On Fri, 2003-09-26 at 00:14, David Masten wrote: > On Fri, 2003-09-26 at 00:03, Thomas McNeill wrote: > > I have recently been doing the math for SSTO using > > H2O2 and other similar Isp combinations. To attain > > the correct DeltaV you either need a very high Isp or > > a very low mass ratio, am I correct? > > Fuel 97% Dry Mass 3% to first approximation. Various tricks, picking the > right orbit, and cutting margins dangerously close can get you down to > 95% maybe.
Okay, this time I'll actually answer the question. Very high ISP, yes. I always get the wording mixed up on mass fraction/ratio. Lots of propellant mass, very low dry mass is what you need. I gave an example based on 300 or so Isp, which is a reasonable approximation for Peroxide/RP1. (warning - I did not do the actual math, I am known to make errors when just grabbing numbers off the top of my head, but I'm pretty sure I remembered it right.) Dave -- David Masten <[EMAIL PROTECTED]> _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
