Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Thu, 4 Apr 91 02:16:57 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 4 Apr 91 02:16:52 -0500 (EST) Subject: SPACE Digest V13 #355 SPACE Digest Volume 13 : Issue 355 Today's Topics: Re: Mt. Venus Re: "Follies" This Nuclear Rocket Thing... SPACE Digest V13 #349 Re: Mt. Venus Re: Chemical rocket complexities (was Re: "Follies") Re: More cost/lb. follies Re: More cost/lb. follies Increasing value/lb. Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 4 Apr 91 02:07:15 GMT From: prism!ccoprmd@gatech.edu (Matthew DeLuca) Subject: Re: Mt. Venus In article <1991Apr3.123509.1@happy.colorado.edu> gapickrell@happy.colorado.edu writes: > >Last night I watched a show about Venus that got me thinking. Now as all of us >know the pressure on Venus is incredible (90 times that of earth) and the >temperature is nearly as bad (900F). The show mentioned that Venus had a >mountain that was 30,000ft tall (1.5 times as tall as Mt. Everest). Just to be picky, Mt Everest is 29,029ft tall. I believe the largest mountain on earth, measured from base to summit, is Mauna Kea, in Hawaii, at some 33,000ft. -- Matthew DeLuca Georgia Institute of Technology "I'd hire the Dorsai, if I knew their Office of Information Technology P.O. box." - Zebadiah Carter, Internet: ccoprmd@prism.gatech.edu _The Number of the Beast_ ------------------------------ Date: Wed, 3 Apr 91 08:30:33 -0500 From: "Allen W. Sherzer" Subject: Re: "Follies" Newsgroups: sci.space Cc: In article <1991Apr2.165653.15383@zoo.toronto.edu> Henry Spencer writes: >ALS's biggest problem, though, is the same one that bedevils any big-launcher >project right now: where's the market? That is a big problem but look at it another way: maybe the existance of a cheap launcher of any type (SSX or HLV) will stimulate a market. Von Braun began development of the F-1s long before the call to go to the moon. He said to himself 'someday we will need a BIG engine'. Had he not done that, Apollo wouldn't have made it's end-of-decade deadline. Now I don't think ALS is that launcher but between HL Delta, Titan V, and new F-1s we see that it can be built. Would it create new markets? Not for a while. What it would do would be to undercut Arianspace and help the US regain market share. Eventually the factor of three reduction would open new markets. The key however is to use what we have today and procure commercially. Allen ------------------------------ Date: 3 Apr 91 20:32:42 GMT From: mojo!SYSMGR%KING.ENG.UMD.EDU@mimsy.umd.edu (Doug Mohney) Subject: This Nuclear Rocket Thing... Most amusing! I think NASA would take a serious look at it (well, *is* taking a serious look at it). Av. Week had a wonderful article a couple of weeks back on various proposals for a nuclear engine. It could cut travel time to Mars by anywhere from 1/3 to 2/3s the time and having that power there allows for MUCH more flexable abort options. Major thrust of the article was to use nuclear energy to cut down on the exposure of astronauts to background radiation during their travels to/from Mars. One Solar Flare could ruin your whole day... DM Signature envy: quality of some people to put 24+ lines in their .sigs -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ ReSent-Message-ID: Resent-Date: Wed, 03 Apr 91 12:09:47 EST Resent-From: Tom McWilliams <18084TM@msu.edu> Resent-To: space+@andrew.cmu.edu Date: Wed, 3 Apr 91 03:17:07 EST Reply-To: space+%ANDREW.CMU.EDU@msu.edu From: space-request+%ANDREW.CMU.EDU%CARNEGIE.BITNET@msu.edu Subject: SPACE Digest V13 #349 Comments: To: space+@ANDREW.CMU.EDU To: david polito <15432DJP@MSU.BITNET>, Tom McWilliams <18084TM@MSU.BITNET> Re: Eclipses >>Has the sun's corona been observed above the Earth's atmosphere? If not, >>isn't possible that it is merely an atmospheric phenomenon, just light >>scatering and refracting around the edges of the moon. >No the Corona is a real part of the sun caused by light emitted and reflected >by particles that are continuously streaming away from the sun. >(refracting around the sun ? HOW?) I think the mechanism was supposed to be diffraction, not refraction. But the answer is still no. Also, the corona has been observed by the creation of fake eclipses. Tommy Mac "Is he insulating his office with magazines?" 