USA Today: NASA and Northrop Grumman recently unveiled two unmanned drones that will be used for atmospheric research. One of the two Global Hawks, a version of the Air Force's top-of-the-line unmanned spy plane, will be outfitted with science instruments this spring and conduct its first earth science mission in June for NASA.

The planes, which are capable of staying aloft for more than 30 hours, will sample greenhouse gases responsible for ozone depletion and verify measurements by NASA's Aura atmosphere research satellite.

"It's a whole new ballgame for us," said project scientist Paul A. Newman of NASA's Goddard Space Flight Center.