Many years ago, in Galaxy magazine, Jerry Pournelle devoted his A Step Farther Out column to describing how satellites could be used to harvest solar energy on a scale impossible underneath Earth’s atmosphere.
The idea never really went away, but it’s been mostly out of the spotlight. Now, Reuters is reporting a study by the International Academy of Astronautics (IAA) which touts orbital power as being technically feasible.
NASA’s former head of concepts John Mankins (now head of Artemis Innovation Management Solutions of California) is quoted as saying “solar power derived from space could play a tremendously important role in meeting the global need for energy during the 21st century” (“could” simultaneously meaning “if someone finds the money”, “if the engineering is as feasible as we think it is”, “if we don’t have a disaster that fries someone Earth-side”, and “if some whacko protest movement doesn’t run up a handy conspiracy theory to bring an end to the whole idea” - El Reg).
Certainly the engineering challenges would be formidable: power would be transferred from satellites to Earth as very high-powered microwave signals to be captured by a network of large antennas.
The satellites, at around 1km across, would be too large to be launched in one shot, so they would need to be assembled in space (the IAA report recommends using low-cost reusable launchers in the long term, with part of the budget for this idea to be spent on spaceship development). And as has been clear ever since Pournelle discussed the idea, control over the satellites and the power-carrying beam would need to be very precise.
Mankins told Reuters a moderate scale demonstration could be accomplished “for tens of billions of dollars less than previously projected”.
The advantages are that in addition to getting much more sunlight than is available under the atmosphere, the “solar satellites” could – space junk permitting – be positioned to operate 24 hours a day.
The 248-page study took two years to complete. ®