Date: Mon, 5 Apr 93 05:00:03 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #419 To: Space Digest Readers Precedence: bulk Space Digest Mon, 5 Apr 93 Volume 16 : Issue 419 Today's Topics: Alaska Pipeline and Space Station! Atlas rocket questio Atlas rocket question DC-X: Vehicle Nears Flight Test DCX "Roll out" (2 msgs) Gemini 8 (was Re: Artificial Gravity) John Sheehan & Russian Space Mission to Seattle Machine intelligence (2 msgs) Mexican Space Program? Oregon L-5 meeting: 2 pm, Sat. April 10, old OMSI Ottawa Astronomy Info Needed! Portable Small Ground Station? Prefab Space Station? pushing the envelope Space Research Spin Off Tommy's Oil 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: Sun, 4 Apr 1993 19:06:55 GMT From: "Allen W. Sherzer" Subject: Alaska Pipeline and Space Station! Newsgroups: sci.space In article <1993Apr4.134543.2848@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >Sure they could, but consider that a commercial concern has to retire >capital expenditures, plus interest, has to cover operating costs, and >make a profit. If the government builds it for their own use, they don't >have to make a profit, nor do they have to borrow the bulk of the money >to pay for it, so interest charges are less. And this, ladies and gentlemen, is why the US has a multi-trillion $$ debt. No Gary, the governemnt does indeed pay interest. >The sticking point is that the government has to sign a firm rental >agreement in advance of construction that guarantees a certain amount >of rent for a specified period once construction is complete. And that >contract has to have penalty clauses sufficient to keep the landlord >solvent if the government reneges on the contract. This has been the >sticking point. Most government contracts have a termination clause Not any more. Last years NASA Authorization bill allows NASA to negotiate termination liability. allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------73 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: 04 Apr 93 09:49:02 From: David.Anderman@ofa123.fidonet.org Subject: Atlas rocket questio Newsgroups: sci.space HS>The key thing to remember is that the Atlas is not a representative HS>vehicle. :-) With the balloon tanks and near-complete absence of any HS>structural members, the engines are *most* of the mass of a stage usin HS>Atlas technology. HS> HS>This is what you get when you really lean on rocket engineers to make HS>a lightweight rocket stage, instead of having them build a heavy-duty HS>tank with rocket engines attached. Which is why Atlas made it into HS>orbit on 1.5 stages in 1958, a performance unequalled to this day. What would it take in materials technology to make an Atlas into a SSTO with return to Earth capability; i.e., where could weight be saved? ___ WinQwk 2.0b#0 --- Maximus 2.01wb ------------------------------ Date: Sun, 4 Apr 1993 23:48:16 GMT From: Henry Spencer Subject: Atlas rocket question Newsgroups: sci.space In article <1plcg3$jjr@access.digex.net> prb@access.digex.com (Pat) writes: >|This is what you get when you really lean on rocket engineers to make >|a lightweight rocket stage... > >Of course, it's fragile like heck. Not really. One of the standard tricks of the GD people was to show skeptics a pressurized section of Atlas skin -- stainless steel about the thickness of a dime -- hand them a sledgehammer and tell them to do their worst. (The thing you had to know was that you should stand well back, because the hammer would bounce much higher than the skeptic expected and he'd usually lose control of it.) It wasn't possible to leave a mark on it, never mind damage it. The thing that it did have to be guarded against was pressure loss, either through compressor failure or through being punctured by something sharp-edged. >I think one got wrecked when it got bumped with >a scaffold. Nope, slashed open by a sharp edge on a motorized work platform. >It may make sense just for proving SSTO, but for reliable >performance I think we need better performing materials >and heavier duty aircraft like rockets. For a reusable rocket, something more fault-tolerant is in order. For an expendable, I don't think it's an unreasonable design approach. -- All work is one man's work. | Henry Spencer @ U of Toronto Zoology - Kipling | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Mon, 5 Apr 1993 00:05:18 GMT From: Henry Spencer Subject: DC-X: Vehicle Nears Flight Test Newsgroups: sci.space In article <2736@snap> paj@uk.co.gec-mrc (Paul Johnson) writes: >This bit interests me. How much automatic control is there? Is it >purely autonomous or is there some degree of ground control? The "stick-and-rudder man" is always the onboard computer. The computer normally gets its orders from a stored program, but they can be overridden from the ground. >How is >the transition from aerodynamic flight (if thats what it is) to hover >accomplished? This is the really new part... It's also one of the tricky parts. There are four different ideas, and DC-X will probably end up trying all of them. (This is from talking to Mitch Burnside Clapp, who's one of the DC-X test pilots, at Making Orbit.) (1) Pop a