Date: Sat, 26 Dec 92 05:00:03 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #598 To: Space Digest Readers Precedence: bulk Space Digest Sat, 26 Dec 92 Volume 15 : Issue 598 Today's Topics: ** BUSSARD RAMSCOOP ** Acceleration, cats Aurora chase planes (was Re: Aurora) EVA troubles (Was Re: ground vs. flight Justification for the Space Program (6 msgs) Manhattan DISTRICT (not Pr......) SSTO vs. 2 Stage Terminal Velocity of DCX? (was Re: Shuttle ...) The Real Justification for Space Exploration 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: 24 Dec 92 17:18:53 GMT From: Jason Cooper Subject: ** BUSSARD RAMSCOOP ** Newsgroups: sci.space Was told to put this message in this area to get more replies, so here it is. I'm doing a science fair project on the Bussard Ramscoop, and am looking for ANY help I can get on the scientific end of it. I'm looking for help specifically on the general theory end of it (things like what polarity the field must be, how best to ionize the hydrogen, how best to FUSE the hydrogen, etc, all already worked out, but in need of checking by somebody who KNOWS what they're doing). Jason Cooper ------------------------------ Date: 25 Dec 92 18:06:59 GMT From: Bruce Dunn Subject: Acceleration, cats Newsgroups: sci.space > John Roberts writes: > > 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. > I think that the main cause of differences in the ability of different creatures to survive falls is our old friend, the square cube law: Count a child as having half the linear dimensions of an adult. Relative to an adult, the "squash room" available for deacceleration is related to the linear dimension (1/2 of an adult). If children had the same body plan as adults, a "half adult size" child would have a mass proportional to her volume, which is proportional to the cube of her linear dimensions --- the child would have a mass of 1/2*1/2*1/2 = 1/8 of the adult (real kids hare probably heavier than this due to the relatively larger sizes of their heads in the overall body plan). Stored energy in a falling body is proportional to mass. The child thus has 1/2 the distance for deacceleration, but 1/8 the energy to get rid of by deformation etc. Mice do quite well when dropped a few meters. Dropping an elephant the same distance would probably create an insurance writeoff. The difference is related to body size, not the special body defences that cats have in addition to their natural size protection (I wouldn't want to drop my pet lion from the balcony of a 10th story apartment). -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ Date: 25 Dec 92 20:02:03 GMT From: Henry Spencer Subject: Aurora chase planes (was Re: Aurora) Newsgroups: sci.space In article shafer@rigel.dfrf.nasa.gov (Mary Shafer) writes: >... Remember that flight test, including the chasing, is >only done by test organizations; operational squadrons (the people who >routinely fly with weapons) are only rarely involved. Dryden, for >example, has absolutely no weapons... A side issue here is that many people don't understand that weapons are *dangerous*. Contrary to what you might think from half-baked war movies, properly-trained troops treat even hand grenades with great respect and considerable caution. Live missiles are dangerous to handle, dangerous to carry, dangerous to have around. Even *storing* them safely takes care and effort. Aircraft don't fly armed without good reason. -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 25 Dec 92 20:07:19 GMT From: Henry Spencer Subject: EVA troubles (Was Re: ground vs. flight Newsgroups: sci.space In article strider@clotho.acm.rpi.edu (Greg Moore) writes: >I'd assume the latter, to safe fuel, and to allow it to "float by' if >something goes wrong. With a Y+ translation if an 'up" thruster >(to stop the Y+ movement) fails, you risk running the shuttle into the >orbiter. With the X+, if something fails, you just float on by... The thruster systems are redundant; a single jet failure won't destroy the ability to maneuver in a particular direction. >>Leasat repair, the hardware was kept very simple and the astronauts' >>arms did almost all the work. (How quickly they forgot these lessons...) > > I don't recall what Leasat was. Could you give me some private email >sometime to jog my memory? (Easier to just include it here, in case anyone else is wondering...) That was the "Frisbee launched" satellite, aka Syncom, which couldn't light its boost motor after deployment from an earlier shuttle mission. > It seems like a good argument for satellite manufacturers to include >a grapple point... If memory serves, the head