Edited by Richard W. Orloff,01/2001/Page 1 

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 

SPACE SHUTTLE 

MISSION 

STS-61 

PRESS KIT 

DECEMBER 1993 

HUBBLE SPACE TELESCOPE SERVICING MISSION-01 
Edited by Richard W. Orloff,01/2001/Page 2 

STS-61 INSIGNIA 

STS061-S-001 -- Designed by the crewmembers, the STS-61 insignia depicts the astronaut symbol 

superimposed against the sky with the Earth underneath. Also are two circles representing the optical 

configuration of the Hubble Space Telescope (HST). Light is focused by reflections from a large primary 

mirror and a smaller secondary mirror. The light is analyzed by various instruments and, according to the 

crewmembers, "brings to us on Earth knowledge about planets, stars, galaxies and other celestial objects, 

allowing us to better understand the complex physical processes at work in the universe." The space 

shuttle Endeavour is also represented as the fundamental tool that allows the crew to perform the first 

servicing of the Hubble Space Telescope so its scientific deep space mission may be extended for several 

years to come. The overall design of the insignia, with lines converging to a high point, is also a symbolic 

representation of the large-scale Earth-based effort--which involves space agencies, industry and the 

universities--to reach goals of knowledge and perfection. 

The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other 

official use as the NASA Administrator may authorize. Public availability has been approved only in the 

form of illustrations by the various news media. When and if there is any change in this policy, which we 

do not anticipate, it will be publicly announced. 

PHOTO CREDIT: NASA or National Aeronautics and Space Administration. 
Edited by Richard W. Orloff,01/2001/Page 3 

PUBLIC AFFAIRS CONTACTS 

For Information on the Space Shuttle 

Ed Campion 

 NASA Headquarters 

 Washington, DC 

Policy/Management 202/358-1778 

 

James Hartsfield 

 Johnson Space Center 

 Houston, TX 

Mission Operations 

Astronauts 

713/483-5111 

 

Bruce Buckingham 

 Kennedy Space Center, Fl 

Launch Processing 

KSC Landing Information 

407/867-2468 

 

June Malone 

 Marshall Space Flight Center 

 Huntsville, AL 

External Tank/SRBs/SSMEs 205/544-0034 

 

Nancy Lovato 

 Dryden Flight Research Center 

 Edwards, CA 

DFRC Landing Information 805/258-3448 

For Information on STS-61 Payloads 

Sarah Keegan 

 NASA Headquarters 

 Washington DC 

HST Program/Science 202/358-1547 

 

Debra Rahn 

 NASA Headquarters 

 Washington, DC 

HST International Elements 202/358-1639 

 

Jim Elliot 

 Goddard Space Flight Center 

 Greenbelt, MD 

HST Project/Science/STOCC 

Operations 

301/286-6256 

 

Michael Finneran 

 Goddard Space Flight Center 

 Greenbelt, MD 

HST Project/Science/STOCC 

Operations 

301/286-5565 

 

Bob MacMillin 

 Jet Propulsion Laboratory 

 Pasadena, CA 

Wide Field/Planetary Camera II 818/354-5011 

 

Jean Paul Paille 

 ESA NASA Headquarters 

 Paris, France 

European Space Agency 011 33 1 42 73 72 92 

 

Ray Villard 

 Space Telescope Science Institute 

 Baltimore, MD 

HST Science, COSTAR 410/338-4514 
Edited by Richard W. Orloff,01/2001/Page 4 

CONTENTS 

GENERAL BACKGROUND MATERIAL 

General Release 5 

Media Services Information 6 

Quick-Look Facts 7 

Shuttle Abort Modes 8 

Vehicle And Payload Weights 9 

Summary Timeline 11 

Orbital Events Summary 12 

CARGO BAY PAYLOADS & ACTIVITIES 

HST Servicing Mission-01 (HST/SM-01) Overview 13 

 History of HST 13 

 Mission Objectives And Success 14 

 First Corrected Image Availability 14 

 Science Accomplishments 15 

 ESA Role in HST Program 16 

Servicing Mission Orbital Verification 17 

Key Hubble Scientific Goals Following the First Servicing Mission 18 

Hubble Space Telescope Rendezvous and Retrieval 19 

Commands to Hubble 19 

STS-61 Extravehicular Activities 20 

Replacement Hardware and Instruments 21 

Primary Servicing Tasks 24 

Secondary Servicing Tasks 33 

HST Tools and Crew Aids 34 

IN-CABIN PAYLOADS 

IMAX Camera 42 

Air Force Maui Optical System (AMOS) 43 

DTO-667 Pilot Inflight Landing Operations Trainer (PILOT) 43 

STS-61 CREW BIOGRAPHIES 44 

ACRONYMS AND ABBREVIATIONS 47 
Edited by Richard W. Orloff,01/2001/Page 5 

RELEASE: 93-204 

FIVE SPACEWALKS TO SERVICE HUBBLE SPACE TELESCOPE 

HIGHLIGHTS SHUTTLE MISSION STS-61 

The December flight of Endeavour on Space Shuttle Mission STS-61 will see the first in a series of 

planned visits to the orbiting Hubble Space Telescope (HST). The 11-day mission has been designed to 

accommodate a record five spacewalks with the capability for an additional two if needed. 

The first HST servicing mission has three primary objectives: restoring the planned scientific capabilities, 

restoring reliability of HST systems and validating the HST on-orbit servicing concept. These objectives 

will be accomplished in a variety of tasks performed by the astronauts in Endeavour’s cargo bay. 

Replacement of the spacecraft’s solar arrays - HST’s source of electrical power - tops the primary servicing 

task list. This is because solar array jitter, or excessive flexing which happens when the telescope passes 

from cold darkness into warm daylight, may be compromising the structural integrity of the arrays. 

The objective to restore the HST’s science capabilities will be accomplished with the installation of the 

Wide Field/Planetary Camera-II and the Corrective Optics Space Telescope Axial Replacement, both of 

which will compensate for the spherical aberration of the primary mirror. 

The installation of new gyroscopes, which are required to point and track HST, along with fuse plugs and 

electronic units will increase the reliability of the HST system. 

Leading the seven-person STS-61 crew will be Mission Commander Dick Covey. Pilot for the mission is 

Ken Bowersox. The mission specialists for the flight are Kathy Thornton, Claude Nicollier, Jeff Hoffman, 

Story Musgrave and Tom Akers. Working in pairs, Hoffman and Musgrave and Thornton and Akers, all of 

whom have previous EVA experience, will perform the five spacewalks scheduled for flight days 4-8. 

Launch of Endeavour on the STS-61 mission is currently scheduled for no earlier than Dec. 1, 1993 at 4:57 

a.m. EST. The planned mission duration is 10 days, 22 hours and 36 minutes. An on-time launch on Dec. 1 

would produce a 3:33 a.m. EST landing on Dec. 12 at Kennedy Space Center’s Shuttle Landing Facility. 

STS-61 will be the 5th flight of Space Shuttle Endeavour and the 59th flight of the Space Shuttle system. 

The Hubble Space Telescope is an international cooperative program between NASA and the European 

Space Agency. 

(END OF GENERAL RELEASE; BACKGROUND INFORMATION FOLLOWS.) 
Edited by Richard W. Orloff,01/2001/Page 6 

STS-61 MEDIA SERVICES INFORMATION 

NASA Select Television Transmission 

NASA Select television is available on Satcom F-2R, Transponder 13, located at 72 degrees west 

longitude; frequency 3960.0 MHz, audio 6.8 MHz. 

The schedule for television transmissions from the orbiter and for mission briefings will be available 

during the mission at Kennedy Space Center, Fla.; Marshall Space Flight Center, Huntsville, Ala.; AmesDryden Flight Research Facility, Edwards, Calif.; Johnson Space Center, Houston and NASA 

Headquarters, Washington, D.C. The television schedule will be updated to reflect changes dictated by 

mission operations. 

Television schedules also may be obtained by calling COMSTOR 713/483- 5817. COMSTOR is a 

computer data base service requiring the use of a telephone modem. A voice update of the television 

schedule is updated daily at noon Eastern time. 

Status Reports 

Status reports on countdown and mission progress, on-orbit activities and landing operations will be 

produced by the appropriate NASA newscenter. 

Briefings 

A mission press briefing schedule will be issued prior to launch. During the mission, status briefings by a 

Flight Director or Mission Operations representative and when appropriate, representatives from the 

science team, will occur at least once per day. The updated NASA Select television schedule will indicate 

when mission briefings are planned. 
Edited by Richard W. Orloff,01/2001/Page 7 

STS-61 QUICK LOOK 

Launch Date/Site: Dec. 1, 1993/Kennedy Space Center, Fla., Pad 39B 

Launch Time: 4:57 a.m. EST (approximate) 

Orbiter: Endeavour (OV-105) 5th Flight 

Orbit/Inclination: 320 nautical miles/28.45 degrees 

Mission Duration: 10 days, 22 hours, 36 minutes (approximate) 

Landing Time/Date: 3:33 a.m. EST (approximate)/Dec. 12, 1993 

Primary Landing Site: Kennedy Space Center, Fla. 

Abort Landing Sites: Return to Launch Site: KSC, Fla. 

 Trans-Atlantic Abort Landing: Banjul, The Gambia 

 Moron, Spain 

 Ben Guerir, Morocco 

 Abort Once Around: Edwards AFB, Calif. 

