The world's largest aircraft took off over the Mojave Desert in California on Saturday, the first flight for the carbon-composite plane built by Stratolaunch Systems Corp., started by late Microsoft co-founder Paul Allen, as the company enters the lucrative private space market.

The white airplane called Roc, which has a wingspan the length of an American football field and is powered by six engines on a twin fuselage, took to the air shortly before 7 a.m. Pacific time (1400 GMT) and stayed aloft for more than two hours before landing safely back at the Mojave Air and Space Port as a crowd of hundreds of people cheered.

"What a fantastic first flight," Stratolaunch Chief Executive Officer Jean Floyd said in a statement posted to the company's website.