Space Digest Fri, 23 Jul 93 Volume 16 : Issue 910 Today's Topics: ACRV return Celebrity Observatories Celebrity Observatories-Whitney Houston, Michael Jackson, Prince.... DC-X Prophets and associated problems (2 msgs) Hubble solar arrays: how'd they foul up? lunar mining and the case for space maximum velocity for gravity assists? Perseid publicity Spaceflight History (was Jupit Space Lottery! Any Ideas? Wanted: Solar sail info Why Fund Space!? 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: 22 Jul 93 11:05:44 BST From: clements@vax.ox.ac.uk Subject: Newsgroups: sci.astro,sci.space In article <1993Jul22.052247.1@vax1.tcd.ie>, apryan@vax1.tcd.ie writes: > A colleague mentioned that a British newspaper recently featured > Whitney Houston's (spelling?) house in which it was revealed she has > an observatory. Interesting. I seem to have missed this... > > Brian May (guitarist with rock group Queen was doing an astrophysics > degree including research in Canary Islands - source BAA Journal 1980+/-3). > Yes, this is indeed true! Brian May was studying at Imperial College for a PhD under Prof. Jim Ring. I'm unsure of the details of the project, but its likely to have included some Canary Islands observations as IC ran the Infrared Flux Collector (now the Carlos Sanchez Telescope) there at the time. I don't know what hios current interest in astronomy/astrophysics is at the moment, but he does go back to IC from time to time to the research groups Christmas parties etc. I did my PhD at IC, which is how I know all this. This makes it all the more galling when the ITV Cart Show announces that his planned career was 'astrologer?'! 2 of the three other members of Queen also came from Imperial, though I can't rmember their fields of study. Freddie Mercury, in contrast, came from the Royal College of Art across the road. > Astronomy Ireland, P.O.Box 2888, Dublin 1, Ireland. > (ONE OF WORLD'S LARGEST ASTRO. SOC. per capita - email re any larger! 0.039%) > Tel: 0 8 9 1 - 8 8 - 1 9 - 5 0 for U.K. Hotline (new message Mondays) > (dial 1550-111-442 in Republic of Ireland) -- ================================================================================ Dave Clements, Oxford University Astrophysics Department ================================================================================ clements @ uk.ac.ox.vax | Umberto Eco is the *real* Comte de dlc @ uk.ac.ox.astro | Saint Germain... ================================================================================ ------------------------------ Date: Thu, 22 Jul 1993 14:38:40 GMT From: Gary Coffman Subject: ACRV return Newsgroups: sci.space In article <3_713_6352c4ba3e9@Kralizec.fido.zeta.org.au> ralph.buttigieg@f635.n713.z3.fido.zeta.org.au (Ralph Buttigieg) writes: >17 Jul 93 19:18, henry@zoo.toronto.edu wrote to All: > > hte> Look at the parts of the globe within 28.5 degrees of the equator. >Lots > hte> of ocean, lots of desert and jungle, lots of underdeveloped countries > hte> with slightly-dubious governments. You'd really like to aim an >emergency > hte> return at somewhere like the great plains of North America or the >Russian > >The primary return area for the ACRV is central Australia. Big, dry and >flat. With resonably non-dubious governments.There were NASA people out here >late last year checking the facilities out. On the other hand, if your capsule floats, as ours used to do, and you have a 7 seas bluewater navy, as we used to have, then you'd got a 2 out of 3 chance of coming down on water even if you fire your retros blind. Water is nearly always big, flat, and free from obstacles. And there aren't any troublesome dolphin governments to deal with. 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 | | ------------------------------ Date: 22 Jul 93 11:07:05 BST From: clements@vax.ox.ac.uk Subject: Celebrity Observatories Newsgroups: sci.astro,sci.space Ooops! I'd better try again! > In article <1993Jul22.052247.1@vax1.tcd.ie>, apryan@vax1.tcd.ie writes: >> A colleague mentioned that a British newspaper recently featured >> Whitney Houston's (spelling?) house in which it was revealed she has >> an observatory. > > Interesting. I seem to have missed this... > >> >> Brian May (guitarist with rock group Queen was doing an astrophysics >> degree including research in Canary Islands - source BAA Journal 1980+/-3). >> > > Yes, this is indeed true! Brian May was studying at Imperial College for a PhD > under Prof. Jim Ring. I'm unsure of the details of the project, but its likely > to have included some Canary Islands observations as IC ran the Infrared Flux > Collector (now the Carlos Sanchez Telescope) there at the time. > > I don't know what hios current interest in astronomy/astrophysics is at the > moment, but he does go back to IC from time to time to the research groups > Christmas parties etc. I did my PhD at IC, which is how I know all this. > > This makes it all the more galling when the ITV Cart Show announces that his > planned career was 'astrologer?'