Long Duration Exposure Facility
Encyclopedia
NASA
's Long Duration Exposure Facility, or LDEF, was a school bus
-sized cylindrical space experiment rack that exposed various material samples to outer space for about 5.7 years, completing 32,422 Earth
orbits.
to deliver a payload to space, leave it there, and on a separate mission retrieve the payload and return it to Earth for measurements. The project was approved in 1974. LDEF was built at NASA Langley Research Center
.
crew of the Space Shuttle
Challenger
deployed LDEF on April 7, 1984.
, Canada
, Denmark
, France
, Germany
, Ireland
, the Netherlands
, Switzerland
, and the United Kingdom
– flew on the LDEF mission. A total of 57 experiments were conducted on the LDEF. They investigated the effects on:
At LDEF's launch, retrieval was scheduled for March 19, 1985, eleven months after deployment. Schedules slipped, postponing the retrieval mission first to 1986, then indefinitely due to the Space Shuttle Challenger disaster
. It was finally recovered by the Shuttle Columbia
on mission STS-32
on January 12, 1990. Columbia approached LDEF in such a way as to minimize possible contamination to LDEF from thruster exhaust. While LDEF was still attached to the RMS arm, an extensive 4.5 hour survey photographed each individual experiment tray, as well as larger areas.
Columbia landed at Edwards Air Force Base
on January 20, 1990. Through the orbiter window, LDEF Project staff viewed and took photographs of LDEF at Edwards. With LDEF still in its bay, Columbia was ferried back using a Shuttle Carrier Aircraft
to the Kennedy Space Center
on January 26. Special efforts were taken to ensure protection against contamination of the payload bay during the ferry flight.
On January 30–31, LDEF was removed from Columbia' s payload bay in KSC's Orbiter Processing Facility
, placed in a special payload canister, and transported to the Operations and Checkout Building. On February 1, 1990, LDEF was transported in the LDEF Assembly and Transportation System to the Spacecraft Assembly and Encapsulation Facility - 2, where the LDEF Project team led deintegration activities.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Long Duration Exposure Facility, or LDEF, was a school bus
School bus
A school bus is a type of bus designed and manufactured for student transport: carrying children and teenagers to and from school and school events...
-sized cylindrical space experiment rack that exposed various material samples to outer space for about 5.7 years, completing 32,422 Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
orbits.
Construction
Researchers recognized the potential of the planned Space ShuttleSpace Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
to deliver a payload to space, leave it there, and on a separate mission retrieve the payload and return it to Earth for measurements. The project was approved in 1974. LDEF was built at NASA Langley Research Center
Langley Research Center
Langley Research Center is the oldest of NASA's field centers, located in Hampton, Virginia, United States. It directly borders Poquoson, Virginia and Langley Air Force Base...
.
Launch
The STS-41-CSTS-41-C
STS-41-C was NASA's 11th Space Shuttle mission, and the fifth mission of Space Shuttle Challenger. The launch on 6 April 1984 was the first direct ascent trajectory for a shuttle mission...
crew of the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
Challenger
Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...
deployed LDEF on April 7, 1984.
Experiments
Engineers imagined that the first mission would last most of a year, and that several long-duration exposure missions would use the same frame. The frame was actually used for only one 5.7-year mission. Fifty-seven science and technology experiments – involving government and university investigators from the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, and the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
– flew on the LDEF mission. A total of 57 experiments were conducted on the LDEF. They investigated the effects on:
- materialsMaterials scienceMaterials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates...
, coatingsPaintPaint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
, and thermal systemsThermodynamicsThermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation... - powerPower (physics)In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...
and spacecraft propulsionSpacecraft propulsionSpacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by forcing a gas from the... - scienceScienceScience is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
(misc experiments) - electronicsElectronicsElectronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
and opticsOpticsOptics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
Retrieval
Space Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...
. It was finally recovered by the Shuttle Columbia
Space Shuttle Columbia
Space Shuttle Columbia was the first spaceworthy Space Shuttle in NASA's orbital fleet. First launched on the STS-1 mission, the first of the Space Shuttle program, it completed 27 missions before being destroyed during re-entry on February 1, 2003 near the end of its 28th, STS-107. All seven crew...
on mission STS-32
STS-32
STS-32 was the 33rd mission of NASA's Space Shuttle program, and the 9th launch of Space Shuttle Columbia. Launching on 9 January 1990, it marked the first time since STS-61-C that Pad A at Kennedy Space Center's Complex 39 was used for a launch; it also marked the first use of Mobile Launcher...
on January 12, 1990. Columbia approached LDEF in such a way as to minimize possible contamination to LDEF from thruster exhaust. While LDEF was still attached to the RMS arm, an extensive 4.5 hour survey photographed each individual experiment tray, as well as larger areas.
Columbia landed at Edwards Air Force Base
Edwards Air Force Base
Edwards Air Force Base is a United States Air Force base located on the border of Kern County, Los Angeles County, and San Bernardino County, California, in the Antelope Valley. It is southwest of the central business district of North Edwards, California and due east of Rosamond.It is named in...
on January 20, 1990. Through the orbiter window, LDEF Project staff viewed and took photographs of LDEF at Edwards. With LDEF still in its bay, Columbia was ferried back using a Shuttle Carrier Aircraft
Shuttle Carrier Aircraft
The Shuttle Carrier Aircraft are two extensively modified Boeing 747 airliners that NASA uses to transport Space Shuttle orbiters...
to the Kennedy Space Center
Kennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
on January 26. Special efforts were taken to ensure protection against contamination of the payload bay during the ferry flight.
On January 30–31, LDEF was removed from Columbia
Orbiter Processing Facility
An Orbiter Processing Facility was one of three hangars where U.S. space shuttle orbiters underwent maintenance between flights. All three such facilities, OPF-1, OPF-2 and OPF-3, were located at NASA's Kennedy Space Center in Florida at Launch Complex 39.They were located west of the Vehicle...
, placed in a special payload canister, and transported to the Operations and Checkout Building. On February 1, 1990, LDEF was transported in the LDEF Assembly and Transportation System to the Spacecraft Assembly and Encapsulation Facility - 2, where the LDEF Project team led deintegration activities.
See also
- Materials International Space Station ExperimentMaterials International Space Station ExperimentThe Materials International Space Station Experiment , is a series of experiments mounted externally on the International Space Station that investigates the effects of long-term exposure of materials to the harsh space environment....
- Mir Environmental Effects PayloadMir Environmental Effects PayloadThe Mir Environmental Effects Payload was a set of four experiments installed on the Russian space station Mir from 1996 to 1997 to study the effects of space debris impacts and exposure to the space environment on a variety of materials...