Anchored to the Space Shuttle Discovery's Remote Manipulator System/Orbiter Boom Sensor System foot restraint, STS-121 mission specialist Piers J. Sellers participates in the mission's first session of extravehicular activity. Discovery's vertical stabilizer is at right. A cloud-covered Earth provides the backdrop for the scene.
Anchored to the Space Shuttle Discovery’s Remote Manipulator System/Orbiter Boom Sensor System foot restraint, STS-121 mission specialist Piers J. Sellers participates in the mission’s first session of extravehicular activity. Discovery’s vertical stabilizer is at right. A cloud-covered Earth provides the backdrop for the scene.Image credit: NASA