Re: SPACE: Roton in New Scientist

mark@unicorn.com
Fri, 14 Aug 1998 04:14:57 -0700 (PDT)

Philip Witham [p.j.witham@ieee.org] wrote, quoting Truax
>Make it ultimately simple (pressure fed, two-stage, single engine per stage), >make it reusable, never make it *too* reliable, and build it *big* (100,000-1 >million pounds to LEO).

While that's certainly a worthwhile route with old technology, it has quite a few flaws. Firstly, there's a limit to how far you can reduce the cost that way, because you're still throwing away the booster every time you launch it. Secondly the payload is much, much too large for launching modern satellites; I'm not sure of the mass of an average comsat these days, but if it's taken as five tons you'd have to launch ten to a hundred satellites per booster! And just imagine putting a hundred billion dollar satellites on a booster with a 95% reliability rating; you've just added an average of $5,000,000,000 to the cost of every launch, because one time in twenty you'll lose the whole hundred billion dollar payload.

You save a lot of money with an SSTO simply because it can safely abort in most launch failures without losing the payload.

Mark