LACE (satellite)

The LACE mission concept began in February 1985 when the Strategic Defense Initiative Organization approached the Naval Research Laboratory to develop an experiment to characterize laser signals transmitted and received through the Earth's atmosphere from a ground station to an orbiting experiment. The laboratory had been involved with spaceflight since the dawn of the space race, having led the Navy's Vanguard program up until 1959. Since then the laboratory had developed satellites to perform experiments relating to solar radiation, radio transmission through the ionosphere, gravity gradient stabilization, and ocean surveillance, among others.{{cite journal |last1=McDowell |first1=Jonathan |title=Naval Research Laboratory Satellites 1960–1989 |journal=Journal of the British Interplanetary Society |date=1997 |volume=50 |pages=427–432 |url=https://planet4589.org/jcm/pubs/space/papers/1997/nrl.pdf |access-date=13 April 2024}}

In July 1985, the Laser Communication Experiment (LACE) began development. The simple, spaceborne experiment was planned to be flown on the next flight of NASA's Long Duration Exposure Facility (LDEF), launched aboard the Space Shuttle. Because the LDEF was a completely passive payload, LACE would've required additional power and communication subsystems to function properly. After the Challenger disaster, shuttle launches were delayed indefinitely, and the LDEF would remain in orbit from the beginning of its first mission until 1990. This led to the further development of LACE into a full satellite by June 1986, and the availability of expendable launch vehicles such as the Atlas, Titan, and Delta rockets to launch government payloads such as LACE. The satellite would later be renamed to be the Low-power Atmospheric Compensation Experiment.{{rp|2}}{{rp|1}}

Before launch, LACE was placed in the Delta II's payload fairing alongside the Relay Mirror Experiment (RME) satellite. Also known as USA-52 and LOSAT-R, it was also sponsored by the SDIO for ground-to-orbit laser tests and was built by Ball Aerospace.{{cite web |last1=Williams |first1=Dr. David R. |editor-last=Bell, II|editor-first=E.|title=RME |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1990-015B |website=NASA Space Science Data Coordinated Archive |publisher=NASA |access-date=30 May 2024 |date=28 October 2022}} The two satellites and a third, LOSAT-X, were originally meant to be launched together, and were all part of the SDIO's LOSAT (LOw-altitude SATellite) program, even though they all had different designs and missions. LOSAT-X was removed from the launch manifest and would launch the following year with the GPS satellite USA-71.{{cite web |last1=Day |first1=Dwayne A. |title=Objects in space: LOSAT-X and QuickStar |url=https://www.thespacereview.com/article/2700/1 |website=The Space Review |publisher=SpaceNews |access-date=30 May 2024 |date=23 February 2015}}

LACE did not have any onboard propulsion systems, instead, it relied on gravity-gradient stabilization to keep its experiments pointed towards Earth. It accomplished this using three {{cvt|150|ft|m}} long booms pointing along the forward, rear, and zenith axes of the spacecraft relative to the direction of its motion. While the zenith boom would remain fully extended during normal operation, the two booms along the forward and rear axes were designed to be extended and retracted 125 times during the 30 months of LACE's planned mission, and successfully did so over 65 times, albeit most movements were minor. The three booms were the largest retractable booms ever flown in space at the time of LACE's launch in 1990.{{cite web |last1=Horan |first1=Donald M. |title=Building the LACE satellite |url=http://ncst-www.nrl.navy.mil/HomePage/LACE/BuildLACE.html |publisher=Naval Research Laboratory Naval Center for Space Technology |access-date=5 June 2024 |archive-url=https://web.archive.org/web/20070917042658/http://ncst-www.nrl.navy.mil/HomePage/LACE/BuildLACE.html |archive-date=17 September 2007 |date=October 1991 |url-status=dead}}{{cite book |last1=Amato |first1=Ivan |title=Taking Technology Higher The Naval Center for Space Technology and the Making of the Space Age |publisher=U.S. Naval Research Laboratory |url=https://www.nrl.navy.mil/Portals/38/PDF%20Files/Taking_Technology_Higher_Amato.pdf?ver=spZbH8Hq4wVXtv57VIHV_g%3d%3d |access-date=5 June 2024 |chapter=13}}{{rp|252}}{{rp|3,10–12}}