drogue chute from the nose, light the engines once the thing stabilizes base-first. Simple and reliable. Heavy shock loads on an area of structure that doesn't otherwise carry major loads. Needs a door in the "hot" part of the structure, a door whose operation is mission-critical. (2) Switch off pitch stability -- the DC is aerodynamically unstable at subsonic speeds -- wait for it to flip, and catch it at 180 degrees, then light engines. A bit scary. (3) Light the engines and use thrust vectoring to push the tail around. Probably the preferred method in the long run. Tricky because of the fuel-feed plumbing: the fuel will start off in the tops of the tanks, then slop down to the bottoms during the flip. Keeping the engines properly fed will be complicated. (4) Build up speed in a dive, then pull up hard (losing a lot of speed, this thing's L/D is not that great) until it's headed up and the vertical velocity drops to zero, at which point it starts to fall tail-first. Light engines. Also a bit scary, and you probably don't have enough altitude left to try again. -- All work is one man's work. | Henry Spencer @ U of Toronto Zoology - Kipling | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 4 Apr 93 16:35:15 GMT From: Gregory Hamlin Subject: DCX "Roll out" Newsgroups: sci.space So, does anyone have any info about the DCX "roll out" on april 3? Was is shown on any news programs? Did anyone take any pictures which could be scanned and posted/ftp'd somewhere as GIF/JPEG files? :) Greg Hamlin hamlin@ral.rpi.edu P.S Anyone else notice the similarity between DCX and the rocket Bugs Bunny rode to Mars? (landing gear extend, and rocket lands tail first) ------------------------------ Date: 4 Apr 1993 21:06:38 GMT From: Diaspar Virtual Reality Network Subject: DCX "Roll out" Newsgroups: sci.space I attended both the press briefing and the rollout and will be putting more information here as I get a chance to write it up. The good news is I got lots of stereoscopic video "footage" and will be converting a number of the best shots to .gifs and it will include shots of not just the vehicle but of some of the people at the press conference. I'll have .gifs that are both normal and stereo pairs (left/right) As a quick summary of the rollout I will mention a few things. First, the weather was perfect: clear, sunny, high 70's to low 80's. The press conference before the rollout was not unduly long, McDonnell Douglas made a major effort to make people welcome and to handle the crowd (est 1500) that was there. One can tell the turnout was larger at the last minute than expected since they ran out of hot dogs (but thankfully not soft drinks as it was hot). Col. Worden brought down the house at one time during the press conference when asked a question about how much money the Air Force had available for projects like these. He replied "I didn't make colonel by telling my contractors how much money I have available to spend." The rollout ceremony was pretty straighforward - a number of not-too-long speeches (including one each from a republican and democrate Congressman) and then the vehicle was pulled out of the The DC-X, as advertised, is about 41 feet tall, round at the top, squarish at the bottom, has rather large landing gear. Was really something to see paretns bringing their kids up and touching it and looking in the access hatches which were open (but covered with plexiglass). The concept of quick turnaround from idea to a finisahed unit and the concept of aircraft-style flight operations is appealing to me. It kind of hit home when people were allowed to touch the thing. I've touched more aircraft in my life that I can count, but this is the first time I've touched a space ship. D D D D D D DX hanger by an interesting little tractor/carrier. The DC ------------------------------ Date: Sun, 4 Apr 1993 23:33:40 GMT From: Henry Spencer Subject: Gemini 8 (was Re: Artificial Gravity) Newsgroups: sci.space In article <1pa5n2$5av@access.digex.com> prb@access.digex.com (Pat) writes: >>Armstrong ... also had to eject from an LLRV when rehearsing a lunar >>landing.) > >From my understanding, The LLRV had some sort of delay in the >control mechanism. Armstrong found that out the hard way. Nope. See the excellent overview article on the LLRV/LLTV program in the Dec 1992 issue of Spaceflight. Despite what you sometimes hear, the things were not that hard to fly, according to the test pilots who checked them out first. Armstrong ejected from LLRV-1 after helium pressure in the peroxide tanks (yes, another peroxide-fuelled rocket!) fell too low and he lost his control thrusters as a result. Some months later, Joe Algranti ejected from LLTV-1 when a sharp gust of wind sent it out of control, and a couple of years later, Stuart Present had to eject from LLTV-2 after an electrical failure. LLRV-2 and LLTV-3 survived to retire after Apollo 17 crew training concluded; LLRV-2 is at Dryden, while LLTV-3 spent some years on display at Marshall and is now at Johnson. -- All work is one man's work. | Henry Spencer @ U of Toronto Zoology - Kipling | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 4 Apr 93 13:57:27 GMT