LDEF
Long Duration Exposure Facility

NASA's Long Duration Exposure Facility (LDEF) was designed to provide long-term data on the space environment, including micrometeoroids, and its effects on materials degradation and satellite systems (including power, propulsion, and optics). The mission's 57 experiments included participation of more than 200 principal investigators from 33 private companies, 21 universities, seven NASA centers, nine Department of Defense laboratories and eight foreign countries. LDEF was released from STS 41-C in April 1984 for a planned one year mission before retrieval by another Shuttle mission. Its planned retrieval was temporarily postponed in March 1985, and then indefinitely postponed by the loss of the Challenger in 1986. It was finally retrieved by STS-32 in January 1990 and returned to Earth. At the time of its retrieval LDEF was about one month away from reentering the Earth's atmosphere. Many of the experiments were enhanced by the extended stay in space. After landing, the experiments were returned to the investigators' institutions for analysis.

Spacecraft
Twelve-sided aluminum, steel, and titanium cylinder. Gravity gradient stabilized. Viscous magetic damper to damp out initial oscillations. No telemetry, power, or propulsion systems. No attitude sensors.

Payload
57 materials, electronics, and micrometeoroid experiments mounted in 86 trays on the outside of the vehicle.

Country of Origin	United States
Customer/User	NASA
Manufacturer(s)	NASA Langley Research Center
Size	9.1 m long x 4.3 m diameter
Orbit	Initially 476 km, incl. = 28.4 deg
Design Life	1 year
Related Sites	LDEF Archives at Langley Research Center

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
LDEF	1984-034B	4/6/84	ESMC	STS 41C	LEO	3625
Long Duration Exposure Facility; deployed from STS 41C 4/7/84; retrieved by STS-32 1/20/90