The Sensor Array Subsystem was the primary payload of the LACE satellite. It contained three sets of sensor arrays with a total of 210 sensors designed to detect laser emissions on-orbit from visible, pulsed, and infrared lasers on Earth.{{cite web |title=Low-Power Atmospheric Compensation Experiment (LACE) |url=https://www.nrl.navy.mil/ssdd/heritage/lace/ |publisher=U.S. Naval Research Laboratory Space Systems Development Department |access-date=5 June 2024 |archive-url=https://web.archive.org/web/20201017000312/https://www.nrl.navy.mil/ssdd/heritage/lace |archive-date=October 17, 2020 |url-status=live}}

The visible sensor array had 85 sensors distributed in the center of the earth-facing "target board". It was specifically designed to detect laser emissions from the Short Wavelength Adaptive Techniques (SWAT) program's argon ion laser at the Air Force Maui Optical Station (AMOS) in Maui, Hawaii. The array was sensitive to laser emissions between 400 nanometers (nm) to 1.06 micrometers (μm). Before launch it was calibrated for the SWAT laser's wavelength of 514.5 nm, which was designed by the MIT Lincoln Laboratory. Later in the mission, this array was re-calibrated to 1.06 μm to support the USAF Starfire Optical Range at Kirtland AFB, New Mexico.{{rp|6}}

The pulsed array's 85 sensors were located in the same housings as the visible array sensors. They were calibrated at 354 nm and 1.06 μm, and were designed to generally support pulsed excimer lasers at wavelengths from 300 to 400 nm and a low-power laser emulator at 1.06 μm. The array detected pulses of durations from 10 nanoseconds (ns) to 2 microseconds (μs) with a maximum repetition rate of 100 pulses per second.{{rp|6}}

Like the visible array, the infrared array was also designed for a specific laser program: the Low Power Chemical Laser (LPCL) at White Sands, New Mexico. The array's 40 sensors were distributed uniformly across the target board, and detected deuterium fluoride chemical laser emissions between 3.6 and 4.0 μm.{{rp|7}}

File:UVPI ConOps.gif

The purpose of the Ultraviolet Plume Instrument (UVPI) experiment was to accurately image and track the plume of a rocket launched from Earth's surface in the ultraviolet spectrum. It was a pointable telescope mounted on the earth-facing side of the LACE spacecraft. Its mission was to collect images of rocket plumes in the near-ultraviolet and midultraviolet regimes from a space-based platform. It was also used to collect background image data of Earth, Earth's limb, and celestial objects. Background imaging included the day, night, and dawn limb, aurora, sunlit and moonlit clouds, and the Earth's surface.

The UVPI consisted of two image-intensified CCD cameras that were boresighted and shared a Maksutov-Cassegrain telescope. The tracker camera was sensitive in the near-ultraviolet/visible wavelength region, had a field of view approximately 14 times larger in each dimension than the plume camera, and was used to locate, acquire, and track a target. The plume camera collected images at four wavelengths from 195 to 350 nm, selected with a filter wheel. The field of view was 0.184 x 0.137 degrees. Its photometric range and sensitivity were optimized for nighttime operations. The tracker camera could image stars as dim as visual magnitude 7. Normal frame rate was 5 per second, but the zoom mode rate was 30 per second with a reduced field of view.{{cite web |last1=Williams |first1=Dr. David R. |editor-last=Bell, II|editor-first=E.|title=Ultraviolet Plume Instrument (UVPI)|url=https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1990-015A-01 |website=NASA Space Science Data Coordinated Archive |publisher=NASA |access-date=4 May 2024 |date=28 October 2022}}{{Source-attribution}}

