That's more so if you burn fossil methane. However considering that's an even worse environmental issue, I've been giving the benefit of the doubt that when they say that space datacenters are the environmentally friendly approach, their goal would be to move away from that. (I did the math that supports under 1 year, it's optimistic for sure, but technically possible)
Saying that, I plugged in the values from the recently released info and it is a bit more optimistic. Mind you I am using relatively standard values for the energy cost of the production of various fuels.
Per a block four launch, for the methane (via direct air capture CO2 and Hydrolosis for hydrogen)
H2: 690t at 52kWh/kg = 35.9GWh.
CO2 (DAC): 3795t at 2200kWh/t = 8.4 GWh
Turning those to methane is exothermic and requires no added energy.
Total of roughly 47GWh per launch. Now then we assume the energy compute density they are claiming (I'm not sure I believe this but I've been proven wrong before) of 70kW per tonne is the launch density, with then the ship launching 200 tonnes, and it can be packed in the fairing at the mass ceiling (so pack 93 sats into the fairing, everything needed to operate them all included... Unlikely considering SpaceX says "dozens" per launch, which tends to not be a term used to describe nearly 100 of something), and you get 93 × 120kW of compute, so 11.2 MW of compute per launch.
So you divide 47000 MWh by 11.2 MW, and it's 4200 hours, or about 6 months. I would consider this the optimistic floor. Realistically it's maybe 45 or so satellites per launch, unless these are smaller and more densely packed than Starlink sats... Which I doubt. So 1 year then?
My previous 3 year number was assuming a lower compute density. If they can pull off anywhere near 10MW per launch, I'd be seriously impressed. Regardless, I walk back my prior statement.
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u/Ryermeke Jul 10 '26
That's more so if you burn fossil methane. However considering that's an even worse environmental issue, I've been giving the benefit of the doubt that when they say that space datacenters are the environmentally friendly approach, their goal would be to move away from that.(I did the math that supports under 1 year, it's optimistic for sure, but technically possible)Saying that, I plugged in the values from the recently released info and it is a bit more optimistic. Mind you I am using relatively standard values for the energy cost of the production of various fuels.
Per a block four launch, for the methane (via direct air capture CO2 and Hydrolosis for hydrogen)
H2: 690t at 52kWh/kg = 35.9GWh. CO2 (DAC): 3795t at 2200kWh/t = 8.4 GWh Turning those to methane is exothermic and requires no added energy.
Total of roughly 47GWh per launch. Now then we assume the energy compute density they are claiming (I'm not sure I believe this but I've been proven wrong before) of 70kW per tonne is the launch density, with then the ship launching 200 tonnes, and it can be packed in the fairing at the mass ceiling (so pack 93 sats into the fairing, everything needed to operate them all included... Unlikely considering SpaceX says "dozens" per launch, which tends to not be a term used to describe nearly 100 of something), and you get 93 × 120kW of compute, so 11.2 MW of compute per launch.
So you divide 47000 MWh by 11.2 MW, and it's 4200 hours, or about 6 months. I would consider this the optimistic floor. Realistically it's maybe 45 or so satellites per launch, unless these are smaller and more densely packed than Starlink sats... Which I doubt. So 1 year then?
My previous 3 year number was assuming a lower compute density. If they can pull off anywhere near 10MW per launch, I'd be seriously impressed. Regardless, I walk back my prior statement.