of Intelsat has said "henceforth we put grapple fixtures on our satellites". Not very likely that there'll be any use for one any time soon, but it sure does save a lot of hassle when the occasion does arise. -- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 25 Dec 1992 10:13:08 GMT From: Bill Blum Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec22.232911.17212@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >In article <22DEC199214411374@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: > > > I will no longer debate you on this subject. You have your "opinions", > > which is all your responses to date have been, and I have mine. You > > work for your worldview and we will work for ours. > > > > You speak of quasi-religiousness when the exact same thing can be said > > of your asserations. > >Oh, *please*. I've posted numerous quantitative arguments in rebuttal >to your claims. I can even provide references for those numbers, if >you'd like. Oh *please*. Both sides can drag quantitative arguments out of every nook and cranny of every publication in existence until the rest of USENET dies at their terminals. Yes, I believe in space exploration. I don'T subscribe to the belief that it is absolutely necessary for survival...I do think that it serves a purpose, and should be continued. I believe that there are some amazing possibilities out there, beyond Earth'S orbit. I've noticed that many people consider "dreaming" about such things and working towards it with all we can bring to bear too overzealous. May I remind some of the skeptics that the Internet itself was the product of a bunch of people who's sole puropose was to ensure a network by which NORAD could communicate. Zealotry pays off in ways you can't imagine in the short term. > > I have work to do. I live in the real world. If you actually think > > things are getting better from a world perspective then you are truly > > blind. This is a simple fact, not a flame. > >By most objective measures, the world is getting better. The world >has never been, on average, wealthier, healthier, better fed, or >better educated than it is today. These are *facts*. You can look up >the numbers. These trends have been going on for decades, in spite of >the continuous (and continuously wrong) doomsaying. Gee, Mr. Dietz. Go to Somalia. Talk with the people. They would strongly disagree with you about being better off. It is a FACT that the future is uncertain. (_Introduction to Nuclear Engineering_, 2nd Edition, John Lamarsh) -begin quote- Whether sufficient uranium will be available to fuel expanding world nuclear capacity is an issue of continuing controversy even among experts. Uranium itself is not an especially rare element. It is present in the earth's crust at a concentration by weight of about four parts per million, which makes uranium more abundant than such common substances as silver, mercury, and iodine. There are an estimated 10^14 tons of uranium located at a depth of less than 12 or 13 miles, but most of this is at such low concentrations it WILL PROBABLY NEVER BE RECOVERED, (boldface added by me) -end quote- Yes, Mr Dietz, there are abundant supplies of some materials on Earth. But be nice to the zealots...they occassionally come up with some brillant ideas which influence a lot of people. Like the Internet. Often, zealots lose sight of reality. YEt just as often, skeptics lose their clues. Here's wishing everyone a Merry Christmas, and a Happy News Year, and (insert any other holiday I missed here). -- Bill Blum * "God willing...we shall return." Purdue University * Gene Cernan, The Moon, Dec 1972(BSEE P.U. 56) School of Nuclear Engineering * Member of the SEDS National Board blumb@sage.cc.purdue.edu * Ad Astra Per Ardua!! ------------------------------ Date: Fri, 25 Dec 1992 13:03:15 GMT From: Paul Dietz Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article blumb@sage.cc.purdue.edu (Bill Blum) writes: >>By most objective measures, the world is getting better. The world >>has never been, on average, wealthier, healthier, better fed, or >>better educated than it is today. These are *facts*. You can look up >>the numbers. These trends have been going on for decades, in spite of >>the continuous (and continuously wrong) doomsaying. > Gee, Mr. Dietz. Go to Somalia. Talk with the people. They would strongly > disagree with you about being better off. What a load of crap. Of course there are people who are in bad situations. But these extreme points prove nothing, except that the world is not completely perfect. As I said, ON AVERAGE, the world is getting better. Fewer people (in