Shuttle Challenger deploys LDEF satellite

In April 1984, the shuttle Challenger deployed an unusual object named LDEF, for Long Duration Exposure Facility, into low Earth orbit. The satellite, a twelve-faced cylinder weighing nearly 9,700 kilograms, was equipped with 57 different scientific experiments.

LDEF's mission and timeline

Its mission was to expose materials and living organisms to the extreme conditions of space, then return them to study the effects of the vacuum, radiation, and thermal variations. The original schedule was for the satellite to remain in orbit for ten months, or a year at most.

Retrieval delayed by Challenger disaster

However, the retrieval, first set for March 1985, was postponed once to 1986. The story abruptly changed when the Challenger shuttle exploded in January 1986, which halted the entire American manned flight program for several years.

LDEF remains in orbit for years

The retrieval of the satellite was indefinitely postponed due to the lack of a shuttle available to retrieve it. As a result, LDEF remained in orbit for 69 months instead of 10, completing 32,422 full revolutions around Earth. Its altitude gradually decreased due to the residual friction of the upper atmosphere.

Tomato seeds carried on the mission

Among its cargo were 12.5 million Rutgers tomato seeds, carried as part of the SEEDS project, a collaboration between NASA headquarters, Langley Research Center, and the seed company George W. Park Seed. These seeds were distributed in 132,000 kits to 3.3 million students across every U.S. state and about thirty foreign countries.

Germination results show minimal differences

Preliminary results of this experiment showed a germination rate of 73.8% for the space seeds compared to 70.3% for the Earth seeds, with a nearly identical average germination delay of 8.0 days compared to 8.3 days. The final results confirmed these findings, with students reporting only very minor visible differences between their two rows of seedlings.

Concerns over radiation-induced mutations raised

In April 1990, the Los Angeles Times revealed the existence of an internal memo written by a NASA subcontractor based in Oklahoma. The document mentioned a minimal possibility that radiation-induced mutations could cause the plants to produce toxic fruits.

NASA dismisses safety concerns

NASA responded by stating that there was no validity to the idea of a danger to students. Jim Alston, research director at Park Seed Co. in South Carolina, confirmed that radiation counters detected absolutely nothing abnormal upon the return of the seeds to Earth.

Controversial memo and mission legacy

The alarming memo, which targeted 120,000 kits distributed to 58,000 teachers, was ultimately refuted, but it remained a notable point in the mission's history. The satellite's extended orbit and the tomato seeds' journey highlight the unpredictable nature of space exploration, even in its most educational missions.

Space-exposed seeds perform similarly

The seeds exposed to space grew just as well, if slightly better, than their Earth-bound counterparts.