The Army Background Experiment was commissioned by the U.S. Army Strategic Defense Command to measure the space neutron background radiation from the LACE satellite. It consisted of four borated plastic scintillator rods 8 in. long by 3 in. in diameter attached to a fold-out panel on the nadir side of LACE. The rods would detect neutrons originating from atmospheric escape and from the spacecraft's body. The experiment was jointly developed by the Grumman Corporation and the Los Alamos National Laboratory, with the support of the U.S. Department of Energy. Within a few months after the launch of LACE, the ABE was reported to be operating nominally, and it was expected to remain in operation through LACE's expected 30 month lifetime.{{cite web |last1=Feldman |first1=W. C. |last2=Auchampaugh |first2=G. F. |last3=Shunk |first3=E. R. |title=Initial Results of the Army Background Experiment |url=https://apps.dtic.mil/sti/pdfs/ADA339053.pdf |website=Defense Technical Information Center |publisher=University of California, Los Alamos National Laboratory |access-date=2 April 2024 |pages=1–11 |date=February 17, 1994}}

Data from ABE was provided to the SDIO for the development of spaceborne systems to discriminate between warheads and decoys.{{cite book |last1=Darling |first1=David |title=The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity |pages=228–229 |year=2003 |publisher=John Wiley & Sons, Inc. |location=Hoboken, New Jersey |isbn=0-471-05649-9 |url=https://books.google.com/books?id=dnruEAAAQBAJ&dq=LOSAT-L&pg=PT326 |access-date=8 April 2024}}

The Radiation Detection Experiment (RDE) was an experiment on the earth-facing side of LACE to detect electromagnetic radiation. It was designed by The Aerospace Corporation for the U.S. Air Force. The classified experiment was the only one not operated for the Strategic Defense Initiative, and was not discussed by the SDIO nor the NRL prior to launch. It collected data for 14 months throughout LACE's mission.{{cite news |title=Combined space test examines directed energy issues |url=https://link.gale.com/apps/doc/A8085396/AONE?u=embry&sid=bookmark-AONE&xid=9837561e |access-date=2 June 2024 |work=Military Space |volume=7 |page=7 |publisher=Access Intelligence, LLC |date=January 15, 1990}}{{rp|1–3, 9, 19}}

File:LACE Overview.jpg

File:LACE and Delta 192 Launchpad.jpg

LACE was launched aboard a Delta II Rocket from Launch Complex 17B at Cape Canaveral Air Force Station on February 14, 1990, separating from the RME satellite approximately 15 minutes later.{{cite news |last1=Halvorson |first1=Todd |title=Delta deploys 'Star Wars' satellites |url=https://www.newspapers.com/article/florida-today-delta-deploys-star-wars/83284498/ |access-date=2 April 2024 |work=Florida Today |date=February 15, 1990 |location=Cocoa, Florida |pages=1, 10}}{{cite web |last1=Naval Research Laboratory |title=LACE |url=https://apps.dtic.mil/sti/pdfs/ADA339075.pdf |website=Defense Technical Information Center |publisher=Naval Research Laboratory |access-date=4 April 2024 |location=Washington, DC |date=October 1, 1991}}{{rp|18}} It was the first Department of Defense payload launched on a commercial launch vehicle.

About a month after launch, it was reported that LACE and RME had experienced some setbacks in their missions, but none critical enough to end their mission. A Pentagon official stated that LACE's retroreflector system wasn't sending back signals at the expected power level, which that official speculated that the issue could be due to heat damage to a reflector.{{cite news |title=LACE/RME experiencing some difficulty. |url=https://link.gale.com/apps/doc/A8837435/AONE?u=embry&sid=bookmark-AONE&xid=279a1fe6 |access-date=2 April 2024 |work=Defense Daily |issue=58 |publisher=Access Intelligence |date=March 27, 1990|volume=166}}

LACE would proceed smoothly through the rest of its 60-day check-out phase, and it began its planned 30-month mission shortly after.{{rp|18}}

Exactly 3 years after its launch date, LACE was deactivated by the SDIO, ending its mission. It decayed into the atmosphere on May 24, 2000.

