Date: Fri, 11 Sep 92 05:02:42 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #184 To: Space Digest Readers Precedence: bulk Space Digest Fri, 11 Sep 92 Volume 15 : Issue 184 Today's Topics: 3 booster questions farthest Laser signal Is NASA really planning to Terraform Mars? (5 msgs) NASA/Rice information request One Small Step for a Space Activist... Vol 3 No 9 Pluto Direct Propulsion Options QUERY Re: Pluto Direct/ options (5 msgs) SPS SSTO Mailing List Formed 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: 10 Sep 92 22:08:51 GMT From: Josh 'K' Hopkins Subject: 3 booster questions Newsgroups: sci.space brettvs@hardy.u.washington.edu (Brett Vansteenwyk) writes: >[2].Atlas still goes *boom* a lot? Is this inherent to the design of having >two of the engines fall off and the difficulty in shutting off the fuel flow >to these engines? Actually, the most recent problem has been the upper stage. Another recent failure was due to a lightning strike. Going through my data, it looks like the booster stage has been a significant cause of failures in the last 20 years bt it's hard to tell if it's caused more problems that first stages of other systems. >[3].It seems, like it or not, that the Shuttle will be flying for at least 10 >more years. Perhaps developing an LRB for the Shuttle will not be justified >on its own. Perhaps developing an HLV will not be justified on its own. >However, if you have an HLV whose first stage will also serve as an LRB >you could amortise development costs pretty fast. Is there something wrong >with this idea? > For example, a single engine "Baby Saturn" based on the F1A may qualify. >If modifying the External Tank design for 3 boosters instead of 2 is not >difficult, and if there is no particular reason that you cannot ride the >Shuttle on "top" of the stack instead of the the bottom (angle of attack >considerations would force this change), then you would have a ready use >for 25-30 of these vehicles per year. Why not? Changing the layout that drastically would require redoing the VAB, the crawler and the two launch complexes among other things. A single engine booster also wouldn't be suitable for the first stage of an HLV as you suggest. Plus, putting the orbiter on top of the ET means you're sending exhaust straight at a tank of LH2/LOX, which is not a great safety feature. > --Brett Van Steenwyk -- Josh Hopkins "If you are sitting in an exit row and you cannot read this card or cannot see well enough to follow these instructions, please tell a crew member." j-hopkins@uiuc.edu -United Airlines safety instructions ------------------------------ Date: 11 Sep 92 05:32:04 GMT From: Ron Baalke Subject: farthest Laser signal Newsgroups: sci.space In article <1992Sep10.150201.15434@ucsu.Colorado.EDU>, knapp@spot.Colorado.EDU (David Knapp) writes... > >Ron, would you be interested in posting some of your planetary probe inormation >to alt.sci.planetary? Sure, I'll post something tonight. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Anything is impossible if /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you don't attempt it. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Thu, 10 Sep 92 17:29:00 GMT From: Doug Mohney Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article <1992Sep10.145918.14933@ucsu.Colorado.EDU>, knapp@spot.Colorado.EDU (David Knapp) writes: >You mean ignoring any possible consequences of ozone loss and maybe even >global warming? Let's even completely ignore increasing risks of nuclear >war (from non-NATO develpment) or from nuclear disaster. We can also ignore >steady expansionism of the populace. Hey, and I bet you were kvetching about the Evil Stockpiles of Nuclear War between the United States and the Soviet Union a couple of years ago. It's gone, so there's something else to blow up, er, INFLATE as a "threat" to civilization as we know it. It's also laughable to look at "global warming" when a single volcanic eruption kicks enough enough ash to DROP temperatures despite our many years of unregulated environmental engineering, hmm? We also don't have enough of a dataset on our world to show what the "real" temperature should be. I kid you not. Would you like to average in the ice ages and the time before the DinosaurKiller impacted? >Even if you ignore all the globe-threatening issues, *population* growth, >which you can *count on*, will still be one of our greatest challenges. It >will keep growing until it simply *can't* and that only happens when world >resources, particularly in food stuffs, become steadily taxed. Don't >kid yourselves, this is *going* to happen whether you like it or agree with >it. I didn't know we had gone to world goverment. Now, who in the third world is going to come and tax US, hmm? Besides, population