! > > 2 of the three other members of Queen also came from Imperial, though I can't > rmember their fields of study. Freddie Mercury, in contrast, came from the > Royal College of Art across the road. > >> Astronomy Ireland, P.O.Box 2888, Dublin 1, Ireland. >> (ONE OF WORLD'S LARGEST ASTRO. SOC. per capita - email re any larger! 0.039%) >> Tel: 0 8 9 1 - 8 8 - 1 9 - 5 0 for U.K. Hotline (new message Mondays) >> (dial 1550-111-442 in Republic of Ireland) -- ================================================================================ Dave Clements, Oxford University Astrophysics Department ================================================================================ clements @ uk.ac.ox.vax | Umberto Eco is the *real* Comte de dlc @ uk.ac.ox.astro | Saint Germain... ================================================================================ ------------------------------ Date: Thu, 22 Jul 1993 14:40:55 GMT From: Gary Coffman Subject: Celebrity Observatories-Whitney Houston, Michael Jackson, Prince.... Newsgroups: sci.astro,sci.space In article <1993Jul22.052247.1@vax1.tcd.ie> apryan@vax1.tcd.ie writes: >A colleague mentioned that a British newspaper recently featured >Whitney Houston's (spelling?) house in which it was revealed she has >an observatory. > >Apart from wanting to knwo if any knows the details of the installation, >I wanted to start a discussion on celebrities who own telescopes, just >how many of them are there, how deep is their interest in space, what >kind of set ups have they got etc? Johnny Carson, formerly of the Tonight Show, is an astronomy nut. He has a telescope in the backyard at Malibu. Bet the seeing is lousy though. 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 | | ------------------------------ Date: Fri, 23 Jul 1993 01:51:16 GMT From: "Phil G. Fraering" Subject: DC-X Prophets and associated problems Newsgroups: sci.space davem@ee.ubc.ca (Dave Michelson) writes: >As a point of comparison, the Shuttle and the B-1/B-1B bomber were developed >in approximately the same time frame and somewhat similar circumstances. >While the Shuttle is disappointing for all the reasons previously noted, >the B-1B is arguably an outright failure. Perhaps I'm being to lenient >on NASA but I figure they did rather well considering all the interference >and second guessing from without. Hindsight is 20/20.... Hmm.... the B-1B still flies more regularly. Perhaps it only looks more like a failure to you because its dedicated mission is nuclear retaliation and we haven't had a reason to show it off yet... I mean, you don't see a successful training mission on the news every time it happens... -- +-----------------------+"And so it went. Tens of thousands of messages, |"Standard disclaimer" |hundreds of points of view. It was not called |pgf@srl03.cacs.usl.edu |the Net of a Million Lies for nothing." +-----------------------+ ------------------------------ Date: Fri, 23 Jul 1993 03:36:31 GMT From: Paul Dietz Subject: DC-X Prophets and associated problems Newsgroups: sci.space In article <1993Jul22.134305.7596@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >> for 1/10 to 1/20 the cost of the shuttle. The development risk would >> have been much lower. It would not have been as much of a jobs >> program for California, though. > > Are you sure? You'd be building 8 new vehicles a year instead of > 3+1 one time. I'd think you'd have more jobs. Well, the plan for BDB was to weld together most of the vehicle near the launch site. I suppose this means California jobs for polar orbits, but most of the work would have been in Florida. The design work would have been in California, perhaps, but it was a much simpler vehicle with a much smaller projected development cost. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 22 Jul 1993 19:01 EST From: David Ward Subject: Hubble solar arrays: how'd they foul up? Newsgroups: sci.space In article <1993Jul21.223929.15756@sfu.ca>, Leigh Palmer writes... >In article <22kejf$ogn@access.digex.net> Pat, prb@access.digex.net writes: > >>What i was wondering is how could this kind of design flaw >>sneak past any sort of reasonable test procedure? > >Good grief, man. How can you ask such a question, even >rhetorically, when the most conspicuous related example >of our time is the mirror on the same spacecraft? > >The answer to your question is, no doubt, the same. >There was not a reasonable test procedure in place, or >if there was, some committee decided not to believe its >negative results, which amounts to the same thing. > >Leigh I'm soory, but I'm afraid you're a bit off-base. A flexible structure like a bi-stem array can be tested thoroughly on the ground, but some assumptions _must_ be made taking ground tests and applying them to space application. In particular, I'm