STS-51-D

During STS-51-D, the shuttle crew deployed two communications satellites: Telesat-I (Anik C1) and Syncom IV-3 (also known as Leasat-3). Discovery's other mission payloads included the Continuous Flow Electrophoresis System (CFES) III, which was flying for sixth time; two Shuttle Student Involvement Program (SSIP) experiments; the American Flight Echo-cardiograph (AFE); two Getaway Specials; a set of Phase Partitioning Experiments (PPE); an astronomical photography verification test; various medical experiments; and "Toys in Space," an informal study of the behavior of simple toys in a microgravity environment, with the results being made available to school students upon the shuttle's return.