Date: Wed, 2 Jun 93 05:00:12 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #654 To: Space Digest Readers Precedence: bulk Space Digest Wed, 2 Jun 93 Volume 16 : Issue 654 Today's Topics: Can we use HST to look at possible Jupiter/comet collision? (2 msgs) Dyson Sphere (for a gaming world).. (2 msgs) Hey Sherz! (For real!) Cost of LEO Liberal President murders spaceflight? (2 msgs) Limits Seen On Human Existence Mining on the Moon? Moon Base NASA To Commercialize Remote-Control Technology Sagan / TAPPS Von Braun and Hg (was Re: About the mercury program) What about Swift/tuttle? (2 msgs) Why a far side Science station. Why is everyone picking on Carl Sagan? 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: 1 Jun 1993 15:14:02 GMT From: "Bruce d. Scott" Subject: Can we use HST to look at possible Jupiter/comet collision? Newsgroups: sci.space How is it that _one_ picture of a collision event would be useful? I should think that to have any bearing on modelling of the collision process one would need a series. Working on turbulence computation, I have seen a lot of this type of problem... -- Gruss, Dr Bruce Scott The deadliest bullshit is Max-Planck-Institut fuer Plasmaphysik odorless and transparent bds at spl6n1.aug.ipp-garching.mpg.de -- W Gibson ------------------------------ Date: Tue, 1 Jun 1993 16:44:16 GMT From: Thomas Clarke Subject: Can we use HST to look at possible Jupiter/comet collision? Newsgroups: sci.space In article <1ufrnqINNcch@nsat.ipp-garching.mpg.de> bds@uts.ipp-garching.mpg.de (Bruce d. Scott) writes: >How is it that _one_ picture of a collision event would be useful? >I should think that to have any bearing on modelling of the collision >process one would need a series. Working on turbulence computation, I >have seen a lot of this type of problem... >-- I think one picture of the spectrum of the colliding comet might be useful in that it could be used as the basis of a chemical analysis of the comet. -- Thomas Clarke Institute for Simulation and Training, University of Central FL 12424 Research Parkway, Suite 300, Orlando, FL 32826 (407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu ------------------------------ Date: Tue, 1 Jun 1993 08:38:04 GMT From: Michael Sandy Subject: Dyson Sphere (for a gaming world).. Newsgroups: rec.games.frp.misc,sci.space I've been working for a long time on a world shaped like a hollow hula hoop. Unlike a ringworld which needs walls to contain the air, gravity and centripital force balance to produce about equal gravity effect over the entire surface. Ignoring the difficulty of construction and the near magical compressive and tensile strengths required, the Toroid has some interesting problems associated with weather. First, a diagram, o / axis of rotation / o ---Plane of orbit--- Sun * O ---------------- O (One character space equals 100,000 km) It takes a little tinkering to figure out the proper rotation rate for the Toroid, I guesstimated to be almost twice Earth's. There are four major regions which are effectively isolated from each other. The polar and equatorial bands form effective barriers that can only be crossed with powerful magic or high technology. The inner two regions experience two eclipses each year that last about 1 % of the year each. A bit about the evolution of this idea: When I studied the Ringworld designed by Niven, I noticed that the huge mass of the Ringworld would cause a small gravitational gradient towards the middle of the band. The ring walls might not be necessary! However, this meant that _everything_ would be pulled towards the middle, air, water, crust! So I redesigned it into a lens shape. For a while I experimented with making its interior habitable, with multiple levels illuminated by artificial suns. Finally, I discovered that a spinning torus would do that most essential thing for a habitable construct, hold an atmosphere and lithosphere approximating Earth's without complicated and _fragile_ mechanisms. By happy coincidence it allowed climate variation that would enable the variety a good sci-fi story or game world requires. The problems I wasn't able to answer, such as pertaining to solar tides, and the effects of Eclipse storms, or Crossover, and the different Coroilis effects for such a huge world, look smaller than the orbital instability of Ringworld and the gravitation problems of a Dyson sphere. The toroid can easily be scaled down by a factor of ten or so in both the tubes' radius