Re: Ares vs DIRECT

John Schilling wrote:
[SNIP]

Major difference is, Henry understands that building shuttle-derived HLVs
is a fundamentally bad idea, suitable only for armchair engineering,
whereas the DIRECT proponents seem to thing NASA ought to actually go
out and build the damn thing.

John,
A fair account overall. I'd make mention that the RS-68 for the upper stage is more difficult than even the SSME would have been. The '68 was not designed for air-start and currently require 14 tons of ground-based hardware just to spin up the turbines during the start sequence. That's a thing I don't believe Brown Bess ever tackled properly.



And please don't get us (the DIRECT Team) wrong - given a clean *** design, an open check book, no schedule limits and no pre-existing political requirements, I too would actually design something other than DIRECT's Jupiter vehicles.

But we do have all those issues to tackle. Politics and NASA's experience of the "brain-drain" following the shut-down of Apollo are driving the requirement to keep Shuttle derived technology at all levels. Money is extraordinarily tight right now as we complete ISS using Shuttle, and won't be very plentiful even for a while after the last Orbiter is back on the ground. The schedule is getting ever-tighter too. All of this defines the size and shape of the 'hole' which we need to fill with a new 'peg'.

We simply believe that Jupiter is the best fitting peg for that hole NASA has been tasked to fill on a given budget and in a given time-frame while re-using a certain workforce. It is not the best possible solution - it is simply the best compromise - and that's normally what you're trying to get in all walks of life.

Ross B Tierney
www.directlauncher.com
.

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