 

Crew: Dick Covey, Commander (CDR) 

 Ken Bowersox, Pilot (PLT) 

 Kathy Thornton, Mission Specialist 1 (MS1/EV3) 

 Claude Nicollier, Mission Specialist 2 (MS2) 

 Jeff Hoffman, Mission Specialist 3 (MS3/EV1) 

 Story Musgrave, Mission Specialist 4 (MS4/EV2) 

 Tom Akers, Mission Specialist 5 (MS5/EV4) 

 

Cargo Bay Payloads: HST SM-01 (Hubble First Servicing Mission) 

 

HST Replacements: SA (Solar Arrays) 

 WF/PC-II (Wide Field/Planetary Camera-II) 

 RSU-1, 2 & 3 (Rate Sensor Units 1, 2 and 3) 

 ECU-1 & 3 (Electronic Control Units 1 and 3) 

 MSS-1 & 2 (Magnetic Sensing Systems 1 and 2) 

 COSTAR (Corrective Optics Space Telescope Axial Replacement 

 SADE (Solar Array Drive Electronics) 

 

Cargo Bay Equip: HST FSS (HST Flight Support System) 

 ORUC (Orbital Replacement Unit Carrier) 

 SAC (Solar Array Carrier) 

 SIPE (Scientific Instrument Protective Enclosures) 

 ICBC (IMAX Cargo Bay Camera) 

 

In-Cabin Payloads: IMAX (IMAX In-Cabin Camera) 

 

Other: AMOS (Air Force Maui Optical Site) 

DTOs/DSOs 

DTO 648: Electronic Still Camera DTO 656: PGSC Upset Monitoring 

DTO 700-2: Handheld Laser Ranging Device DTO 700-8: Global Positioning System Flight Test 

DTO 1211: Water Dumps at 10.2 psi Cabin DSO 326: Window Impact Observation 

DSO 469: Inflight Radiation Dose/Distribution DSO 483: Back Pain in Microgravity 

DSO 485: Inter-Mars Tissue Equivalent Counter DSO 487: Immunological Assessment of Crew 

DSO 489: EVA Dosimetry Evaluation DSO 604: Visual-Vestibular/Function of Adaptation 

DSO 617: Skeletal Muscle Performance DSO 624: Cardiovascular Response to Exercise 

DSO 901: Documentary Television DSO 902: Documentary Motion Picture 

DSO 903: Documentary Still Photography 
Edited by Richard W. Orloff,01/2001/Page 8 

STS-61 SPACE SHUTTLE ABORT MODES 

Space Shuttle launch abort philosophy aims toward safe and intact recovery of the flight crew, 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-nautical mile orbit with orbital maneuvering system engines. 

• Abort-Once-Around (AOA) - Earlier main engine shutdown with the capability to allow one orbit 

around before landing at Edwards Air Force Base, Calif. 

• Trans-Atlantic Abort Landing (TAL) - Loss of one or more main engines midway through powered 

flight would force a landing at either Banjul, The Gambia, Moron, Spain, or Ben Guerir, Morocco. 

• Return-To-Launch-Site (RTLS) - Early shutdown of one or more engines, and without enough energy 

to reach Banjul, would result in a pitch around and thrust back toward KSC until within gliding 

distance of the Shuttle Landing Facility. 

STS-61 contingency landing sites are the Kennedy Space Center, Edwards Air Force Base, Banjul, Moron 

or Ben Guerir. 
Edited by Richard W. Orloff,01/2001/Page 9 

STS-61 VEHICLE AND PAYLOAD WEIGHTS 

Pounds

 

Orbiter (Endeavour) empty and 3 SSMEs 173,014 

Flight Support System (FSS) 4,200 

IMAX Cargo Bay Camera (ICBC) 608 

IMAX (in cabin) 329 

Orbital Replacement Unit Carrier (ORUC) 6369 

Solar Array Carrier (SAC) 3829 

Solar Array II 702 

Rate Sensor Units (3) 73 

Wide Field/Planetary Camera II 613 

Corrective Optics Space Telescope Axial Replacement 660 

Electronic Control Units (2) 35 

Magnetic Sensing System (2) 30 

Co-processor 140 

Goddard High Resolution Spectrograph Redundancy Kit 7 

Changeout complement total (launch) 2300 

High-Speed Photometer 603 

WF/PC I 624 

Solar Array I 668 

RSU (3) 73 

ECU (2) 35 

Changeout complement total (Earth return) 2135 

DSOs/DTOs 104 

Total Vehicle at SRB Ignition 4,511,115 

Orbiter Landing Weight 209,383 
Edited by Richard W. Orloff,01/2001/Page 10 
Edited by Richard W. Orloff,01/2001/Page 11 

STS-61 SUMMARY TIMELINE* 

Flight Day 1 Flight Day 7 

Ascent HST Extravehicular Activity 4 

OMS-2 burn (310 n.m. x 297 n.m.) (Thornton and Akers: Corrective Optics Space Telescope Axial 

ICBC activation Replacement/Secondaries) 

NC-1 burn (310 n.m. x 302 n.m.) 

Flight Day 8 

Flight Day 2 HST reboost burns (320 n.m. x 313 n.m.) 

Remote Manipulator System checkout HST Extravehicular Activity 5 

Cabin pressurization to 10.2 psi (Hoffman and Musgrave: Solar Array Drive Electronics/Secondaries) 

Space Support Equipment checkout/survey 

Configure Flight Servicing Structure Flight Day 9 

NPC burn (310 n.m. x 302 n.m.) Group B power up 

NSR burn (310 n.m. x 304 n.m.) HST grapple 

Extravehicular Mobility Unit checkout HST unberth 

NC-2 burn (317 n.m. x 305 n.m.) HST release (320 n.m. x 313 n.m.) 

 Separation burns 1, 2 and 3 (320 n.m. x 311 n.m.) 

Flight Day 3 Group B power down 

HST rendezvous operations 

NH burn (320 n.m. x 305 n.m.) Flight Day 10* 

NC-3 burn (320 n.m. x 310 n.m.) Cabin pressurization to 14.7 psi 

NCC burn (320 n.m. x 310 n.m.) Off-duty half day (MS1, MS3, MS4, MS5) 

TI burn (320 n.m. x 312 n.m.) Off-duty half day (CDR, PLT, MS2) 

HST grapple (320 n.m. x 313 n.m.) 

HST berth Flight Day 11 

HST survey Group B power up 

Group B powerdown Flight Control Systems checkout 

 Reaction Control System hot fire 

Flight Day 4 Cabin stow 

HST Extravehicular Activity 1 

(Hoffman and Musgrave: Two Rate Sensor 

Units/Secondaries) Flight Day 12 

Space Support Equipment power down 

Flight Day 5 Deorbit preparations 

HST Extravehicular Activity 2 Deorbit burn 

(Thornton and Akers: Solar Arrays) Entry 

 Landing 

Flight Day 6 

HST Extravehicular Activity 3 

(Hoffman and Musgrave: Wide Field/Planetary 

Camera; Two Magnetic 

Sensing Systems) 

*SPECIAL NOTE ON STS-61 SUMMARY TIMELINE 

On every Shuttle mission, some day-to-day replanning takes place to adjust crew and event timelines 

according to unforeseen developments or simply to optimize the use of time in orbit. 

During STS-61, the bulk of the daily replanning will be undertaken, while the crew sleeps, by the planning 

shift in mission control. During the EVA days, this team will play a crucial role in making the most of the 

astronauts time in Endeavour’s payload bay. To maximize crew productivity and to adapt to any 

unexpected challenges, the planning team will have the ability to reorder the sequence of individual tasks 

within any given spacewalk or to shift tasks from one day’s agenda to another. 

Each day’s replanning effort will produce an execute plan defining the approach for the next day’s 

activities in space and on the ground. 
Edited by Richard W. Orloff,01/2001/Page 12 

STS-61 ORBITAL EVENTS SUMMARY 

Event 

Start 

Time 

(dd/hh:mm:ss) 

Velocity 

Change 

(feet 

per second) 

Orbit 

(n.m.) Notes 

OMS-2 00/00:45:00 461 310 x 297 

NC-1 00/05:33:00 8 310 x 302 Adjusts the rate at which Endeavour is closing on HST 

NPC 00/23:12:00 .5 310 x 302 Fine-tunes Endeavour’s ground track to be exactly in line 

with HST track 

NSR 01/03:57:00 5.5 310 x 304 Adjusts Endeavour’s closing rate on HST 

NC-2 01/04:32:00 12 317 x 305 Adjusts Endeavour’s closing rate on HST 

NH 01/17:22:00 4 320 x 305 Adjusts altitude of Endeavour’s orbital high point, fine-tunes 

course to arrive at a point 40 nautical miles behind HST at 

same altitude 

NC-3 01/18:10:00 10 320 x 310 Fired at 40 n.m. behind HST, begins closing in on HST; 

initiates closing rate of about 16 n.m. per orbit aimed to 

arrive at a point 8 n.m. behind HST, at same altitude as HST, 

two orbits later 

NCC 01/20:23:00 TBD 320 x 310 First burn calculated by onboard computers using onboard 

navigation derived from orbiter star tracker sightings of 

HST; fired while orbiter is about closing on point 8 n.m. 

behind HST to fine-tune course 

TI 01/21:23:00 3 320 x 312 Fired upon arrival at point 8 n.m. behind HST; begins 

terminal interception of HST 

MC1-MC4 TBD TBD TBD Mid-course corrections; calculated by onboard computers, 

double- checked by ground; fine-tune final course toward 

HST, may or may required 

MANUAL 01/22:57:00 TBD TBD Begins about 45 minutes prior to HST grapple, less than 1 

nautical mile from HST. Commander takes manual control of 

orbiter flight, fires braking maneuvers to align and slow final 

approach 

GRAPPLE 01/23:42:00 n/a n/a HST captured with mechanical arm 

HST REBOOST 06/17:45:00 TBD TBD Performed only if amount of available propellant allows, lifts 

Endeavour’s orbit to reboost HST’s orbit while HST is in 

cargo bay 

HST REBOOST 06/18:33:00 TBD TBD Performed only if amount of available propellant allows, lifts 

Endeavour’s orbit to reboost HST’s orbit while HST is in 

cargo bay 

HST RELEASE 08/00:43:00 n/a n/a HST is released from Endeavour’s mechanical arm 

SEP-1 08/00:44:00 1 320 x 313 Begins a slow separation of Endeavour from vicinity of HST 

SEP-2 08/01:08:00 2 320 x 313 Increases rate at which Endeavour is departing vicinity of 

HST 

SEP-3 08/01:32:00 3 320 x 311 Puts Endeavour on final course departing vicinity of HST 

DEORBIT 10/20:31:00 508 

LANDING 10/21:45:00 

NOTE: All planned burns are recalculated in real time once the flight is underway using the latest 

information for the position of HST and will likely change slightly. Depending on how accurate the 

orbiter’s navigation and course is at certain times, some smaller burns listed above may not be required. 

However, the times for major burns and events are unlikely to change by more than a few minutes. 
Edited by Richard W. Orloff,01/2001/Page 13 

HUBBLE SPACE TELESCOPE/SERVICING MISSION-01 (HST-SM-01) 

OVERVIEW OF MISSION 

History 

Launched on April 24, 1990, NASA’s Hubble Space Telescope was designed to be the most powerful 

astronomical observatory ever built. And indeed, HST far surpasses the capabilities of ground-based 

optical telescopes for many types of research. The keys to Hubble’s power are its operation in space, far 

above the interference of the Earth’s atmosphere, and to the unique instruments it carries as it orbits the 

planet. In addition HST was the first observatory designed for extensive on-orbit maintenance and 

refurbishment. 

While the launch on the Space Shuttle Discovery more than 3 years ago was flawless, Hubble was not. 

Two months after HST was deployed into orbit 370 miles (595.5 km) high, Hubble produced a disquieting 

discovery not about space, but about itself. The curvature of its primary mirror was slightly - but 

significantly - incorrect. Near the edge, the mirror is too flat by an amount equal to 1/50th the width of a 

human hair. 

