In this historical photo from the U.S. space agency, the pale blue Earth serves as backdrop for astronaut Michael Gernhardt during his Extravehicular Activity (EVA). He is standing on a Manipulator Foot Restraint (MFR) attached to the Remote Manipulator System (RMS).
He is positioned over the Payload Bay and Endeavour's forward section is reflected in his visor. A thermal cube is attached to the RMS and records temperatures during spacesuit evaluations. Unlike earlier spacewalking astronauts, Gernhardt was able to use an electronic cuff checklist, a prototype developed for the assembly of the International Space Station (ISS).
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).