home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: sci.space
- Path: sparky!uunet!convex!convex!ewright
- From: ewright@convex.com (Edward V. Wright)
- Subject: Re: SSTO vs 2 stage
- Sender: usenet@news.eng.convex.com (news access account)
- Message-ID: <ewright.726181992@convex.convex.com>
- Date: Mon, 4 Jan 1993 21:13:12 GMT
- Distribution: sci
- References: <ewright.725734633@convex.convex.com> <1992Dec30.180058.28938@cs.rochester.edu> <ewright.725755862@convex.convex.com> <1992Dec31.015157.14864@cs.rochester.edu> <ewright.725820847@convex.convex.com> <93002.220235SAUNDRSG@QUCDN.QueensU.CA> <ewright.726166318@convex.convex.com> <93004.130256SAUNDRSG@QUCDN.QueensU.CA>
- Nntp-Posting-Host: bach.convex.com
- Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
- X-Disclaimer: This message was written by a user at CONVEX Computer
- Corp. The opinions expressed are those of the user and
- not necessarily those of CONVEX.
- Lines: 45
-
- In <93004.130256SAUNDRSG@QUCDN.QueensU.CA> Graydon <SAUNDRSG@QUCDN.QueensU.CA> writes:
-
- >>I understood that too. Perhaps you did not understand what I meant
- >>when I said, if there are enough heavy cargoes to justify a new
- >>vehicle, it would be more cost-effective to build a larger SSTO
- >>than a two-stage kludge?
-
- >Rather depends on how many heavy cargoes there are, doesn't it?
-
- No, I don't think so. Building and testing a new two-stage vehicle
- would be more expensive than building and testing a new one-stage
- vehicle. So costs would be greater no matter how many, or how few,
- payloads you spread them out over.
-
-
- >As I understand it, the point to an SSTO is to make expendables
- >non-cost effective. So there *won't* be another vehicle fairly
- >soon after DC-1's get flying in numbers if they work as advertised.
-
- I don't think Boeing gave up when McDonnell Douglas introduced
- the DC-3. If one company demonstrates a successful space
- transportation system that makes money, other companies
- won't let them have the market all to themselves for long.
-
-
- >If there's one or two heavy cargoes a year, Bruce's quick and simple
- >second stage might make a great deal more sense than scaling up
- >an SSTO design by a factor of five, which I would expect to be quite
- >difficult, since it's a complete re-design and probably needs new
- >engines.
-
- Bruce's "quick and simple" concept requires *two* new designs.
- You couldn't just put 5x the cargo into an existing DC-1. Unless
- it was unusually dense, it wouldn't fit into the cargo bay. Even
- if you could, the vehicle's balance would be off. So you're talking
- a major redesign, then component testing of both the first and second
- stages, then testing both the first and second stages together....
-
- And I can't understand why a larger SSTO would need new engines
- while a TSTO with a comparable liftoff weight wouldn't.
-
-
-
-
-
-