and the hoop's radius. -- Michael Sandy michaels@m2xenix.psg.com "I resolve to make no non-tautological New Year's Resolutions!" ------------------------------ Date: Tue, 1 Jun 1993 10:52:06 GMT From: "G.R. Roberts" Subject: Dyson Sphere (for a gaming world).. Newsgroups: rec.games.frp.misc,sci.space,rec.arts.sf.science Probably been said before, but a Dyson Sphere is impractical as a gaming world, due to extreme size. Then again, those gaming worlds which don't appear to be set on a planet at all, but on a flat surface, may well be on the inner surface of a huge Dyson sphere. ------------------------------ Date: 1 Jun 1993 09:50 CDT From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space In article <1993May26.193103.28480@mksol.dseg.ti.com>, mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes... >In <1ttm8j$90i@access.digex.net> prb@access.digex.net (Pat) writes: > >>Ken, > >>pat. > >>Don't include contingency satellitte return missions. It would have >>been cheaper to build new ones and pop them off. >-- >Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. It is real funny for me to read the "experts" talking about the cost of satellite construction from those who have never laid their hands on one, or been responsible for the construction and operation of one. If you want to make statements like this back them up with numbers both the cost of reconstruction and the cost in lost revenues during the construction period. Dennis, University of Alabama in Huntsville ------------------------------ Date: Tue, 1 Jun 1993 12:22:01 GMT From: fred j mccall 575-3539 Subject: Liberal President murders spaceflight? Newsgroups: sci.space In <1uf2e9$1a13@hal.gnu.ai.mit.edu> rjc@hal.gnu.ai.mit.edu (Ray) writes: >In article <1993May31.222356.3357@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >>In pgf@srl05.cacs.usl.edu (Phil G. Fraering) writes: >> >>>mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >>Power Issues and Choices_. I will just quote from the conclusion with >>regard to nuclear recycle, which starts on page 333. >> >>"There is no compelling national interest to be served by >>reprocessing. There appears to be little, if any, economic incentive >>and it is unlikely that reprocessing and recycle could proceed without >>subsidy. The noneconomic benefits of reprocessing are small: fuel >>supply for LWRs would be little enhanced; present experience with >>reprocessing or plutonium stockpiles has little present value since >>the introduction of breeders is sufficiently far in the future and >>uncertain; and contemporary waste management risks with reprocessing >[...] > I agree that the anti-nukes have some good arguments, but some of >them take it to a whole 'nother level and are not even willing to >entertain the notion that one day nuclear power could be safe, economical, >and effective. Note that the 1977 study I cited (_Nuclear Power Issues and Choices_ is not 'anti-nuke'. It is intended to be a disinterested look at the pros and cons of various technologies, funded by the Ford Foundation and administered by MITRE. In point of fact, the conclusion they seem to arrive at is that fission power is safer than coal, but that recycle and breeder reactors are economically indicated against, more risky technologically, and provide adverse policy effects even if those other things weren't true. They also examine several other possible energy sources and find them to be econonomically unfeasible given the costs of coal, oil, and uranium. >Gore's attitude towards Nuke power reminds me of >Bush's attitude toward fetal tissue research. Gore seems to want to >silence any further work on future nuclear technology (The Wall >Street Journal had an article on him the other day about his attempts >to censor data from the scientific community which contradicts some >of his esoteric ideas) I'm not sure Wall Street Journal is the best source for information about something like this, although I don't necessarily find it particularly surprising that Gore would be against nuclear power. After all, this is not exactly the favorite administration for the target audience of Wall Street Journal. > The Clinton administration "...constitutes a move away from >nuclear power" (their own words), so even DoE funding for fusion >research is being cut. I don't have a real problem with reliance >on fission power being reduced (or moves toward energy efficiency), >but nuclear power (fission and fusion) has real uses