In April 1942 a Douglas A-20a bomber, with Major Paul Dane as pilot, took off from Muroc Army Air Force Base (now known as Edwards Air Force Base) using two liquid JATO units. They were designed by the Air Corps Jet Propulsion Research Project, JPL's predecessor, and built by the Aerojet Engineering Corporation, a local company started by several JPLers.
The distance required for takeoff was shortened from 2,320 feet to 1,570 and the time of takeoff from 25.1 to 16.8 seconds.