Launch from Cape Canaveral (KSC); landing on Edwards AFB.

First mission of orbiter "Discovery". Planned launch was delayed twice because of a variety of technical problems, including rollback to the VAB to replace a main engine.

Deploying of communications satellites SBS-D (USA), Telstar 3-C (USA) and Syncom IV-2/Leasat 2 (US Navy); solar wing (31 m) was extended from payload bay. The wing carried a number of different types of experimental solar cells and was extended to its full height several times. It was the largest structure ever extended from a manned spacecraft and demonstrated the feasibility of large lightweight solar arrays for future application to large facilities in space such as the Space Station.

Walker was the first commercially-sponsored payload specialist to fly aboard the Shuttle. He worked on the Continuous Flow Electrophoresis System .