in outer >space. Not all areas of the solar system have the compounds needed >for producing chemical fuels, wind power is obviously out of the picture, >and solar arrays aren't much better if you want to build a large >ship with lots of thrust. From what I understand, Gore is not exactly pro-space, either, so I don't think this is an issue for this administration. > What ever happened to NERVA (or a modified version for space only), or >Nuclear Electric propulsion? Were they killed by the test ban, or >anti-nuke hysteria of the 60s/70s? (ugh, remember all the paranoia and hysteria >over Galileo's RTGs?) As I recall, that's pretty much what the program died of, although it was much prior to Galileo. > Will solar/wind power ever be able to deliver the performance >needed to make laser sail propulsion feasable? I've heard the power >requirements are pretty steep. Solar power is somewhere between 3 and 8 times more expensive than nuclear power (including all costs for both). It simply isn't practical. It also varies through the day and the year, so some sort of storage would be necessary. Wind power, which is really just another form of solar energy, suffers from the same sorts of problems. One could conceivably get enough power for just about anything through the use of solar, but it would be hideously expensive. > As for the material you quoted, it has a lot of validity, but I don't see >how it's going to help the world situation. The way I see it, the nuclear >genie is out of the bottle. Sooner or later thr third world is going to >develop the technology to build both a-bombs and h-bombs -- it's only a matter >of time. True, but better later than sooner; this is the reason for the policy prescriptions the study arrives at. Also note that that is only one of several reasons (technological risks, uneconomic at current or projected uranium prices, etc.) for not investing in recycle or breeders. >Not to mention, that Europe and Japan already have plans to pursue >breeders, and there would be little we could do to stop nations like China >from pursuing them. Note that in both Japan and Germany, nuclear plants are *required* to recycle fuel. This law was based on their apparent belief that this makes the waste disposal problem more tractable, but this does not actually appear to be the case. Also note that all the nations so far involved are already either nuclear armed or could be in a relatively short time (including, of course, China). >Our time would be better spent developing defenses against >ballistic missile attacks, and helping to promote democracy and trade among >the nations of the world. Countries which trade heavily with each other rarely >try to anhillate their neighbors (customers). I think our time is probably better spent doing *both* (discouraging the spread of nuclear technologies and large, worldwide trade in plutonium) and defense technology development. However, you should also note that developing BMD doesn't really protect you from nuclear attack; it merely makes doing it by one method more difficult. >or to quote someone famous, "when goods don't cross borders, armies will." > The plutonium economy argument seems to be a little bit of a red >herring (like the terrorists-bomb-nuke-plant argument). All I can suggest is that you find a copy of the study and read it. I only posted the conclusion of one chapter, and really have no desire to type in all 400+ pages of it. You re, however, apparently under some misapprehensions about the thrust of the study and the concern about largescale trade in plutonium is hardly a "red herring". >-Ray >p.s. What is going to happen to the Integral Fast Reactor? >>-- >>"Insisting on perfect safety is for people who don't have the balls to live >> in the real world." -- Mary Shafer, NASA Ames Dryden > This quote applies neatly to energy generation and nuke power. There are >always risks with every technology, the goal is to make risks acceptable. >Nuclear power may not be acceptable to a lot of people now, but I see no >reason why we can't eventually develop solutions to the problems it >has. Powered flight used to be dangerous, uncomfortable, and the risks >unacceptable (in my view). Ditto for the current Space Shuttle design. > Personally, I'm more afraid of driving down the highway or walking >the streets of Baltimore than I am of having a nuclear plant in my >back yard. Me too, but so what? The question was about recycle (uneconomical, unnecessary, and