ELI5: Explain Like I'm 5

Spacelab

Spacelab was a laboratory that flew in space on the Space Shuttle from 1983 to 1998. It was like a flying space lab where astronauts could do experiments in space. Astronauts could put special experiments in Spacelab and the experiments would float in the world of zero gravity. They could also do experiments that were impossible to do here on Earth because of the special environment of Spacelab.