The MRPV (Multi Research Payload Vehicle) was a satellite designed to carry out 21 experiments for the USAF. These experiments were mounted on both the front end and the aft payload rack of the Agena-D upper stage and were not intended to be separated from it. Procured through the Corona program reconnaissance satellite initiative, the MRPV was designated as Corona 99. Among the experiments carried were investigations into night air glow, ionospheric properties, plasma frequencies, erosion, magnetism, cosmic rays, electrical potentials, horizon sensing, fuel cells, radiometry, radio frequencies, and various biological studies.