absolute numbers, not just as a fraction of the world's population) are living in countries that experience famines that did a generation ago. On average, people are getting more nutrition, and living longer. >It is a FACT that the future is uncertain. >(_Introduction to Nuclear Engineering_, 2nd Edition, John Lamarsh) >-begin quote- > > Whether sufficient uranium will be available to fuel expanding > world nuclear capacity is an issue of continuing controversy even among > experts. Uranium itself is not an especially rare element. It is present > in the earth's crust at a concentration by weight of about four parts per > million, which makes uranium more abundant than such common substances as > silver, mercury, and iodine. There are an estimated 10^14 tons of uranium > located at a depth of less than 12 or 13 miles, but most of this is at such > low concentrations it WILL PROBABLY NEVER BE RECOVERED, (boldface added by > me) I cannot imagine what you are trying to prove by this quote. Let's consider a world with 10,000 1 GWe reactors. It will consume somewhere less than 20,000 tons of uranium per year. Those 10^14 tons would last 5 billion years at that rate. So, indeed, much of that uranium never gets recovered -- because it decays, or the sun burns out, before we need it! Note that being at a depth of 12 or 13 miles doesn't really matter, because we would use it so slowly that erosion (and isostatic uplift) would move it to the surface sufficiently quickly. I understand that if you pulverize granite and wash with acid, about 1/3 of the uranium and thorium can be easily mobilized (the rest could be recovered by more vigorous treatment). This fraction eluted from a ton of granite is equivalent to about 15 tons of coal, if used in some sort of breeder. However, no doubt richer deposits will be attacked first (for example, organic-rich shales; the Chattanooga Shale, for example, is estimated to contain 5 million tons of uranium at about 60 ppm). I know of no nuclear experts who think there is not sufficient recoverable uranium to run a breeder-based economy for far longer than is reasonable to plan for. There is some controversy on how long burner reactors can be fueled without breeding, especially if the number of such reactors grows. Fortunately, accelerator breeders can be used to make fuel for burner reactors, with a doubling time of about 3 years, so if fuel ever did become unexpectedly short we could adapt quickly. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 25 Dec 92 17:43:41 GMT From: Herman Rubin Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec25.130315.12336@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >In article blumb@sage.cc.purdue.edu (Bill Blum) writes: >>>By most objective measures, the world is getting better. The world >>>has never been, on average, wealthier, healthier, better fed, or >>>better educated than it is today. These are *facts*. You can look up >>>the numbers. These trends have been going on for decades, in spite of >>>the continuous (and continuously wrong) doomsaying. >> Gee, Mr. Dietz. Go to Somalia. Talk with the people. They would strongly >> disagree with you about being better off. >What a load of crap. Of course there are people who are in bad >situations. But these extreme points prove nothing, except that the >world is not completely perfect. As I said, ON AVERAGE, the world is >getting better. Fewer people (in absolute numbers, not just as a >fraction of the world's population) are living in countries that >experience famines that did a generation ago. On average, people are >getting more nutrition, and living longer. Baloney. The US economy is in a shambles, and will probably continue to go downhill. In real terms, income and incentives are DOWN. The universities are giving in to the almost illiterate (at least in mathematics and the sciences) high school preparation of the students, and contributing to the demise of our academic and research capabilities. The government wants to essentially abandon the pure research on which the future depends. Our taxes go to pay interest on our mistakes, and most of the rest goes to encourage incompetence. The overpopulation of the world, and also of the US, is increasing at an alarming rate, and the "politically correct" thing to do is to keep encouraging this to go on at an even greater rate. This is by actions, not by words which nobody listens to. >>It is a FACT that the future is uncertain. >>(_Introduction to Nuclear Engineering_, 2nd Edition, John Lamarsh) >>-begin quote- >> Whether sufficient uranium will be available to fuel expanding >> world