A United Launch Alliance Atlas V rocket, carrying an X-37B experimental robotic space plane, lifts off from launch complex 41 at the Cape Canaveral Air Force Station, Tuesday, Dec. 11, 2012, in Cape Canaveral, Fla.
"The ability to return to Earth carries a high price," Grego said in a statement.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.