From: "P. Douglas Reeder" Subject: John Sheehan & Russian Space Mission to Seattle Newsgroups: sci.space [ The following article first appeared in StarSeed, the newsletter of the Oregon L-5 Society, and is reprinted by permission of the editor. ] Russian Space Mission to Seattle by John Sheehan I've covered many exciting and curious events as a videographer. Most began, as this one did, with a last minute phone call. Bob Walsh & Associates, the master promoters who brought Seattle the "Goodwill Games", asked me if I would like to videotape the recovery of a Russian satellite. As part of "Europe America Space Flight 500", the even t was being billed as "the final chapter ending the Cold War." And so, after checking my equipment and renting extra batteries, I drove to the airstrip at Grays Harbor. Eight other journalists and I were shuttled by helicopter 25 miles off the Washington coast to a mysterious Russian ship. My partner in the helicopter that day was Tim Crosby, a photojournalist from Edmonds who had traveled to Siberia for Outside Magazine. Once in the air the dark shape of a large ship loomed on the horizon. Before we could get our bearings we were deposited on a rolling deck. The "Marshal Krylov" is a 680 foot missile tracking ship, until recently top secret and off-limits to foreigners. We were welcomed aboard by Commander Alexander Rosskazov on behalf of Captain Vadim Yevgenievich Shardyn. Soon we were taken on a short tour of the ship which included a theater with a balcony, a steam bath ("bahnya" in Russian), and a ships museum featuring models of space vehicles such as "Buran", the Russian shuttle craft. Our first night at sea was spent sailing into the teeth of a fierce wind storm. Gales of 60 knot winds and 40 foot seas tossed the huge ship about like a cork. Luckily, I had taken my Dramamine so I wasn't too uncomfortable. Still it took me most of the next day to acquire my "sea-legs" and stop bouncing off of bulkheads. As I recovered, the other American observers and I covered the routine of the Russian sailors as they went about their work. Aside from the obvious language barriers, I found the Russian sailors a lot like the seamen that I served with in the U.S. Coast Guard. Many are very young (as I was) and see naval service as a way to travel abroad and see world. They were curious about America and told me that their only impressions of The United States, other than the bleak news stories fed to them under the previous regimes, came from the violent American action films which are sadly a s popular in Russia as they are here On Sunday morning we gathered in the impressive "Capsule Descent Communications Center" and watch a 40 foot screen as the re-entry began. Soon however, we realized that the data on the screen was being updated by hand. The telemetry with the capsule and tracking was actually being relayed to the ship from Moscow via radio telephone. The actual recovery itself ,th ough, was a daring bit of seamanship. As the ship bucked in heavy seas, the deck crew struggled to swing a boom with a steel cable net over the side, all the time battling howling winds. With great effort they succeeded to scoop the 3 ton satellite out of the water and hoist it onto deck. Once secured in its cradle, the payload was checked by grim technicians from Samara, where the satellite was built. This Siberian city, once secret and officially off limits, is devoted entirely to aerospace manufact uring. With their mission completed and the visit to Seattle ahead of them, the crew relaxed and celebrated with a talent show in the theater. The show featured a rock band, a guitar strumming balladeer, and the triangular "ballalyka" accompanied by a button accordion. The next morning, as we sailed through the straights and into Puget Sound, many of the sailors pointed to the Olympic Mountains and commented on how much the geography reminded them of Kamchatka peninsula, where the "Krylov" is based. But as the tall buildings of Seattle loomed up before them, they seemed to realize that they truly were visiting an American city of heroic proportions. Many of the men came out on deck and took pictures of th eir comrades at the rails with the Space Needle over their shoulders. My videotape of the recovery appeared on several major networks including CNN. Tim Crosby's photos were featured in Newsweek and the German magazine Der Stern. One of my friends, upon hearing of my adventure, remarked "Oh gosh, we only see things like that on TV!" I had to remind her that some one like me has to be there with a camera before it can be shown. -- Doug Reeder Internet: reeder@reed.edu Div, Grad & Curl USENET: ...!tektronix!reed!reeder programming & derivative work I am actively seeking scientific programming contracts. ------------------------------ Date: Sun, 4 Apr 93 15:40:17 EDT From: John Roberts Subject: Machine intelligence >From: mccall@mksol.dseg.ti.com (fred j mccall 575-3539) >Newsgroups: sci.space,talk.politics.space >Subject: Re: Luddites in space >Date: 2 Apr 93 16:37:34 GMT >Organization: Texas Instruments Inc [On the topic of advanced automation for unmanned spacecraft.] >You might also want