NASA administrator Sean O'Keefe lays a wreath at the Space Shuttle Challenger Memorial January 28, 2003 at Arlington National Cemetery in Virginia. The Challenger exploded shortly after take-off January 28, 1986, killing the entire crew. They are: Michael Smith, Ronald McNair, Ellison Onizuka, Judith Resnick, Dick Scobee, Greg Jarvis and Christa McAuliffe. O'Keefe also used the occasion to remember the crew of Apollo 1, Roger Chaffee, Ed White and Gus Grissom, who died in a fire on the launch pad on January 27, 1967. (Photo by Bill Ingalls/NASA/Getty Images)