by The idea of transporting power to an energy-starved Earth from space has long been studied. It was first suggested over 80 years ago in science fiction.
“It was quiet in the officer’s room in Solar Station #5 – except for the soft purring of the powerful Beam Director somewhere far below,” wrote famed author Isaac Asimov in his April 1941 story “Reason” appearing in the “Astounding Science Fiction” magazine. .”
Asimov had his characters tending a solar energy collection station in space that sent energy rays to receivers Worldas well as Mars. Fast forward to the 21st century, and investigations here on Earth and now in space seem to strengthen the concept. Still, space Some see solar power beaming as a far-fetched technology, an economically dubious concept that makes for good science fiction. Space.com caught up with a few technologists to ask them what’s new, what’s old and what’s still missing when it comes to transmitting power to Earth from space.
Related: Scientists have brought solar power to Earth from space for the 1st time ever
Three technologies
Caltech’s Space Solar Power Project (SSPP) is seen by some as a beacon of hope for technology.
More than a year has passed since the SSPP demonstrator technology was launched into the test bin in Earth orbit. While in orbit, the SSPD-1 spacecraft tested three technological innovations designed to help swing the solar-powered space needle closer to full reality. They were:
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DOLCE: Orbit Deployable UltraLight Composite Experiment to demonstrate new packaging and deployment scheme.
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SCOTLAND: 32 different types of photovoltaic (PV) cells to find out how they stand up to the harsh space environment.
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MAPLE: MICROWAVE ARRAY FOR POWER TRANSFER Low Orbit Experiment based on custom integrated circuits with precise timing control to selectively direct power to two different receivers to demonstrate wireless power transmission far in space.
Take it to the limit
“Many things worked, and the things that worked well we pushed them until they stopped working,” said Ali Hajimiri, co-director of the Caltech Space-based Solar Power Project.
Hajimiri is focused on integrated circuits and their applications in various disciplines, such as biotechnology, communication and sensing, covering a wide range of frequencies from high-speed and radio frequency to high-precision low-frequency circuits.
Yes, Hajimiri pointed out, there were high points over SSPD-1’s nine-month mission. “We had a literal snag in the deployment, but the team worked it out. Even in the wireless energy transfer, we had all kinds of situations. Then we really stressed the system towards the end of the mission – to the point where we tried to do damage actively.”
Roof construction
On May 22, 2023, the payload for SSPD-1 literally hit the roof atop Caltech’s Gordon and Betty Moore Engineering Laboratory. For 90 seconds, the spacecraft’s MAPLE hardware beamed down energy to Earth captured in space.
Hajimiri quickly explains that the level of energy found at the roof level was ultra-small. It was mostly about detection, he said, but the real buzz was to consider the small amount of energy gained as one small step for space solar power.
SSPD-1 is soon to be decommissioned and left to go into a destructive disaster The Earth’s Atmosphere.
The project’s attention is now focusing on solving issues such as scaling, enabling autonomous deployment, and developing lighter structures.
Things unknown
“There are a lot of ‘unknown unknowns’ that still need to be figured out,” Hajimiri said. At this stage of the work the team is looking at manufacturing processes for fabric-like and low-cost arrays. Also, timing synchronization is very challenging, especially on a flexible and floppy structure that is running in space.
“We’ve developed new ways of thinking about this problem,” Hajimiri said, “ways in which an array can determine its own shape and make corrections to that through its electronics.”
Even with SSPD-1’s ‘goodbye and so far’ status, a series of valuable milestones have been achieved, Hajimiri said. “The biggest challenge is to raise awareness and make the case clear that what we did is true.”
A scalable solution
There is no clean, reliable, navigable energy technology other than Space Based Solar Power (SBSP) according to Troy, Virtus Solis Technologies Inc.
John Bucknell is the CEO and founder of the group. “Those of us who have compared all the viable energy technologies know that a scalable solution must be low complexity, low mineral intensity, manufacturing mass and able to deliver stable, safe, low cost e-power as fuels recent fossil. 200 years,” he said.
Bucknell and his colleagues are piloting an SBSP system that will meet all those criteria—a constellation of 16 arrays in space that each pump out 20 gigawatts of power. Together, 320 gigawatts can be delivered to anywhere on the planet, he said, a scalable system to be much larger.
“With a 50 percent year-over-year growth in capacity, SBSP could get up to 100 terawatts of generation in 30 years and satisfy the needs of a planet with a population of 10 billion,” said Bucknell.
Disconnect
“There is still a disconnect between academic studies and studies of aerospace prime manufacturing costs and what private industry can achieve,” Bucknell believes. “As a result, our forecast of $200 million to complete the research and development and get a functioning pilot plant into orbit seems incredible.”
For Bucknell’s money, and investors as well, it’s the energy industry that needs to hear and understand these options, he suggested, rather than the space industry.
“SBSP still seems like science fiction because they don’t know that all the basic technologies have matured and they need a commercial space launch to get there. Virtus Solis was the first to incorporate around this opportunity,” said Bucknell, “designed from the ground up to target costs to address the global energy market.”
Investors want to see no risk to income, according to Bucknell. “An orbital demonstration means you have a real product, so the remaining risk of on-orbit assembly and power transmission is demonstrated and then the product can scale.”
Standing room only
John Mankins of Artemis Innovation Management Solutions in Santa Maria, California, is a leader in harnessing solar energy from space.
Mankins participated in the April International Conference on Solar Energy from Space hosted by the European Space Agency (ESA) and the UK Space Agency at the Royal Aeronautical Society in London.
“It was standing only,” Mankins recalls. “Almost none of the 200 people were regular players, and that was a big change,” say Chinese researchers working on space-based power plant technology for Europe’s SOLARIS initiative. There is ongoing work in the UK, as well as a progressive look at power beaming in Japan and other countries, he said.
Reusable readiness
Mankins said the foundations for power beaming have been laid repeatedly by experiments on the ground. “For me, power beaming was demonstrated as a function decades ago,” he said, “and now the real issue is how to make large systems.”
For any kind of mega project in space, “the most visible obstacle to space solar power seems ready to fall,” Mankins suggested, and that is low-cost reusable launchers.
A reusable rocket has been pioneered by SpaceX and its Falcon-class boosters and now the giant Starship flight program. The same, Blue OriginThe New Glenn launcher is nearing its first flight. Other nations are pursuing reusable readiness in the booster business, such as ESA and China.
Power up
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— Space-based solar power could be one step closer to reality, thanks to this key test (video)
— Japan’s satellite will beam solar power to Earth in 2025
However, there is work to be done in the coming years.
Referring to the future, Mankins said that systems-level demonstrations can address issues such as finding the right design, or determining how well the technologies can scale and at the price. It is also vital for spacecraft engineers to see what is happening rapidly in robotics here on Earth and apply it to construction in space.
In addition, power beaming from space must go beyond Caltech’s nanowatts per square centimeter experiment to microwatts per square centimeter, Mankins suggested.
“But in 2-3 years a thousand times more power. There is going to be incredible progress,” according to Mankins, “then the cows are out of the barn.”