A NASA investigative board later determined that the flaw was caused by the incorrect Adjustment of a 

testing device used in building the mirror. The device, called a “null corrector,” was used to check the 

mirror curvature during manufacture. 

The result is a focusing defect or spherical aberration. Instead of being focused into a sharp point, light 

collected by the mirror is spread over a larger area in a fuzzy halo. Images of extended objects, such as 

stars, planets and galaxies, are blurred. 

NASA has been coping with Hubble’s fuzzy vision with computer processing to sharpen images. For 

bright objects, this technique has yielded breathtaking detail never seen from the ground. NASA also has 

been concentrating on the analysis of ultraviolet light, which ground-based telescopes cannot see because 

of the Earth’s intervening atmosphere. 

To realize the full potential of HST, however, the spacecraft must be serviced. The telescope mirror itself 

cannot be fixed or changed. However, corrective optics can be applied to the HST instruments to 

compensate for the aberration, much the same as glasses or contact lenses correct human sight. The new 

optics should allow Hubble to accomplish most, if not all, of it’s originally planned objectives. 

The mission, though, will accomplish much more than improved vision. Hubble was designed to spend 15 

years in space. Even before the spherical aberration was known, several servicing missions, including one 

in 1993, had been planned so that failed parts could be replaced and others improved with better 

technology. This mission will perform that type of servicing in addition to installing corrective optics. 

Endeavour will carry some 16,000 pounds (7,257 kilograms) of servicing hardware into space. During 

nearly 2 weeks in orbit around the Earth, astronauts will use the Shuttle as a kind of orbiting service station 

from which they will venture to work on the 12.5-ton (11.34-metric ton) telescope as it hurtles around the 

planet at 18,000 miles (28,968 km) an hour. 

The crew will spend some 30 hours in space during at least five separate spacewalk periods, undertaking a 

series of tasks more complex than any ever attempted in orbit, to ensure that Hubble remains a viable and 

productive national resource throughout its planned 15-year lifetime. 
Edited by Richard W. Orloff,01/2001/Page 14 

Mission Objectives and Success 

The three objectives of the first Hubble servicing mission are to restore the planned capabilities of the 

telescope by correcting the optics, to restore reliability of the spacecraft and to validate that the concept of 

Hubble on- orbit servicing is viable. 

The top priorities are installation of the replacement solar arrays; two rate sensing units, one with an 

electronics control unit; the Wide Field/Planetary Camera II (WF/PC-II) and fuses; the Corrective Optics 

Space Telescope Axial Replacement (COSTAR); at least one new magnetometer; and a new Solar Array 

Drive Electronics unit. 

For the first servicing mission to be considered fully successful, these top priority items must be 

accomplished. In addition, other tasks may be performed on a time-available basis. The minimum criteria 

for mission success are to leave Hubble with three newer-design gyroscope systems and either an 

operational WF/PC-II or COSTAR. 

First Corrected Image Availability 

The first fully corrected Hubble images are estimated to be available 6 to 8 weeks after the servicing 

mission. This time is necessary for Adjustments to ensure telescope stability and the best possible focus. 

During this period, telescope operators on the ground will remotely calibrate the gyros, which help keep 

the HST fixed on its targets, and position the corrective mirrors in the Corrective Optics Space Telescope 

Axial Replacement (COSTAR) and the Wide Field/Planetary Camera 2 (WF/PC-II). 

COSTAR is being installed to remedy the blurred vision of three observing instruments on HST. The 

WF/PC-II is a replacement camera that has its own corrective optics. 

More information on activities after STS-61 necessary to produce a fully corrected Hubble image can be 

found in the section on Servicing Mission Orbital Verification. 

Science Accomplishments 

Despite the flaw in the primary mirror, the bus-size Hubble still has been able to gather a wealth of 

scientific data, most of which would have been impossible to collect if the telescope did not exist. In the 

last 3 years, HST has conducted a variety of scientific investigations that have rapidly expanded knowledge 

of what lies beyond the Earth, from the relatively nearby planets in Earth’s solar system to the most distant 

reaches of the universe. 

Hubble’s studies have ranged from Earth’s neighbor Mars, to the evolution of stars from birth to death, to 

the characteristics of galaxies beyond, and finally to a field known as cosmology, which probes the 

fundamental nature of the universe itself. 

The following is a small sampler of some of Hubble’s discoveries and work in progress: 

• The Planets 

Even prior to the servicing mission, Hubble conducted and continues to conduct long-term observations of 

global weather changes on Mars. Hubble has observed the development of a rare, planet-wide storm on 

Saturn. The telescope also resolved, as two distinct objects, the most distant planet in the solar system, 

Pluto and its moon Charon. Previously, no telescope had been able to separate clearly the two bodies. 
Edited by Richard W. Orloff,01/2001/Page 15 

HST also has been studying long-term weather changes on Jupiter and its auroral activity. Hubble also has 

been measuring the extent of the atmosphere of the Jovian moon Io and also has looked for changes in the 

satellite’s surface. 

• Stellar Evolution 

Hubble uncovered the strongest evidence yet that many stars form planetary systems. This evidence was 

the discovery of disks of dust around 15 newly formed stars in the Orion Nebula, a starbirth region 1,500 

light- years away. Such disks are considered a prerequisite for the formation of solar systems like Earth’s. 

The HST images confirm more than two centuries of speculation, conjecture and theory about the genesis 

of a solar system. 

• Star Clusters 

HST discovered young globular star clusters at the core of a peculiar galaxy. The discovery of these stars 

early in their evolution was the equivalent of finding a “Jurassic Park” in space. 

The space telescope found “blue straggler” stars in the core of globular cluster 47 Tucanae, providing 

evidence that some stars “capture” others and merge with them. 

• Galaxies 

HST uncovered circumstantial evidence for the presence of a massive black hole in the core of the 

neighboring galaxy M32 as well as the giant elliptical galaxy M87. Both galaxies have a central 

concentration of starlight that probably is shaped by the gravitational field of the black hole. This implies 

that massive black holes may be quite common among “normal” galaxies, perhaps even Earth’s. 

Hubble yielded direct evidence for galaxy evolution by resolving the shapes of galaxies that existed long 

ago. HST revealed that many ancient spiral galaxies have since disappeared, possibly through fading or 

collisions and mergers with other galaxies. 

• Cosmology 

The space telescope allowed astronomers to take a major first step in determining the rate at which the 

universe is expanding. HST detected 27 stars called Cepheid variables. These stars are “standard candles” 

for estimating distances to galaxies. The expansion rate, known as the Hubble Constant, is one of two 

critical numbers needed for making a precise determination of the size, age and fate of the universe. 

HST discovered boron, the fifth lightest element, in a very ancient star. This star would have been one of 

the earliest formed after the Big Bang explosion that most scientists believe began the universe. If boron 

was produced in the first few minutes of the birth of the universe, it implies that the Big Bang was not a 

uniform explosion. 

Hubble precisely determined the ratio of deuterium to hydrogen in interstellar gas clouds. This value shows 

that the universe has only 6 percent of the observable matter required to prevent itself from expanding 

forever. 
Edited by Richard W. Orloff,01/2001/Page 16 

European Space Agency (ESA) Role in HST 

The Hubble Space Telescope is a program of joint cooperation between NASA and ESA. ESA provided 

Hubble’s deployable solar arrays, the major source of electrical power, which collects energy from the sun 

to recharge the spacecraft’s six nickel-hydrogen batteries. ESA’s second contribution was the Faint Object 

Camera (FOC), which was intended for imaging of the faintest objects in the visible and ultraviolet spectral 

regions at very high spatial resolution. These elements are discussed further in the section addressing 

replacement hardware and instruments. 

Claude Nicollier, a mission specialist on this flight, is an ESA astronaut. 
Edited by Richard W. Orloff,01/2001/Page 17 

SERVICING MISSION ORBITAL VERIFICATION (SMOV) 

The purpose of SMOV is to “recommission” HST so that it can begin science operations as soon as 

possible following the first servicing mission. This involves a thorough engineering checkout of all 

serviced subsystems; optical alignment and initial calibration of all science instruments; and the phasing in 

of astronomical observations. SMOV begins when HST is released from the Shuttle and is expected to last 

approximately 13 weeks. 

Key Activities During SMOV 

• Activation and engineering checkout of the science instruments. 

• Optical alignment and focusing of WF/PC-II and COSTAR. 

• Initial calibration of WF/PC-II and the COSTAR-corrected science instruments. 

• Early science observations. 

Engineering Checkout Activities 

• Decontaminate the WFPC II detectors (charge-coupled devices or CCDs) of any foreign substances by 

heating the detectors to “drive-off” contaminants. 

• Establish proper operating temperature of WFPC II CCDs by monitoring ultraviolet (UV) light from a 

calibration star. 

• Monitor pressure drop (due to outgassing) until it is safe to turn on high voltage to the COSTARcorrected science instruments. 

• Determine the effects of the servicing mission on the basic (pre-COSTAR) optical performance of the 

science instruments. 

Steps in Focusing the Science Instruments 

• Check out the first generation instruments and conduct prefocusing tests. 

• Adjust the secondary mirror in HST’s Optical Telescope Assembly to set focus for WF/PC-II and 

correct for residual coma in the Optical Telescope Assembly. 

• Deploy COSTAR arms. 

• Adjust COSTAR and WF/PC-II optics and mirrors, including mirror tilt, coarse Adjustment, fine 

alignment and focus. 

Science Instruments Calibration 

• A series of tests and measurements to establish the actual performance of the science instruments in 

the areas of sensitivity, resolution and detector response characteristics. 
Edited by Richard W. Orloff,01/2001/Page 18 

KEY HST SCIENTIFIC GOALS FOLLOWING THE FIRST SERVICING MISSION 

• Hubble will determine, precisely, the expansion rate of the universe by measuring the light curve of 

Cepheid Variable stars in galaxies out to the distance of at least 50 million light-years. 

Cepheids are pulsating stars that become alternately brighter and fainter with periods (duration of the 

states of brightness or faintness) ranging from 10 to 50 days. Astronomers have known for over 50 

years that the periods of these stars precisely predict their total luminous power, which allows their 

distance to be measured. 

In the expanding universe, the Hubble Constant (Ho) is the ratio of the recession velocities of galaxies 

to their distance. (Recession velocity is the speed at which the galaxy is moving away from Earth.) The 

age of the universe can be estimated from the Hubble Constant. The age currently is estimated to be 

between 10 and 20 billion years, but a more precise measurement of the Hubble Constant is required to 

narrow this range to an accuracy of 10 percent. 

