Date: Thu, 24 Dec 92 05:21:57 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #592 To: Space Digest Readers Precedence: bulk Space Digest Thu, 24 Dec 92 Volume 15 : Issue 592 Today's Topics: Acceleration, cats Alaska, Poker Flats asteroids beyond Jupiter DCX/DC-1/DC-0 and what is it.. Depleted uranium Famous quotes fast-track failures Giotto Sample Return ? Greek Science (was Re: Justification for the Space Program ground vs. flight I thinI see our problem. (Was Re: Terminal Velocity of DCX? Latest Pegasus news? Lunar ice MOL (was Re: Terminal Velocity of DCX? (was Re: Shuttle (2 msgs) Overhead Pilots must be stupid? (Re: DC vs Shuttle capabilities Stupid Shut Cost arguements (was Re: Terminal Velocity Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX? 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: Wed, 23 Dec 92 22:39:38 EST From: John Roberts Subject: Acceleration, cats -From: gbt@cray.com (Greg Titus) -Subject: Re: Acceleration, cats... -Date: 23 Dec 92 20:27:45 GMT -Organization: Cray Research, Inc. -In article jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins) writes: ->pgf@srl03.cacs.usl.edu ("Phil G. Fraering") writes: -> ->>... some cats have fallen from ten or twenty stories and sometimes ->>survived ... -> ->>What I want to know is, how the ability to fall from 100-150 feet ->>up was _selected for_ by evolution. It implies that they went through ->>a period of development where cats that could do that were outcompeting ->>cats that weren't, to the extent that a large number of cats today can ->>do it. -It turns out that cats have a particular muscular/skeletal arrangement -they go into when they enter free fall, which is designed to maximize -the shock absorbance of the whole cat and minimize damage to any -particular part of it. However, this mode does not work all the way -up to feline terminal velocity, with the result that as fall height -increases past 10 or 15 feet, cats experience more and more damage -upon landing. Above 30 or 40 feet, they are usually very badly -injured. However, the tensed-up shock absorbing mode does not last -very long. If no landing occurs, then the cat begins relaxing, with -the result that a cat falling from 80 to 100 feet lands as a blob, and -often has very minor injuries. I've read that small children often survive long falls with surprisingly little injury. It was speculated that they may be more likely to relax than adults. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 23 Dec 92 23:34:12 GMT From: nsmca@acad3.alaska.edu Subject: Alaska, Poker Flats Newsgroups: sci.space Does anyone know anything about the University of Alaska Fairbanks Poker Flats space program.. Michael Adams alias Ghost Wheel/Morgoth NSMCA@acad3.alaska.edu ------------------------------ Date: 24 Dec 92 01:56:06 GMT From: "J. Furr" Subject: asteroids beyond Jupiter Newsgroups: sci.space,alt.folklore.urban In article jfurr@polaris.async.vt.edu (J. Furr) writes: >In article <1992Dec22.235420.19821@hpcvaac.cv.hp.com> billn@hpcvaac.cv.hp.com (bill nelson) writes: >>jfurr@polaris.async.vt.edu (Joel K. Furr) writes: >>: In article <1992Dec22.185915.27317@hpcvaac.cv.hp.com> billn@hpcvaac.cv.hp.com (bill nelson) writes: >>: >: >>: >: Well, stay tuned. Object 1992QB1 is reckoned to be a good candidate for a >>: >: distant (40-50 A.U.) minor planet and may be the first of many discovered at >>: >: that distance. >>: > >>: >The statement was asteroid - not planetoid. The asteroids originate in the >>: >asteroid belt. It is doubtful if any of them could be perturbed enough to >>: >reach the orbit if Neptune. >>: > >>: >The planetoids are a different matter. It is possible that some of them >>: >came from outside the Solar System. They could also have been formed just >>: >about anywhere in the system, so the same limitations do not apply to >>: >them. I would not argue that a planetoid could not have been captured >>: >by Neptune - although the fact that Pluto has a moon makes this very >>: >unlikely. >>: >>: No, Bill, you're wrong. There are many flat-out ASTEROIDS that orbit that >>: far. You're not an astronomer, don't lecture us from a vacuum of knowledge. >> >>I could easily be wrong. This is AFU - after all. >> >>Guess I will have to do