[skoocda]

That gravimetric energy density is about 2 orders of magnitude higher than lithium ion batteries.

[audunw]

The difference in volumetric energy density is not that big though, and hydrogen is not as flexible as jet fuel or even batteries when it comes to how you can store it in the vehicle.

To be fair, high gravimetric density is a fairly large advantage for an air plane. But the bad volumetric energy density does present some serious challenges.

[dzhiurgis]

So why it’s not used in rockets?

[imtringued]

It was used in the Space Shuttle and SLS uses the same engine as the shuttle.