Astronauts Tom Marshburn (left) and Christopher Cassidy stand suited and almost ready to participate in the July 24 flight day 10 spacewalk. The two are scheduled to wrap up the EVA work with a fifth overall session on July 27. The mission specialists are part of a 13-member aggregation of astronauts and cosmonauts currently onboard the orbital outpost while its crew of six plays host to Endeavour's crew of seven.