some study of the recent research. Do you have some >>cites to simplify my astronomical task? >> > >Well, yes. I've been trying to get into a library to get actual books to >cite from, but they're all closed here at Va. Tech for the holiday. You >claim that all true asteroids orbit between Mars and Jupiter. Then, I ask >you, what about the asteroids that show up in the papers zooming past >Earth every so often? Every year or so they tell us that another one came >within a million miles. Furthermore, although the name of the asteroid >class escapes me while I'm unable to get at books, there is a whole class >of asteroids that spends most of their time out around Saturn and beyond, >in highly elliptical orbits that infrequently bring them in nearer the >Sun. Saturn and Jupiter now have so many moons verified as orbiting them >that it's not big news anymore. Each has ten or so tiny rocks that used >to be asteroids orbiting way out. From what I recall reading in astronomy >books, some of these will orbit their gas giant for a few million years >and then escape again. Pluto's "moon", however, doesn't strike me as a >likely asteroid capture because Pluto just wouldn't have the gravitational >pull to snag something nearly as large as itself and keep it there. I post this whole mess to sci.space and say "help" because it seems that one side in a.f.u. is arguing as follows: _all_ asteroids occur between the orbits of Mars and Jupiter. Therefore Neptune, Pluto, etc. could not possibly have captured asteroids because asteroids don't go out that far. Joel "a rose by any other name would probably still cost a lot around the middle of February" Furr jfurr@polaris.async.vt.edu ------------------------------ Date: 23 Dec 92 23:52:29 GMT From: nsmca@acad3.alaska.edu Subject: DCX/DC-1/DC-0 and what is it.. Newsgroups: sci.space I must have missed something, I speak from ignorance, so please forgive me. What is the DCX or DC-1 or DC-0? Please email me some info on it.. Thank you. Michael Adams alias Ghost Wheel/Morgoth NSMCA@acad3.alaska.edu ------------------------------ Date: Wed, 23 Dec 92 22:46:22 EST From: John Roberts Subject: Depleted uranium -From: vulch@kernow.demon.co.uk (Anthony Frost) -Subject: Re: Breeder reactors -Date: 23 Dec 92 00:14:34 GMT -Organization: VCS Kernow - >> cost? (For that matter, how much does U235-depleted uranium - >> cost?) - > I'd think it should be free to anyone wanting to haul it - > away (though the governement probably doesn't treat it that - > way). -I believe a fair quantity of it gets used in munitions. A depleted uranium -slug coming out of some form of gun goes through armour plating quite -nicely. Apparently, along with the bits that go bang, kids in Kuwait are -encouraged not to pick up any they see round the desert due to slight -residual radioactivity! The antimissile Phalanx guns on warships use uranium slugs. I don't know about other weapons. I believe depleted uranium is also used as ballast in commercial aircraft. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Wed, 23 Dec 92 22:59:32 EST From: John Roberts Subject: Famous quotes -From: 0001964967@mcimail.com (Daniel Burstein) -Subject: numerous/ 1:ASAT 2:Water 3:misquotes -Date: 23 Dec 92 15:53:19 GMT -b) On a different topic, some people have given the -wrong attribution to the saying "because it's there." -As per Bartlett's sixteenth edition, p. 593, this quote -was -not- from "EH", but was by George Leigh Mallory, who -used it to explain why he wanted to climb Everest. Don't forget the famous Far Side cartoon: A group of climbers, poised at the edge of a deep gorge. The leader, apparently responding to a question from one of the other climbers: "Because it's *not* there." :-) John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 24 Dec 92 02:31:58 GMT From: David Smith Subject: fast-track failures Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: >In <1992Dec20.192544.2996@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes: > By the time you add in all the overhead (benefits, office space, social security) yah, an engineer does cost you $100K. That's the figure I've seen used at a number of companies as a rule of thumb for costing out projects. -- David L. Smith smithd@discos.com