry

Deputy, Office of Public Affairs

757‐864‐6120

UNITED SPACE ALLIANCE 

Mike Curie

Space Flight Operations Contract

281‐483‐9251

321‐861‐3805

Kari Fluegel

Houston Operations

281‐280‐6959

Tracy Yates

Florida Operations

321‐861‐3956

BOEING 

Ed Memi

Media Relations

Boeing NASA Systems

281‐226‐4029