NPR Story
12:39 pm
Fri April 27, 2012

An Astronaut Explores NASA's Scientific Frontiers

Originally published on Fri April 27, 2012 12:47 pm

He's flown the space shuttle five times, and performed eight spacewalks to service the Hubble telescope. Now astronaut and astrophysicist John Grunsfeld heads up NASA's Science Mission Directorate, where he manages scientific investigations on the home planet--and beyond.