Musk responds to doubts about heat dissipation for space AI data centers: aluminum radiators facing away from the sun can reach about 1,300 watts per square meter
Musk responded to doubts about heat dissipation for space AI data centers, saying that aluminum radiators facing away from the sun and toward deep space can achieve a thermal radiation power of about 1,300 watts per square meter, with orientation and material being key. Previously, OpenAI CEO Sam Altman said that putting data centers in space is currently absurd, and Jan Broersen, a professor at Utrecht University, also believed that vacuum can only dissipate heat through radiation and that space data centers are almost impossible to build. The media outlet noted that 1,300 watts per square meter is still a performance claim put forward by Musk, with no on-orbit measured results provided.
Body · AI translation
On November 4, tech media outlet Wccftech published a blog post yesterday (November 3) reporting that, in response to the controversy over heat dissipation for space-based AI data centers, the world's richest person, Elon Musk, said that an aluminum radiator facing away from the sun can achieve a thermal radiation power of about 1,300 watts per square meter.
Citing the blog post, the report explains that this heat dissipation controversy centers on a seemingly counterintuitive question: space is very cold, so why is it still difficult to cool equipment? Some commenters pointed out that the vacuum environment lacks air convection, and equipment must mainly rely on thermal radiation to expel heat, thus questioning the feasibility of orbital data centers.
In an interview with The Indian Express in February this year, OpenAI CEO Sam Altman said that "under the current circumstances, the idea of putting data centers in space is absurd." But he believes that in the long run, deploying AI computing power in space is worthwhile, adding: "Within this decade (through 2030), orbital data centers will not be used on a large scale, but they will become possible in the future."
Jan Broersen, a professor at Utrecht University in the Netherlands (@broudsov), posted on X on November 2, arguing: "Vacuum is the best insulation environment. In space, heat dissipation can only rely on radiation. Space data centers are almost impossible to build (and of course, we certainly won't see them in our lifetime)."
Musk responded that an aluminum radiator facing away from the sun can achieve a thermal radiation power of about 1,300 watts per square meter; the orientation and material of the radiator are key, and if it faces away from the sun and toward deep space, it can reduce the heat input from solar irradiation.
According to Musk's statement, one can imagine an electric heater operating continuously at 1,300 watts; a 1-square-meter radiator would need to continuously expel heat equivalent to what it generates. The difference is that an electric heater releases heat in a room, while a satellite radiator expels heat outward through thermal radiation. Over one continuous hour, it expels heat corresponding to about 1.3 kilowatt-hours of electricity: converted at 1,300 watts, a 1-square-meter radiator operating for 1 hour can expel about 1.3 kWh of heat.
However, the media outlet pointed out that 1,300 watts per square meter is still a performance claim put forward by Musk, and the report did not provide on-orbit measured results. Radiative heat dissipation capability is also related to factors such as surface temperature, emissivity, and area, and cooling effectiveness cannot be judged merely from the coldness of deep space.
The power density of solar panels is about 250 W/m², so their area should be about 5 times that of the radiator. Most of a satellite's mass comes from the solar panels.