Michael "Rich" Clifford and Linda Godwin wear masks during pre-breathe

STS076-346-017 (22-31 March 1996) --- Astronauts Michael R. (Rich) Clifford and Linda M. Godwin, the assigned space-walking mission specialists for STS-76, go through a "pre-breathing" period on the Space Shuttle Atlantis' middeck. This practice is normal procedure for space-walkers in preparation for their Extravehicular Activity (EVA) and the wearing of their Extravehicular Mobility Units (EMU). The photograph was taken with a 35mm camera by one of the crew members.