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- Path: sparky!uunet!ogicse!emory!rsiatl!ke4zv!gary
- From: gary@ke4zv.uucp (Gary Coffman)
- Newsgroups: sci.space
- Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
- Message-ID: <1992Dec16.145221.805@ke4zv.uucp>
- Date: 16 Dec 92 14:52:21 GMT
- Article-I.D.: ke4zv.1992Dec16.145221.805
- References: <1992Dec9.133030.6288@ke4zv.uucp> <ewright.724021208@convex.convex.com> <1992Dec11.175719.24880@ke4zv.uucp> <1glgrrINN6jj@mirror.digex.com>
- Reply-To: gary@ke4zv.UUCP (Gary Coffman)
- Organization: Gannett Technologies Group
- Lines: 48
-
- In article <1glgrrINN6jj@mirror.digex.com> prb@access.digex.com (Pat) writes:
- >In article <1992Dec11.175719.24880@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
- >>on several grounds, the low chamber pressures lead to very high
- >>loads on the turbopumps because so much more fuel per unit time
- >>has to flow to achieve the high thrust required with low pressure
- >>engines. Reducing stress in one area can lead to increased stress
- >>
- >I dont think that is an unsolvable problem. THe Saturn F-1's sucked
- >fuel like no tomorrow. The soviet's haul fuel to feed those
- >big protons and energiya engines.
-
- I agree. My point was that low pressure engines don't necessarily mean
- lower stress, just different stresses.
-
- >Horizontal take off is not simple. while it makes people comfortable
- >it means the bird has to sit a long time in the soup, sucking in
- >O2 and feeding the engines. The stress is high. the heat buildup
- >is enormous. NASP is going berserk on this problem.
- >Flight near MACH 12 can be a real trick.
- >
- >McDaC, chaose to just fly right out of this soup and take a simpler
- >approach.
-
- I basically agree with this too. MACH 12 is a tough thing in heavy
- atmosphere, but most flyback booster designs didn't try to achieve
- MACH 12 before switching to rocket power. Note that I'm not wedded
- to SSTO concepts here.
-
- >Wings are not useful if they only generate lift up to abou;t 20 miles,
- >and you have to keep climbing another 130 miles.
-
- Well that sort of depends. If you can get above most of the atmosphere
- with wing assist and air breathing engines, your job of getting to orbit
- is made much easier. Again I'm not wedded to SSTO, the jets don't have
- to continue to orbit with you. They can be part of a flyback booster.
-
- >Also if an HTHL, is going to be mostly lifting body, then so will the DC.
- >
- >As i understand it, it will blunt fly down to mach 3 and then roll
- >tail first. engines will provide terminal management. most velocity
- >will be shed by passive shielding.
-
- That sounds more like a re-entry capsule, ala Apollo, than a classic
- lifting body that can glide all the way down to a landing. The only
- difference with Apollo seems to be substituting rockets for parachutes
- in the terminal phase.
-
- Gary
-