Follow along on NASA TV and the agency's website for the live launch broadcast, happening now. Before NASA's Pegasus XL rocket can carry the agency's ICON satellite to low-Earth orbit, Northrop Grumman's L-1011 Stargazer aircraft has to reach an altitude of 39,000 feet, which requires about an hour of flight time. Once there, Pegasus will …
ICON Launch Countdown Continues
