On Fri, 26 Sep 2003, Thomas McNeill wrote: > ...the correct DeltaV you either need a very high Isp or > a very [high] mass ratio, am I correct?
Correct... or some reasonable combination thereof. You need an excellent mass ratio unless your Isp is most unreasonably high. > Anyone here an advocate for using H2O2 on a SSTO craft? Oh, I think one or two such folks could be found here. :-) It has advantages (high density, room temperature) and disadvantages (not the hottest of oxidizers). The idea is challenging but not ridiculous. > I continue to calculate very high G forces. > Anyone have any good ideas on how to accomplish this > without high Gs? I think you're assuming constant thrust, which is a bad assumption for most any flavor of SSTO. Given the necessary mass ratio, it's pretty much essential to have some sort of deep-throttling capability, so thrust near the end of ascent is very much reduced from thrust at takeoff. One good way to do this, given the difficulties of deep throttling for rocket engines, is to have multiple engines and shut some of them down. Not even a LOX/LH2 SSTO can run at constant thrust, if only because the high Gs impose too much load on the structures, and the situation is even worse for lower-Isp combinations that need higher mass ratios. Henry Spencer [EMAIL PROTECTED] _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list