Apogee: 211 km (131 mi).

The Space Radar Laboratory (SRL) was a pallet of equipment mounted in the space shuttle payload bay to (1) acquire radar imagery of the Earth's surface for studies in geology, geography, hydrology, oceanography, agronomy, and botany; (2) gather data for future space-borne radar systems including Earth Observing System (EOS); and (3) provide measurements of the global distribution of carbon dioxide (CO2) in the troposphere. Instruments on board included the Shuttle Imaging Radar-C (SIR-C) with multi-frequency (C- and L-Bands), multi-polarization (HH, VV, HV, VH), and multi-incidence angle (15 to 55 degrees) capabilities thus lending itself to a wide range of earth surface applications; the X-band Synthetic Aperture Radar (X-SAR), an X-band, VV-polarized imaging radar system, built by Dornier (Germany) and Alenia (Italy) for the German Space Agency (DARA)/German Aerospace Research Establishment (DLR) and the Italian Space Agency (ASI); and, the Mapping Air Pollution from Space (MAPS) for the study of global air pollution. Also, on-board the SRL, was an ocean wave spectra processor, designed and built by Johns Hopkins Applied Physics Laboratory, which collected data on ocean surface wave length, direction, and height.