**FILE** Dr. Jon Clark, husband of space shuttle Columbia astronaut Laurel Clark, poses near a sign in honor of the seven astronauts killed in the shuttle accident in a Thursday, March 6, 2003 file photo. Female astronauts make "more sacrifices than the 'Right Stuff' guys," said Clark. "They have to balance two careers _ to be a mom and wife and an astronaut. "(AP Photo/David J. Phillip, File)