Full Description: This illustration depicts the configuration of the Spacelab-2 in the cargo bay of the orbiter. Spacelab was a versatile laboratory carried in the Space Shuttle's cargo bay for scientific research flights. Each Spacelab mission had a unique design appropriate to the mission's goals. A number of Spacelab configurations could be assembled from pressurized habitation modules and exposed platforms called pallets. Spacelab-2 was the first pallet-only mission. One of the goals of the mission was to verify that the pallets' configuration was satisfactory for observations and research. Except for two biological experiments and an experiment that used ground-based instruments, the Spacelab-2 scientific instruments needed direct exposure to space. On the first pallet, three solar instruments and one atmospheric instrument were mounted on the Instrument Pointing System, which was being tested on its first flight. The second Spacelab pallet held a large double x-ray telescope and three plasma physics detectors. The last pallet supported an infrared telescope, a superfluid helium technology experiment, and a small plasma diagnostics satellite. The Spacelab-2 mission was designed to capitalize on the Shuttle-Spacelab capabilities, to launch and retrieve satellites, and to point several instruments independently with accuracy and stability. Spacelab-2 (STS-51F, 19th Shuttle mission) was launched aboard Space Shuttle Orbiter Challenger on July 29, 1985. The Marshall Space Flight Center had overall management responsibilities of the Spacelab missions.