thinking of how hard it is to assess a structure's damping ratio in a 1-g environment. Since we don't have "anti- gravity" yet to allow the structure to float in a weightless, free-free (unsupported) state, there is some residual damping from the support structure in any mechanical mode testing performed. Usually, the assumptions made come from a reasonable structural analysis. If it sound like an intuitive process, sometimes without 3 sigma hard numbers before flight, that's pretty close to my impression. On the ACS side, we'd prefer nice, stiff, heavy arrays with easier to analyze modes, to avoid the types of problems HST has. On a similar note, I'm aware that some of Goddard's dynamics guys, some of Marshall's guys, and some Lockheed guys spent a great deal of time devising a control system that effectively adds damping to the solar arrays, so that the thermal snap effect is currently only a problem for about a minute at the terminator (a similar note was posted from one of the science ops guys earlier this week). Such a fact raises a question: why is NASA so eager to put _another_ unknown (new arrays) on HST, and how high of a priority is the solar array replacement. I'm afraid the answer is: very high, because of political pressures. Comments? David W. @ GSFC ------------------------------ Date: 22 Jul 1993 22:36:30 GMT From: hans f barsun Subject: lunar mining and the case for space Newsgroups: sci.space here is a thought somewhat off the not-so-beaten-track to orbit. a while back, i remember hearing about a man who had invoked some old US statute to place a mining claim on some portion of the moon. i was driving home with one of my roommates and his girlfriend one night and there was a full moon. in my foolishness, i mentioned that claim. my roommie's girlfriend became very irate and said, "we can't go out and mess up other worlds before we clean up what we have done here." i think i bristled, blew smoke out my ears and told her that a) the moon was dead...there is nothing there to hurt and b) that mining the moon (or the asteroids for that matter) might let us stop tearing the tops of mountains here. needless to say she was not convinced.....since there are so many social problems that must be solved here. so i guess that i am asking for any and all information that will allow me to argue the case for space research and exploration. of course, after being raised on a steady diet of science fiction, it is simple. we need to go to space because we must. unfortunately, it would be nice to have more ammo. e-mail would be great, thanks. Hans barsun@crank.unm.edu ------------------------------ Date: Fri, 23 Jul 1993 02:09:50 GMT From: Al Globus Subject: maximum velocity for gravity assists? Newsgroups: sci.space Does anyone know if there is a maximinum practical velocity that can be achieved using Jupiter gravity assists? I'm thinking about using such assists to propell space colonies for multi-generational trips to nearby stars and want to know about how many generations I'm talking about. From a simplistic view only the acceleration of the colony is limited so that multiple gravity assists could (very theoretically) achieve any velocity short of the speed of light. However, I have a feeling there is some factor I'm not thinking of that limits, as a practical matter, the maximum velocity achievable, for example, the pull of Jupiter's gravity as one leaves the area. ------------------------------ Date: Fri, 23 Jul 1993 01:54:27 GMT From: "Phil G. Fraering" Subject: Perseid publicity Newsgroups: sci.astro,sci.space gary@ke4zv.uucp (Gary Coffman) writes: >In article <1993Jul18.174504.1811@sfu.ca> Leigh Palmer writes: >>I do like to watch with other people, but there seems to be little >>point to assembling vast numbers, unless by so >>doing you can evengelize successfully about light polution. I have >>given up on this cause in cities like Vancouver. Too many of my congeners >>are Yahoos who will never care. I wish you success, Mr. Ryan. If you >>succeed in raising public support for, say, shielded outdoor lighting >>I'll be impressed. California's ruined. I've failed miserably here. Maybe >>I should emigrate to Ireland next. (Funny that you use the term Yahoo. You know where it comes from? Do you know the alleged geographical location?) >So gather your astronomer buddies and buy a Pacific island. If Marlon >Brando can do it, so can you and a few of your friends. When your nearest >neighbor is a thousand miles away, it can get real dark. Dull, no night >life, you say? Well, them's the breaks, as the Yahoos say. A neon sky >is more to their liking. It makes it easier to see the mugger sneaking >up to rob you. Just wondering, but does all that lighting really decreace crime? NYC has a lot of light pollution and a much higher crime rate than relatively dark-skied Pecan Island... or Ireland, which is a better comparison