Christina M. Hammock, one of the eight-member 2013 class of NASA astronaut candidates, speaks to a special media-day crowd at the Johnson Space Center.
JSC2013-E-076195 (20 Aug. 2013) — Christina M. Hammock, one of the eight-member 2013 class of NASA astronaut candidates, speaks to a special media-day crowd at the Johnson Space Center’s Space Vehicle Mock-up Facility on Aug. 20. Photo credit: NASA