Enlarge / The Falcon Heavy rocket took off at 3:45pm ET Tuesday, Feb. 6, with all 27 engines firing. (credit: Trevor Mahlmann for Ars Technica) When SpaceX debuted the Falcon Heavy rocket in February, one of the biggest questions concerned who, exactly, would use the large booster and its 27 engines. Now we have an answer: the US Air Force, which on Thursday announced that it had selected the Falcon Heavy to launch its Air Force Space Command-52 satellite. The military launch is presently scheduled to occur in September 2020 from Kennedy Space Center in Florida.