growth is self-correcting. People who have nothing better to do start little piss-ant wars and end up killing themselves off. >Even after you look at the population curve and make some simple extrapolations, >keeping in mind things like fossil fuel depletion in the next 50 years, >shifting agricultural zones, you do not see this? Another Club of Rome member. We've been running out of fossil fuels for 100 years. Before that, there was a fear of a great shortage of whale oil, due to overhunting. Could you tell me what the current demand for whale oil is? Furthermore, the Club of Ignorance also ignores little things like A) Technological Innovation is not static, B) Free-market economies stimulate the development of more efficient use of resources and substitutes. >You do not know there is no life on Mars or anywhere else other than Earth. >I don't see the relevance of arguing over the label of 'back yard'. I don't >think as a society, or even a planet, we have yet learned how to manage our >*own* planet, not even a *little*. Because of this I don't think we are >qualified to begin applying our ignorance to anther planet. > >Luckily, this will not be an issue for many years. Naw, you'd better line up now to put Saturn's rings off-limits to Szabo's Ice Mining, Inc. And then prepare to go out there and enforce your law, hm? Support U.N. military force against Serbia -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 10 Sep 92 18:27:02 GMT From: Don Roberts Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article <1992Sep10.145918.14933@ucsu.Colorado.EDU> knapp@spot.Colorado.EDU (David Knapp) writes: >You mean ignoring any possible consequences of ozone loss and maybe even >global warming? Let's even completely ignore increasing risks of nuclear >war (from non-NATO development) or from nuclear disaster. We can also ignore >steady expansionism of the populace. Yep. Ignore it. Contrary to Chicken Little Opinion, we don't understand global warming very well and unless you're planning to move to Antarctica, I wouldn't get in a tizzy about the "ozone hole." [see Physics Today, Dec '91 for a discussion of the polar stratospheric cloud mechanism for ozone depletion by CFC's]. As for the "increasing risk of nuclear war" due to nuclear proliferation, Nonsense. The threat of all-out thermonuclear war *is gone* (huzzah!). The threat of despotic countries seeking to develop nuclear weapons *is* real, and requires more stringent efforts in UN inspections, non-proliferation research, and development of both a defense against limited strikes and the abililty to disable a "terrorist bomb." Complaining about the "global threat" won't make it go away. >Even if you ignore all the globe-threatening issues, *population* growth, >which you can *count on*, will still be one of our greatest challenges. It >will keep growing until it simply *can't* and that only happens when world >resources, particularly in food stuffs, become steadily taxed. Don't >kid yourselves, this is *going* to happen whether you like it or agree with >it. Haven't we had about enough of this in the last 200 years?? Ever since Malthus first came up with the idea, we've been in Imminent Peril of choking the planet with people. Fortunately, there have been enough people (!) cleverer than ol' Tom that we've managed well enough. Try telling the people in Singapore, Japan, or Taiwan that high population densities guarantee abject poverty and starvation. Ever stop to think there might be more to it than that? -- Dr. Donald W. Roberts University of California Physicist Lawrence Livermore National Laboratory Recreational Bodybuilder dwr@llnl.gov Renaissance Dude ------------------------------ Date: 10 Sep 92 12:55:04 GMT From: Richard Nickle Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article <1992Sep9.211307.15734@ucsu.Colorado.EDU> knapp@spot.Colorado.EDU (David Knapp) writes: >In article rick@trystro.uucp (Richard Nickle) writes: >>In article tomk@netcom.com (Thomas H. Kunich) writes: >>>Without references it is difficult to remember, but isn't there >>>water, water vapor and possible liquid water along the interface of >>>the Martian north pole? >>> >>>If so, shouldn't this represent a possible seeding area for life forms? >>> >>>I also seem to remember that the upper atmosphere of Venus was >>>mostly water vapor even though the bulk of the atmosphere was >>>sulphuric acid. >>> >>>Perhaps I didn't make myself clear enough. I don't believe that >>>Venus could ever be made earthlike. I see the chance, however, >>>of seeding life there and letting it make it's own way. >>> >>>The same with Mars. All of the grandiose plans aside I can't see >>>the bulk of the necessary machinery being transported to Mars to >>>terraform it and then the project continued