undesirable from a policy standpoint) and breeders (ditto). Personally, given a choice, I'd rather live next to a CANDU- style HWR than one of the PLWR's that we use in this country. Even though the CANDU design is better for the amateur bomb builder (fuel can be cycled in and out of the reactor without power down, so it's much harder to police the fuel cycle), they are also a much safer design (no radioactive pressurized core, for example). -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Ames Dryden ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. ------------------------------ Date: 1 Jun 1993 12:38:10 -0400 From: Pat Subject: Liberal President murders spaceflight? Newsgroups: sci.space In article <1993Jun1.122201.11250@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >Solar power is somewhere between 3 and 8 times more expensive than >nuclear power (including all costs for both). It simply isn't The trick for most people who move off the grid, solar/wind/water power cycle, is that they also materially reduce their energy consumption. High efficiency devices, Super insulation, etc. It's actually quite possible and to still maintain a high tech lifestyle, but one must become very aware of sources of power drain. >>or to quote someone famous, "when goods don't cross borders, armies will." This line wasn't from fred, it was from the guy from UI. A detailed analysis of the Iraqi/kuwaiti trade figures would seem to belie that somewhat simplistic argument. States make war for numerous reasons. Trade is only part of the equation. Germany in both pre war eras was trading extensively with, Russia, France, england and poland. It did not seem to be a deterrent to either the Kaisers actions or Hitlers. We have almost no trade with Rwanda, yet i haven't heard of a rwandan war. it's kind of a facetious point, but it serves as a logical razor. Improved trade may help improve relations, but wars are somewhat independent of trade. Look at the serbian race war. Serbia conducted all it's trade with croatia, bosnia and slovenia, yet their tactical plans were to destroy everything in sight. I know people think that countries can either send zeros or monteros, but it's not that easy |though the CANDU design is better for the amateur bomb builder (fuel |can be cycled in and out of the reactor without power down, so it's |much harder to police the fuel cycle), they are also a much safer |design (no radioactive pressurized core, for example). That must create a real problem from efficiency. The absence of a pressure cycle, severley limits the carnot efficiency of the system. Does HWR mean Heavy water? and does Heavy water have a significantly higher boiling point or heat of vaporization? pat ------------------------------ Date: Tue, 1 Jun 1993 14:45:41 GMT From: aezpete@deja-vu.aiss.uiuc.edu Subject: Limits Seen On Human Existence Newsgroups: sci.space Has anyone read this article in the Science Times of today's New York Times? A certain Dr. J. Richard Gott has developed a method for predicting the likely maximum lifetime of a given object. He maintains that the "longevity of things can be estimated remarkably well from their histories," and that all one needs to do that is know how old a given thing is now, and to assume that there is nothing special about it to distinguish it from other like things or events. Case in point was the likely longevity of the manned space program, which he estimates a 95 per cent probability of continuing for a maximum of 1,250 years, and a minimum of 10 months, given only that it is 32 years old. Dr. Gott further maintains that this is a finite window of opporitunity to establish a permanent presence in space, and that we'd better get busy before the 1,250 years is up. After 1,250 years is up, the manned space program will end for whatever reason, and humans will be marooned on earth forever more until their inevitable extinction. I find his theory hard to accept, and am tempted to loudly say "Poppycock!" I don't think the universe is that predictable, and that such a theory could apply very well to things like human activity (space programs). It seems to carry with it some very heavy assumptions. Peter Schlumpf aezpete@deja-vu.aiss.uiuc.edu University of Illinois at Urbana-Champaign -- __________________________________________________________________ Peter Schlumpf aezpete@deja-vu.aiss.uiuc.edu ------------------------------ Date: Tue, 1 Jun 1993 14:41:19 GMT From: Paul Dietz