Four STS 51-G crewmembers huddle in a corner of the Discovery's middeck area. Daniel C. Brandenstein, mission commander, assists Steven R. Nagel with the treadmill device while John O. Creighton and Shannon W. Lucid look on.

ASTRONAUTS DISCOVERY ORBITER MIDDECK ONBOARD ACTIVITIES TREADMILLS PHYSICAL EXERCISE SPACE SHUTTLE MISSION 51-G

Four STS 51-G crewmembers on Discovery's middeck