for thousands of years. >>I never understood this machinery bit though...my understanding of >>Martian terraforming was that the timescale would be large, but the >>steps taken would be rather simplistic: slamming large ice blocks > ^^^^^^^^^^^^^^^^^^ >>from the belt or Saturn's rings (though why anybody would want to >>throw away all that nice water, I don't know...maybe they could just >>send the low-grade ore towards mars), using orbiting mirrors to melt >>the poles, or covering the poles with dark matter to assist in raising >>the surface temperature. > >I think you and I have different ideas of what is 'simplistic' It's you're not transporting megatons of machinery to Mars, and you don't have to worry about the problems of soft-landing anything on the surface. Adding water requires small robot probes to go retrieve ice and move it to mars. The robots would attach themselves to the appropriate piece of ice, and use the ice itself as reaction mass to move them from wherever you got them (Saturn, the belt) to Mars, whereupon they would fall onto mars and release tons of water. You just set up your ice-retriever robot factory someplace convenient: Lunar orbit? And begin mass-producing the things. Now, Luna doesn't have any water, right? So, well, you pay for the cost of the robot factory by using the robots principally to move water to Luna, not Mars. Once you've paid off all your creditors and are making a steady profit, the factory owner makes the magnamonious gesture of diverting a certain percentage of his ice-retrieval robots to moving ice to Mars as well. If the robots are reusable (they can retrieve their payload and steal enough water to propel themselves back to where they got the ice), it's even better. Your number of robots working on the project continually increases, and water delivery to Mars begins to skyrocket. Add any potential colonies on Mars who actually need the water for immediate use, delivered to a specific spot, and it's even better, they'll be willing to pay for the delivery system. >Do you understand how many 'mirrors' would be required to raise the polar >caps one degree centigrade? Use solar sails to transport cargo to Mars orbit: (sensing gear, microbe packages (when needed), the dirt for covering the poles to help it absorb heat, gear for colonies....and just leave them there. Have you worked out the mirror surface area for a one-degree centigrade rise in a cap? Any pointers where I could find the data? >David Knapp University of Colorado, Boulder >Perpetual Student knapp@spot.colorado.edu -- richard nickle rick@trystro.uucp 617-625-7155 v.32/v.42bis ------------------------------ Date: 10 Sep 92 18:44:03 GMT From: Sam Warden Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space gary@ke4zv.uucp (Gary Coffman) writes: >In article samw@bucket.rain.com (Sam Warden) writes: >>Were Venus ever to cool off, I would expect ferocious amounts of >>oxidation/carbonation weathering to occur, for example. >Remember that chemical reactions like oxidation proceed at a rate >proportional to temperature. >... a hell of battery acid and acidic complexes. Nearly every member of >the metal group is bound to be fully oxidized. Venus is a natural >toxic waste dump. The surface is above the decomposition temperature of most sulfates, carbonates, and some oxides. That's why all that stuff is in the atmosphere. -- samw@bucket.rain.com (Sam Warden) -- and not a mere Device. ------------------------------ Date: Thu, 10 Sep 92 21:18:21 GMT From: "Thomas H. Kunich" Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article rick@trystro.uucp (Richard Nickle) writes: > >It's you're not transporting megatons of machinery to Mars, and you >don't have to worry about the problems of soft-landing anything on the >surface. Adding water requires small robot probes to go retrieve ice >and move it to mars. The robots would attach themselves to the appropriate >piece of ice, and use the ice itself as reaction mass to move them from >wherever you got them (Saturn, the belt) to Mars, whereupon they would >fall onto mars and release tons of water. You just set up your ice-retriever >robot factory someplace convenient: Lunar orbit? And begin mass-producing >the things. Now, Luna doesn't have any water, right? So, well, you pay for >the cost of the robot factory by using the robots principally to move water >to Luna, not Mars. Once you've paid off all your creditors and are making It's always nice to see people write refreshing things like, "All you have to do is move Mars several thousand miles into a closer orbit." Or some such. Do you remember that lunatic that was interviewed on 60 Minutes about the Soviet antiballistic missle system -- the one where he said, "All you have to do is, first, contain a