Meet Ravn X—a fully autonomous, air-launched rocket for small satellites
The company is named Aevum, and until now it has largely operated in the background. But now, it’s ready to show off some hardware, and it’s starting with the “Ravn X” launch system’s first stage. This autonomous aircraft and launch vehicle measures 24 meters long and has a wingspan of 18 meters. It has a gross takeoff mass of 25,000kg—massive for an uncrewed aerial vehicle.
Also, Ravn X looks really slick. Without a pilot on board, the drone can pull significantly higher g-loads and steeper ascent trajectories as it releases a rocket at altitudes between 10 and 20km.
“We claim that our aircraft is a first stage because it actually contributes delta V,” Jay Skylus, Aevum’s founder and CEO, said in an interview with Ars.
A physicist by training, Skylus founded Aevum in June 2016 after a few years at NASA and several commercial space companies, including Boeing and Firefly Aerospace. His company presently has about 180 full-time employees and has so far conducted about five rounds of Angel investment fundraising. It is aiming to launch its first orbital mission in 2021.
Launching with an airplane-like first stage is the key to developing truly responsive launch, he said, because planes can take off in varying weather conditions from multiple locations. The Ravn X first stage, he said, can fly from any 1-mile runway.
However, existing air-launch systems—Northrop Grumman’s Pegasus booster and Virgin Orbit’s LauncherOne vehicle—actually start with negative delta V, despite releasing their rockets at an altitude of about 10km, Skylus said. This is because after the rocket is released from the aircraft, it takes several seconds for the plane’s pilots to pull away to a safe distance, and by the time the rocket ignites its engines, it is accelerating back toward Earth.
“When you do that analysis, you end up finding that ground launch is superior to any kind of piloted air launch platform,” Skylus said. “We thought no way this is going to work. There was not a solution that was sustainable. The physics did not favor this, so we have to come up with something else.”
This led the company to its concept of an autonomous first stage. After its unveiling, this vehicle will begin a test flight campaign, with taxi testing, full avionics integration, a flight termination system, and more. This first model will serve as a “workhorse” for the test campaign, and Skylus said the plan is to bolt its engines onto a second airframe for a launch campaign.
Testing rocket engines
Even as it has finalized the Ravn X first stage, Aevum has been developing a rocket capable of delivering 100kg to about 500km Sun-synchronous orbit. This rocket has two liquid-fueled engines for its main stage, each with 5,000 pounds of thrust and a single upper-stage engine. These engines have been hot-fire tested beyond their full duration burns, Skylus said, and have gone through qualification and acceptance testing.
Both Ravn X and the launch vehicle use Jet-A fuel, which is available at nearly all US airports, for propellant. Compared to RP-1, this causes a 1 to 2 percent performance penalty on the rocket engines, but the key is to provide a response capability. “We did not want to be in a position where we had to have fuel delivered,” Skylus said. Initially, the company will fly missions from Cecil Spaceport, which is managed by the Jacksonville International Airport.
The US military definitely seems interested in the concept. Lt. Col. Ryan Rose, chief of the Space and Missile Systems Center’s Small Launch and Targets Division at Kirtland Air Force Base in New Mexico, attended Thursday’s rollout. She described the company’s efforts as “bold” and “innovative.”
Moreover, Aevum claims it has secured launch contracts worth more than $1 billion over the next decade, including the Air Force’s ASLON-45 mission, which is currently targeted for Ravn X’s first launch.