In 1998, while LACE was described as a "dead" satellite by the U.S. Army, its retroreflector was used as a target for the Low Power Chemical Laser and tracked with the SeaLite Beam Director at the High Energy Laser Systems Test Facility to support the DoD's MIRACL program.{{Cite journal |last=Dupont |first=Daniel G. |date=December 9, 1998 |title=Service more tight-lipped about MIRACL's ASAT mission: Army Continuing to Refine Laser's Ability to Track, Defear Satellites|url=https://www.jstor.org/stable/43971813 |journal=Inside Missile Defense |volume=4 |issue=25 |pages=22 |jstor=43971813 |issn=2164-8158 }}

The LACE program's net funding was $122.3 million over its lifetime.{{rp|23}}

File:LACE Shuttle Encounter MRK-1.png

Several attempts were made between 1990 and 1992 to image the plumes fired by the Space Shuttle from its Orbital Maneuvering System pods and Reaction Control System thrusters as it orbited in low-earth orbit at a lower orbital inclination than LACE. The UVPI was listed as a secondary experiment in about half of the shuttle's missions launched during LACE's operation, including in pre-flight press kits and media resource kits, and post-flight mission summaries published by NASA.{{efn|Eleven shuttle missions in total:

STS-35{{cite web |last1=Camp |first1=David W. |last2=Germany |first2=D. M. |last3=Nicholson |first3=Leonard S. |title=STS-35 Space Shuttle Mission Report |url=https://ntrs.nasa.gov/api/citations/19920007757/downloads/19920007757.pdf |website=NASA Technical Reports Server |publisher=NASA |access-date=21 April 2024 |location=Houston, TX |page=4 |date=January 1991}}{{rp|2{{hyphen}}43}}
STS-39{{cite web |last1=Hardie |first1=Kenneth O. |last2=Hill |first2=William C. |last3=Finkel |first3=Seymour I. |title=Mission Safety Evaluation Report for STS-39 – Postflight Edition |url=https://ntrs.nasa.gov/api/citations/19920011935/downloads/19920011935.pdf |website=NASA Technical Reports Server |publisher=NASA – Office of Safety and Mission Quality |access-date=21 April 2024 |location=Washington, DC |page=2{{hyphen}}8 |date=August 30, 1991}}{{rp|2{{hyphen}}47}}

STS-43{{cite web |last1=Hill |first1=William C. |last2=Finkel |first2=Seymour I. |title=Mission Safety Evaluation Report for STS-43 – Postflight Edition |url=https://ntrs.nasa.gov/api/citations/19920013997/downloads/19920013997.pdf |website=NASA Technical Reports Server |publisher=NASA – Office of Safety and Mission Quality |access-date=21 April 2024 |location=Washington, DC |page=2{{hyphen}}12 |date=October 31, 1991}}{{rp|2{{hyphen}}49}}{{Cite press release |title=STS-43 Press Information |date=July 1991 |publisher=Rockwell International Space Systems Division Office of Media Relations |pages=7, 77 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_042-STS-043_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-44{{cite web |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/pk/Flight_044_STS-044_Press_Kit.pdf|title=Space Shuttle Mission STS-44 – Press Kit|publisher=NASA|editor-last=Orloff|editor-first=Richard W.|date=January 2001|orig-date=November 1991|access-date=April 21, 2024|pages=6, 22–23}}{{rp|2{{hyphen}}51}}{{Cite press release |title=STS-44 Press Information |date=November 1991 |publisher=Rockwell International Space Systems Division Office of Media Relations |pages=7, 51 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_044-STS-044_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-42{{cite web |last1=Legler |first1=Robert D. |last2=Bennett |first2=Floyd V. |title=Space Shuttle Missions Summary |url=https://sma.nasa.gov/SignificantIncidents/assets/space-shuttle-missions-summary.pdf |publisher=Mission Operations Johnson Space Center |access-date=21 April 2024 |date=September 2011}}{{rp|2{{hyphen}}52}}

