Prince Philip, left, speaks with veteran space walkers John M. Grunsfeld, center, and Michael J. Massimino at NASA's Goddard Space Flight Center. Photo Credit: (NASA/Chris Gunn)
Prince Philip, left, speaks with veteran space walkers John M. Grunsfeld, center, and Michael J. Massimino at NASA's Goddard Space Flight Center. Photo Credit: (NASA/Chris Gunn)