Space-Based Data Centers Could Power AI with Solar Energy—at a Cost

Data centers in space aren't as wild as they seem

TO Jeremy Xu edited by Eric Sullivan

According to Silicon Valley, artificial intelligence is outgrowing the planet on which it was born. Data centers will be responsible for nearly half of US electricity demand growth until 2030, and their global electricity needs may will double by the end of this decade as companies train larger artificial intelligence models. Local officials began to object to the approval of new server farms that were gobbling up land. mains voltage And a sip of cooling water. Some tech executives are now talking about putting servers in space as a way to avoid those who allow fights.

Orbital data centers can run on virtually unlimited solar energy without interruption due to cloudy skies or darkness at night. The idea is that if it becomes increasingly difficult to continue building larger server farms on Earth, perhaps the solution is to send some of the most energy-intensive computing to space. But such orbital data centers will not become cost-effective unless rocket launch costs will be significantly reduced— and independent experts warn they could have even greater environmental and climate impacts than their Earthly counterparts.

In early November, Google announced Project Suncatcher, which aims to launch solar-powered satellite constellations equipped with custom artificial intelligence chips, with a demonstration mission planned for 2027. Around the same time, startup Starcloud celebrated the launch of a 60-kilogram satellite powered by an NVIDIA H100 GPU as a prelude to an orbital data center expected to require five gigawatts of power by 2035.

About supporting science journalism

If you enjoyed this article, please consider supporting our award-winning journalism. subscription. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping our world today.

These two projects are part of a broader wave of concepts that will take some computing beyond the planet. China has begun launching spacecraft for the Xinshidai “space data center” constellation, and the European Union is exploring similar ideas as part of project known as ASCEND.

“Orbital data centers will benefit from continuous solar power generated by arrays of photovoltaic cells,” says Benjamin Lee, a computer architect and engineer at the University of Pennsylvania. “This could solve long-standing challenges in delivering low-carbon data center computing power.” Most proposals assume that orbital data centers would be in a sun-synchronous dawn-to-dusk orbit, aligned with the boundary between day and night on Earth, so that their solar panels would receive near-constant sunlight and gain an efficiency advantage beyond Earth's atmosphere.

But the same physics that makes orbital data centers attractive also creates new engineering challenges, Lee says. Their computer equipment must be protected from high levels of radiation through shielding or error-correcting software. To cool, orbital platforms require large radiators that can radiate heat into the vacuum of space, adding significant mass that must be launched on rockets.

All of these plans ultimately face one stubborn limitation: getting equipment into space. Rocket launch costs alone pose a major challenge to building large orbital data centers, not to mention the need to replace onboard chips every five to six years. “The costs of launching reusable rockets are falling, but we will still need a very large number of launches to create orbital data centers that will compete with those on Earth,” says Lee. The Google Suncatcher team estimates that startup costs should drop to less than $200 per kilogram by 2035 so that their vision makes sense.

Even if they become economically feasible, orbital data centers may impose additional costs on the world to ensure sustainability. Starcloud estimates that a solar-powered data center in space could achieve 10 times less carbon emissions than a ground-based data center powered by natural gas generators. But researchers from Saarland University in Germany, who published a paper entitledDirty bits in low Earth orbit“calculated that an orbital solar-powered data center could still generate orders of magnitude greater emissions than a data center on Earth, taking into account emissions from rocket launches and the entry of spacecraft components through the atmosphere. Most of these additional emissions come from the combustion of rocket stages and equipment upon reentry,” says Andreas Schmidt, a computer scientist at Saarland University and co-author of the paper. This process produces pollutants that could further deplete the Earth's protective ozone layer.

Astronomers have their own worries. Johnston says that in an ideal sun-synchronous orbit, the orbiting data centers would only be visible in the night sky at dawn or dusk. But Samantha Lawler, an astronomer at the University of Regina in Saskatchewan, notes that some observers rely on twilight to hunt for near-Earth asteroids, and she is wary of any orbital data center with a multi-kilometer array of solar panels. She also worries that such projects could worsen the growing space debris problem as more equipment is launched and more debris and fragments fall back into the atmosphere. “There's already so much pollution from atmospheric entries and pieces falling to the ground,” she says.

At this point, orbital data centers are mostly an idea, a few small prototypes, and a stack of ambitious slides. The basic physics of near-constant sunlight in orbit is real, and launch costs are moving in the right direction. But environmental, astronomical and regulatory issues are pressing. The world will have to decide whether sending hardware into space is a smart way to enhance AI or just a way to hide its side effects.

It's time to stand up for science

If you liked this article, I would like to ask for your support. Scientific American has been a champion of science and industry for 180 years, and now may be the most critical moment in that two-century history.

I was Scientific American I have been a subscriber since I was 12, and it has helped shape my view of the world. science always educates and delights me, instills a sense of awe in front of our vast and beautiful universe. I hope it does the same for you.

If you subscribe to Scientific Americanyou help ensure our coverage focuses on meaningful research and discovery; that we have the resources to report on decisions that threaten laboratories across the US; and that we support both aspiring and working scientists at a time when the value of science itself too often goes unrecognized.

In return you receive important news, fascinating podcastsbrilliant infographics, newsletters you can't missvideos worth watching challenging gamesand the world's best scientific articles and reporting. You can even give someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.