Long Duration Exposure Facility
NASA's Long Duration Exposure Facility, or LDEF (pronounced "eldef"), was a cylindrical facility designed to provide long-term experimental data on the outer space environment and its effects on space systems, materials, operations and selected spores' survival. It was placed in low Earth orbit by Space Shuttle Challenger in April 1984. The original plan called for the LDEF to be retrieved in March 1985, but after a series of delays it was eventually returned to Earth by Columbia in January 1990.
LDEF, shortly before deployment, flies on the RMS arm of Space Shuttle Challenger over Baja California. | |
| Mission type | Materials research |
|---|---|
| Operator | NASA |
| COSPAR ID | 1984-034B |
| SATCAT no. | 14898 |
| Website | crgis |
| Mission duration | 2076 days |
| Distance travelled | 1,374,052,506 km (853,796,644 mi) |
| Orbits completed | 32,422 |
| Spacecraft properties | |
| Manufacturer | Langley |
| Launch mass | 9,724 kg (21,438 lb) |
| Dry mass | 3,629 kg (8,001 lb) |
| Start of mission | |
| Launch date | April 6, 1984, 13:58:00 UTC |
| Rocket | Space Shuttle Challenger STS-41-C |
| Launch site | Kennedy LC-39A |
| End of mission | |
| Recovered by | Space Shuttle Columbia STS-32 |
| Recovery date | January 12, 1990, 15:16 UTC |
| Landing date | January 20, 1990, 09:35:37 UTC |
| Landing site | Edwards Runway 22 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Eccentricity | 7.29E-4 |
| Perigee altitude | 473.0 km (293.9 mi) |
| Apogee altitude | 483.0 km (300.1 mi) |
| Inclination | 28.5 degrees |
| Period | 94.2 minutes |
It successfully carried science and technology experiments for about 5.7 years that have revealed a broad and detailed collection of space environmental data. LDEF's 69 months in space provided scientific data on the long-term effects of space exposure on materials, components and systems that has benefited NASA spacecraft designers to this day.