point, being more populous}i... >Gary >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 | | -- +-----------------------+"And so it went. Tens of thousands of messages, |"Standard disclaimer" |hundreds of points of view. It was not called |pgf@srl03.cacs.usl.edu |the Net of a Million Lies for nothing." +-----------------------+ ------------------------------ Date: Thu, 22 Jul 93 22:02:00 BST From: h.hillbrath@genie.geis.com Subject: Spaceflight History (was Jupit > Date: Wed, 21 Jul 1993 16:54:04 GMT > Henry Spencer Writes: >>... At some point, before there really were "real" Jupiters, >>they converted the Redstone as a reentry test vehicle, and called it >>the "Jupiter-C." Partly, the reason for that was that was, I am sure, >>"disinformation." > Actually, the various sources are pretty much in agreement on > this one: it was done because von Braun's crew noticed that when > the Cape people set schedules, they (a) tended to give new > programs higher priority, Thank you for your comment, Henry (is everyone here named that?) Yes, well, I never heard that particular story, but it could well be at least one part of the explanation. (Not to wander completely of the subject, but I have frequently held that words, including names, have a "life of their own" and not even the people that invent them control them. So, no matter who selected the name, or how, the world had to accept it, and once it did, it couldn't be "put back in the box". "Delta" is a good example of a name that escaped, and took over a whole program, an upper stage that at the booster.) I didn't say what the object of the disinformation was. I have been on programs that were hyper sensitive about security and the Soviets were no higher than third on our list of concerns. What I do know, for sure, is that in the summer of 1957, before Sputnik, I was working as a "Summer Student" at Redstone Arsenal. And, I was highly interested in the Jupiter, and anything concerned with it, and I was reading everything available on it, Aviation Week, Missiles and Rockets, etc. The designation certainly confused me, and I think a lot of other people at the time. If priority was all they were looking for, they could have done the same as the Air Force, and have given it an "X" number. Their equivalent was the "X-17," and reentry vehicle development was pretty "hot" (clever, eh?) at the time. There really were people with exemplary credentials that thought that ICBM/IRBM reentry vehicles were like landing on the Moon, fundamentally impossible (due to dust layers, or whatever). BTW I checked Baker's "The Rocket." He gives quite a discussion of the early, formative, days of Saturn, and manages to get all the way through it without saying "S III" even once. Most of the discussion is correct, as far as I know, he gives a reasonable explanation of E-1s vs. H-1s, the H-1 pump location change, etc. but he is apparently following an "Army Scenario" in discussing the H-1 changes, without mentioning, or realizing, that most of them had already been demonstrated on the Atlas and the Thor. That is not anything new and different. The fact that things have already been done (by some other agency) has never had any influence on peoples perception of what is possible in many areas, Huntsville being in the forefront. Sort of an extension of The "NIH syndrome." There are a few errors in the discussion. The date he gives for the S-IC contract award was much too late, over a year after I had already accepted a job on the program, and even after I had very belatedly reported for it (Sept. 25, 1962). I have another book, somewhere, that has some rare and esoteric early Saturn lore, I will check what is says, if I can find it. Another personal experience with some bearing on the early development of Saturn, a matter of 2 or 3 weeks before the Mercury/Atlas flight of John Glenn (Feb. 20, 1962) I (as a very junior engineer) was assigned to witness the disassembly of an Atlas engine (in the Rocketdyne Canoga Park facility) that had failed during a static test (and which assumed great importance, when it was suggested that the JG MA-2/6 engine might have the same fault.) While we were taking our engine apart, some other guys were putting another one together in the next assembly position, the very first static test article J-2 engine. (The first flight of the J-2 was Feb. 26, 1966, a very compressed engine schedule. Beware of engine suppliers who say they can do better.) The J-2 was, and is, BTW a very weird engine, in the details of its construction (plumbing, in particular) very unlike other Rocketdyne engines. ------------------------------ Date: 23 Jul 93 00:52:11 GMT From: nsmca@acad3.alaska.edu Subject: Space Lottery! Any Ideas? Newsgroups: sci.space Lottery in Space and heart problems and other likely diseases/injuries for a Lottery Winner. Ever heard of the "Release Form".. People all over