Overview of the New LH2 Sphere at NASA Kennedy Space Center [pdf]
energy.gov
energy.gov
> circa 1970 Accidental production of first glass bubbles at 3M plant in Guin, AL
> circa 1975 Cryogenic research testing by G. R. Cunnington and C. L. Tien at UC Berkeley
10 years from now, SLS will likely be winding down. Few see it as the long-term answer. How long it has to last, really depends, I think, on how quickly SpaceX can get Starship operational.
Once SLS is finally mothballed – whether that happens in 5 years or 10 – then what happens to all this hydrolox infrastructure? Methalox can use the oxygen tanks, but how feasible would it be to put methane in the hydrogen tanks?
Opinions vary widely as to how much adoption hydrogen is actually going to see in coming decades. Attempts to commercialise it thus far have seen quite limited success, and sceptics who question whether there will be any greater success in the future could be right.
Even if those sceptics are wrong, and the "hydrogen economy" really takes off – how close is this hydrogen storage infrastructure going to be to the actual supply, demand and transit points? It might turn out to be in an inconvenient location given the geography of the supply chain, and end up seeing little use as a result. Is the fact that this is right next to a rocket launchpad – which I assume will still be in use for decades to come, even if not for SLS – going to impose a limit on potential non-space uses?
[1] https://earthobservatory.nasa.gov/features/NASASeaLevel/page...
More SLS brain damage.
SLS is planned as an expendable launch system that will put spacecraft far beyond Earth orbit. They need the specific impulse that hydrogen offers.
And in related news, liquid hydrogen is going to become just as mainstream as LNG is today, within a decade from now. All the major LNG ship builders (KHI, GTT etc.) are building and testing LH2 transport ships as we speak. Suiso Frontier began operational sailing more than a year ago.
On top of that cryo methane and oxygen are at closer temperatures than hydrogen and oxygen, which simplifies storage further.
So effectively the difference is that Hydrogen embrittles everything and makes development more expensive even without reuse considerations, making Methane superior unless you're SLS and being wasteful is a feature.
Either way it's disappointing NASA is determined to keep the Space Shuttle's white tech elephant going.
They wanted it, sure: there's more than one way to build a big rocket, and the choice that Congress/NASA made was to use hydrogen on a sustainer stage.
They could have made other choices.
The only reason to not design a reusable launch system in the past 7 years is because you lack foresight, or you have a design by committee where you're being forced into poor decisions for political gain.