18084tm@msu -my girlfriend, after seeing where my boss works. Acknowledge-To: <18084TM@MSU> ------------------------------ Date: 4 Apr 91 03:00:31 GMT From: sun-barr!newstop!exodus!concertina.Eng.Sun.COM!fiddler@lll-winken.llnl.gov (Steve Hix) Subject: Re: Mt. Venus In article <25510@hydra.gatech.EDU> ccoprmd@prism.gatech.EDU (Matthew DeLuca) writes: >In article <1991Apr3.123509.1@happy.colorado.edu> gapickrell@happy.colorado.edu writes: >> >>Last night I watched a show about Venus that got me thinking. Now as all of us >>know the pressure on Venus is incredible (90 times that of earth) and the >>temperature is nearly as bad (900F). The show mentioned that Venus had a >>mountain that was 30,000ft tall (1.5 times as tall as Mt. Everest). > >Just to be picky, Mt Everest is 29,029ft tall. I believe the largest mountain >on earth, measured from base to summit, is Mauna Kea, in Hawaii, at some >33,000ft. But Everest (Chomlungma?) cheats! It sits on on a 14,000' plateau. Mt. Denali in Alaska is higher, base-to-peak, sitting nearly at sea level. -- ------------ The only drawback with morning is that it comes at such an inconvenient time of day. ------------ ------------------------------ Date: 1 Apr 91 22:05:31 GMT From: unisoft!fai!sequent!crg5!szabo@ucbvax.Berkeley.EDU (Nick Szabo) Subject: Re: Chemical rocket complexities (was Re: "Follies") In article <1991Apr1.070046.26072@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: > >The big one is not technical but organizational: they all (even Pegasus, >although not to quite the same extent) are built based on military missile >technology by missile-technology organizations, Shuttle? Delta? Scout? Ariane? H-1? Of course, chemical rockets _are_, when all is said and done, military missile technology -- this has been the dominant use in their 1,000+ year history. They are quite suitable as missiles, and have proven only marginally suitable for orbital launches, at high costs and very low reliability. While we're changing the organization, let's also try changing the technology to something that has been fundamentally designed for the task, instead of crudely retrofitted. >...to whom cost is no object...the current customer base sees nothing >wrong with that. They are complex and costly because nobody has seriously >tried to build one simple and cheap. Nobody has tried because the customers >haven't asked for it. Listen to yourself, Henry. I suppose you always shop for gas at the highest-price station, and throw in a tip to boot? You accept whatever price the car salesman offers, and let's throw in _all_ the options, thank you so much. Sheesh. Yes, Henry, it's true: NASA, DoD, and satcom operators have been yelling as loud as space fans for years for lower launch costs, with the same end effect. Shuttle, ALS, Ariane, H-1, all designed from scratch, both technologically and organizationally, to lower cost/lb., all failed or failing miserably at this goal, because they used the same old chem rocket technology. >The customers haven't asked because their payloads >cost far more than the launches, This is sort of like expecting truck customers to ship sand instead of machinery, in the hope that trucking costs will go lower. The payload/transport cost ratios for launchers (1/1-5/1) are as low as they get for a transportation system. A more normal range is 10/1-100/1. Payload/transport cost ratios are already as low as they are, due to the incredible unreliability of rockets and the accompanying insurance rates. This sort of thinking really demonstrates just how stretched and desparate the rocket launch cost situation really is. If there really was room for technological or organizational improvement, we would be working on that instead of placing such incredible blame on customers that have already bent themselves way out of shape to live with the idiosynchricies of chem rockets. >so launch costs are relatively unimportant >and reliability (that is, use of well-proven existing launchers) is vital. Since when has transportation reliability ever been unimportant? Please, study up on, and think about, the economics of transportation systems before coming up with these wild theories of payload costs, customer motivation, and organizations. Of course, rocket fans get really pissed when the question of reliability comes up, because chem rockets simply cannot deliver the reliability of a normal transportation system, at any price. Thus the outrageous insurance premiums, and the emphasis of customers on reliability as well as cost/lb. and other factors all important to a true transporation system. This blame the customer routine will only hasten the demise of chemical rockets, since no customer is willing to put up with such a perverse attitude for long. Customers will start looking for choices -- EML, gas gun, and laser launch will start looking worth