sorry for asking but i kinda dont see the merit of LH2 in stock. its just way too less dense for any reasonable use,even considering the impressive isp of nuke engines...as the density for LF is way more superior , i kinda end up using stock parts only. I consider volume as much as mass considering aerodynamics. any help here? pretty please? i just dont know how to use these LH2 fuels and engines in a reasonable way...some pointers will be really helpful