Date: Fri, 25 Dec 92 05:10:57 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #597 To: Space Digest Readers Precedence: bulk Space Digest Fri, 25 Dec 92 Volume 15 : Issue 597 Today's Topics: DC vs Shuttle capabilities LEI financing SSTO vs. 2 Stage Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX? Terminal Velocity of DCX? (was Re: Shuttle ...) Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 25 Dec 92 00:54:51 GMT From: Gary Coffman Subject: DC vs Shuttle capabilities Newsgroups: sci.space In article <1992Dec22.182600.29193@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In strider@clotho.acm.rpi.edu (Greg Moore) writes: > >> I think we differ big-time when it comes to DC-1. Allen seems >>to me to be saying, "Things will work out, and this is how it will be." > >From a technical point of view I am saying that a fully reusable SSTO >vehicle carrying a reasonable payload (10 to 20 K pounds) and operational >costs of $10 to $29 million per flight *CAN* be built with available >technology. I also believe that operational costs can drop to $1 to $5 >million range if utilization is high enough. > >I believe this partly from my own assessment and the fact that every >assessment done has concluded that it is possible. Even the internal >NASA assessment say it can be done and that it could save billions. > >Now this doesn't mean that DC-Y WILL work. The biggest problems however >are managerial, not technical. Using conventional government procurement, >it will be impossible to build SSTO. Using a commercial like process however >should work. Finally, an intelligent position on SSTO from Allen. I would quibble, however, that while there are no known *theoretical* technical issues unresolved, there remain numerous practical technical problems to solve in the DC program. DC is a complex technical vehicle, even if it is designed to be much simpler than Shuttle, and like any complex mechanism, teething problems are almost certain to arise. That's the type of contingency for which less optimistic management systems provide alternative actions and funding. Whether McDD and any government sugar daddies they can attract will be willing to continue to fund them through the inevitable setbacks remains to be seen. I also suspect that cheaper alternatives to SSTO are technically possible with MSTO expendibles for some missions, though whether anyone will build them remains unknown. I wish McDD luck, but ask that they stay away from Hartsfield International until they've developed a good track record of operations. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ Date: 25 Dec 92 01:52:49 GMT From: Gary Coffman Subject: LEI financing Newsgroups: sci.space In article David.Anderman@ofa123.fidonet.org writes: > >Daniel Goldin. Under his administration, NASA is saying and doing things that >would have been hard to imagine years ago. Their Procurement office is talking >about not only purchasing lunar, but also Martian, data as well. It is >possible that the LRDPA (what an acronym) may become obsolete next year, as >NASA may decide, through the President, to request funding for purchase of >lunar data. It seems to me that data purchase belongs more under NSF charter than NASA's R&D charter. Not that data purchase is a bad idea mind you, just that you're probably looking in the wrong pocket. Of course it's all the same pair of pants. :-) Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ Date: 25 Dec 92 01:13:50 GMT From: Gary Coffman Subject: SSTO vs. 2 Stage Newsgroups: sci.space In article <1h8ca7INN9nk@news.cerf.net> davsmith@nic.cerf.net (David Smith) writes: >There's an advantage (I believe) of SSTO vs multi-stage systems that's >getting left out here. When launching a DC-1 all the engines are started >and then throttled up. This means that if an engine refuses to start, >OR if there is a major fuel system problem such that none of the engines >will start you can abort the launch on the pad. With the two-stager >enough engines have to start at separation time to assure that the DC-1 >can at least abort. Well that's true with a vertical stack, but if you use a cluster stack like Shuttle does, except no solids, then you can fire up all the engines on the pad and make sure they're running right before liftoff. Picture the putative DC-0 as a ring structure with the DC-1 nested in the middle. Your major problem comes at separation time. If separation fails completely, you just land the whole thing, if separation succeeds, you're home free, but if separation *partially* fails, you're screwed. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ Date: 25 Dec 92 01:46:27 GMT From: Gary Coffman Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX? Newsgroups: sci.space In article <1992Dec23.132824.14131@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In article <9gt204c@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes: > >>If this is teh case, than >>you have to treat the shuttle development costs as sunk costs. > >I have no problem treating the research vehicles which supported >Shuttle (like X-24) being treated as sunk costs but I don't think >development costs should be. That simply makes commercial development >that much harder. In military procurement, the development costs are charged against the prototypes, X, Y, etc, and the operational vehicles of the procurement are charged at "flyaway" cost. Following this model, Enterprise ate the development costs, and it's retired. Current Orbiters are only liable for their $1.5 billion flyaway cost and their operational costs. Payload costs, including mission specialists and their ground support staffs, belong to the customer for the payload, Now in NASA's case, these costs all come out of the same pocket, but you're making faulty conclusions when you insist on lumping them for Shuttle while separating them, and ignoring large parts of them, for your favorite projects. Remenber that the data gathered, and techniques developed by the Shuttle program, the RL-10 development program, NASP materials, etc are available free to McDD for their program. Are you going to charge these costs against DC? To be consistent with the way you treat Shuttle, you should, but of course this is nonsense accounting. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ Date: 25 Dec 92 01:03:42 GMT From: Gary Coffman Subject: Terminal Velocity of DCX? (was Re: Shuttle ...) Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: >In <1992Dec20.195520.3587@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes: > >>It'll still be more cost effective to assemble and test >>the bulk of space payloads on the ground and boost them to orbit >>on larger capacity launchers, especially if some effort is put into >>designing a heavy lifter for low labor costs. > >Just as it's more cost-effective to assemble and test >office buildings at a central factory, then ship them >to the worksite. Especially if some effort is put into >designing a heavy freighter for low costs. ;-) Indeed, modular housing units *are* cheaper than stick built housing. Most industrial construction utilizes modular building systems. Some builders are now using modular sections for multi-story office structures. The problems with widespread adoption of these methods isn't technical or economic, it's archaic building codes. Would you prefer that UAW workers show up in your driveway and build your new Buick, or would you rather pay a hundred times less for one from a factory? Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ End of Space Digest Volume 15 : Issue 597 ------------------------------