• HST will look for the gravitational signature of massive black holes in the cores of normal and active 

galaxies. A black hole is a theoretical object that is so compact and dense, nothing can escape its 

gravitational field. The HST spectrographs will measure precisely the velocities of gas and stars 

orbiting the center of a galaxy. If the stellar velocities increase rapidly toward the galaxy center, it 

would be the signature of a massive, compact central object. 

• Hubble will be able to determine the shapes of galaxies that are very distant. Because remote objects 

also are relics of the early universe, HST will be able to study how galaxies have evolved since the 

beginning of the universe. Nearby galaxies have spiral, elliptical and irregular shapes, however, these 

shapes should have changed over time because the universe is evolving. 

• Hubble will be able to precisely measure the ages of globular clusters by observing the faintest stars in 

the clusters. Globular clusters are considered to be the oldest objects in the universe, and their ages 

provide insights into how stars evolve and also provide an independent estimate of the age of the 

universe. 
Edited by Richard W. Orloff,01/2001/Page 19 

HUBBLE SPACE TELESCOPE RENDEZVOUS AND RETRIEVAL 

The rendezvous and retrieval operational procedures for the Hubble Space Telescope will be similar to 

those conducted on previous missions requiring capture of a free-flying satellite in orbit. 

For the HST mission, Endeavour’s crew will perform many orbit Adjust burns to catch up with and retrieve 

the telescope on flight day three of the mission using the Shuttle’s robot arm. 

Once the Shuttle is safely in orbit and the payload bay doors opened, the space support equipment 

activation is performed. This includes activating the flight support system and orbital replacement unit 

carrier heaters. Other pre-rendezvous activities will include checkout of the robot arm, the orbiter Ku-band 

dish antenna used as a radar system during rendezvous and the ground command system. 

The terminal initiation burn occurs about 2 hours prior to capture at a distance of approximately 40,000 

feet (12,192 m) in front of the telescope. Several small mid-course correction burns follow before the 

Commander takes over manual control of the Shuttle about 1,200 feet (366 m) below and 500 feet (152 m) 

behind the telescope. 

The orbiter approaches Hubble from underneath, just after orbital sunset. This approach technique is 

designed to minimize potential contamination from the Shuttle’s thruster firings. 

Prior to capture, a ground-commanded maneuver of the telescope will be performed to align the grapple 

fixture on the HST with Endeavour’s robot arm. The size of the telescope maneuver will depend on the 

angle to the Sun and ranges from about 70 degrees to 180 degrees. 

When the telescope is grappled, using the robot arm’s end effector, it will be lowered into the payload bay 

and berthed in the flight support system, a turntable likened to a lazy susan for its rotation and tilt ability to 

assist in the servicing tasks. An electrical cable is remotely attached to provide orbiter power to the 

telescope. 

COMMANDS TO HUBBLE 

Commands to HST are issued from the Space Telescope Operations Center (STOCC) at Goddard Space 

Flight Center, Greenbelt, Md., which manages the orbiting observatory. The STOCC has been the nerve 

center for Hubble operations since the telescope was launched. Commands to Hubble are issued from the 

STOCC and data gathered by the spacecraft arrive there first. 

The STOCC is responsible for most commanding of the HST during STS-61, although the crew can send a 

limited number of commands from Endeavour. The STOCC will send commands configuring the space 

telescope for retrieval by the orbiter; integrate commands with crew activities during extravehicular 

activities (EVAs) to configure various spacecraft hardware and perform hardware checkouts and send 

commands to configure the space telescope for deployment from Endeavour. 
Edited by Richard W. Orloff,01/2001/Page 20 

STS-61 EXTRAVEHICULAR ACTIVITIES 

A total of five spacewalks are planned on STS-61 to service the HST. Unlike past Shuttle repair work 

performed on satellites such as Intelsat on STS-49, HST was designed with the objective of servicing it in 

orbit through Shuttle spacewalks. As such, it has two grapple fixtures for the Shuttle’s mechanical arm, 

many handholds for spacewalkers and bolts and electrical connections designed to be serviced by a 

spacewalker. 

However, the amount of work to be performed on STS-61 has increased above what originally was 

projected for the first servicing flight to the telescope due to deficiencies and equipment problems that have 

occurred or been discovered since HST was launched. Since there is such a large amount of work to be 

accomplished on STS-61, the various tasks have been prioritized by the HST program officials. 

The primary tasks on STS-61 will be to install two Rate Sensor Units, one with an Electronics Control 

Unit, the Solar Arrays, the Solar Array Drive Electronics, the Wide Field/Planetary Camera and four 

instrument fuse plugs, the Corrective Optics Space Telescope Axial Replacement and one Magnetic 

Sensing System. 

Secondary tasks that may be performed during the spacewalks if time permits include installing the 

Goddard High Resolution Spectrograph Redundancy Kit, a 386 coprocessor, a second Magnetic Sensing 

System, four gyro Fuse Plugs and one Electronic Control Unit. A third Rate Sensor Unit is being carried in 

the payload bay for use if needed. 

The spacewalks will be performed by STS-61 extravehicular crew members Jeff Hoffman, Story 

Musgrave, Kathy Thornton and Tom Akers. Each spacewalk will be performed by two crew members, one 

of whom will be in a foot restraint mounted at the end of Endeavour’s mechanical arm. During all EVAs, 

the crew member mounted at the end of the arm will be referred to as Extravehicular Crew Member 2, or 

EV2, while the other spacewalker will be designated EV1. 

The EVA crew can be distinguished by markings on the legs of their spacesuits. Hoffman will have a solid 

red stripe around the legs of his suit; Musgrave will have no stripes on the legs of his suit; Thornton will 

have a dashed red stripe around the legs of her suit; and Akers will have a diagonal, broken red stripe 

around the legs of his suit. 

In planning for the mission, the EVAs have been designed to take into account the possibility that crew 

members may encounter unforeseen difficulties either in tasks or equipment that could cause the 

preplanned schedule for installation of various equipment to change. All four EV crew members have 

cross-trained so that any one is capable of performing any given task. 

For all of the various tasks, the Flight Support Structure in Endeavour’s cargo bay on which HST will be 

mounted, once it is retrieved, will be rotated so the area being worked on faces forward to allow better 

visibility. Those specific tasks and the EVA work required to complete them are described in the following 

sections. 
Edited by Richard W. Orloff,01/2001/Page 21 

REPLACEMENT HARDWARE AND INSTRUMENTS 

While the servicing mission is complex, steps have been taken to make the spacecraft as straightforward to 

work on as possible. Since HST was designed for servicing in space from it’s inception, many of its 

subsystems are modular, standardized and accessible. Hubble has 49 different modular subsystems 

designed for servicing, ranging from small fuses to large scientific instruments. The space telescope, which 

is 43.5 feet (13.25 meters) long, also has 225 feet (69 meters) of handrails and 31 footholds to aid 

astronauts in servicing tasks. And more than 200 tools - from screwdrivers to hardware designed 

specifically for HST servicing - are available for use on this mission. 

NASA’s Goddard Space Flight Center, Greenbelt, Md., is responsible for the components that will be 

serviced or replaced on Hubble. The components make up a primary servicing task list that will be carried 

out during the mission, followed by a secondary task list to be undertaken if time and conditions allow. 

The mission’s primary objective is to restore the HST’s science capabilities with the Wide Field/Planetary 

Camera-II and the Corrective Optics Space Telescope Axial Replacement, both of which will compensate 

for the spherical aberration of the primary mirror. 

However, the replacement of the spacecraft’s solar arrays - HST’s major source of electrical power - tops 

the primary servicing task list. This is because solar array jitter, or excessive flexing, may be compromising 

the structural integrity of the arrays. By replacing the arrays first, the observatory still will be able to 

perform science even if an emergency causes the mission to be called off and forces astronauts to release 

the telescope from the Space Shuttle before installing the optics packages 

Likewise the replacement of one gyro pair is second on the task list, because if more gyros fail, the 

pointing of the spacecraft at science targets cannot be accurately controlled. 

The primary servicing task list includes: 

• Solar Array II (SA II). 

• Gyro Pair 2. 

• Wide Field Planetary Camera 2 (WFPC2) and four instrument fuse plugs. 

• Corrective Optics Space Telescope Axial Replacement (COSTAR) 

• Magnetometer System 1. 

• Gyro Pair 3 with Electronics Control Unit (ECU). 

• Solar Array Drive Electronics 1 (SADE). 

The secondary servicing task list includes: 

• A redundancy kit for the Goddard High Resolution Spectrograph (GHRS). 

• The 386 co-processor on the spacecraft’s primary computer, called the DF-224. 

• Magnetometer System 2 

• Four gyro fuse plugs. 

• Electronics Control Unit for Gyro Pair 1. 
Edited by Richard W. Orloff,01/2001/Page 22 
Edited by Richard W. Orloff,01/2001/Page 23 
Edited by Richard W. Orloff,01/2001/Page 24 

PRIMARY SERVICING TASKS 

Gyroscope Pairs (Rate Sensing Units) and Electronics Control Unit 

Three gyroscopes (or gyros) are required to point and track HST. Three more gyros are onboard as 

backups. The total of six gyros are packaged in pairs of two, called Rate Sensing Units (RSU). One gyro 

failed in December 1990; a second failed in June 1991 and a third in November 1992. 

Two of these three gyros, one located in pair 2 and the other in pair 3, contain hybrid electronics that are 

suspected of causing the failures. Gyro pairs 1 and 3 also have experienced a failure in one channel of their 

Electronics Control Unit (ECU), the cause of which is suspected to be a random electronic part failure. 

While these failures have not affected HST’s performance, replacing the failed hardware will increase 

system reliability. 

The Rate Sensor Units are inside the housing of HST. To begin the replacement work, the spacewalking 

astronaut, standing in a foot restraint mounted on the end of the Shuttle’s mechanical arm, will first back 

out several bolts to open doors covering the star tracker near the base of HST. One of the four bolts 

holding the doors, called the star tracker seal, must be completely removed to unlatch the doors. 

A programmable power wrench will be used to loosen and tighten all bolts during the RSU replacement. 

While the arm-mounted astronaut unlatches the doors, his fellow spacewalker, mounted on a foot restraint 

attached to a support structure in the Shuttle’s bay, will assist. Once the doors are unlatched, they will be 

swung open to provide access to the bay area. 

The Rate Sensor Units are located behind the cone-shaped star tracker shades in the bay area of the 

telescope. To replace an RSU, these shades may have to be removed. If so, three bolts must be loosened 

and the shade pulled off. The shade then can be temporarily stowed outside the work area. The shades are 

reinstalled by pushing them back into place and then retightening the three bolts. 

