Built by rocket launch company Stratolaunch, the 500,000-pound plane with a 385-foot wingspan lifted off shortly after 10AM ET from Mojave Air and Space Port in Mojave, California.
It was a critical first test flight for the aircraft, designed to launch rockets into orbit from the air.
The inaugural flight lasted for 150 minutes, according to the company, after which the plane safely landed.
During the first phase of the flight, Stratolaunch tested the airplane’s handling qualities.
Update April 13th 2:20PM ET: The article has been updated to reflect that the Stratolaunch plane safely landed after its inaugural flight with executive comments from a press call.