This is an extract from a piece by a researcher in The Conversation:

Most plans for orbital data centres depend on the future success of SpaceX’s heavy-lift Starship. But every Starship launch burns over 1,000 tonnes of liquid methane, releasing around 80,000 tonnes of CO₂ (about the same as what 20,000 cars emit in a year). The warming associated with soot emissions in the upper atmosphere is 500 times more intense than the same emissions at ground level. We know soot from rockets reduces stratospheric ozone – the stuff shielding us from harmful UV rays. In the lower atmosphere, most soot falls back to Earth in weeks. In the stratosphere, soot stays there for up to four years, prolonging its damaging effects.

While it is always sunny in space, solar panels degrade much quicker there. Microchips are also easily damaged, falling prey to a phenomenon known as “bit flipping” – when high-energy particles rewrite memory hardware randomly changing data from 1 to 0. Retrieving busted hardware from space is not financially viable. SpaceX satellites have a five-year shelf life before being incinerated as they fall back to Earth. The environmental impacts of things burning up in the atmosphere are not well known. Musk’s AI satellites would be connected by lasers. Should any one of the million or so satellites become untethered and collide with another, it would create further debris, creating more risk of collisions, more debris, and so on. Scientists call this the Kesler Syndrome and worry that orbital debris fields could hinder human activities in space for a very long time.

Orbital data centres would have a huge water footprint too. To catch toxic dust and protect their concrete launch pad from heat damage, a typical spaceport uses a deluge system releasing around 2 million litres of water with every launch. SpaceX has repeatedly broken environmental laws with its deluge system, allowing contaminated run-off from Starship launches to enter protected waters off the coast of Texas.

Some suggest these sci-fi schemes are designed to prop up SpaceX’s teetering stock price, rather than humanity’s computing needs. Others see orbital data centres as just one of many ambitious visions to tackle the environmental costs of AI. Either way, my research suggests this quest to off-world the industry’s headaches will have profound implications that are not well understood.

https://theconversation.com/why-ais-environmental-footprint-wont-disappear-into-orbit-287310