or davsmith@nic.cerf.net ------------------------------ Date: 24 Dec 92 00:01:22 GMT From: Henry Spencer Subject: Giotto Sample Return ? Newsgroups: sci.astro,sci.space In article <1992Dec23.194709.4135@bnlux1.bnl.gov> wagener@gown.das.bnl.gov (Richard Wagener) writes: >... Its [Giotto's] orbit brings it to within 210000 km of Earth on >July 1, 1999. Although the spacecraft still has some fuel left, ESA >has no plans for more Giotto missions. - Stephen Cole > >Is there enough fuel to change the orbit for a closer encounter >with Earth? Could it be aerobrake'd into a stable orbit from which it >could be captured and returned by the shuttle? Giotto couldn't safely do more than the most minimal aerobraking; it's not built for it. It could do a very small aerobraking maneuver, as was done by Hiten and as the Magellan team hopes to do, but it wouldn't be enough to accomplish much. (The Magellan aerobraking will -- if done -- be able to lower Magellan's orbit quite a bit, but only because Magellan will fly an aerobraking maneuver every hour or two for *months*. Giotto only gets one pass.) There is undoubtedly enough fuel to target for a closer Earth encounter, if you start early. It doesn't take much to make that big a difference when it accumulates over a period of years. Problem is, there probably isn't enough to fly a useful third mission, e.g. another comet encounter. There certainly isn't enough to make any kind of Earth orbit. A secondary problem is that it's not clear ESA will still be able to talk to Giotto in 1999. Maintaining such a capability (while facilities get modernized for other purposes) costs money, and it may not be thought worth the trouble. >Would the returned probe contain scientifically useful cometary >samples? The encounter velocities were rather high, especially at Halley, but some useful science could undoubtedly be done, if the thing could be retrieved easily. -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 24 Dec 92 04:27:00 GMT From: Greg Moore Subject: Greek Science (was Re: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec23.141408.1860@murdoch.acc.Virginia.EDU> rbw3q@rayleigh.mech.Virginia.EDU (Brad Whitehurst) writes: >In article <_ft2g9b@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes: >> Actually, before you start blaming the Greeks, keep in mind >>that they had a good idea the earth was curved. They even developed >>a rough approximation of the diameter based on the shadow of the sun. >> >> It was a Greek (the name escapes me) that described a >>heliocentric solar system. Unfortunately Plotemly had better press. >> > I KNOW IT!!!! Why do you think I made the allusion? I'M NOT >BLAMING GREEKS!!! Alright, for the metaphorically impaired: Greek >mathematicians (don't remember name..started with "T") showed the >Earth was round and estimated diameter using the relative positions of >shadows at the bottoms of wells. DESPITE this marvelous scientific >work, the general belief that the world was round did NOT become >accepted until some damn-fool sailors went out and PROVED it. That >was my whole point...that otherwise perfectly intelligent people hold >to certain views until some daredevil goes out and DEMONSTRATES the >contrary, usually by doing something that everyone tells him will get >him killed! Sorry, I missed your metaphor. It sounded to me like you were saying that the Greeks were great at science but couldn't determing that the earth was round. You are right, the general belief was that the earth was not round. (And it's turtles all the way down. :-) However, among the educated, the truth was known. Even most sailors at knew the earth was at least curved (as islands and such dissapeared over the horizon). Even today a friend ran into someone who didn't know how we could communicate with satellites near Saturn, "After all, space is a vacumn, and how can you hear radio waves in a vacumn." Or even ask most people what an atom looks like. They will describe a nice looking atom that lokos like and behaves like the solar system. However, perfectly intelligent people know a little better. It's interesting to listen to how people believe that Columbus proved the world was round. Actually, he and most people he argued with