Spacelab. NASA public domain image colelction.

Astronauts Joseph Kerwin (left) and William Lenoir familiarize themselves with equipment aboard the Spacelab mockup during a 1976 visit to the Marshall Space Flight Center. Kerwin and Lenoir were part of an astronaut group briefed on Spacelab subsystems and crew activities by Marshall scientists and engineers. The Marshall Space Flight Center had management responsibility for Spacelab.