The world's largest aircraft, whose wingspan is almost as long as a football field, has completed its very first flight.
The twin-engined six-engine stratolaunch with a 117-meter wingspan flew over the Mojave Desert in California for two hours, reaching a top speed of 189 mph.
The jet hit heights of up to 17,000 feet and landed safely at the Mojave Air and Space Port.
Jean Floyd, CEO of Stratolaunch, called the fear a "fantastic first flight".
She added that the plane had made a "spectacular" landing and said it was amazing "to see this majestic bird flying".
The jet can release rockets from the middle of its huge wings.
Stratolaunch was founded in 2011 by the late Microsoft co-founder Paul Allen.
The company is vying to make access to orbit more accessible and "as routine as a commercial flight is caught today," claims its website.
"We all know that Paul was proud to testify to the historical achievement of today," said the deceased billionaire's sister, Jody Allen.
"The aircraft is a remarkable technical achievement and we congratulate everyone involved."