to note that Herman Rubin is right. Machines >*can't* be intelligent. The question, of course, is just how much >intelligence is required for a given task... >Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. The question of current and near-term capabilities of machines is a valid one. But I'd like to know your reasoning for the first statement, that machines are inherently capable of displaying intelligent behavior. This has been discussed in Scientific American, and I didn't think much of some of the arguments presented there. Some people argue that intelligence is a human concept, so by definition, only humans can be intelligent. I'd say it will be embarrassing if we ever encounter an alien civilization, and have to break the news to them that they're not really intelligent - they just *think* they are. :-) Some of the other arguments given: - Religious reasons. You have to have a soul to be intelligent. (Can't really be argued one way or another on scientific grounds.) - Computational speed. The brain is faster than current computers, which is especially noticeable in speech recognition and image recognition. (An invalid argument - speed of operation has nothing to do with the abstract concept of intelligence. Storage capacity isn't an issue either - computer memory can be made as large as necessary.) - Only living cells can embody intelligence. (The New Age equivalent of the religious argument.) - Only certain kinds of hardware can perform the operations of intelligence (flip-flops, or neural nets, or organic compounds regulating propagation of sodium-potassium imbalances). (Which strikes me as a considerable leap of faith in itself. More below.) The thing to remember about computational machines is that other than computational speed (which I don't accept as a valid criterion for posession of abstract intelligence), an outside observer can't distinguish a correct *emulation* from a hardware implementation. Consider, for example, neural nets, which are patterned after the behavior of human neurons. Some people think that computers made with neural nets could be made intelligent, while conventional computers can not. But if you can completely describe the behavior of a neural net component, then you can write a program that runs on a conventional computer which causes it to behave like a neural net (though perhaps slower). Even random or chaotic behavior can be modeled if you can describe it properly and can come up with adequate random number generators, etc. In general, *any* computational or data-manipulating task can be emulated by a general-purpose computer with an appropriate program and sufficient memory (as shown by Mr. Turing). The only way a computer *can't* be made to work in a way that to an outside observer is indistinguishable from what we consider intelligent is if the operations of intelligence are in some way inherently indescribable. There are people who claim that's the case, but I'd really like to know how they're *sure*. (By the way - the questions of how intelligent we can make machines now, or how intelligent we can currently make machines that are small enough to fit on a spacecraft, or how intelligent we *want* machines to be are separate issues from the potential ability to make them intelligent.) So - in what way do you feel that machines can't be intelligent? John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Sun, 04 Apr 1993 22:28:35 GMT From: nathan wallace Subject: Machine intelligence Newsgroups: sci.space As a low-level grunt in the neural-nets/ai field, I thought I might add a comment or two here. (Asbestos Underwear ---ON!) "Intelligence" in this context usually means the ability to duplicate *all* human behavior which impacts cognitive activity. This includes reasoning, both formal and "common- sense", and a property sometimes called "intentionality", which is a way of describing the ability to make personal decisions *not* deterministically predictable from inputs. Any entity, be it a computer or a creature from Tau Ceti IV, which displays these abilities is very likely going to be considered "intelligent" by the current cog-sci community. (An interesting side note on this whole business is that the imputation of intentionality to anyone but ourselves runs into the problem described by Descartes, namely that we have to more or less take it on faith that other people who look like us and act like us have mental states like us, even though we can't directly percieve those states in others!) If this seems to be rapidly getting bogged down in verbiage, you're right! Trying to grapple with these concepts keeps us ai types in business at the moment, and far more time is spent splitting rabbits in the literature than revealing profound new insights into intelligence and so forth! At the moment, we have hit dead ends on getting machines to either have common- sense reasoning, or display intentionality. Until somebody can break through these two barriers, ai and the concept of "machine intelligence" is pretty much at a standstill. Except for neural nets.... The above was about "strong" or "classical" ai, which uses things like lisp and tries