[avmich]

Soyuz rocket takes 9 minutes to get to orbit. Raptors are multiple-use engines, their lifetimes could be hours of work, which is a lot for rocket engines. However it could be possible to increase lifetimes at least another order of magnitude - an NK-33 engine once run uninterrupted for 14 thousands seconds. Consumed a lot of kerosene.

RL-10 can avoid too big stresses, at least not heating to high temperatures, so this is another hint on possibly long working rocket engines...