Spacelab Pallet

Spacelab was a reusable laboratory used on certain spaceflights flown by the Space Shuttle. The laboratory comprised multiple components, and were arranged in various configurations to meet the needs of each spaceflight. Spacelab components flew on a total of 32 Shuttle missions. Spacelab allowed scientists to perform experiments in microgravity in earth orbit.
The Spacelab Pallet is a U-shaped platform for mounting instrumentation, large instruments, experiments requiring exposure to space, and instruments requiring a large field of view, such as telescopes.This particular pallet was flown on three different Space Shuttle missions, aboard three different Shuttle Orbiters: Columbia (STS-35, Astro-1), Endeavor (STS-67, ASTRO 2), and Atlantis (STS-104,ISS 7A) during its final mission to the International Space Station. (FLOWN Artifact)