Subject: Mining on the Moon? Newsgroups: sci.space In article <1uafd3INNgfc@nsat.ipp-garching.mpg.de> bds@uts.ipp-garching.mpg.de (Bruce d. Scott) writes: >|> Essentially nothing is known about this. Ore deposits are, almost by >|> definition, rare events -- the results of extreme conditions. We have > > Except that titanium is so abundant in lunar surface material that it > has been said to qualify as medium to high-grade ore by terrestrial > standards. I think I saw this in some G Harry Stine-like propaganda > some years ago, so I am not completely sure of its veracity. Of course, titanium is so abundant on earth that these lunar deposits are not "ores" in the economic sense (ilmenite concentrate on earth currently sells for < $.10/lb). Lunar high-Ti basalts are 8 - 14% TiO2; there are enormous volumes of alkaline basalts on earth with about 3% TiO2 (not to mention the less abundant very high grade deposits currently being mined, some of which are > 50% TiO2.) Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Tue, 1 Jun 1993 15:08:54 GMT From: Brad Whitehurst Subject: Moon Base Newsgroups: sci.space In article <1993May31.150520.15309@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >In article <1993May28.200304.29032@leland.Stanford.EDU> bill@leland.Stanford.EDU (William Mills) writes: >>> investment. It's akin to attempting to plant a colony in a malarial swamp >>> when there is nice fertile high ground just over the next rise. The first >> >> Remember Jamestown: a colony in a malarial swamp near fertile high ground. >>It survived for about 90 years because it was on the water, and had easier >>transportation back to England. A Moon Base would have a similar advantage >>over Mars or asteroids. > > >Only if it could import Negros and grow tobacco. Remember the story of >Virginia Dare, the first Englishwoman to be born in the New World? >Her colony simply disappeared between voyages from England. Jamestown went >through "the starving" when the ships from England failed to return on >schedule. The colony wasn't self sufficient, it was an appendage of >the English mercantile explorers. It wasn't until the fertile areas were >settled that English presence in the New World became secure. > >Gary Welll, actually it was mostly due to the Englishmen's ignorance of their new home. After a few years, they came to appreciate the abundance provided by the land, rivers, and Chesapeake Bay. BUT they first had to learn the ropes of how, what, where, and when to farm in the New World, what could be found in the waters, etc. (Englishmen STILL wilt in our Virginia summers, until they acclimate!) A cautionary tale, perchance? They put up with the malarial swamps ('tho they didn't know what caused malaria...) because ports were so important to them. Charleston, SC was an even worse swamp, but offered a good harbor, so they lived with it, and still do. There'll be a learning curve when living in any new environment, with the potential for disaster omnipresent. That doesn't necessarily mean that the environment does not have advantages. You have to try to live with it a while before you can say what the tradeoffs really are. Permanent moon colonies would likely find advantages we've not considered. Likewise for orbital/asteroidal settlement. And the advantages will not necessarily be the same for both, or mutually exclusive for that matter. -- Brad Whitehurst | Aerospace Research Lab rbw3q@Virginia.EDU | We like it hot...and fast. ------------------------------ Date: 1 Jun 1993 15:54 UT From: Ron Baalke Subject: NASA To Commercialize Remote-Control Technology Newsgroups: sci.space,alt.sci.planetary,comp.robotics Charles Redmond Headquarters, Washington, D.C. June 1, 1993 (Phone: 202/358-1757) Jim Doyle Jet Propulsion Laboratory, Pasadena, Calif. (Phone: 818/354-5011) RELEASE: 93-100 NASA TO COMMERCIALIZE REMOTE-CONTROL TECHNOLOGY A remote-control technology used by NASA scientists to guide a robot in a recent cross-country test soon will be turned over to private industry. The remote-control technology is being licensed to a private firm for commercial development, said Dr. Antal Bejczy, the experiment Technical Manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. The firm's identity is being withheld while negotiations are in progress. In the test, researchers at JPL used a new, graphically- oriented program to remotely control -- or "teleoperate" -- a robotic arm at NASA's Goddard Space Flight Center, Greenbelt, Md. This