to find clever algorithms to implement on binary hardware. ann's (artificial neural nets) can run rings around the best classical ai solutions in many fields, and actually have some people hoping to break through the common-sense reasoning barrier with them, by finding a new way to let a net "learn" commonsense properties rather than have to explicitly list them to it. Intentionality, which might also be called "self-awareness", though, is a bit farther off. This is where most religious arguments seem to apply. Strong proponents say that the right formal system instantiated on the right hardware will develop intentionality. Strong opponents say otherwise, for reasons listed in a previous post plus others. Us nn guys tend to stay out of this argument, I've noticed. Another important point about ann's: note that "a" on the front. Our current implementation of "artificial" neural nets have about as much in common with the neurons of the brain in humans as an abacus has with a workstation; both compute, but there are many fundamental differences in the method and abilities. Current ann's are far more like specialized statistical analysis programs than real neuron simulations. (My personal contribution is to try and increase our understanding of the real neurons so we can make anns' more like them!) For a definitely not-strong-ai perspective on the matter, one might try reading a book by Hans Jonas entitled "The Phenomenon of Life". It has some interesting historical perspectives on the whole ai field/debate. (Asbestos Underwear---OFF!) Just my $0.02 worth, as a space enthusiast with some cs background. Any opinions here are strictly mine and not my college's, my advisor's, or my mother's! --- C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/ C/ Nathan F. Wallace C/C/ "Reality Is" C/ C/ e-mail: wallacen@cs.colostate.edu C/C/ ancient Alphaean proverb C/ C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/ ------------------------------ Date: Sun, 4 Apr 1993 09:03:39 GMT From: Nick Szabo Subject: Mexican Space Program? Newsgroups: sci.space,talk.politics.space gary@ke4zv.uucp (Gary Coffman) writes: >The US government is not in the business of exporting >US jobs with taxpayer funds, nor is it in the business of exporting >the technological industrial base on which it's security depends. >All the cries to "Buy Russian", or "Move Boeing to Tijuana" neglect >these issues. Quite the opposite -- the cries to keep everything in the U.S. just like it is ossify the U.S. industry, prevent it from growing. The $billions we spend right now on labor-intensive manufacturing could be shifted towards retraining and high-skill, high-wage jobs like engineering if we let the free market operate. Right now we have gross overproduction and duplication of function at incredibly high costs. Having over ten launchers on the planet to handle a demand for 100 launches per year is completely ridiculous by commercial aerospace standards. In a free market a glut causes lower prices, which in turn would make space industry more affordable and expand the market. The ecconomic level might be 500 launches per year by 4 or 5 launchers in the 2000 timeframe. That's five times the number of launches for half the tooling, or up to a factor of 10 reduction in launch costs just from removing protectionist barriers. More benefits come from sharing technology and freeing U.S. engineers to design the next generation launcher, and, even more importantly, the next generation of payloads to open up new markets made possible by lower launch costs and greater engineering talent dedicated to the payloads. DBS and cellsats need only about a factor of 2-4 launch cost reduction to go from marginal to >$10 billion per year industries, and some kinds of space manufacturing (eg electrophoresis, protein crystal growing, & other biotech stuff) might also reach the economical range. But I have to admit that the argument you make is the easy way out for those working for government contractors, and thus there is a large political pressure to maintain protectionism. Alas, if that prevails we can expect a continuation of our system of stifling space bureaucracy, and we can forget about ideas to lower launch costs or expand space industry; trying to compete with tax collectors is a losing proposition (as AT&T in the 1960s, AMROC and Gerry O'Neill in the 1980s, and many others have found to their chagrin). -- Nick Szabo szabo@techboook.com ------------------------------ Date: 4 Apr 93 13:52:52 GMT From: "P. Douglas Reeder" Subject: Oregon L-5 meeting: 2 pm, Sat. April 10, old OMSI Newsgroups: sci.space Our April 10 meeting is our quarterly Space Update at the OMSI Annex (old OMSI building), for which we have two special presentations. Videographer John Sheehan was aboard the Russian recovery ship for a good-will satellite drop offshore from Seattle and is producing a video documentary of the project. He will tell us about his experiences and hopefully have some video footage to show us. Seattle Lunar Group Studies' Hugh Kelso and associates will be here to present some of their work in preparing for lunar settlement. This well-respected group is