nuclear capacity is an issue of continuing controversy even among >> experts. Uranium itself is not an especially rare element. It is present >> in the earth's crust at a concentration by weight of about four parts per >> million, which makes uranium more abundant than such common substances as >> silver, mercury, and iodine. There are an estimated 10^14 tons of uranium >> located at a depth of less than 12 or 13 miles, but most of this is at such >> low concentrations it WILL PROBABLY NEVER BE RECOVERED, (boldface added by >> me) >I cannot imagine what you are trying to prove by this quote. Let's >consider a world with 10,000 1 GWe reactors. It will consume >somewhere less than 20,000 tons of uranium per year. Those 10^14 tons >would last 5 billion years at that rate. But we cannot build nuclear plants which are safer than the coal plants. And those who do not recognize the value of human ingenuity want us to waste the time of the productive people by making them wait for public transportation, and keeping the bright from getting an education by putting them in classes with the mentally deficient. Communism may be passe in the former Soviet Union and Eastern Europe, but some of the worst aspects of it are pervading Western Europe and the United States. What else can one call the government blocking of human endeavor, including going to space? Name ONE sufficiently large (to accomplish) country in which the individual with enterprise is not boxed in by the socialists who insist that the wealth must be shared. -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 Phone: (317)494-6054 hrubin@snap.stat.purdue.edu (Internet, bitnet) {purdue,pur-ee}!snap.stat!hrubin(UUCP) ------------------------------ Date: Fri, 25 Dec 1992 18:28:10 GMT From: Paul Dietz Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article hrubin@pop.stat.purdue.edu (Herman Rubin) writes: >>world is not completely perfect. As I said, ON AVERAGE, the world is >>getting better. Fewer people (in absolute numbers, not just as a >>fraction of the world's population) are living in countries that >>experience famines that did a generation ago. On average, people are >>getting more nutrition, and living longer. >Baloney. The US economy is in a shambles, and will probably continue >to go downhill. The US economy is growing, not "going downhill". Manufacturing productivity is growing smartly. Moreover, the US is not the world. Less developed countries can and do use technologies that have already been worked out by the west; naturally, the tendency is for the underdogs to catch up, if the mechanisms for wealth creation are in place. Consider China. The private sector there will grow more than 20% this year, and exceed the size of the public sector; aggregate GNP growth will be in double digits. At current growth rates, China's GNP could exceed the entire OECD's by the year 2010. The per capita GNP could reach current US levels within a generation, at current rates of growth. >>I cannot imagine what you are trying to prove by this quote. Let's >>consider a world with 10,000 1 GWe reactors. It will consume >>somewhere less than 20,000 tons of uranium per year. Those 10^14 tons >>would last 5 billion years at that rate. >But we cannot build nuclear plants which are safer than the coal plants. Bullshit. Existing coal plants kill more people than existing nuclear plants, and we can build nuclear plants that have accident rates much lower than the current generation, low as they are. > Communism may be passe in the former Soviet Union and Eastern Europe, > but some of the worst aspects of it are pervading Western Europe and > the United States. What else can one call the government blocking of > human endeavor, including going to space? Name ONE sufficiently large > (to accomplish) country in which the individual with enterprise is not > boxed in by the socialists who insist that the wealth must be shared. Capitalism is quite robust, and can create wealth even in unfree countries, as the example of China demonstrates. Again, your argument confuses perfection (a probably unrealizable libertarian utopia) with progress (a world in which the aggregate statistics are improving). Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 25 Dec 92 18:31:01 GMT From: Joe Cain Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space Both Drs. Dietz and Rubin have made some good points. I hope the subject can now be changed to focus more on a specific facet with its own subject rather than continuing the present one whose thread seems to be all inclusive. There are now several cross discussions going with this reference and their own sub-threads. Joseph Cain cain@geomag.gly.fsu.edu cain@fsu.bitnet scri::cain Department of Geology B-160 Florida State University ------------------------------ Date: Fri, 25 Dec 1992 19:35:21 GMT From: Herman Rubin Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec25.182810.20775@cs.rochester.edu> you write: >In article hrubin@pop.stat.purdue.edu (Herman Rubin) writes: >>>world is not completely perfect. As I said, ON AVERAGE, the world is >>>getting better. Fewer people (in absolute numbers, not just as a >>>fraction of the world's population) are living in countries that >>>experience famines that did a generation ago. On average, people are >>>getting more nutrition, and living longer. >>Baloney. The US economy is in a shambles, and will probably continue >>to go downhill. >The US economy is growing, not "going downhill". Manufacturing >productivity is growing smartly. Moreover, the US is not the world. >Less developed countries can and do use technologies that have already >been worked out by the west; naturally, the tendency is for the >underdogs to catch up, if the mechanisms for wealth creation are in >place. The US economy might be growing in dollar terms, but not in real terms per capita. And one does not benefit if others catch up at one's expense. Academic salaries are lower in real terms now than 20 years ago, and the research which drives the future is being curtailed. The emphasis on short-term practical results is a vain attempt to keep a reasonable position, and will soon backfire. The US now has more government jobs than manufacturing. The universities are catering to the ignoramuses coming out of the high schools, and standards are just about dead. It is even getting into the doctoral program. We are paying far more to clean up the S&L fiasco, produced primarily by the government, than for all of our space activities. >Consider China. The private sector there will grow more than 20% this >year, and exceed the size of the public sector; aggregate GNP growth >will be in double digits. At current growth rates, China's GNP could >exceed the entire OECD's by the year 2010. The per capita GNP could >reach current US levels within a generation, at current rates of >growth. Does the world have enough resources for this? As I have often said that I consider the US substantially overpopulated for the available resources available to us, what will happen when China attempts to get 4 times as much of them? >>>I cannot imagine what you are trying to prove by this quote. Let's >>>consider a world with 10,000 1 GWe reactors. It will consume >>>somewhere less than 20,000 tons of uranium per year. Those 10^14 tons >>>would last 5 billion years at that rate. >>But we cannot build nuclear plants which are safer than the coal plants. >Bullshit. Existing coal plants kill more people than existing >nuclear plants, and we can build nuclear plants that have accident >rates much lower than the current generation, low as they are. There is a misunderstanding here. We agree on the safety, but the political climate will not let those nuclear plants be built. >> Communism may be passe in the former Soviet Union and Eastern Europe, >> but some of the worst aspects of it are pervading Western Europe and >> the United States. What else can one call the government blocking of >> human endeavor, including going to space? Name ONE sufficiently large >> (to accomplish) country in which the individual with enterprise is not >> boxed in by the socialists who insist that the wealth must be shared. >Capitalism is quite robust, and can create wealth even in unfree >countries, as the example of China demonstrates. Again, your argument >confuses perfection (a probably unrealizable libertarian utopia) with >progress (a world in which the aggregate statistics are improving). The world is not better off with 10 billion people making $5000/year on the average than with 2 billion people making $15000/year on the average. The first case will not support the individual drive, the exploration, the aspiration to the stars (any version of this) which the second will. Short run capitalism is quite robust, but the accumulation of excess wealth by individuals who will try to do something with it which those individuals, unfettered by the demands of the populace, feel worthwhile. Governments are not capable of doing this except when pushed by the exigencies of danger to their security or to national pride. We had better face the fact that without war we probably would not yet have done much in space, and without the cold war, not much beyond the technology of the early 