teleoperation technique is designed for free-flying robots that would service orbiting satellites, and also has many potential uses on Earth, according to Bejczy. Possible terrestrial applications for teleoperations include nuclear or toxic waste site cleanup, decommissioning of hazardous facilities, special emergency medical operations, construction and building planning, and remotely operated highway maintenance. In the recent JPL-Goddard experiment, a robot arm equipped with a power screwdriver was placed in front of a mockup of a satellite at the Goddard center. The satellite was fitted with a replaceable module designed to be changed out by astronauts or robots. The robot arm's job was to insert the screwdriver through a 18-inch (45- centimeter) long hole to reach a latching mechanism that holds the replaceable module on the satellite, then to unlatch and remove the module. Finally, the robot arm was to place the new module on the satellite's frame and latch it in place. Throughout the experiment, the arm was controlled by an operator thousands of miles away in California. JPL researchers developed a software program that allows the remote operator to superimpose high-fidelity computer graphics models of the robot arm, screwdriver and satellite module onto television pictures of the live scene. These synthetic TV camera views make visible the robot's critical motion events that otherwise are hidden from the operator in a normal TV camera view, said Bejczy. "The operator can generate and predict or preview the motions without commanding the actual hardware," said Bejczy. "Moreover, the operator can see the consequences of motion commands in real time, without time delay, through the simulation method overlaying the actual work scene." After verifying an action of the robot arm and its result through the synthetic TV view, the operator then commands the robot arm and tool to actually execute the next action. During the test, computer commands were sent from JPL to Goddard over the Internet computer network. TV views of the robot arm and satellite mockup were sent back to the JPL control station over NASA's satellite TV system. "The module exchange task was originally designed to be performed by astronauts working in pressurized suits in the Space Shuttle's cargo bay," said Bejczy. "The success of the experiment shows that the same work can be done by robotic hardware controlled from Earth." Bejczy also said that the graphics-based, remote-control technique will form the basis for new features added to commercially available computer graphics software packages. JPL's work on this experiment is being performed with funding from NASA's Office of Advanced Concepts and Technology, Washington, D.C. -end- ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand, |_____|/ |_|/ |_____|/ | has three eyes. ------------------------------ Date: Tue, 1 Jun 93 14:56:02 EET From: flb@flb.optiplan.fi (F.Baube[tm]) Subject: Sagan / TAPPS From: fred j mccall 575-3539 > > flb@flb.optiplan.fi ("F.Baube[tm]") writes: > > > >From: "John F. Woods" > >> > >> this, then, was used to trumpet the fact that nuclear war is bad > >> (OK, folks, hands up -- how many in the audience here were saying > >> to themselves, "Gee, I thought nuclear war was a splendid idea > >> until TAPPS proved their nuclear winter idea!"). > > > >Well, don't forget that there were psychopathic > >statements from the Pentagon brass like > >"In the event of nuclear war, just lay a door over > >a hole in the ground and shovel some dirt over it." > >I believe this was said in testimony to Congress. > > Well, this makes more sense than going outside to watch! Actually, > dirt is a fiarly good shielding material, so if you don't happen to > have a bomb shelter handy, this is probably the best advice you're > going to get. Agreed ! But .. I for one got the distinct impression at the time that Dr Strangelove was alive and living at FEMA, plotting post-holocaust fun with Ollie. Give Sagan a little credit for injecting into the discus- sion a bit of rational thought about the ultimate effects of such a war. Something more complex and long-term than planning how to collect taxes and corral dissidents. -- * Fred Baube (tm) * Quick Quiz: "Liberalism rejects ideological * GU/MSFS/88 * struggle and stands for unprincipled peace, * baube@optiplan.fi * thus giving rise to a decadent, philistine * #include * attitude and bringing about political