# Has solidifying liquid propellant been considered for space exploration?

• Liquid hydrogen is $0.071 g/cm^3$
• Solid hydrogen is $0.086 g/cm^3$

Since denser fuel is desirable, has solid hydrogen been considered for use in space exploration?

I suspect the very low temperature (hydrogen melting point is 14K) to be impossible to manage.

Maybe hydrogen ice cubes in the tanks would help reduce boil off?