a spin-off of the now-defunct Seattle NSS chapters. -- Doug Reeder Internet: reeder@reed.edu Div, Grad & Curl USENET: ...!tektronix!reed!reeder programming & derivative work I am actively seeking scientific programming contracts. ------------------------------ Date: Sun, 4 Apr 1993 13:45:23 GMT From: Ray Moyneur Subject: Ottawa Astronomy Info Needed! Newsgroups: sci.space I am looking for information on any type of Amateur Astronomy meetings that might take place in the Ottawa/hull area. thanks, -- +---------------------------------------------------+ / \ ( Ray Moyneur -- aa556@freenet.carleton.ca ) \_____________________________________________________/ ------------------------------ Date: Sun, 4 Apr 1993 23:37:33 GMT From: Henry Spencer Subject: Portable Small Ground Station? Newsgroups: sci.space In article <1993Apr2.214705.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >How difficult would it be to set up your own ground station? Ground station for *what*? At one extreme, some of the amateur-radio satellites have sometimes been reachable with hand-held radios. At the other, nothing you can do in your back yard will let you listen in on Galileo. Please be more specific. -- All work is one man's work. | Henry Spencer @ U of Toronto Zoology - Kipling | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Sun, 4 Apr 1993 23:46:56 GMT From: "Allen W. Sherzer" Subject: Prefab Space Station? Newsgroups: sci.space In article <1993Apr4.135748.2944@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >Some of the problems with Shuttle C are political, but there are >other issues as well. The sticking point is the cost of SSMEs. >They're too expensive to throw away on an expendible launch. This is not an issue for two reasons. First of all, Shuttle is so expensive that a Shuttle-C using brand new SSME's would still be much cheaper than Shuttle. Even doubling the cost of Shuttle C would still result in multi-billion $$ savings for Fred construction. Secondly, this puts the cart before the horse. The issue is heavy lift, not Shuttle C. Both Martin Marrettia and McDonnell douglas have proposed Titan and Delta variants easilly developed for far less than Shuttle. We could build and operate BOTH these options for Freedom assembly and save billions. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------73 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: Sun, 4 Apr 1993 10:00:30 GMT From: David Pugh Subject: pushing the envelope Newsgroups: sci.space In article <1993Apr3.233154.7045@Princeton.EDU>, lije@cognito.Princeton.EDU (Elijah Millgram) writes: |> A friend of mine and I were wondering where the expression "pushing |> the envelope" comes from. Anyone out there know? Aircraft and the like have a "flight envelope" which describes the conditions in which the plane can fly safely. A trivial example is the stall and "never exceed" speeds for an airplane: flying outside that speed range is a bad idea (though not always immediately fatal). The flight envelope is determined by the simple approach of having someone demonstrate that the plane can safely fly under the given conditions. "Pushing the envelope" is what happens when someone intentionally flys outside the flight envelope (going faster, higher, with a heavier payload, at a larger angle of attack, etc.) to prove that the plane is safe under the new conditions. If the plane is "safe" under the new conditions (nothing bent, control response was good, etc.), then the flight envelope is extended to include the new conditions. -- ... He was determined to discover the David Pugh underlying logic behind the universe. ...!seismo!cmucs!dep Which was going to be hard, because there wasn't one. _Mort_, Terry Pratchett ------------------------------ Date: 4 Apr 1993 20:31:10 -0400 From: Pat Subject: Space Research Spin Off Newsgroups: sci.space In article <1993Apr2.213917.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >Question is can someone give me 10 examples of direct NASA/Space related >research that helped humanity in general? It will be interesting to see.. TANG :-) Mylar I think. I think they also pushed Hi Tech Composites for airframes. Look at Fly by Wire. ------------------------------ Date: Sun, 4 Apr 1993 08:56:04 GMT From: Nick Szabo Subject: Tommy's Oil Newsgroups: sci.space,sci.chem.engr >On Date: 30 Mar 93 04:45:31 GMT, William Reiken >writes: >/ A Question: Has oil been found anywhere eles in our Solar System >/ in the raw form that we dig it up in here on earth? Methane, ethane, and several other hydrocarbons have been seen in varying abundance (<1% to 5% for methane) in comets. If you want to get rich in 2020, design a system to extract the methane from the water & ammonia ice and the gravel/muck of comets, perhaps by doing "distillation" by creating a large gas/plasma interface (cf. comet tail dynamics). Bonus points for separating out the ammonia, or coming up with a water/ammonia/methane mix that can be kept frozen and used as a thermal propellant (no need to haul tank from earth). -- Nick Szabo szabo@techboook.com ------------------------------ End of Space Digest Volume 16 : Issue 419 ------------------------------