To remove an RSU, the spacewalker, standing in an Adjustable foot restraint attached to the telescope, will 

loosen three bolts and disconnect two electrical plugs. The RSU then may be removed by holding a 

handrail located at the top of the unit. 

During these activities, the astronaut standing on the end of the arm will assist his partner from behind. The 

new RSU, carried aloft in an Orbital Replacement Unit Carrier (ORUC) in the Shuttle’s bay, will be 

installed by sliding it into place and then retightening the three bolts and hooking up the two electrical 

plugs. 

The time required to set up, remove two RSUs, install two RSUs and then clean up the area during training 

has been around 3.5 hours, including the possible removal and reinstallation of the star tracker shades. 

Electronic Control Units 

The Electronic Control Units are the electrical brains for the Rate Sensor Units and are located in a service 

bay on the Hubble Space Telescope. Once the compartment door is opened, two of the three ECUs will be 

replaced by removing four bolts and disconnecting each one’s electrical cable. The new units, which are 

retrieved from a protective container in the payload bay, will be installed in a similar fashion. 
Edited by Richard W. Orloff,01/2001/Page 25 

Solar Array II 

The Solar Arrays were built in Europe under the auspices of ESA. The solar arrays provide the telescope 

and its instruments with 5 kW of electrical power at the start of their lifetime. They constitute the 

spacecraft’s two “wings” and consist of 50,000 silicon photoelectric cells, covering a surface area of 84 

square yards/6.6 x 39.6 x 9.24 ft (70 square meters/2 x 12 x 2.8 m). 

The arrays are the flexible “roll-out and roll-up” type and are made of huge sheets of plastic (fiberglassreinforced Teflon) held in place by horizontal metal struts, which also unroll. Each wing weighs about 352 

lbs. (160 kg). 

But the arrays create a jitter that interferes with spacecraft stability and affects its pointing capability. The 

arrays now on Hubble were supposed to accommodate the expansion and contraction caused by heating 

and cooling as the space telescope moves in and out of daylight during its 96-minute orbits. However, a 

compensation device that allows for the expansion and contraction of the solar array blankets does not 

expand and contract as smoothly as expected. 

As a temporary fix, engineers created software that commanded Hubble’s pointing system to compensate 

for the jitter automatically. This procedure occupies a large portion of the on-board computer memory, 

though, and to truly fix the problem, the solar arrays must be replaced. 

ESA redesigned and provided to NASA a set of spare solar arrays to reduce the jitter to an acceptable 

level. This set will be installed on the HST after the existing arrays are removed; the arrays now on the 

spacecraft will be returned to Earth. To significantly reduce jitter, the new arrays have thermal insulation 

sleeves on the array supports, called bi-stems, to minimize heating and cooling of the support during each 

orbit. Springs that work like shock absorbers also will take up tension at the array ends. 

To replace the HST Solar Arrays, first the old arrays are retracted by commands from the Space Telescope 

Operations Control Center. Once they have been retracted and stowed, the arm-mounted spacewalker will 

release three latching points on the first array to be removed. Once the three latches have been released, the 

array can be removed and handled using a transfer handhold mounted to the array. 

The array then is carried by having the mechanical arm moved to position the astronaut within reach of a 

temporary stowage bracket for the old arrays, mounted on the right-hand side of the Solar Array Carrier in 

Endeavour’s cargo bay. While being moved from place to place at the end of the arm, the crew member 

also may evaluate the handling characteristics of the array to prepare for carrying the new array up to its 

installation position. Throughout the removal operation, the arm-mounted astronaut will be assisted by his 

counterpart, who will be moving about via handholds on the telescope and Shuttle. 

The new solar array is removed from the SAC by disconnecting a power and a data connection and then 

unlatching three latch points exactly like the latch points on the telescope. A temporary transfer handle 

allows the arm-mounted astronaut to carry the new array up to the installation location. His counterpart will 

assist with the installation by standing in a foot restraint mounted to the telescope near the work area. 

While the array is being transported, the power and data connectors are secured in temporary holding 

brackets on the array. To install the new array, first it is moved into position and once seated, the three 

latch points are locked in place and the connectors plugged in. The second array is removed and its 

replacement installed in exactly the same fashion. 

During training, the time required to perform a changeout of the solar arrays was about 5 hours, and one 

full spacewalk is dedicated to this task. The new arrays are not planned to be deployed during the 

spacewalk performed to install them. 
Edited by Richard W. Orloff,01/2001/Page 26 
Edited by Richard W. Orloff,01/2001/Page 27 
Edited by Richard W. Orloff,01/2001/Page 28 

Wide Field/Planetary Camera-II (WF/PC-II) 

The current WF/PC has been used to study bright, high-contrast objects, such as major solar system planets 

and nearby star clusters and galaxies. Spherical aberration, however, has hampered the ability of the 

camera to provide high-resolution images of the very faintest objects, or objects in a field crowded with 

other objects. 

The WF/PC-II is a spare instrument developed, beginning in 1985, by the Jet Propulsion Laboratory (JPL) 

team, Pasadena, Calif., that built the first WFPC. When Hubble’s mirror was found to be flawed, NASA 

and the WFPC science team immediately began working on an optical correction that could be built into 

WFPC2. The new design incorporates an optical correction by the refiguring of relay mirrors already in the 

optical train of the cameras. Each relay mirror is polished to a new prescription that will compensate for the 

incorrect figure on HST’s primary mirror. Small actuators will fine- tune the positioning of these mirrors 

on orbit, ensuring the very precise alignment that is required. 

Through a servicing bay door built into the side of HST, astronauts will slide out the 610-pound (277-

kilogram), wedge-shaped WFPC, as they would a giant drawer, and replace it with WFPC2. The removed 

WFPC will be returned to Earth. 

The WFPC2 will have three wide-field cameras and one planetary camera instead of the original total of 

eight. The WFPC2 team chose to reduce the number of cameras to four in order to develop a system to 

align the corrective relay mirrors on-orbit. Improved Charged Coupled Devices (CCDs) are incorporated 

into WFPC2 to improve its sensitivity, particularly in the ultraviolet. 

To remove and replace the Wide Field/Planetary Camera (WF/PC), the doors to the service bay at the base 

of the telescope are opened and specially designed guide rails are installed to assist with removal of the 

instrument. 

A temporary handhold then is installed on the WF/PC. Using this handhold, the arm-mounted spacewalker 

pulls the WF/PC out of its installed position while his counterpart watches the alignment of the WF/PC on 

the rails and ensures it is level as it is removed. Once removed from the telescope cavity, the arm-mounted 

astronaut is positioned within reach of a temporary parking fixture for the old WF/PC in Endeavour’s 

cargo bay, where it is stowed. 

A temporary handhold is installed on the new unit, WF/PC-II, in its Scientific Instrument Protective 

Enclosure (SIPE) in Endeavour’s cargo bay. The WF/PC-II is pulled from the SIPE by the arm-mounted 

crew member, who is later moved to the installation site by the arm operator. Meanwhile, the SIPE door is 

temporarily latched by his crew mate. 

Before sliding the WF/PC-II into place inside the telescope, a cover over its mirror is removed. Then, the 

arm-mounted spacewalker slides it into the telescope slot while his fellow spacewalker checks to ensure 

that it is aligned on the guide rails. Once inserted in place, the handhold is removed from the instrument 

and the guide rails are detached. 

Finally, the old WF/PC is removed from its temporarily stowed position in the parking fixture and inserted 

into the SIPE that carried WF/PC-II, where it is secured for Endeavour’s trip home. 

Removal of the old WF/PC and the installation of WF/PC-II has taken about 4 hours and 15 minutes 

during training. 
Edited by Richard W. Orloff,01/2001/Page 29 
Edited by Richard W. Orloff,01/2001/Page 30 

Corrective Optics Space Telescope Axial Replacement (COSTAR) 

COSTAR is designed to optically correct the effects of the primary mirror aberration on three instruments 

besides the WFPC: the Faint Object Camera (FOC), the Faint Object Spectrograph (FOS) and the Goddard 

High Resolution Spectrograph (GHRS). 

The FOC, provided by ESA, is designed to detect very low-luminosity celestial bodies and to provide the 

most detailed images on HST. It consists of an electronic conventional scanning camera (of the television 

type), whose front part is a powerful image intensifier tube. Its performance has been degraded by the 

spherical aberration, but the sharp image cores still allow the camera to detect details not seen by groundbased telescopes. 

The FOS analyses the light from very faint objects in the visible and ultraviolet spectral regions. While the 

faintest objects now cannot be reached, observations of brighter sources are only moderately degraded. 

The GHRS is intended for very detailed analysis of ultraviolet radiation. The instrument now loses spectral 

resolution on the faintest objects, but observations of brighter sources are only moderately degraded. 

COSTAR was invented by the Hubble Space Telescope Strategy Panel, a group of scientists and engineers 

brought together at the Space Telescope Science Institute, Baltimore, Md., in the fall of 1990 to consider 

how to fix HST. Built by Ball Aerospace, Boulder, Colo., under contract to NASA, COSTAR has no 

detectors or cameras. It will use precisely shaped mirrors, ranging from about the size of a dime to a 

quarter, to correct for the spherical aberration. 

Through a servicing bay door, astronauts will pull out the 487-pound (221-kilogram), phone booth-size 

High Speed Photometer (HSP) and install in its place the identically sized COSTAR. Once in place, 

COSTAR will deploy a set of mechanical arms, no longer than a human hand, that will place corrective 

mirrors in front of the openings that admit light into the Faint Object Camera, the Faint Object 

Spectrograph and the Goddard High Resolution Spectrograph. COSTAR’s corrective mirrors will refocus 

light relayed by HST’s primary mirror before it enters these three instruments. COSTAR will restore the 

optical performance of these instruments very close to the original expectations. 

To install COSTAR, the spacewalkers first will open doors to the bay, that enclosed the HSP, by loosening 

several bolts. Once the doors are open, latches that hold the HSP in place will be loosened and then four 

electrical connectors and a ground strap will be disconnected from the instrument. 

Then the HSP is lowered from its position to guide rails for the unit. The arm-mounted spacewalker and his 

crew mate, standing in a foot restraint attached to the telescope, will coordinate efforts to remove the 

device. The arm-mounted crew member will slide HSP out while his fellow spacewalker ensures that it is 

aligned with the guide rails. 

Once removed, the HSP is held by the crew member standing on the end of the arm while the arm is 

positioned so the HSP can be placed in a temporary parking fixture mounted in the cargo bay. After it is 

temporarily stowed, a handhold is attached to COSTAR and it is lifted from its protective enclosure. A 

ground strap is disconnected and, while the arm-mounted astronaut is lifting COSTAR out, his crew mate 

is assisting by ensuring COSTAR is squarely aligned with the enclosure as it is extracted. 

