WASHINGTON — A U.S. Naval Research Laboratory experiment to capture solar power in space for use on Earth is now in orbit and ready to be tested.

The experiment flew to orbit on May 17 aboard the U.S. Air Force X-37B spaceplane. The technology aboard the plane is a “photovoltaic radio-frequency antenna module” to be tested as part of a comprehensive investigation into terrestrial use of solar energy captured in space, program manager Chris Depuma said May 18 in a news release.

“To our knowledge, this experiment is the first test in orbit of hardware designed specifically for solar power satellites, which could play a revolutionary role in our energy future,” said the principal investigator Paul Jaffe.

The 12-inch square tile module will test whether power can be harvested from its solar panel and transform the energy to a radio frequency microwave. The experiment has been in the works for more than a decade.

The module converts sunlight for microwave power transmission. Depuma said engineers decided to not use optical power transmission because a lot of energy would be lost through clouds and atmosphere.

The Naval Research Laboratory said the results of the experiment could drive the design of a dedicated spacecraft to test the transmission of energy back to Earth. The Pentagon is interested in this technology to provide energy to remote installations like forward operating bases and disaster response areas.

Researchers believe that a space solar system traveling above the atmosphere would catch far more energy than it would be possible on the ground due to the abundant and unimpeded sunlight in space.

One of the concerns is the thermal performance of the hardware. “It’s kind of a tricky problem to have something that’s in direct sunlight all the time and maintain the temperature of the electronics,” said Jaffe.

Solar power satellites could provide energy anywhere in the world, he said. “So a really important component of these kind of satellites would be a device that can convert the sunlight into microwaves or some other form of electromagnetic energy that’s suitable for sending to Earth. Now is the time to test it in space and see how it performs.”

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...