During the course of testing , Engle earned his USAF astronaut wings , a Distinguished Flying Cross and other awards .
Engle helped to flight test the joint NASA - Air Force X-15 rocket airplane .
During the course of testing , Engle earned Engle 's USAF astronaut wings , a Distinguished Flying Cross and other awards .
Engle helped to flight test the joint NASA - Air Force X-15 rocket airplane .