this post was submitted on 08 Sep 2023
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Sorry, I wasn’t exactly bee-ing nice last night.
SLS takes off from Earth, but that doesn’t mean successor Hydrogen rockets will, and that doesn’t mean that the Hydrogen has to come from Earth once space infrastructure is in place.
By tackling challenges with hydrogen storage and transport, SLS is an investment in our future and in other parts of the green hydrogen economy. Hydrogen is very small and leaks. This is one of the biggest technical challenges wherever hydrogen is used. NASA overcomes technical and engineering challenges on large scales. Investment in hydrogen rockets is investment in green energy for the future.
Major benefits of NASA and space travel come from challenging ourselves to do things the “right” and “hard” way. Tackling these hard challenges provides technology that improves life and jumpstarts the economy across many sectors.
Going cheap-and-dirty and cutting corners is potentially dangerous for those using the cheap rockets, uses up underground organic reserves that are vital to ecosystems, and promotes a “throwaway” culture.
I should have challenged myself to reply to you the “right” and “hard” way instead of being dismissive and rude.
Thank you for writing this response. My general thoughts on hydrogen for rocketry have been that it doesn't seem worth the trouble (temps, leaks, storage, etc), but I hadn't considered the environmental or future angles. I'm not convinced that it's the right choice now, but thanks for giving me something to think about.
The really annoying thing about hydrogen is that it's most useful once you're already in space, where the density and thrust of the fuel doesn't matter so much and insulation is generally easier. Since all our rockets so far are built and launched from Earth's surface hydrogen ends up being a thing that'd be really nice in concept but not so good in practice.
I wouldn't be terribly concerned with the environmental impact of methane rocket fuel, personally. Although currently Starbase gets is methane shipped in by trucks from elsewhere, SpaceX's ultimate goal with Starship is to land and return from Mars and they'll need to refuel on Mars for that to work. So the long-term plan for Starbase is to build a Sabatier process methane production plant powered by solar panels, much like they'll be building on Mars, to convert CO2 into methane. Once that's up and running Starship will be a carbon-neutral launch vehicle.
No worries. Tbh I kind of jumped on a hydrogen rant, that was all I wanted to talk about, rather than SLS as a whole. I agree we need NASA making things for space, we definitely don't want SpaceX to be the only player. However it bears mentioning that NASA have also contracted SpaceX to make their moon rockets, in exactly the same way they contract Boeing and others (the only difference is SpaceX already had a suitable rocket in development). So there is no sign of NASA rockets going away, if anything they have more suppliers to choose from.
Hydrogen also does have its place in combustion, and it's good that there's some development in this area. However, as someone who works in the electricity industry, adjacent to hydrogen ballooning into the energy markets, I'm intentionally wary of development as much of it seems to be pushed by those looking to sell more hydrogen using disengenuous claims about the reality of it being green.