STS-45{{rp|2{{hyphen}}53}}{{Cite press release |title=STS-45 Press Information |date=March 1992 |publisher=Rockwell International Space Systems Division Office of Media Relations |page=77 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_046-STS-045_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-49{{cite web |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/pk/Flight_047_STS-049_Press_Kit.pdf|title=Space Shuttle Mission STS-49 – Press Kit|publisher=NASA|editor-last=Orloff|editor-first=Richard W.|date=January 2001|orig-date=May 1992|access-date=April 21, 2024|page=5}}{{rp|2{{hyphen}}54}}{{Cite press release |title=STS-49 Press Information |date=May 1992 |publisher=Rockwell International Space Systems Division Office of Media Relations |pages=7, 41 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_047-STS-049_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-50{{rp|2{{hyphen}}56}}{{Cite press release |title=STS-50 Press Information |date=June 1992 |publisher=Rockwell International Space Systems Division Office of Media Relations |pages=9, 73 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_048-STS-050_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-46{{cite web |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/pk/Flight_049_STS-046_Press_Kit.pdf|title=Space Shuttle Mission STS-46 – Press Kit|publisher=NASA|editor-last=Orloff|editor-first=Richard W.|date=January 2001|orig-date=July 1992|access-date=April 21, 2024|pages=8, 53}}{{rp|2{{hyphen}}58}}{{Cite press release |title=STS-46 Press Information |date=July 1992 |publisher=Rockwell International Space Systems Division Office of Media Relations |pages=9, 65 |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/mrk/FLIGHT_049-STS-046_MRK.pdf |via=NASA Johnson Space Center History Portal |access-date=2024-05-03}}

STS-47{{cite web |last1=Fricke, Jr. |first1=Robert W. |title=STS-47 Space Shuttle Mission Report |url=https://ntrs.nasa.gov/api/citations/19930016771/downloads/19930016771.pdf |website=NASA Technical Reports Server |publisher=Lockheed Engineering and Sciences Company / NASA |access-date=21 April 2024 |location=Houston, TX |page=1 |date=October 1992}}

STS-53{{cite web |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/shuttle_pk/pk/Flight_052_STS-053_Press_Kit.pdf|title=Space Shuttle Mission STS-53 – Press Kit|publisher=NASA|editor-last=Orloff|editor-first=Richard W.|date=January 2001|orig-date=December 1992|access-date=April 21, 2024|page=7}}}} Shuttle astronauts were briefed on the UVPI experiment during training sessions before their missions,{{cite web |author1=NASA |title=STS-49 Astronaut Training - Ultraviolet Plume Instrument Familiarization Briefing |url=https://catalog.archives.gov/id/80618690 |website=National Archives Catalog |publisher=National Archives and Records Administration |access-date=2 April 2024 |date=December 19, 1991}} and they took photos of thruster firings on board the shuttle done to support the UVPI, particularly on STS-50.{{cite web |author1=NASA |title=STS-50 |url=https://catalog.archives.gov/search-within/20933255?q=Ultraviolet%20Plume |website=National Archives Catalog |publisher=National Archives and Records Administration |access-date=2 April 2024 |date=July 9, 1992}} However, no thruster firings were successfully imaged by the UVPI while the Space Shuttle was in orbit. There were a number of reasons why it was difficult for this to happen, according to "The NRL LACE Program Final Report":{{cite web |last1=Horan |first1=D. M. |last2=Perram |first2=R. E. |last3=Palma |first3=R. E. |title=The NRL LACE Program Final Report |url=https://apps.dtic.mil/sti/pdfs/ADA270861.pdf |website=Defense Technical Information Center |publisher=Naval Research Laboratory |access-date=2 April 2024 |location=Washington, DC |date=August 27, 1993|id=ADA270861}}{{Source attribution}}{{rp|15}}

• Two bodies traveling at orbital velocities were involved.
• The observation opportunity inevitably occurred away from LACE ground stations and had to be controlled by stored commands.
• The shuttle could and did change its orbit after the controlling commands were stored in the LACE satellite.
• NASA could never guarantee that there would be plume-generating activity during the few seconds of the observation opportunity.