1950s. A famous automobile executive stated that one should lead, follow, or get out of the way. Governments cannot lead, except other governments; they do not know how to follow, and they refuse to get out of the way. They have enough clout that only other governments can get around their blocking. Ours is now blocking progress on as many fronts as it can manage. -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 Phone: (317)494-6054 hrubin@snap.stat.purdue.edu (Internet, bitnet) {purdue,pur-ee}!snap.stat!hrubin(UUCP) ------------------------------ Date: 25 Dec 92 18:59:03 GMT From: Daniel Burstein Subject: Manhattan DISTRICT (not Pr......) Newsgroups: sci.space (note: I tried replying direct to the person who first wrote back to me, but the system refused to take his address. A problem we've all encountered once or twice...) ----- Transcript of session follows ----- 554 tffreeba@ivax... The site ivax does not exist in our domain To: tffreeba@ivax Subject: Re: numerous/ 1:ASAT 2:Water 3:misquotes Newsgroups: sci.space References: <1992Dec24.001733.201@ivax> The bit about calling the process the "Manhattan Project" has become so entrenched that you have to look har d to find it referred to by it's true name. The (unfrotunately) late Isaac Asimov used to comment about this specific mis-naming frequently in his columns, generally in the science articles he wrote for Fantasy and Science Fiction. I'll try to dig up a referenence or two from my pile. Other places the correct name appears are pretty rare. Generally, if you can find material written or produced immediately after the War, you'll find proper mention. For example, the movie "Beginning or the End" which is a semi-fictionalized documentary of the program has the top people sitting around the table. The actor playing General Groves says "You'll be working on the Manhattan District. Project 'Y' is uranium purification, project 'X' is the bomb site." (this is not the exact quote from the movie, but the DISTRICT vs. PROJECT distinction is correct) Or, more recently, NOVA did a segment on SZILARD, one of the prime scientists in the undertaking. In the interviews with various contemporiaries (damn, I forget who they spoke to/with), they constantly refer to it as the Manhattan DISTRICT. take care danny or <----direct e-mail address ------------------------------ Date: Fri, 25 Dec 1992 18:45:27 GMT From: Bruce Dunn Subject: SSTO vs. 2 Stage Newsgroups: sci.space Regarding my comments that a DC-1 used as an upper stage in a two stage vehicle would be able to survive an engine failure after separation... > Edward V. Wright writes: > However, you've overloaded the DC-1 to get that 5x payload capacity > you talk about. It's going to be over max takeoff weight. I am not quite sure what your argument is. The following explanation of takeoff conditions therefore may or may not answer your objections. Putting 5 times the payload on a DC-1 used as an upper stage only raises the gross mass slightly. A 500 ton DC-1 in SSTO mode with a 10 ton payload has a total mass of 510 tons. In two stage mode, the payload is raised to 50 tons which increases the total mass to 550 tons. I think you are arguing that this increased mass makes it impossible to deal with an engine out or engine start problem. However, you have forgotten that in contrast to a ground takeoff, the upper stage of a two stage vehicle is operating in a vacuum and has increased thrust. The increase in thrust depends on the engine expansion ratio and chamber pressure, but might be something like the 20% or so that the Shuttle SSME experiences in climbing from sea level to space. The increased thrust of a DC-1 in two-stage mode more than makes up for the payload increase. If any problems are created by the increased payload, they will be in the landing phase after an abort from a two stage launch. Assuming the payload isn't jettisoned, the landing mass will be roughly double that of am abort landing of an SSTO DC-1. This will require beefing up the landing gear if the DC-1 is used as an upper stage. In compensation, it would be possible to eliminate complicated extendible nozzles for the majority of DC-1 engines, with only a minimum set of engines capable of atmospheric operation in the event of an abort situation. > > Or if you have negative separation, or separation followed by a > collision, or several other scenarios you need to worry about. > > The problems of staging are not nearly as trivial as you make > them out. We have been launching staged rockets for nearly half a century. I think the problems of staging, if not trivial, are solvable. Certainly, historical evidence indicates that staging is less of a technical challenge than SSTO operation. For Edward and others tracking this discussion, I would like to again note that I am strongly in favor of the DC-1 SSTO concept. I am not proposing that the DC-1 SSTO capability be scrapped, or that a "DC-0" (to use Greg's nice name) be immediately developed. I think of the DC-0 as a potentially useful extension to an existing DC-1 flight program, to be developed if and only if: 1) Very large amounts of cargo have to be put into orbit. 