When the X-37B launches on May 16, it will carry a technology that could eventually allow drones to stay aloft indefinitely anywhere on the globe.
The shadowy X-37B, the Air Force’s unmanned, reusable spacecraft, is set to launch for its sixth flight on May 16 from Cape Canaveral Air Force Station, Florida. While most of the payloads set for the flight are standard fare for space experiments, at least the ones that are disclosed, one of them has immense potential implications for the future of remote power generation and especially long-endurance unmanned aircraft propulsion.
The X-37B’s upcoming mission is known as both Orbital Test Vehicle-6 (OTV-6) and U.S. Space Force-7 (USSF-7). It will carry out missions that will assess the effects of cosmic radiation and other “space effects” on plant seeds and various material samples. According to a Space Force press release, which went out on May 6, another payload aboard the X-37B will be an experimental system designed by the Naval Research Laboratory that is capable of capturing solar power and beaming that energy back to Earth in the form of microwaves.
While the press releases of the Department of Defense and the Space Force are scant on details, the Naval Research Laboratory’s head of beamed power has explicitly stated in the past that this system has enormous implications when it comes to long-endurance unmanned aerial vehicles (UAVs). In addition, it could allow satellites to provide reliable power anywhere on the planet or even to spacecraft or other satellites in orbit.
The U.S. Naval Research Laboratory (NRL) has been promoting similar-sounding technologies over the last year. In October 2019, the NRL conducted a three-day long demonstration of the Navy’s latest power-beaming capabilities at the Naval Surface Warfare Center in Bethesda, Maryland. In the demonstration, the NRL transmitted a completely silent, invisible beam of 2-kilowatt laser power over 300 meters through the air over attendees’ heads. The demonstration was meant to showcase the safety and technological readiness of this utterly transformative concept.
As far as the aforementioned applications of this capability, research or military outposts in remote locations would no longer have to rely on low-power solar systems or haul heavy generators and large amounts of fuel, but instead could bring a rectifying antenna, or rectenna, to capture energy in the form of microwaves beamed from satellites overhead. In addition, areas ravaged by natural disasters could use the system to generate electricity to aid in reconstruction efforts long before traditional electrical infrastructure is rebuilt. It could even power autonomous ships at sea.
Dr. Paul Jaffe, an electronics engineer with the U.S. Naval Research Laboratory who is leading the NRL’s research into power beaming, says that the technology will open up entirely new frontiers in terms of long-endurance unmanned aircraft. “If you have an electric drone that can fly more than an hour, you’re doing pretty well,” Jaffe said. “If we had a way to keep those drones and UAVs flying indefinitely, that would have really far-reaching implications. With power beaming, we have a path toward being able to do that.” The Navy was granted a patent for a similar system in 2016 invented by Jaffe.
Using lasers to beam power to small UAVs has been a subject of research for some time. The U.S. Air Force began testing lasers as a source of propulsion for small “lightcraft” as early as the 1980s and managed to get small cone-shaped craft to fly hundreds of feet in the air propelled only by laser beams. This new concept is different, though, in that the beamed power UAVs the Navy envisions will feature traditional propulsion systems (such as rotors or propellers) and instead have rectennas that capture the energy from directed energy beams to constantly replenish their electrical power reserves.