the R&D, even over the short term. Even high up-front costs (although lower than the costs of the larger chem rocket projects) are preferable to people who don't understand your needs and have such a narrow view of what constitutes a transportation system. Anybody who really cares about getting their payloads into space, be you astronomer or satcom operator or would-be space colonist, take careful heed of the rocket community's definition of "transporation". It is time to start looking for a truly efficient, truly reliable way to get into space. -- Nick Szabo szabo@sequent.com "If you want oil, drill lots of wells" -- J. Paul Getty The above opinions are my own and not related to those of any organization I may be affiliated with. ------------------------------ Date: 3 Apr 91 00:27:32 GMT From: mips!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!wa4mei!ke4zv!gary@apple.com (Gary Coffman) Subject: Re: More cost/lb. follies In article <9103291818.AA14594@iti.org> aws@ITI.ORG ("Allen W. Sherzer") writes: > >In article <21437@crg5.UUCP> Nick Szabo writes: >>First, this configuration has not flown yet. >Come now Mr. Szabo, this is a conservative use of a well understood >technology. Using those numbers is perfectly valid. Well this well understood technology just went blooey on the test stand. Nice pictures on CNN. Gary ------------------------------ Date: Wed, 3 Apr 91 09:15:05 -0500 From: "Allen W. Sherzer" Subject: Re: More cost/lb. follies Newsgroups: sci.space Cc: In article <2665@ke4zv.UUCP>: >>>First, this configuration has not flown yet. >>Come now Mr. Szabo, this is a conservative use of a well understood >>technology. Using those numbers is perfectly valid. >Well this well understood technology just went blooey on the test stand. Every now and then any technology goes blooey. I'll bet money that this accident has only minor impact on the program schedule. We have been building solid motors for a long time and it is well understood. Allen -- +-----------------------------------------------------------------------------+ |Allen W. Sherzer | If you love something, let it go. If it doesn't come back | | aws@iti.org | to you, hunt it down and kill it. | +-----------------------------------------------------------------------------+ ------------------------------ Date: 1 Apr 91 20:37:31 GMT From: unisoft!fai!sequent!crg5!szabo@ucbvax.Berkeley.EDU (Nick Szabo) Subject: Increasing value/lb. In article 18084TM@MSU.EDU (Tommy Mac) writes: >If the goal is building a space-mining-infrastructure (a very GOOD goal, IMHO) Space mining & manufacturing are indeed the critical path technologies of exporting space industries and space colonization. >then it should be obvious that SOME kind of rocket will be needed in large >volume. At least for crew carrying, if nothing else. Not necesarilly. The alternative to costly, environmentally damaging high volumes is increasing value/lb. In fact, we have been making much more progress increasing value/lb. than decreasing cost/lb, even though the space community has placed less emphasis on this important variable. It has taken new technolgoy and cleverness, and it will take quite a bit more, but there is no shortage of these when we let our minds take in the whole picture instead of focusing on a single narrow variable. The following technologies/knowledge sets are progressing much more rapidly than chem rocket launch costs: * astronomy: Knowledge of what & where resource are. As recently as the 70's, we were stuck thinking the Moon was the only convenient resource. Now, through orbital mechanics and the observations of a handful of astronomers, we know that asteroids and comets can give us an order of magnitude or more improvement in convenience and variety over the lunar surface. Despite lack of attention and funding, we are rapidly discovering more, and devising was to retreive these resources by letting the solar system do the work for us (eg gravity maneuvers, aerobraking, solar power, etc.) The more I get into the details of space colonization, the more I realize the massive gains to be made simply from increasing our knowledge of where it is we intend to go. * robotics Japan has gone from a few dozen specialized robots to tens of thousands in little over a decade, with the West reluctantly following suit. However, MIT is devising a new generation of "insect robots" that will obsolete the previous generation. Where labor is expensive (eg space, where it costs $1,000,000/hr.), we will soon have automation to the point where most mining and manufacturing tasks can be