The Plasma Diagnostic Package (PDP) spacecraft was designed and built in the Department of Physics and Astronomy at the University of Iowa under the direction of Prof. Stan Shawhan. The spacecraft was originally flown on the space shuttle Columbia in March 1982 as part of the OSS-1/STS-3 mission, and was the first object to be grappled and manipulated by the remote manipulator system (RMS), the robotic 'arm' on the shuttle. After the successful mission in 1982, the PDP was re-flown on the space shuttle Challenger STS-51F mission in July 1985. During the 1985 mission, the RMS removed the PDP from the shuttle bay and released the PDP into Earth's orbit; the crew then manuevered the shuttle around the spacecraft before the RMS re-captured the spacecraft, secured it in the shuttle bay.