degen- * * eration." -- Mao Ze-Dong or Ronald Reagan ? ------------------------------ Date: 1 Jun 1993 09:44 CDT From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov Subject: Von Braun and Hg (was Re: About the mercury program) Newsgroups: sci.space In article , nastasi@cbnewsk.cb.att.com (joseph.l.nastasi) writes... >In article <1993May18.174340.1@fnalo.fnal.gov>, higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey) writes: > >> In article <1tb0uo$qpe@access.digex.net>, prb@access.digex.net (Pat) writes: >> > Von Brauns original plan was to have the capsule fully automatic, >> > with the occupants, performing a few bio experiments. >> >> Did Wernher von Braun actually have anything to do with the Mercury >> program, or did pat just see *The Right Stuff* too many times? (A >> lousy way to get your history, by the way...) >> > >Van Braun had very little to do with Mercury. For a very good review >of the political and technological decisions in the early space >program, read David Baker's "The History of Manned Spaceflight" >It was written in the very early eighties and most of the facts >are still valid today... > >Joe Nastasi >nastasi@mtgpfs1.att.com > > Dr. Von Braun did not have too much to do with the capsule except to make sure that the interface between the capsule and the Mercury Redstone was compatible. However, to say that he had little to do with the Mercury program is simply wrong. As we all know the Redstone is little more than an upgraded V2, from the engines to the guidance control. To say that Von Braun had little to do with Mercury is like saying that Henry Ford had little to do with the Model T. The Redstone was flying successfully years before the Atlas and at a time when the only Atlas flights were the nice little fireworks on the pad the Redstone was putting up live payloads. Dennis, University of Alabama in Huntsville ------------------------------ Date: 1 Jun 1993 12:20:03 -0400 From: Pat Subject: What about Swift/tuttle? Newsgroups: sci.space I saw something in the paper, where they were concerned that Swift tuttle might have shed fragments with enough drift velocity to srike earth on the next pass. Has anyone heard anything more about this? pat ------------------------------ Date: 1 Jun 1993 16:56:13 GMT From: Greg F Walz Chojnacki Subject: What about Swift/tuttle? Newsgroups: sci.space From article <1ufvjj$ci0@access.digex.net>, by prb@access.digex.net (Pat): > > I saw something in the paper, where they were concerned that > Swift tuttle might have shed fragments with enough drift > velocity to srike earth on the next pass. > Well, we know that P/S-T has shed lots of particles that strike Earth -- that's what the Perseid metoer shower is. I also an article expressing some concern over extra Perseids possibly endangering LEO sats, especially big onces like Hubble. However, the densities of the swarms made the odds something like 0.1% -- and there's lots of uncertainty about the density. Also, the 0.1 was for HST; other smalelr satellites are as smaller risk. [Can anyone remember: Was is 0.1 or 0.1%?] Greg ------------------------------ Date: Tue, 1 Jun 1993 14:07:52 GMT From: Gary Coffman Subject: Why a far side Science station. Newsgroups: sci.space In article <1u5i3g$49e@access.digex.net> prb@access.digex.net (Pat) writes: > >Is the earth uniformly radio noisy? > >I can see the US and Europe being real loud, But over Big chunks of asia > and the oceans, it should be quiter, or does the variation >not matter enough? It matters at UHF through SHF, that's why there are radio quiet zones around major radio telescopes. However, there's much of interest to listen for at VHF/HF/MF/LF/VLF and even ELF, that are all troubled by over the horizon propagation modes, and problems with the ionosphere. For these radio bands, there is no quiet zone short of the lunar farside. And, as we venture into the millimeter wavelengths, the troposphere itself becomes a major source of noise and attenuation. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: Tue, 01 Jun 93 15:06:35 MET From: PHARABOD@frcpn11.in2p3.fr Subject: Why is everyone picking on Carl Sagan? > If we are going to bust on Sagan, we should get together > and lynch Teller. He's a much worse offender. > Pat (28 May 93 20:31:05 GMT) Beware, young iconoclast ! Bashing Sagan is profitable, bashing Teller may be dangerous ! J. Pharabod ------------------------------ End of Space Digest Volume 16 : Issue 654 ------------------------------