suffer from more stress and such than a space launch, ever ridden in some of those nifty carnival rides.. Also ever heard of the "Flight Physical" to find those nifty problems, and correct them, so it might add on to the cost of the launch, but you can claim it as an advertising expense latter on your taxes.. Or does NASA not pay taxes, well then claim it as a operating expense or Public Relations, liek the Air Farce does..OR is that recruiting.. === Ghost Wheel - nsmca@acad3.alaska.edu ------------------------------ Date: Thu, 22 Jul 1993 23:48:08 GMT From: raja@uhunix.uhcc.Hawaii.Edu Subject: Wanted: Solar sail info Newsgroups: sci.space I'm posting this for David Hayter, who doesn't have net.access. I will forward any replies to him. If you have any info, please EMAIL me if possible, since I don't usually read this newsgroup... Regards, Raja. ---------------------- Message from david J. Hayter begins: I am interested in finding information about a proposed "Solar sail race", due to take place in 1995, I think! As I understand it the race starts from earth orbit, goes to the moon, with the first one back being the winner. If you have any knowledge about this proposed race, I would appreciate your reply. I'm also intersted in any info/references on solar sails in general. Raja already gave me h the references from the "FAQ." Any others? Thank you very much, David J. Hayter. ------------------------------ Date: 23 Jul 93 00:32:12 GMT From: nsmca@ACAD3.ALASKA.EDU Subject: Why Fund Space!? Newsgroups: sci.space Reasons for funding space: New drugs, and chemicals and materials for on earth use.. Purer chemicals nad materials to.. Alos as long as human population expands, we need to expand our resource available areas, and space will provide that. Once a nation stops expanding, it has a habit of dying. Namely the larger nations, but it happens elesewhere.. If a nation has a "stable" population, it does not need more resources (or atleast as much) and there for can expand slowly. But here in the US and other nations, we has large, "unstable" population growth, and we need to mineral/resource expansion that space can give us. I know notnow, but near future.. Especially since we lock up some of the best mineral resources land into parks, preserves and such, we need to expand in ways that does not interfer with those parks/preserves.. So until some one can coem up with a way to nicely control the population growth of humanity, and basically live with in our means here on earth, we need space.. === Ghost Wheel - nsmca@acad3.alaska.edu ------------------------------ From: "Theodore F. Vaida ][" Newsgroups: sci.space Subject: Potential Markes for DC-# Message-Id: <1993Jul22.213619.14215@ns1.cc.lehigh.edu> Date: 22 Jul 93 21:36:19 GMT Organization: Lehigh University Lines: 71 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU Fill # with your prefered model (I like the DC-1 personally!) What about the commercial uses for the DC series? (including the original dc-x that might be usefull for sub-orbitals!) CREWLESS OPERATIONS: 1: Airborne Express (Federal Express, UPS, USPS, Percolator Courier...) need reliable QUICK trasportation of some INCREDIBLY urgent payloads (like documents from the president to the russian president perhaps?) 2: Breadbox science experiements that sitck out on an arm when the DC-1 is in orbit (speical doors needed?) 3: Landing at the 50 yard line of the superbowl (kudos to the person who thought this one up...) 4: Pulling tree-stumps from the yard... :O) -- ---------==============Sig file cover sheet=====================--------- ->POLAR CAPS<- or tfv0@lehigh.edu Student Konsultant Making the world safe for computing! Pages including this page: 1 ----- ------------------------------ From: "Theodore F. Vaida ][" Newsgroups: sci.space Subject: Re: DC-1 and FAA Message-Id: <1993Jul22.211932.64671@ns1.cc.lehigh.edu> Date: 22 Jul 93 21:19:32 GMT Organization: Lehigh University Lines: 60 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article , voss@cybernet.cse.fau.edu (stephen voss) writes: >If DC-1 is going to be approved for manned flight or not >FAA then maybe >then FAA >should stand for FEDERAL AEROSPACE ADMINISTRATION DAMM STRAIGHT, if there is one (and only one) federally funded agency that is designed to provide saftey in the these united states that has done its job, i would have to say that it is the FAA! My family used to own an airplane (Piper Cherokee 6) and we flew quite extensivly to many places. In all the time of dealing with the FAA (liscencing, flight plans, saftey inspections registrations and medical certificates) the FAA preformed impressivly and kept the hasstle to a minimum (they even fund several companies to provide FREE weather service information over modems that is up to the minute correct!). I am not privy to the corporate angle as to how much hasstle the plane making comanies