didn't debate that point. His claim was that the earth was about 12,000 miles in diameter. Most people believe he was way off and they were right. Lucky for Columbus Pangea had broken up millions of years before and provided the America's for him to run into. >*Flame off* If you feel the need to flame for someome simply missing a metaphor, have fun... Not taht I really think the above was a flame... I've seen worse flames. You at least stuck to the topic. :-) > Sorry, but sometimes I despair at getting a net.point across >with any attempt at subtlety or metaphor. Loosen up a little and >avoid too much literalness! :-) As I teach people in the email class I teach for one of my clients, ALWAYS be careful with attempts at subtlety in the spoken word, especially in email. It tends to get lost. And right now, I'm pretty loose. I got the one major project I had to do before the holiday done! > Anyway, time to pack the bags and the presents, go tune up the >sleigh, and file some flight plans! :-)*** > Peace on Earth (and off!), and goodwill to all men. > Same to you. >Merry Christmas! > >-- > >Brad Whitehurst | Aerospace Research Lab >rbw3q@Virginia.EDU | We like it hot...and fast. ------------------------------ Date: Thu, 24 Dec 1992 04:14:52 GMT From: Greg Moore Subject: ground vs. flight Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1jt2zfd@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes: >> I wasn't aware of this. What did Michael Collins do while on >>the Agena? > >Apart from just generally evaluating how easy it was to do -- not very -- >he retrieved a micrometeorite experiment package that had been put on >the Agena in hopes that it could be returned to Earth eventually. > Actually Henry, that supports my original point, that EVA to and on and unstabilized platform isn't easy. However, I do find that this was sone very interesting. Any idea how much if any tumbling the Agena was doing? >> ... what is >>the maximum mass that the RMS can handle? > >I think it's rated for the theoretical maximum shuttle payload, 65klbs. >It's not rated for the full mass of an orbiter, which is why the station >arm will eventually take over the capture-for-docking job. > I meant to ask about this earlier. I thought at one point I saw a diagram for a special "arm" to do this, basically something that could pull in and out, and may wiggle the end a bit. Was this just a mistake? or was this dropped. Also, given that the bottom of the shuttle is covered with tile, can the orbiter exert a Y+ (i.e. vertically up) translation? This is something that I've always wondered. >> BTW, what has the success rate been with the RMS on grabbing >>stuff with a handle? Anyone have any clue? 80% 90%? Let's >>not even consider the stuff it's had to attempt to grab that didn >>have handles... > >The arm really *can't* grab anything that doesn't have a proper grapple >fixture on it, because the "hand" isn't a general-purpose gripper -- it's >designed solely and only to grab grapple fixtures, and is very specialized >for exactly that job. > Hmm, I'd have to look over what I was thinking of. I'm aware of the design on the end effector, so I should have thought about the question better. :-) >As far as I know, the success rate for grapple fixtures is 100%. They've >sometimes had to proceed slowly and carefully, but I don't think they've >ever had to abandon a grabbing attempt. Didn't they ahve to manually slow down a rotating satellite since the arm couldn't grapple the fixture fast enough? (Solar Max?) >-- >"God willing... we shall return." | Henry Spencer @ U of Toronto Zoology > -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 24 Dec 92 03:55:59 GMT From: Greg Moore Subject: I thinI see our problem. (Was Re: Terminal Velocity of DCX? Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: >In strider@clotho.acm.rpi.edu (Greg Moore) writes: > >> In reality it sounds more like you are talking about DC-10, >>DC-12, etc. >> Unless you are saying that a 747 is the same plane as a DC-3 >>was. >> If your claims are about 50 years from now, or even 20 >>eyars from now, I'll buy them. > >I think it would do you a world of good to go out to your local >airport and look around. > Are you stupid, or do you jsut like being argumentative? >Do you have any idea how many DC-3s are still flying? After 50 >years? > I never claimed that DC-3's aren't flying. What I am claiming, is taht DC-3's aren't flying 400+ passengers on trans-atlantic routes. 