Two astronauts prepare to leave Discovery's airlock for a spacewalk during STS-63 in 1995.
In this historical photo from the U.S. space agency, STS-63 astronauts Bernard A. Harris, Jr., payload commander (right), and C. Michael Foale, mission specialist (left), are ready to exit Discovery's airlock for a spacewalk.
The pair would test new insulation to protect astronauts from the cold during extravehicular activity, but the Mission Control cut their spacewalk short after the men reported feeling very cold in their suits. On this EVA, Harris became the first African American to walk in space.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).