[2] STS-9's six-member crew, the largest of any human space mission at the time, included John W. Young, commander, on his second shuttle flight; Brewster H. Shaw, pilot; Owen K. Garriott and Robert A. Parker, both mission specialists; and Byron K. Lichtenberg and Ulf Merbold, payload specialists – the first two non-NASA astronauts to fly on the Space Shuttle.

Commanding the mission was veteran astronaut John W. Young, making his sixth and final flight over an 18-year career that saw him fly twice each in Project Gemini, Apollo, and the Space Shuttle, which included two journeys to the Moon and making him the most experienced space traveler to date.

Young, who also commanded Columbia on its maiden voyage STS-1, was the first person to fly the same space vehicle into orbit more than once.

STS-9 marked the only time that two pre-Shuttle era astronaut veterans (Garriott and Young) would fly on the same Space Shuttle mission.

Also added to the shuttle were higher capacity fuel cells and a Ku-band antenna for use with the Tracking and Data Relay Satellite (TDRS).

[4] The mission's original launch date of October 29, 1983, was scrubbed due to concerns with the exhaust nozzle on the right solid rocket booster (SRB).

Usually, Young and Shaw were assigned to the flight deck, while the mission and payload specialists worked inside the Spacelab.

The Spacelab 1 mission was highly successful, proving the feasibility of the concept of carrying out complex experiments in space using non-NASA persons trained as payload specialists in collaboration with a POCC.

Post-flight analysis revealed the GPCs (General Purpose Computers)[7] failed when the RCS thruster motion knocked a piece of solder loose and shorted out the CPU board.

This allowed NASA to take Columbia out of service for an extensive renovation and upgrade program to bring it up to date with Challenger as well as Discovery and later on Atlantis, which would be delivered in 1985.