performed by automated and teleoperated facilities. * teleoperation JPL has demonstrated the ability to perform complex maneuvers even across several hours of round-trip light-time. Meanwhile, more real-time teleoperation has made great strides, for example in deep-ocean exploration and salvaging. Virtual reality has gone from nothing to very convincing prototypes in ten years, and will soon be hooked up to sea- and space-borne teleoperators. * computation Both robotics and teleoperation have benefitted greatly from the c. 3 orders of magnitude improvement in computation since Apollo, and this pace continues, with the end nowhere in sight (cf. new 50 MIPS computer from HP, and multiprocessing). * communications The bandwith of the DSN system has quadrupled in a decade, and this with no new antennas, merely retrofitting the old technology. New radio bands and optical bands have the potential for 5 or more orders of magnitude improvement. These advances are also opening up brand new markets, such as the phone cell satellite market being developed by Iridium. Circuit density on satcoms is doubling every decade. * microdevices/nanotechnology Custom VLSI, atom-by-atom writing, and hair-sized motors were inconceivable even well after Apollo. By early in the next century, these will be commonplace for spacecraft. * thin-film vapor deposition Civil engineering in free space is a whole new beast. Throw out all the rules of structure based on gravity; space structures can do the spider one better. Many of the strucutures we will need, including mirrors, shades, and even pressure hulls, can be vapor deposited using techniques borrowed from earth-side vacuum chambers, but scaled up many orders of magnitude in the limitless vacuum of space. Large, kilometer-sized structures can handle amazing amounts of solar energy with very little mass. * microgravity manufacturing Containerless processing and a whole host of other techniques have made great strides, but will not come to their full fruition until they can be built from space-based resources, and themselves process space-based resources on scales many orders of magnitude larger than the limited experiments launched from earth today. If we can work with these trends, it is not inconceivable that the "vitamins" for a teleoperated mining/manufacturing infrastucture will mass only a few dozen Pegasus or EML launches. In fact, I am currently designing a system that uses solar-thermal power, gravity well maneuvers, and aerobraking to retreive small comets into LEO. The whole system takes only 4 Pegasus launches to start up. After that, each set of 4 Pegasus launches can supply thousands of tons of refined materials (H20, LOX, LH, LN, CH4, NH3, etc. etc.) for space industry. Unlike lunar mining, this provides a whole suite of chemicals at a far lower price ($10/kg instead of $1,000/kg or more). This uses "today's technology" in the sense that no nanotechnology, AI advances, etc. are needed. The biggest limiting factor: we aren't tracking the #@!$!$#@ comets yet! We _do_ need advances in astronomy to make this scheme work. I hope to see such advances in the next 5-15 years -- a combination of the new telescopes coming on-line, and a new emphasis on comets as space resources by the space community. Small asteroids (silicon, metals) could be retrieved with a somewhat more sophisticated effort, but this effort would not necesarily involve more launch mass. Ice is much easier to mine than hard dirt and rock, but we will need to also develop techniques for the latter. As is usual with technology, the expertise and products gained from the smaller-scale operations will allow us to bootstrap into the larger-scale tasks of building large-scale space industries and space colonies at a far lower cost than that of trying to accomplish such a gargantuan project from scratch. Now, that is not to say that this is easy. Intellectually, at least, this path is much more difficult than the old chem rocket/space station/ Moon/Mars paradigm. However, economically and politically it is far, far cheaper. If we follow the old failed paths, we are doomed to defeat. By consiously working towards increasing value/lb. and letting the solar system do the work for us, we _can_ achieve space colonization, the "work of generations" (Goddard). -- Nick Szabo szabo@sequent.com "If you want oil, drill lots of wells" -- J. Paul Getty The above opinions are my own and not related to those of any organization I may be affiliated with. ------------------------------ End of SPACE Digest V13 #355 *******************