2) A full scale cost study suggests that it is ***clearly*** less expensive to develop the two stage system than to simply build more DC-1s. I am of the opinion that when it gets closer to designing the DC-1, it would be helpful to keep the two stage concept in mind so that where possible design decisions favor approaches which would not rule out the later use of the DC-1 as an upper stage (for instance, using landing gear which could easily replaced with beefed up derivative rather than integrating the landing gear deeply into the body). Finally, I think that the two stage concept should be kept in mind as a potential backup strategy should the DC-1 fail to meet its performance goals. As I pointed out in a previous posting, an "obese" DC-1 which has even a zero payload to orbit in SSTO mode still would make a very fine upper stage for a two stage vehicle. -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ Date: 25 Dec 1992 20:27:18 GMT From: Pat Subject: Terminal Velocity of DCX? (was Re: Shuttle ...) Newsgroups: sci.space In article <1992Dec25.002926.4218@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >>their Shuttle. > >Nonsense. The Russians have built no space stations and are having >trouble raising the funds to operate the one they inherited from >the Soviet Union. Comparing what was done by a command economy using >what amounts to slave labor to what's done in an open society where >people expect to get paid fairly for their work is meaningless accounting. > a Consider that the russians/CIS/USSR built a major space program with the GNP the size of France. And by the Way, unlike the germans, or chinese i dont believe the russians have ever been charged with using slave labor. Now the russians had a strange command economy, but things still cost, but there were major problems in distribution. the russian/SU economy was sorta like massachusetts meets new york via sweden. high taxes, severe rent control and social provision of major services. SUre, they didnt pay their scientists what we paid them here, but they provided them with housing, medicine, etc. Also, the motivation of most russian space workers was so great, that they didn't mind the bad conditions. the problems within the russian system, were of productivity, design cycle, and provision of consumer goods. The chinese use slave labor, and then sell it over here. the russians paid their workers poorly, and the workers pretended to work. the gulags were not used as factories to my knowledge. ------------------------------ Date: Fri, 25 Dec 1992 10:24:48 GMT From: Bill Blum Subject: The Real Justification for Space Exploration Newsgroups: sci.space,talk.politics.space In article yamauchi@ces.cwru.edu (Brian Yamauchi) writes: >Asking "why explore space?" is like asking "why feed the starving?", >"why create art?", or "why do basic science?" It all comes down to >basic human drives, and I would argue that the drive to explore is >just as basic as the drive to help, to create, or to learn. Good point, Brian. That's like asking "Why flame people on USENET?" It's just a basic, human desire. > >The major achievement of Apollo was not Teflon. The major achievement >of Apollo was putting a man on the moon. > A Purdue Graduate, no less! :) (Sorry..just had to plug my school :) ) > >At some level, perhaps the most honest answer to the "why explore >space?" question is the simplest -- "If you have to ask, you'll never >understand." Science has produced many things which have resulted in giant leaps in the quality of life on Earth. However, one can't take giant leaps without making some small steps beforehand. ....20 Jul 1969, Mare Tranquilitatis is my favorite example, but, I'm biased, and according to some people, i'm a "zealot." :) Zealots unite! -- Bill Blum * "God willing...we shall return." Purdue University * Gene Cernan, The Moon, Dec 1972(BSEE P.U. 56) School of Nuclear Engineering * Member of the SEDS National Board blumb@sage.cc.purdue.edu * Ad Astra Per Ardua!! ------------------------------ End of Space Digest Volume 15 : Issue 598 ------------------------------