747's are. And 747's came long after the DC-3. To make it a little clearer, since you seem to want to twist everything I say: DC-1 won't do everything. It may do a lot, and Joe Schmoe SpaceLines may be flying one in 2095, but by 2095 I expect we'll have the space equilavent of the 747. >And the 747, which you cite as an example of a modern airplane, >is well over 20 years old! > So? What's your point? Let me make my point clear: "DC-1 will NOT be doing everything from satellite delivery to satellite repair, to delivering cabbages, to lunar landing, to fuel supplies, etc within the next 5 years. Perhaps not even within the next 10. But, it's follow-ons will do even more. A DC-3 doesn't do everything. That's why we have the DC-9, DC-10, L-1011, 747-100,200,300,400 etc." > ------------------------------ Date: 24 Dec 92 00:34:37 GMT From: Henry Spencer Subject: Latest Pegasus news? Newsgroups: sci.space In article <1992Dec23.201155.29373@microsoft.com> steveha@microsoft.com (Steve Hastings) writes: >What are the Pegasus folks up to right now? The third launch is slated for January. If that works out okay, they hope to ramp things up very quickly in 1993. There's a backlog of payloads waiting for the second-launch problems to be solved. (Yes, problems plural: apparently they had both a first/second-stage separation problem, and a fairing-separation problem.) (Yet more proof that God did not mean us to build rockets that shed parts on the way up. :-)) -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 23 Dec 1992 17:23:40 MST From: "Richard Schroeppel" Subject: Lunar ice I notice the proposed LEI probe doesn't include imaging. (1) How do they know where the probe is looking when it's taking data? (2) Since "permanent solar shadow" != "permanent Earth shadow", how about looking for ice glints by Earthlight? Rich Schroeppel rcs@cs.arizona.edu ------------------------------ Date: 24 Dec 92 04:16:03 GMT From: Brian Stuart Thorn Subject: MOL (was Re: Terminal Velocity of DCX? (was Re: Shuttle Newsgroups: sci.space >In article henry@zoo.toronto.edu (Henry Spencer) w >rites: >>In article <1h2egpINNmk9@mirror.digex.com> prb@access.digex.com (Pat) writes: >>>>>You heard wrong. One MOL flew (unmanned). >>>>Could somebody provide data ? >>> >>>According to a friend of mine who was a MOL engineer. One MOL flew >>>Manned. only it was called ASTP. >> >>He's pulling your leg. ASTP involved one Apollo, one Soyuz, and a docking >>module. The docking module might perhaps have inherited a bit of technology >>from MOL, but no way was it a MOL. For one thing, it was a fraction of the >>size. > >The very first MOL flight (and only one, if I recall correctly) >was basically a test of the Titan III, on its way to being man-rated. >(Does anyone remember if the strap-ons were solids?) The MOL was a >mock-up, just a cylinder the right size and shape. The Gemini capsule >was a donation to the Air Force from NASA, the former "Gemini 2" >capsule that had flown unmanned. > >I think it all orbited for a few days before burning on reentry. Yes, >it was certainly unmanned. > >tombaker >#include > The MOL launch used a standard Titan IIIC but was designated as Titan IIIM for the MOL program. It's strap-ons were indeed solids. -Brian ------------------------------------------------------------------------- Brian S. Thorn "If ignorance is bliss, BrianT@cup.portal.com this must be heaven." -Diane Chambers, "Cheers" ------------------------------------------------------------------------- ------------------------------ Date: 24 Dec 92 04:16:41 GMT From: Brian Stuart Thorn Subject: MOL (was Re: Terminal Velocity of DCX? (was Re: Shuttle Newsgroups: sci.space >No, this guy was quite serious. he said that something called "Apollo >Telescope Mount" was the SOn of MOL. It was my mistaken assumption that >that meant it had been recycled into the ASTP. Dennis newkirk and i >have exchanged e-mail on this. I am wondering if he was referring >to the astronomical section of SKYLAB? he was dead serious