The arm-mounted crew member then is positioned up to the installation area while his fellow spacewalker 

moves to the site via handrails on the telescope. COSTAR then is aligned with the guide rails, with the 

arm- mounted spacewalker watching the alignment of a rail at the upper left-hand corner of COSTAR and 

his counterpart checking the alignment of a rail at the lower right corner. 

Once COSTAR slides into place, the four electrical connections, disconnected from HSP, are connected to 

COSTAR along with the grounding strap, and the latches are tightened to hold COSTAR in place. 

In training, removal of the HSP and installation of COSTAR has taken about 3 hours and 15 minutes. 
Edited by Richard W. Orloff,01/2001/Page 31 
Edited by Richard W. Orloff,01/2001/Page 32 

Solar Array Drive Electronics 1 (SADE) 

Each solar array wing has an electronics control assembly that includes a drive electronics unit. These units 

transmit positioning commands to the wing assembly. One of these Solar Array Drive Electronics units has 

failed due to transistor overheating. A replacement SADE, provided by ESA, will restore that lost 

capability and provide better heat protection for the transistors. 

The Solar Array Drive Electronics are mounted on the inner side of one of the doors to an HST service 

bay. Two electronics boxes are mounted on the inside of the door, but only one is being replaced. Once the 

door is opened, the two spacewalkers - one mounted on the arm and one holding handrails on the telescope 

- will loosen six bolts to free the old SADE unit and disconnect electrical connectors attached to the unit. 

The new SADE unit is installed in the reverse of this process. 

Magnetometer System 1 

The HST’s two magnetometers (also known as magnetic sensing systems) measure the spacecraft’s relative 

orientation with respect to the Earth’s magnetic field. Neither magnetometer is functioning at full 

capability. Both replacements have improved electronics and thermal blankets added. The replacement 

magnetometers will be snapped into place over the existing magnetometers, which will not be removed 

from the HST. 

Both of the magnetic sensing systems are located near the top of the telescope near the aperture door. The 

new units will be installed using four rotating knob connectors and will be attached directly on top of the 

old units by removing some insulation and removing and reinstalling the electrical cable. These units are 

used to help measure the observatory’s position relative to Earth’s magnetic field. 

Fuse Plugs 

Fuses for both the gyros and instruments will be replaced to correct sizing and wiring discrepancies. 

The fuses that will be replaced on the HST are located on the inside of a compartment door. Eight of the 

fuse plugs will be removed and replaced by the spacewalking astronauts. Once all have been replaced, 

checks will be made to ensure they are working properly. 
Edited by Richard W. Orloff,01/2001/Page 33 

SECONDARY SERVICING TASKS 

Co-Processor 

The DF-224 is the HST’s flight systems computer. One of the computer’s six memory units has failed and 

another has partially failed. Hubble requires only three memory units to fully function, so the failures have 

not affected telescope operations. However, to restore the memory redundancy and augment the telescope’s 

memory capacity and speed, a co- processor, based on 386-computer architecture, will be integrated into 

the flight systems computer, which will increase both flight computer memory and the speed of some 

operations. 

The DF-224 co-processor will be installed on top of the HST computer located in a compartment on the 

telescope. The memory upgrade is installed using handles on the computer and attaching four bolts using a 

power tool. 

Goddard High Resolution Spectrograph Redundancy Kit 

The GHRS has two detector systems. Because of the anomalous behavior of a low-voltage power supply, 

the side-one detector no longer is used. The redundancy kit consists of an externally mounted relay box 

that enhances system redundancy so that the side-one detector can be used and the side- two detectors will 

not be compromised if the anomaly recurs. 

Made up of four cables and a relay box, the Goddard High Resolution Spectrograph redundancy kit is 

designed to bypass an erratic detector system on the science instrument located in an instrument bay on the 

lower portion of the HST. The relay box is installed first using a power tool similar to an electric drill. This 

is followed by attachment of the four cables. 
Edited by Richard W. Orloff,01/2001/Page 34 

HUBBLE SPACE TELESCOPE TOOLS AND CREW AIDS 

The crew of STS-61 has more than 200 tools and crew aids with them for the servicing of the Hubble 

Space Telescope. The tools and crew aids, known as Space Support Equipment (SSE) hardware, range 

from a simple bag for carrying some of the smaller tools to sophisticated, battery operated power 

equipment. These tools will be used by the EVA crew members servicing the spacecraft. 

Crew Aids 

Crew aids are defined as those that are fixed in place and those that are portable equipment items but not 

hand tools, used to assist crew members in accomplishing servicing mission tasks. SSE equipment crew 

aids permit the crew members to maneuver safely or to restrain themselves, transfer Orbital Replacement 

Units (ORUs) and other portable items, protect equipment and themselves during changeout activities and 

temporarily stow or tether equipment during EVAs. 

Examples of crew aids are handrails, handholds, translation devices, transfer equipment, protective covers, 

tethering devices, grapple fixtures, foot restraint sockets and stowage and parking fixtures. 

Tools 

Tools are hand-operated or manipulated devices that allow the EVA astronauts to increase the efficiency of 

performing intricate, labor-intensive tasks. 

Stowage 

The tools and crew aids will be stowed on or in the Solar Array Carrier (SAC), Orbital Replacement Unit 

Carrier (ORUC), Flight Support System (FSS), HST Tool Box, Sidewall-mounted adapter plates, 

Provisions Stowage Assembly (PSA), an Adaptive Payload Carrier (APC), middeck lockers, aft flight-deck 

and airlock. Tools and crew aids are provided by Johnson Space Center, Houston, and Goddard Space 

Flight Center, Greenbelt, Md. 

Uses 

Tools and crew aids considered “general,” with a wide variety of uses, include the Power Ratchet Tool 

(PRT), Multi-setting Torque Limiter (MTL), Adjustable extension with 7/16th-inch sockets, ingress aids, 

portable work- light receptacle and a locking connector tool. More specific, but still considered general, 

items are a low-gain antenna (LGA) cover, umbilical connector covers, a flight support system (FSS), 

berthing and positioning system (BAPS), support post and a multi-layer insulation (MLI) repair kit. 

To be used on the changeout of the Wide Field Planetary Camera 2 (WFPC2) are the WFPC handholds, 

WFPC guide studs, quick-release zip nuts, WFPC pick-off mirror cover, forward fixture, aft fixture and the 

HST radial bay cover. 

For the High Speed Photometer (HSP) replacement with the Corrective Optics Space Telescope Axial 

Replacement (COSTAR), tools and aids to be used will be the COSTAR contamination cover, a COSTAR 

handling aid, an HSP handling aid, forward fixture, aft fixture and an axial Science Instrument Protective 

Enclosure (SIPE) safety bar. 

For the solar array replacement, the astronauts will use articulating foot restraints, solar array primary drive 

mechanism handles, solar array temporary stowage brackets (TSBs), solar array transfer handles, solar 

array jettison handle, solar array spines, Portable Flight Release Grapple Fixture (PFRGF) and a Marmon 

clamp. 
Edited by Richard W. Orloff,01/2001/Page 35 

For the changeout of the gyro rate sensor units, crew members will use a Portable Foot Restraint (PFR) 

socket converter (90-degree), Fixed-Head Star Tracker (FHST) light shade covers and a FHST delta plate 

cover. 

Portable Foot Restraint 

There are two Hubble Space Telescope portable foot restraints built for use on the STS-61 mission. These 

restraints are used by the spacewalking astronauts during the five extravehicular activities to provide a 

stable platform from which to work. Both restraints are stowed in the payload bay, one on the left side and 

the other on the flight support system. 

Tool Box 

The HST tool box is designed to stow individual tools, tool boards and tool caddies that will be used 

throughout the mission. The box is mounted on the right side of the payload bay. Each tool inside the box 

is stowed in a specific location with markings to assist the astronauts in the retrieval and stowage. 

Power Ratchet Tool (PRT) 

The Goddard-provided power ratchet tool (PRT) is powered by a 28-volt battery. Made of titanium and 

aluminum, the 17-inch (43-centimeter) tool will be used for tasks requiring controlled torque, speed or 

turns and can be used where right-angle access is required. It will provide 25 foot-pounds of pressure in the 

motorized mode and 75 foot-pounds of pressure in the manual mode. It has a speed of 10 to 30 revolutions 

per minute. A spare power ratchet will be carried on the mission, as will spares for all other tools to be 

used by the astronauts. 

HST Power Tool 

This tool is a modified, battery-operated power tool with torque and rpm control. The design includes a 

3/8-inch drive fitting, forward and reverse drive rotation, torque ranges from 50 to 300 inch-pounds and a 

bracket for mounting the tool to the spacesuit. 

Mini-Power Tool 

The mini-power tool is a battery-operated screwdriver intended for use when a larger power tool is not 

required and when work space is limited. It can be used as a power tool or with the power off, the output 

shaft is locked automatically for use as a manual driver. 

Multisetting Torque Limiter 

This tool is provided to prevent damage to hardware due to the application of torque which may exceed the 

design limits. Multisetting torque limiters are used in conjunction with the power tools or hand tools that 

interface with bolts and latches on the telescope. 

Adjustable Extensions 

Several extensions were designed to be Adjustable to ease the movement of the astronauts while reducing 

the time required for tool changeouts. The Adjustable extensions replace several fixed length extensions by 

providing Adjustment from 12 to 16.5 inches. Another Adjustable extension provides lengths from 15 to 

24 inches. When retracted, these extensions reduce the potential for damage to other hardware. 
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IMAX 

THE IMAX project is a collaboration between NASA and the Smithsonian Institution’s National Air and 

Space Museum to document significant space activities using the IMAX film medium. This system, 

developed by IMAX Systems, Corp., Toronto, Canada, uses specially designed 70 mm film cameras and 

projectors to record and display very high definition large- screen pictures. 

An IMAX camera system will be flown on Shuttle Mission STS-61 and will be used by Endeavour’s crew 

to collect material for upcoming IMAX productions. IMAX cameras have flown on several Shuttle 

missions and film from those missions was used to form the IMAX productions The Dream is Alive and 

The Blue Planet. 

In-Cabin IMAX Camera Equipment 

The IMAX system consists of a camera, lenses, rolls of film, two magazines with film, an emergency speed 

control, a Sony recorder and associated equipment, two photographic lights, supporting hardware in the 

form of mounting brackets to accommodate the mode of use, two cables and various supplemental 

equipment. 

