> Buran was using LOX, storing it for up to two weeks with a cryocooler and a complicated cooling system They had insulation and active stirring system, that w

> Buran was using LOX, storing it for up to two weeks with a cryocooler and a complicated cooling system They had insulation and active stirring system, that was enough for 15-20 days. To fly up to 30 days they needed a microcryocooler. http://buran.ru/htm/odu.htm http://buran.ru/htm/odu.htm > Crew Dragon can be rated for hundreds of days Isn't Soyuz rated for 200+ days? > Dreamchaser with its propane/N2O thruster is a better counterexample. Agree, a good example.