For example, during the STS-44 mission, the SDIO planned to observe thruster firings from the Space Shuttle Atlantis's OMS and PRCS pods with LACE and the UVPI over four to six orbital conjunctions.{{cite news |title=Shuttle crewman will make observations of military targets; SDIO seeking four to six conjuctions. |url=https://link.gale.com/apps/doc/A11428752/AONE?u=embry&sid=bookmark-AONE&xid=72aa28ff |access-date=25 May 2024 |work=Defense Daily |publisher=Access Intelligence |volume=173 |number=20 |pages=162+ |date=Oct 29, 1991}} However, due to Atlantis maneuvering to avoid a spent Soviet booster in orbit, and a failure of one of its IMUs, NASA's flight rules brought the mission to an early end.{{cite news |title=Shuttle returns early/SDI experiment cancelled. |url=https://link.gale.com/apps/doc/A11637899/AONE?u=embry&sid=bookmark-AONE&xid=351bd928 |access-date=25 May 2024 |work=Defense Daily |publisher=Access Intelligence |date=Dec 3, 1991 |volume=173 |number=42 |page=356}}

{{Gallery

| title =

| align =

| footer =

| style =

| state =

| height =

| width =

| perrow =

| mode =

| whitebg =

| noborder =

| captionstyle =

|File:Launch of Delta 192 - Feb 14 1990.jpg|A Delta II rocket at launch carrying the LACE satellite for the Department of Defense's Strategic Defense Initiative.

| alt1=

| File:LACE acoustic.jpg

| LACE undergoing inspection in an acoustic chamber

| alt2=

| File:LACE UVPI - Ultraviolet Rocket Plume.jpg

| The plume of a Black Brant XI third stage as imaged by the UVPI

| alt3=

| File:LACE2 Video.webm

| Short video about the LACE satellite produced by the NRL

| alt4=

}}

• {{Cite journal |last1=Fisher |first1=Shalom |last2=Schultz |first2=Kenneth I. |last3=Taylor |first3=Lawrence W. |date=July 1995 |title=Vibrations of the Low Power Atmospheric Compensation Experiment satellite |url=https://arc.aiaa.org/doi/10.2514/3.21443 |journal=Journal of Guidance, Control, and Dynamics |volume=18 |issue=4 |pages=650–656 |doi=10.2514/3.21443 |bibcode=1995JGCD...18..650F |issn=0731-5090|url-access=subscription }}
• {{cite web |last1=Walters |first1=Wesley F. |title=Dynamic Analysis of the Low Power Atmospheric Compensation Experiment (LACE) Spacecraft |url=https://apps.dtic.mil/sti/pdfs/ADA241361.pdf |website=Defense Technical Information Center |publisher=Naval Postgraduate School |access-date=4 April 2024 |location=Monterey, CA |date=June 1990}}
• {{cite web |last1=Welch |first1=Jeanne A. |last2=Light |first2=Bonnie |last3=Trusty |first3=Gary L. |last4=Cosden |first4=Thomas H. |title=A Laser Test Set for the Low-Power Atmospheric Compensation Experiment Satellite |url=https://apps.dtic.mil/sti/pdfs/ADA242703.pdf |website=Defense Technical Information Center |publisher=Naval Research Laboratory |access-date=3 June 2024 |location=Washington, DC |date=October 24, 1991}}

{{Notelist}}

{{Reflist}}

{{Reflist|group=Shuttle}}

{{Commons category|Low-Power Atmospheric Compensation Experiment (LACE)|LACE (satellite)}}

• [https://space.skyrocket.de/doc_sdat/lace.htm LACE at Gunter's Space Page]
• [http://www.astronautix.com/l/lace.html LACE at Encyclopedia Astronautica]

{{Orbital launches in 1990}}

Category:Strategic Defense Initiative

Category:Cold War

Category:USA satellites

Category:Spacecraft launched in 1990

Category:Spacecraft which reentered in 2000