about >this part, i dont think he was having a go with me. > >Henry, do you think this was the case? he implied that it had been >transmorged, but that it still had a lot of MOL-like systems and fixtures. > >pat > The SkyLab Apollo Telescope Mount looked nothing like an MOL, in size shape or function. In fact, early SkyLab drawings showed a converted Lunar Module serving as the ATM. I think the flight article was a one-of-a-kind NASA design unrelated to MOL. Some instruments aboard may have had their origin in MOL, but ATM was a solar telescope, so what did MOL donate to it? -Brian ------------------------------------------------------------------------- Brian S. Thorn "If ignorance is bliss, BrianT@cup.portal.com this must be heaven." -Diane Chambers, "Cheers" ------------------------------------------------------------------------- ------------------------------ Date: Wed, 23 Dec 92 22:23:23 EST From: John Roberts Subject: Overhead -From: ewright@convex.com (Edward V. Wright) -Subject: Re: fast-track failures -Date: 23 Dec 92 23:06:47 GMT -Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA -In <1992Dec20.192544.2996@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes: ->Today's overhead is horrible, but $100,000 1940s dollars is only about ->$2 million 1992 dollarettes.... That's about 20 engineers in a Motel 6 ->for six months, no machine shops, hangers, mechanics, flight test equipment, ->nada. -You think a typical engineer earns $100,000 a year? You're assuming 100% overhead on the engineers' salaries? That may be a trifle low. (I believe the allowance for overhead varies from company to company.) On the other hand, overhead of a Motel 6 might be less than that of an engineering facility. :-) John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Thu, 24 Dec 1992 04:06:28 GMT From: Greg Moore Subject: Pilots must be stupid? (Re: DC vs Shuttle capabilities Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: >In strider@clotho.acm.rpi.edu (Greg Moore) writes: > >>>You can walk from one place to another carrying a four-ton >>>cargo container? On Earth? I doubt it. > >> Carry it while walking? no, but I can drive it. > >If you have a flat tire? > I think I never made my original point clear enough, though Hnery did later elaborate on it. On earth you have friction and gravity that aid in controlling the movement of objects (granted, they also do create some problems). >See, for every "greater difficulty" you can think of in >space, I can think of one on Earth. > Gee, good for you. Now, since it has been made clear to me that a DC-1 will have a docking capability, (and as I already assumed, a RMS could and probably will be built) I withdraw my objections. But, if you wish to pick nits, go right ahead. I'm going on vacation. > >> Again, I think I see were we are differing. See my other >>post on timeframes. But to recap, I agree, after a couple thousand >>more hours of EVA time, we'll have a lot more down. > >If the cost of putting one man into space was $50,000, instead >of $5,000,000, you'd be able to rack up a thousand man-hours >of EVA time pretty fast. > And I don't argue with that. That's why I support DC-X. It's also why I support NASA's decision to increase the number of EVA's on upcoming flights. Granted, shuttle flights are expensive, but since they are the only manned access we have right now (until DC-1 or whatever comes on line), we might as well make use of it. It adds to the database of experience. > >>A diver can swim back. Or, with enough air (which they should >>always have) resurface. > >Not if they're SEALs in a combat zone. Or cave divers. Or >under ice. Or working in an underground sewer system. All >of which are done routinely today. > What can't be done? Swimming back? or planning on having enough air? I don't know a single cave diver who doesn't make sure she has a way out and enough air to get back (plus a healthy reserve). Besides, this is a nit pick. It does nothing to dispute my claim that an astronaut who "floats" away can have more serious problems. > >>>What makes you think a DC-1 can't accomplish a hard docking. >>> >> I wasn't aware that it could. This I understand would >>have to be an added capability? HOw does it dock? through