Two weeks after completing taxi tests, Boeing’s Phantom Eye, the liquid-hydrogen powered unmanned airborne system, took to the skies Feb. 25 for its second flight at NASA’s Dryden Flight Research Center at Edwards Air Force Base, Calif.

The flight lasted 66 minutes, reaching an altitude of more than 8,000 feet and a speed of 62 knots.

“The first flight was pretty incredible, because it proved that the technology and our design worked, but this second flight is a major step closer to bringing Phantom Eye to the market, providing the customer with a capability that has never been available before,” said Drew Mallow, Phantom Eye program manager.

Phantom Eye is designed to stay airborne for up to four days at 65,000 feet providing intelligence, surveillance, and reconnaissance capabilities to support a variety of missions.

Phantom Eye is self-funded by Boeing as a contender in the Air Force’s preliminary search for a high-altitude, long-endurance drone. Boeing has billed the plane as a surveillance aircraft or an alternative to expensive communications satellites.

It’s designed to carry a 450-pound payload for up to four days at an altitude of 65,000 feet. Boeing was gentle on Phantom Eye in the latest flight, sending it to an altitude of about 8,000 feet for 66 minutes, according to the press release.

The plane is propelled by two wing-mounted engines adapted from those in Ford Ranger pickup trucks. The engines run on liquid hydrogen and oxygen, and give off water as exhaust.

Ultimately, Boeing hopes to build a larger, operational version with a wingspan of 250 feet and a 2,000-pound payload capacity.

For a more in-depth look at Phantom Eye watch this video from Boeing’s Innovation Series.