nuclear explosion. Then ---", I sort of turned off at that point. Here we are, with great difficulty even getting antennas to point in the correct direction and this guy suggests that we can throw jillions of tons of matter at a planet accurately. Yes indeed, really refreshing. > >If the robots are reusable (they can retrieve their payload and steal enough >water to propel themselves back to where they got the ice), it's even better. >Your number of robots working on the project continually increases, and water >delivery to Mars begins to skyrocket. Add any potential colonies on Mars who >actually need the water for immediate use, delivered to a specific spot, and >it's even better, they'll be willing to pay for the delivery system. How do we build these water recovery robots in the first place? Hwo do these martian colonists get to Mars? How are they supported while you are throwing enough mass at the planet to cause cataclismic damage? ------------------------------ Date: 10 Sep 92 19:52:31 GMT From: Paul Havlak Subject: NASA/Rice information request Newsgroups: talk.politics.space,sci.space,bit.listserv.space,tx.general,houston.general,rice.general I'm forwarding this request from Jim Kelly at the Houston Press: ***** I'm working on a piece for Sallyport, the Rice University alumni magazine, centering on the Rice/NASA relationship over the last 30 years. For example, I'd like to hear about Rice astronauts (alumni and faculty), NASA-sponsored Rice research, and the Rice/Humble Oil (now Exxon)/NASA land deal that brought Johnson Space Center to Clear Lake. In particular, I'm interested in the role of U.S. Rep. Albert Thomas (D-Houston, Rice '20) in the deal. Any other connections between Rice and NASA are also of interest. Please send mail to houstonpress@igc.org, attention Jim Kelly. Thanks ***** Jim doesn't have Usenet access, and I'll be out of town, so he won't be able to use any information you don't send directly. You can also reach him by fax (713-783-1320) or snailmail: Jim Kelly Houston Press P.O. Box 540167 Houston, TX 77254-0167 Thanks, Paul -- Paul Havlak Dept. of Computer Science Graduate Student Rice University, Houston TX 77251-1892 PFC/ParaScope projects (713) 527-8101 x2738 paco@cs.rice.edu ------------------------------ Date: 10 Sep 92 21:49:00 GMT From: Josh 'K' Hopkins Subject: One Small Step for a Space Activist... Vol 3 No 9 Newsgroups: talk.politics.space,sci.space kentm@aix.rpi.edu (Michael V. Kent) writes: >In article <1992Sep9.193128.20635@iti.org> aws@iti.org (Allen W. Sherzer) writes: >>On the plus side, station supply will mean placing a lot of >>mass into LEO, and this could make the market for launch >>services a LOT bigger, which could help reduce launch >>costs. But the way things currently are, NASA intends to use >>only the Shuttle (with its high cost) for resupply. Not only >NASA intends to use only the Shuttle for resupply ONLY until something >better comes along. Also, one of the design missions of the Delta Clipper >is station resupply. ESA has also done studies of an Ariane Transfer Vehicle to do logistics for Freedom. It has two advantages I see over either of the above suggestions. First, its launched on a vehicle that, while still vaporware, is looking to be done one time and inexpensive to launch. Second, if ESA does the resupply, we don't have to pay anything. -- Josh Hopkins "If you are sitting in an exit row and you cannot read this card or cannot see well enough to follow these instructions, please tell a crew member." j-hopkins@uiuc.edu -United Airlines safety instructions ------------------------------ Date: 11 Sep 92 05:13:41 GMT From: Ron Baalke Subject: Pluto Direct Propulsion Options Newsgroups: sci.space In article , pgf@srl03.cacs.usl.edu ("Phil G. Fraering") writes... >Henry Spencer, net.authority, pontificates: >/You really cannot do a Pluto >\orbiter in a reasonable amount of time with 1960s propulsion technology, >/which is what all currently-planned missions use. >Just out of curiosity, is there a way to convince them to use post-early- >1960's technology, like an ion drive of some sort? JPL is currently studying the stationary plasma thrusters that the Department of Defense recently obtained from the Soviets. These plasma thrusters perform better than ion thrusters and are in a small package about 10 times smaller, and they weigh only 4 kg. The plan is to build scaled-up versions of the Soviet thrusters that would provide the primary propulsion for spacecraft for transfer to geosynchronous orbit. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Anything is impossible if /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you don't attempt it. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Thu, 10 Sep 92 17:36:54 GMT From: Doug Mohney Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space References: <1992Sep7.173253.1837@access.digex.com> , <1992Sep10.135754.1491@eng.umd.edu>,<1992Sep10.160322.29761@elroy.jpl.nasa.gov> Reply-To: sysmgr@king.eng.umd.edu Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1992Sep10.160322.29761@elroy.jpl.nasa.gov>, baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >In article <1992Sep10.135754.1491@eng.umd.edu>, sysmgr@king.eng.umd.edu (Doug Mohney) writes... >>In article , henry@zoo.toronto.edu (Henry Spencer) writes: >> >>>It is extremely difficult to combine a reasonable payload and a manageably >>>short trip time with an orbiter mission. Pluto is *a long way away*; to >>>get there in under a decade, the probe has to be fast. Killing all that >>>velocity is inordinately expensive in mass. >> >>Aerobrake? >> > >We don't have that much practical experience with aerobraking into orbit >capture - it has never been attempted before. If given the chance, Magellan >will perform a number of aerobrake maneuvers through the atmosphere of >Venus to circularize its orbit, but the uncertainty is so great that we >can only estimate that it will take from 100 to 300 days. Pluto does have a >tentative atmosphere, but we know so little about it. A flyby mission will >help to enlighten us. If you haven't noticed already, the basic blueprint >for planetary exploration is to do a flyby first, then follow it up with >an orbiting mission, and then follow that up with a lander. Wouldn't we find out more if we tried to dip the probe INTO the atmosphere? After all, we'd get much better close-up pictures :-). As well some better feel for the composition of the atmosphere upon entry. I suppose for imaging purposes, a flyby makes more sense, but if the seat-of-the pants aerobrake worked, you get more imaging time, plus some data on atmosphere density, etc. OK, it would be impolite to dump the RTGs on Pluto's surface if it doesn't work...minor details... Support U.N. military force against Serbia -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 11 Sep 92 01:55:53 GMT From: Ron Baalke Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article <1992Sep10.173654.4246@eng.umd.edu>, sysmgr@king.eng.umd.edu (Doug Mohney) writes... >Wouldn't we find out more if we tried to dip the probe INTO the atmosphere? >After all, we'd get much better close-up pictures :-). As well some better feel >for the composition of the atmosphere upon entry. Actually, the radio science experiment will tell us a lot about the atmosphere. As the spacecraft flies by, the radio signal will be transmitted through the atmosphere to Earth. How the radio signal is affected by the atmosphere will tell us its density and composition. This is a common technique already performed with all of the other planets. I believe from what we do know about Pluto's atmosphere is that it quite thin and extends out quite a ways, even encompassing Charon. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Anything is impossible if /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you don't attempt it. |_____|/ |_|/ |_____|/ | ------------------------------ Date: 10 Sep 92 18:05:09 GMT From: Dave Jones Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article <1992Sep10.173654.4246@eng.umd.edu> sysmgr@king.eng.umd.edu writes: > >Wouldn't we find out more if we tried to dip the probe INTO the atmosphere? >After all, we'd get much better close-up pictures :-). As well some better feel >for the composition of the atmosphere upon entry. > >I suppose for imaging purposes, a flyby makes more sense, but if the >seat-of-the pants aerobrake worked, you get more imaging time, plus some data >on atmosphere density, etc. > >OK, it would be impolite to dump the RTGs on Pluto's surface if it doesn't >work...minor details... > Err, like not being able to get the stored pictures sent back to you. Remember these things aren't done in real time. There was a mention of several weeks playback time for data in a previous posting. You can't blame mission designers for avoiding the risk of losing the entire craft by staying well away from the planet's surface. -- ||)) Those who wallow in ignorance ))) Policemen are numbered in case))| ||)) must dwell in Limbaugh for a time ))) they get lost - S. Milligan ))| ||))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))| ||Dave Jones (dj@ekcolor.ssd.kodak.com) | Eastman Kodak Co. Rochester, NY | ------------------------------ Date: 10 Sep 92 20:09:20 GMT From: Nick Janow Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space henry@zoo.toronto.edu (Henry Spencer) writes: > In article <1992Sep10.135754.1491@eng.umd.edu> sysmgr@king.eng.umd.edu > writes: >+> ... Pluto is *a long way away*; to get there in under a decade, the probe >+> has to be fast. Killing all that velocity is inordinately expensive in >+> mass. >+ >+ Aerobrake? > > In what? :-) Pluto does have an atmosphere of sorts at the moment, but I'd > guess it's too thin to do much aerobraking in, even if we knew its properties > well enough to plan an aerobraking mission, which we don't. Would it be possible to aerobrake at Uranus or Neptune, perhaps also using the atmosphere to change trajectory significantly? This would provide a fast flight for much of the journey and have the remaining part at a speed slow enough for aerobraking in Pluto's atmosphere, or at least a much slower pass by Pluto. It would also allow a mission at Uranus or Neptune. I can see lots of problems with this, but sometimes wild ideas are workable. -- Nick_Janow@mindlink.bc.ca ------------------------------ Date: 10 Sep 92 21:29:49 GMT From: Gerald Cecil Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space In article <1992Sep10.173654.4246@eng.umd.edu> sysmgr@king.eng.umd.edu writes: >Wouldn't we find out more if we tried to dip the probe INTO the atmosphere? >After all, we'd get much better close-up pictures :-). As well some better feel >for the composition of the atmosphere upon entry. >I suppose for imaging purposes, a flyby makes more sense, but if the >seat-of-the pants aerobrake worked, you get more imaging time, plus some data >on atmosphere density, etc. You're skimming the atmosphere at 20 km/s! In an aerobrake, your speed roughly halves each time you sweep up atmospheric mass equal to your own (drops somewhat faster if you radiate heat). Use even the *surface* pressure of the Pluto atmosphere (I don't have that # at hand) and you're sure to require more than the few 10's of kms that are available. So, Lithobreak it is! -- Gerald Cecil cecil@wrath.physics.unc.edu 919-962-7169 NC 27599-3255 USA If we don't succeed, we run the risk of failure. -- Chairman of US Space Council. ** Be terse: each line cost the Net $10 ** ------------------------------ Date: Thu, 10 Sep 92 20:31:12 BST From: amon@elegabalus.cs.qub.ac.uk Subject: SPS > Actually, you don't have to fool around with aluminum-oxygen (which is > a hassle as a rocket fuel, because both the aluminum and the aluminum > oxide are solids, where you'd really like liquid and gas respectively). > Henry: Not really. The way the fellow I know was doing it in a way that was quite hassle free. The fuel consists of, roughly speaking, tightly wrapped aluminum foil. The oxidizer is water that is introduced to a lithium igniter. The resulting heat causes the H20 to dissociate. The O2 and the Al then react and release supply enough heat to continue to dissociate the water as it is introduced. Specific impulse is okay but not wonderful. But it hardly matters because the engine is so cheap and safe. The reactions are self sustaining (until you turn off the spigot). The plume is quite nice (I've seen a photo of an engine firing on a test stand in the middle of a farm in Somewhere, USA). I've not spoken to him in several years. He was talking about going to a different igniter. A fairly standard one whose name escapes me at the moment. Don't know if he has used it yet or not. Or even if he has gone any farthur at all. But from what I know of the person, I suspect he is still moving ahead. ------------------------------ Date: Thu, 10 Sep 1992 20:44:18 GMT From: "Allen W. Sherzer" Subject: SSTO Mailing List Formed Newsgroups: sci.space,talk.politics.space SSTO Mailing List Charter This group is for people interested in promoting the development of Single Stage to Orbit vehicles in general and the current SDIO Single Stage Rocket Technology (SSRT) program (DCX and DCY) in particular. The group will disseminate technical and political information on the project and promote discussions on both the technology and how best to promote this technology to the government and general public. Members are expected to be ACTIVE supporters who will be willing do work in their communities and with their elected representatives to publicize this program. If you sign up you WILL be expected to help (writing to and perhaps meeting with your representatives at the very least). If you simply want to read about it, stick to sci.space or space-tech. How to sign up: Send mail to ssto-request@hela.iti.org. In the message include: 1. Your name 2. Address 3. Phone number 4. New congressional district (if known) 5. New congresscritter's name (if known) -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "If they can put a man on the Moon, why can't they | | aws@iti.org | put a man on the Moon?" | +----------------------226 DAYS TO FIRST FLIGHT OF DCX----------------------+ ------------------------------ End of Space Digest Volume 15 : Issue 184 ------------------------------