the >>nose? or along the side? > >The McDAC illustration shows it docked alongside. I'm sure >the docking adapter would be an added capability, carried in >the cargo bay. Why carry it along on flights where you don't >need it? > Makes sense to me. Shuttle does that, so it would make even more sense for a cost-effective system like DC-1 to make every pound count. >If you consider this a problem, well, the Shuttle's docking >adapter works the same way. > I realize that. Actually, Shuttle's docking adapter WILL work taht way... they haven't docked to anything yet. > > > ------------------------------ Date: 24 Dec 92 04:17:25 GMT From: Brian Stuart Thorn Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity Newsgroups: sci.space >Correct. But Shuttle is now flying at or very near its maximum rate. >A working DC (if it works) will have much higher flight rates and can >thus amoritze over more flights. No, I disagree here. NASA has never had four working shuttles in service at the same time (not even late '85, Discovery was down for Vandenberg preps) so we cannot yet say Shuttle is flying at its peak. Near yes, if you consider three or four more flights per year 'near'. I think NASA could easily handle 12 flights per year, but politics has forced them to cut down to eight. In 1992, all four orbiters flew twice, but Discovery was offline from February to November, Columbia offline from January to May, and Atlantis offline from August to December. Take away those downtime periods and you can add three more flights. This is all moot, since NASA apparently does not want to push its luck prior to SSF assembly, but it does show that the launch rate is lower than it could be. >>Right now, if you stopped all flights, >>you could argue this cost (excluding interest) is about $150 million >>a flight. (10 flights/orbiter, $1.5 Billion per orbiter). > >You left out the $34 billion (in 86 $$) development costs which must >be amortized. Which is probably why Boeing has not taken the plunge into the SST airliner or a 747 successor. This cost seems to effect just about everything except the DC series. -Brian ------------------------------------------------------------------------- Brian S. Thorn "If ignorance is bliss, BrianT@cup.portal.com this must be heaven." -Diane Chambers, "Cheers" ------------------------------------------------------------------------- ------------------------------ Date: 24 Dec 92 00:09:17 GMT From: Henry Spencer Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX? Newsgroups: sci.space In article steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes: >... And are you sure that the first 747 didn't >fly? Even the first 707 flew and that was a far more groundbreaking >test article... >Henry, you there to arbitrate? I'm not up on the details of the 747's history, but there was (possibly still is) a fatigue-test airframe tucked away in a building at Boeing, being pressurized and depressurized and stressed and relaxed regularly, simulating flight cycles at a greater rate than operational 747s to clear their structures for continued operation. It wouldn't be a fully- fitted-out 747, but all the structure would be "for real". This is part of the cost of safety certification for most any substantial aircraft. -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ To: bb-sci-space@CRABAPPLE.SRV.CS.CMU.EDU Newsgroups: sci.space Path: crabapple.srv.cs.cmu.edu!cantaloupe.srv.cs.cmu.edu!rochester!udel!gatech!usenet.ins.cwru.edu!agate!spool.mu.edu!uunet!microsoft!wingnut!steveha From: Steve Hastings Subject: Latest Pegasus news? Message-Id: <1992Dec23.201155.29373@microsoft.com> Date: 23 Dec 92 20:11:55 GMT Organization: Microsoft Applications Division Lines: 7 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU What are the Pegasus folks up to right now? I have a sci.space posting from 1990 that speculated that by the end of 1992, there might be one Pegasus launch per *month* (thus, 12 launches in 1993). I don't think this is happening. But what is happening? -- Steve "I don't speak for Microsoft" Hastings ===^=== ::::: uunet!microsoft!steveha steveha@microsoft.com ` \\==| ------------------------------ End of Space Digest Volume 15 : Issue 592 ------------------------------