The IMAX and supporting equipment are stowed in the middeck for in- cabin use. The IMAX uses two 

film magazines which can be interchanged as part of the operation. Each magazine runs for approximately 

3 minutes. When both magazines are consumed, reloading of the magazines from the stowed supply of film 

is required. Lenses are interchanged based on scene requirements. The IMAX will be installed in the 

orbiter middeck approximately 7 days prior to launch. 

IMAX Cargo Bay Camera (ICBC) 

During Shuttle Mission STS-61, an IMAX Cargo Bay Camera (ICBC) will be carried in the payload bay of 

Endeavour and used to document activities associated with the servicing of the Hubble Space Telescope. 

The camera is mounted in a pressure sealed container with a viewing window. The window has a sliding 

door which opens when the camera is in operation. The camera is controlled from the aft-flight deck, 

exposing the film through a 30 mm fisheye lens. 
Edited by Richard W. Orloff,01/2001/Page 43 

AIR FORCE MAUI OPTICAL SYSTEM 

The Air Force Maui Optical System (AMOS) is an electrical-optical facility on the Hawaiian island of 

Maui. No hardware is required aboard Discovery to support the experimental observations. The AMOS 

facility tracks the orbiter as it flies over the area and records signatures from thruster firings, water dumps 

or the phenomena of “Shuttle glow,” a well-documented fluorescent effect created as the Shuttle interacts 

with atomic oxygen in Earth orbit. The information obtained by AMOS is used to calibrate the infrared and 

optical sensors at the facility. 

DTO-667: PILOT INFLIGHT LANDING OPERATIONS TRAINER (PILOT) 

One of the challenges to flying long duration Shuttle missions is the issue of orbiter landing tasks requiring 

a high level of skill and proficiency yet data showing that a pilot’s landing skills degrade after an extended 

absence from a landing trainer such as the Shuttle Training Aircraft. During Shuttle Mission STS-61, a 

portable scientific workstation designed to aid the Shuttle commander and pilot in maintaining those 

landing skills will be demonstrated for the second time. 

The PILOT system hardware, which flew on Shuttle Mission STS-58 in October 1993, consists of a 

portable scientific workstation, a high resolution color display and a hand controller with orbiter look and 

feel. The software used in the system was transferred from the Shuttle Engineering Simulator software 

which is used to validate Shuttle flight software. This provides PILOT with orbiter handling and guidance 

characteristics. 

The PILOT system is stowed in lockers on the flight deck and middeck areas of the Space Shuttle. When a 

member of the crew wants to use the system, the workstation is mounted on a console directly in front of 

the pilot’s seat on the flight deck and the PILOT system hand controller is attached to the orbiter’s hand 

controller. 

In addition to evaluating the ability to maintain landing skills of a Shuttle crew in Earth-orbit, the PILOT 

system may be integrated into the standard training activities of all Shuttle crews at the Johnson Space 

Center in Houston. 
Edited by Richard W. Orloff,01/2001/Page 44 

STS-61 CREWMEMBERS 

STS061-S-002 -- STS-61 crew portrait. Left to right (seated) are astronauts Kenneth D. Bowersox, pilot; 

Kathryn C. Thornton, F. Story Musgrave, and Claude Nicollier, all mission specialists. Left to right 

(standing) are astronauts Richard O. Covey, mission commander; Jeffrey A. Hoffman and Thomas D. 

Akers, mission specialists. On the left side of the table is a model of the Hubble Space Telescope, on the 

right a model of the Space Shuttle. In the middle is the STS-61 insignia. 

No copyright is asserted for this photograph. If a recognizable person appears in the photo, use for 

commercial purposes may infringe a right of privacy or publicity. It may not be used to state or imply the 

endorsement by NASA or by any NASA employee of a commercial product, process or service, or used in 

any other manner that might mislead. Accordingly, it is requested that if this photograph is used in 

advertising and other commercial promotion, layout and copy be submitted to NASA prior to release. 

PHOTO CREDIT: NASA or National Aeronautics and Space Administration. 
Edited by Richard W. Orloff,01/2001/Page 45 

BIOGRAPHICAL DATA 

RICHARD O. COVEY, 47, Col., USAF, is Commander (CDR) of STS-61. Selected as an astronaut in 

January 1978, Covey considers Fort Walton Beach, Fla., his hometown and will be making his fourth 

space flight. 

Covey graduated from Choctawhatchee High School, Shalimar, Fla., in 1964; received a bachelor of 

science degree in engineering sciences with a major in astronautical engineering from the U.S. Air Force 

Academy in 1968, and a master of science degree in aeronautics and astronautics from Purdue University 

in 1969. 

Covey first flew as Pilot for Shuttle mission STS 51-I in August 1985. He next flew as Pilot on STS-26 in 

September 1988. On his most recent flight, he was Commander for STS-38 in November 1990. Covey has 

logged over 385 hours in space. 

KENNETH D. BOWERSOX, 37, Cmdr., USN, will serve as Pilot (PLT). Selected as an astronaut in June 

1987, Bowersox was born in Portsmouth, Va., but considers Bedford, Ind., his hometown and will be 

making his second space flight. 

Bowersox graduated from Bedford High School, Bedford, Ind.; received a bachelor’s degree in aerospace 

engineering from the Naval Academy in 1978 and a master of science degree in mechanical engineering 

from Columbia University in 1979. 

Bowersox first flew as Pilot for Shuttle mission STS-50 in June 1992. He has logged over 331 hours in 

space. 

TOM AKERS, 42, Lt. Col., USAF, will serve as Mission Specialist 5 (MS5) and as one of the 

extravehicular activity crew members. Selected as an astronaut in June 1987, Akers was born in St. Louis, 

Mo., but considers Eminence, Mo., his hometown and will be making his third space flight. 

He graduated from Eminence High School and received bachelor and master of science degrees in applied 

mathematics from the University of Missouri-Rolla in 1973 and 1975, respectively. 

Akers served as a mission specialist on STS-41 in October 1990. His next flight was as a mission specialist 

on STS-49 in May 1992. Akers was one of the EVA crew members of a three-person spacewalking team 

that successfully captured the stranded International Telecommunications Satellite. He also performed a 

second EVA on STS-49 to evaluate space station construction techniques. He has logged over 311 hours of 

space flight. 

JEFFREY A. HOFFMAN, 49, will be Mission Specialist 3 (MS3) and serve as one of the extravehicular 

activity crew members. Selected as an astronaut in January 1978, Hoffman considers Scarsdale, N.Y., his 

hometown and will be making his fourth space flight. 

Hoffman graduated from Scarsdale High School, received a bachelor’s degree in astronomy from Amherst 

College, received a doctorate in astrophysics from Harvard University and received a master’s degree in 

materials science from Rice University. 

Hoffman first flew on STS-51D in April 1985, a mission during which he performed a spacewalk in an 

attempt to rescue a malfunctioning satellite. He next flew on STS-35 in December 1990. Hoffman made his 

third space flight as Payload Commander and mission specialist on STS-46 in July 1992. 
Edited by Richard W. Orloff,01/2001/Page 46 

BIOGRAPHICAL DATA 

F. STORY MUSGRAVE, 58, will be Mission Specialist 4 (MS4). He also will serve as Payload 

Commander and as a member of the extravehicular activity team. Selected as an astronaut in August 1967, 

Musgrave considers Lexington, Ky., his hometown and will be making his fifth space flight. 

Musgrave graduated from St. Mark’s School, Southborough, Mass., in 1953; received a bachelor’s degree 

in mathematics and statistics from Syracuse University in 1958; received a master’s degree in operations 

analysis and computer programming from the University of California at Los Angeles in 1959; received a 

bachelor’s degree in chemistry from Marietta College in 1960; received a doctorate in medicine from 

Columbia University in 1964; received a master’s degree in physiology and biophysics from the University 

of Kentucky in 1966 and received a master’s degree in literature from the University of Houston in 1987. 

Musgrave flew as a mission specialist on STS-6 in April 1983, on Spacelab-2 in August 1985 and on STS33 in November 1989. More recently, he served aboard Space Shuttle Atlantis, STS-44 in November 1991. 

He has logged more than 598 hours in space. 

CLAUDE NICOLLIER, 49, will be Mission Specialist 2 (MS2). Under an agreement with the European 

Space Agency and NASA, he was selected as an astronaut in 1980. Nicollier was born in Vevey, 

Switzerland, and will be making his second space flight. 

Nicollier graduated from Gymnase de Lausanne, Lausanne, Switzerland, received a bachelor’s degree in 

physics from the University of Lausanne and received a master’s degree in astrophysics from the 

University of Geneva. Nicollier first flew as a mission specialist on STS-46 in July 1992 and has logged 

more than 191 hours in space. 

KATHRYN C. THORNTON, 41, will serve as Mission Specialist 1 (MS1) and as one of the 

extravehicular activity crew members. Selected as an astronaut in May 1984, Thornton was born in 

Montgomery, Ala., and will be making her third space flight. 

Thornton received a bachelor of science degree in physics from Auburn University and a master of science 

degree and a doctorate in physics from the University of Virginia. Thornton was awarded a NATO 

postdoctoral fellowship to continue her research at the Max Planck Institute of Nuclear Physics in 

Heidelberg, Germany. 

