What significant engineering penalty arises from the extremely low density of liquid hydrogen?

Answer

It requires massive fuel tanks to store sufficient propellant mass.

Because $ ext{LH}_2$ is very light with low density (around $70.8 ext{ kg/m}^3$), storing enough mass for orbital missions requires significantly larger fuel tanks compared to denser propellants.

What significant engineering penalty arises from the extremely low density of liquid hydrogen?

#Videos

Why SpaceX is Using a New Fuel - YouTube

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