29th April

On April 29, 1985, the European Space Agency’s Spacelab launched on the space shuttle Challenger on mission STS-51B. This was the second time the Spacelab went to space and the first time it flew in a fully operational configuration.¬†

Spacelab pallets had flown to space on three previous shuttle missions, but this was the first time that the entire laboratory was used to conduct research in microgravity. Spacelab provided a platform for five fields of research: astronomy, atmospheric physics, materials science, life science and fluid dynamics. 

The lab was shaped like a cylinder and measured about 23 feet long, or about the length of a short school bus. The pressurized module was housed in the shuttle’s cargo bay. Seven astronauts, two monkeys and 24 rodents launched with Spacelab during STS-51B. After spending a week doing research in space, they landed safely at Edwards Air Force Base.

Source: https://www.space.com/39251-on-this-day-in-space.html