When we first heard about the Solar Power Satellite via Arbitrarily Large Phased Array (SPS-ALPHA) – a proposed flower shaped solar power energy collector that beams down concentrated microwave energy back to Earth – it sounded absolutely preposterous. Now in a recent interview with Motherboard, John Mankins, a NASA veteran from Artemis Innovation Management Solutions, divulged some more details on exactly how the world’s first practical orbital solar plant will work when it hopefully launches by 2025.
Mankins explains that the SPS-ALPHA is much more approachable than the idea of a solar plant in space first conceived in the 1970s. This new “21st century satellite employs much more efficient solar technology as well as smaller modules that act together like a swarm of ants. The SPS-ALPHA is equipped with a large array of thin-film mirrors to reflect and concentrate sunlight directly onto a central photovoltaic element on the back of the satellite’s array. Once the satellite processes the solar energy, it beams back the energy as microwaves in the form of radio waves.
Back on earth, Mankins says Artemis Innovation Management Solutions will build a massive microwave receiver dish about 3.7 to five miles in diameter, positioned three to six miles above the ground. Despite the collector’s massive size, Mankins says it would barely affect the surrounding wildlife. The dish could even be hung over farmland – like the Arecibo Telescope – without impacting the ecology underneath the dish.
Manikins says the team of scientists considered beaming the energy back to Earth as a higher frequency laser to reduce the size of the transmitter on the satellite and receiver on Earth. But the high frequency blasts could be damaging to eyesight and potentially ignite fires or explosions.
“Think about the Death Star,” Mankins warned in an interview with Motherboard. The risk factor outweighs the seductive, compact grace offered by lasers. After all, nobody wants Earth to go the way of Alderaan.
As for when this project will actually take off, Mankins hopes to rapidly prototype the SPS-ALPHA in three year increments with a fourth generation prototype finally launching in 2025. However, he says there are still many hurdles to face, including developing materials that can cool quickly in space. Nonetheless, the team hopes to reduce the cost of energy down to 10 cents per kilowatt hour—about two cents less than the average US citizen pays.