go through, but knowing that many people build their own planes from kits and get them certified (and rarely do certified planes have airworthyness problems unless the owner does no upkeep) I would have to say that the FAA knows its job, and thats what it does. The fact that the FAA controls the air space over this country (and that NASA has to ask the FAA to clear its airspace over KSC) makes it a good argument to extend their coverage up into LEO, plus that would give the governement a mandate to continue a reasonable (read inexpensive) presence in space to keep things straight. Essentially the FAA is an executive operation (under the prez) so unless them pesky congress critters get antsy, the FAA can run a tight ship with litte or no legislative overhad biting them in the back. Anyway... now its time to hand the soap box to somone else... -- ---------==============Sig file cover sheet=====================--------- ->POLAR CAPS<- or tfv0@lehigh.edu Student Konsultant Making the world safe for computing! Pages including this page: 1 ----- ------------------------------ Xref: crabapple.srv.cs.cmu.edu sci.space:67464 Newsgroups: sci.space Path: crabapple.srv.cs.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!magnesium.club.cc.cmu.edu!news.mic.ucla.edu!library.ucla.edu!agate!howland.reston.ans.net!gatech!wa4mei!ke4zv!gary From: Gary Coffman Subject: Re: DC-X Prophets and associated problems Message-Id: <1993Jul22.140756.7703@ke4zv.uucp> Reply-To: Gary Coffman Organization: Destructive Testing Systems References: <22jbtb$lj8@voyager.gem.valpo.edu> <1993Jul21.142043.29168@iti.org> Date: Thu, 22 Jul 1993 14:07:56 GMT Lines: 60 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1993Jul21.142043.29168@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In article <22jbtb$lj8@voyager.gem.valpo.edu> mjensen@gem.valpo.edu (Michael C. Jensen) writes: > >>I feel compelled to note a historical similarity in recent posting to an >>event in the recent past, and hopefully help aviod a repeat. Currently, >>those DC-X/1 Prohpets are fortelling of a glorious time when the DC >>is flying. [Goes on to say the same claims where made for Shuttle.] > >>Well, I listen to the DC-X/1 crowd and >>can't help worrying. Not because it's nesessarily an impossible task. >>Rather, because they are making VERY extravagent claims. > >Which claims are extravagent? Sure, it's moderately risky but it's >not extravagent. If it won't work, we will know after investing less >than the cost of a single Shuttle flight in the concept. Claims of 50 flights per year per vehicle are extraordinary. No other space launcher has come close to these rates. There's no experience that shows it's possible. Aircraft experience doesn't count, it's too different. The claim of $400 a pound to LEO is also extraordinary. No other system comes close. These are revolutionary orders of magnitude improvements over current practice in a single generation. There's good reason to be skeptical. SSTO is a radically different way of doing spacefight. It may indeed bring remarkable savings, or be a dead end boondoggle. It's way too early to be booking passage at guarranteed rates. Or more to the point, it's way too early to be planning on depending on this thing for other missions like SSF. >This is the famous "a project has failed therefore all projects must >fail" arguement. In the early 1900's you could have used this arguement >to 'prove' that we would never have airplanes based on Langly's failures. No, that's *your* strawman that you love to knock down. What it really is is a comparison with other programs of like claims. There's only been one other, Shuttle, in spaceflight, though the phrase "Too cheap to meter" should haunt you as well. Many new technologies make extravagant claims in their benchtop days, but fail to live up to them in operational service, if they get that far. >Note that to manrate a spacecraft you add tens of millions of $$ in cost per >flight yet all that extra money doesn't improve the safety record one bit. >Un-rated launchers are just as safe as the rated ones. Not true. US experience has been that unmanned launchers have had higher failure rates. In all of US manned spaceflight there has only been one catastropic launch failure. How many unmaned boosters have failed? Man rating includes a lot more than just some redundant hardware. Mainly it's an exhaustive system of *procedures* followed on the ground before launch, that standing army, that insures that all systems are in peak condition for launch. Look at Atlas, it had a flawless record as a man rated launcher, but only an 85% record as an unmanned launcher. The hardware's the same, but the procedures are relaxed for the unmanned missions. 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 | | ------------------------------ End of Space Digest Volume 16 : Issue 910 ------------------------------