Thornton first flew as a mission specialist on STS-33 in November 1989. On her second flight, she served 

on the crew of STS-49 in May 1992. On STS-49, Thornton performed an extravehicular activity to 

evaluate space station assembly techniques. She has logged over 333 hours in space. 
Edited by Richard W. Orloff,01/2001/Page 47 

STS-61 ACRONYMS AND ABBREVIATIONS 

A-h ampere-hour 

ac alternating current 

ACE actuator control electronics 

ACP astronaut control panel 

AD aperture door 

AFD aft flight deck 

APS antenna pointing system 

AS aft shroud 

ATM Apollo Telescope Mount 

BAPS berthing and positioning system 

BCU bus coupler unit 

BOD bright object detector 

BOL beginning of life 

BOT beginning of travel 

BPRC battery protection and reconditioning circuit 

bps bits per second 

BPRC battery protection and reconditioning circuit 

BPSK biphase shift keyed 

BREC body rate error check 

C&DH communication and data handling 

C/C configuration control 

CC cargo control 

CCC charge current controller 

CCTV closed-circuit television 

CDI command and data interface 

CDU command detector unit 

CFRP carbon-fiber-reinforced plastic 

CGG contingency gravity gradient 

CIF computer interface 

CMD command module 

COM communications module 

CORU candidate orbital replacement unit 

CPM central processor module 

CPU central processing unit 

CSM cargo systems manual 

CSS coarse Sun sensor 

CU/SDF control unit/science data formatter 

D/A digital to analog 

DAK double-aluminized Kapton 

DBA diode box assembly 

dc direct current 

DCE deployment control electronics 

DIH discrete input high 

DISP display 

DIU data interface unit 

DIUI DIU interface module 

DMS data management subsystem 

DMU data management unit 

DPC direct power converter 
Edited by Richard W. Orloff,01/2001/Page 48 

ECA electronics control assembly 

ECU electronics control unit 

ED engineering data 

EDB external data bus 

EMI electromagnetic interference 

EOL end of life 

EOT end of travel 

EP/TCE electrical power/thermal control electronics 

EPS electrical power subsystem 

ES equipment section 

ESA European Space Agency 

ESTR engineering/science tape recorders 

EU electronics unit or expander unit 

EVA extravehicular activity 

FEP fluorinated ethylene-propylene 

FGE fine guidance electronics 

FGS fine guidance sensor 

FHST fixed head star tracker 

FHSTI FHST interface 

FIFO first in first out 

FMDM flexible multiplexer/demultiplexer 

FOC faint object camera 

FOD Flight Operations Directorate 

FOS faint object spectrograph 

FOV field-of-view 

F/S filter/shaper 

FPA focal plane assembly 

FPDA focal plane deck assembly 

FPSA focal plane structure assembly 

FS forward shell 

FSS flight support system 

FWH flexible wire harness 

GEA gimbal electronics assembly 

GG gravity gradient 

GGM GG mode 

GPC general purpose computer 

GSE ground support equipment 

GSFC Goddard Space Flight Center 

GSTDN ground spaceflight tracking and data network 

HGA high-gain antenna 

HLD high-level discrete 

HOSC Huntsville Operations Support Center 

HRS high resolution spectrograph 

HSP high-speed photometer 

HST Edwin P. Hubble Space Telescope 

HWL hardware load 
Edited by Richard W. Orloff,01/2001/Page 49 

I&C instrumentation and communication 

ICAPC increased capacity adaptive payload carrier 

ICU instrumentation control unit 

IDB internal data bus 

IMU inertial measurement unit 

IOU input/output unit 

IPCU interface power control unit 

IR infrared 

JSC Lyndon B. Johnson Space Center 

KA keep alive 

kbps kilo bits per second 

KSC Kennedy Space Center 

LGA low-gain antenna 

LLD low-level discrete 

LMU logical memory unit 

LS light shield 

LMSC Lockheed Missiles and Space Company 

MA multiaccess 

Mbps megabits per second 

MCC Mission Control Center 

MCC-H MCC - Houston 

MCE monitor and control electronics 

MCU mechanism control unit 

MDB multiplexed data bus 

MET mission elapsed time 

MLD manual locking device 

MLI multi-layer insulation 

MMS multi-mission modular spacecraft 

MOD Mission Operations Directorate 

MR main ring 

MRA main ring assembly 

MSB most significant bit 

MSFC Marshall Space Flight Center 

MSS magnetic sensing system 

MT magnetic torquer 

MTE magnetic torquer electronics 

MTP master timing pulse 

MTS magnetic torquing system 

MU memory unit 

N.m Newton meter 

NASA National Aeronautics and Space Administration 

NASCOM NASA communications 

NGT NASCOM ground terminal 

nm nanometer 

NSSC-I NASA Standard Spacecraft Computer, Model I 
Edited by Richard W. Orloff,01/2001/Page 50 

OAO Orbiting Astronomical Society 

OCE optical control subsystem 

OCS optical control subsystem 

OCXO oven-controlled crystal oscillator 

OLD offload device 

OPI Orbiter payload interrogator 

ORU orbital replaceable unit 

ORUC ORU carrier 

OSO Orbiting Solar Observatory 

OTA optical telescope assembly 

OV orbital verification 

P-E Perkin-Elmer Corporation 

PC planetary camera 

PCM pulse-code modulation 

PCS pointing control subsystem 

 pointing control system 

PCU power control unit 

PDI payload data interleaver 

PDM primary deployment mechanism 

PDU power distribution unit 

PI payload interrogator 

PI/KUSP PI/Ku-band signal processor 

PIT process interface table 

PLBD payload bay door 

PLR payload recorder 

PM primary mirror 

PMA primary mirror assembly 

PMB primary mirror baffle 

PMT photomultiplier tube 

PMU physical memory unit 

PN pseudo-random noise 

POCC Payload Operations Control Center 

PRCS primary react ion control system 

PRI primary 

PRIPL unregulated Orbiter power 

PRLA payload retention latch assembly 

PROM programmable read-only memory 

PSEA pointing and safe-mode electronics assembly 

psi pounds per square inch 

psia pounds per square inch absolute 

PSP payload signal processor 

PSP/PI PSP/payload interrogator 

QD quick disconnect 
Edited by Richard W. Orloff,01/2001/Page 51 

RBM radial bay module 

RED redundant 

RF radio frequency 

RFI radio frequency interface 

RGA rate gyro assembly 

RGAI RGA interface 

RIG rate integrating gyro 

RIU remote interface unit 

RMGA retrieval mode gyro assembly 

RM remote module 

RMS remote manipulator system 

ROM read-only memory 

RPA reaction plate assembly 

RSOC Rockwell Shuttle Operations Company 

RSU rate sensor unit 

RTC real-time command 

RWA reaction wheel assembly 

SA solar array 

SAD SA drive 

SADA SA drive adapter 

SADE SA drive electronics 

SADM SA drive mechanism 

SD science data or scientific data 

SDM secondary deployment mechanism 

SI scientific instrument 

SIC&DH scientific instrument control and data handling 

SIP standard interface panel 

SIPE scientific instrument protective enclosure 

SISS SI support structure 

S/M safe mode 

SM secondary mirror 

SMA secondary mirror assembly 

SMB secondary mirror baffle 

SMC safemode computer 

SMCH standard mixed cargo harness 

SMSA secondary mirror subassembly 

SM4 safe-mode utility 

SOC state-of-charge 

SPA solar panel assembly 

SPC stored program command 

SPG single-point ground 

SQPSK staggered quadriphased, shift-keyed 

SS safing system 

SSA S-band single-access 

SSC Science Support Center 

SSE space support equipment 

SSM support systems module 

SSM-ES SSM equipment shelf 

SSP standard switch panel 

SSS star selector servo 

STACC standard telemetry and command components 
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STDN space flight tracking and data network 

STINT standard interface 

STOCC Space Telescope Operations Control Center 

STS Space Transportation System 

STSCI Space Telescope Science Institute 

TAG two-axis gimbal 

TBD to be determined 

TCE thermal control electronics 

TCS thermal control subsystem 

TCXO temperature controlled crystal oscillator 

TDRS tracking and data relay satellite 

TDRSS TDRS system 

TFC TLM format control 

TIM timing interface module 

TLM telemetry 

TRI tape recorder interface 

TTL transistor-to-transistor logic 

UDM umbilical disconnect mechanism 

ULE ultralow expansion 

URM umbilical retraction mechanism 

UV ultraviolet 

VATA Vehicle Assembly and Test Area 

VCO voltage controlled oscillator 

VSS vehicle support software 

VSWR voltage standing wave radio 

WF/PC wide field/planetary camera 

WFC wide field camera 

WSGT White Sands Ground Terminal 
Edited by Richard W. Orloff,01/2001/Page 53 

SHUTTLE FLIGHTS AS OF DECEMBER 1993 

58 TOTAL FLIGHTS OF THE SHUTTLE SYSTEM -- 33 SINCE RETURN TO FLIGHT 

STS-51 

09/12/93 - 09/22/93 

STS-56 

04/08/83 - 04/17/93 

STS-58 

10/18/93 - 11/01/93 

STS-53 

12/02/92 - 12/09/92 

STS-55 

04/26/93 - 05/06/93 

STS-42 

01/22/92 - 01/30/92 

STS-52 

10/22/92 - 11/01/92 

STS-48 

09/12/91 - 09/18/91 

STS-50 

06/25/92 - 07/09/92 

STS-39 

04/28/91 - 05/06/91 

STS-46 

07/31/92 - 08/08/92 

STS-40 

06/05/91 - 06/14/91 

STS-41 

10/06/90 - 10/10/90 

STS-45 

03/24/92 - 04/02/92 

STS-35 

12/02/90 - 12/10/90 

STS-51L 

01/28/86 

STS-31 

04/24/90 - 04/29/90 

STS-44 

11/24/91 - 12/01/91 

STS-32 

01/09/90 - 01/20/90 

STS-61A 

10/30/85 - 11/06/85 

STS-33 

11/22/89 - 11/27/89 

STS-43 

08/02/91 - 08/11/91 

STS-28 

08/08/89 - 08/13/89 

STS-51F 

07/29/85 - 08/06/85 

STS-29 

03/13/89 - 03/18/89 

STS-37 

04/05/91 - 04/11/91 

STS-61C 

01/12/86 - 01/18/86 

STS-51B 

04/29/85 - 05/06/85 

STS-26 

09/29/88 - 10/03/88 

STS-38 

11/15/90 - 11/20/90 

STS-9 

11/28/83 - 12/08/83 

STS-41G 

10/05/84 - 10/13/84 

STS-51-I 

08/27/85 - 09/03/85 

STS-36 

02/28/90 - 03/04/90 

STS-5 

11/11/82 - 11/16/82 

STS-41C 

04/06/84 - 04/13/84 

STS-51G 

06/17/85 - 06/24/85 

STS-34 

10/18/89 - 10/23/89 

STS-4 

06/27/82 - 07/04/82 

STS-41B 

02/03/84 - 02/11/84 

STS-51D 

04/12/85 - 04/19/85 

STS-30 

05/04/89 - 05/08/89 

STS-57 

06/21/93 - 07/01/93 

STS-3 

03/22/82 - 03/30/82 

STS-8 

08/30/83 - 09/05/83 

STS-51C 

01/24/85 - 01/27/85 

STS-27 

12/02/88 - 12/06/88 

STS-54 

01/13/93 - 01/19/93 

STS-2 

11/12/81 - 11/14/81 

STS-7 

06/18/83 - 06/24/83 

STS-51A 

11/08/84 - 11/16/84 

STS-61B 

11/26/85 - 12/03/85 

STS-47 

09/12/92 - 09/20/92 

STS-1 

04/12/81 - 04/14/81 

STS-6 

04/04/83 - 04/09/83 

STS-41D 

08/30/84 - 09/05/84 

STS-51J 

10/03/85 - 10/07/85 

STS-49 

05/07/92 - 05/16/92 

 

OV-102 

Columbia 

(15 flights)

OV-099 

Challenger 

(10 flights)

OV-103 

Discovery 

(17 flights)

OV-104 

Atlantis 

(12 flights)

OV-105 

Endeavour 

(4 flights)