Date: Sun, 11 Oct 92 05:00:03 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #306 To: Space Digest Readers Precedence: bulk Space Digest Sun, 11 Oct 92 Volume 15 : Issue 306 Today's Topics: Bootstrap hardware for LunaBase (2 msgs) Drop nuc waste into sun (3 msgs) ENV SATELLITE SHUTDOWN IN DEC 1992 Getting the job done GMT of Sputnik 1 Launch? (2 msgs) HRMS It's dead, Jim. (was Re: Pioneer Venus) Laser Space Mirror Mars Observer info? NASA Daily News for 10/02/92 (Forwarded) Odyssey system for cellular phone comms SETI NOT POSITIVE SPS Telepresence Wealth in Space (Was Re: Clinton and Space Funding) 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: Sat, 10 Oct 1992 12:04:49 GMT From: "Allen W. Sherzer" Subject: Bootstrap hardware for LunaBase Newsgroups: sci.space In article <1992Oct10.014257.7624@techbook.com> szabo@techbook.com (Nick Szabo) writes: >>You provided an estimate of the cost which >>was totally based on unrealisticly high launch costs. >This completely cracks me up. Actual commercial launch costs >is "unrealistically high". What Allen wishes launch costs were >is quite real, by comparison. :-) :-) Well I would have thought you would understand the point but aparently not. I'll explain it to you in greater detail and maybe then you will understand where you made your mistake. Now in general, when markets get larger costs tend to come down. This is because development costs are amortized over a larger market and the larger lot sizes allow greater investment in automation which greatly increases productivity. Launchers are no different. With today's launchers manufacturers have often said that if launchers where bought 20 at a time or so prices would drop by over 1/2. To date the market just isn't big enough to justify that. Now with the effort being proposed, the market for launches will grow by leaps and bounds. Competition for this market will inevitabally reduce existing luanchers and cause new, far cheaper, launchers to be developed to service this market. ANY estimate of cost must consider this factor in its estimates. >You are also still completely missing the point that lower >launch costs benefit every kind of space project, But not equally. You often point out that it takes more energy to get to the moon. Therefore Lunar approaches will see greater cost reductions than Asteriod approaches. >and do >not change the comparison of lunar mining vs. alternatives. Also correct. However the advantage of the moon isn't cost, is't time. Eventually we will make extensive use of asteroids and comets. But first we will use the advantage of close Lunar material because it's faster and provides easier access to the people needed to operate and debug the facility. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------197 DAYS TO FIRST FLIGHT OF DCX----------------------+ ------------------------------ Date: 10 Oct 92 23:19:41 GMT From: Nick Szabo Subject: Bootstrap hardware for LunaBase Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >As Allen pointed out, there's more than enough money there >for commercial development of a dozen new launch systems. More than enough money _where_? The SEI budget is in the $10's of millions. Commercial funding for moon ventures is zero. Have I finally treaded into the central segment of a mass delusion here? These people's numbers are off by four orders of mangntiude, yet they are all chiming in unison! -- Nick Szabo szabo@techboook.com Hold Your Nose: vote Republocrat //////// Breathe Free: vote Libertarian ------------------------------ Date: 10 Oct 92 15:20:56 GMT From: Stan Bischof Subject: Drop nuc waste into sun Newsgroups: sci.space In sci.space, dnk@cs.mu.OZ.AU (David Kinny) writes: >sma@waikato.ac.nz (Stephen Anderson) writes: >Why on earth do you think that fusion doesn't produce waste? >Read up on the effects of neutron bombardment. Commercial fusion >reactors will produce substantial amounts of waste, but it won't >be in the form of spent fuel rods. >>Stephen.. >..David Last I saw, one of the goals was to eventually get to a D-D reaction so that the only byproduct is an energetic alpha, as opposed to the 14MEV neutron from the easier D-T fusion. It's that hot neutron that causes the problems you are referring to, and which indeed creates some nasty byproducts in the reaction chamber walls. At the worst, however, a DT reactor should produce much less waste than a fission reactor. Long time off in any case, which is a shame. Stan Bischof HPSR ------------------------------ Date: Sat, 10 Oct 1992 18:04:22 GMT From: Michael Robert Williams Subject: Drop nuc waste into sun Newsgroups: sci.space I'm amused at the incidence of this question; I've been a net follower for years, and it keeps showing up like clockwork. For my senior thesis in aerospace engineering I designed a solar sail cargo vehicle to carry stuff to the Moon for a future manned base. It seems to me that the same technology could be used to drop nuclear waste into the Sun (although I think there are better ways to get rid of it). The plan works like this: launch the vehicle into a fairly high deploy- ment orbit ~1000 km or so (this is to reduce the effects of atmospheric drag). Then unfurl the sail and spiral out on an Earth-escape trajectory, which might take a while (~200 days with 50% of the vehicle weight devoted to cargo). Then, when you have reached escape velocity, you turn the vehicle and let it 'tack,' using sunlight pressure to slow down. This will lower the aphelion. If you want to reuse the vehicle (no reason that you couldn't) you wait untill aphelion is very close to the Sun's surface, then drop the cargo. Turn the vehicle so that radiation pressure pushes it back into an Earth-rendezvous orbit, and voila! No more nuclear waste, and you have a reusable garbage truck. This way you do not need the tremendous ammounts of propellant to get rid of the waste, and you only have to build one guidance package. Now, I admit this is all off the cuff; I haven't done the math, so it may turn out that in order to dispose of the waste, it is neccessary to bring the solar sail so close to the Sun that the sail melts, or so close that it will not be able to climb back out before it melts, but fiddling with the payload ratio should fix that. What do all of you out in netland think? In Real Life:Mike Williams | Perpetual Grad Student e-mail :mrw9e@virginia.edu| - It's not just a job, it's an indenture --------------------------------------------------------------------------- The probability of something happening is inversely proportional to its desirability ------------------------------ Date: Sat, 10 Oct 1992 18:32:36 GMT From: "robert.f.casey" Subject: Drop nuc waste into sun Newsgroups: sci.space >In article henry@zoo.toronto.edu (Henry Spencer) writes: >>Actually, as Larry Niven pointed out, if you can get the stuff as far as >>Venus, you might as well just fly it *into* Venus. It's not as if Venus >>is good for anything else. (Although one would want to do rather more >>thorough studies of Venus before starting to use it as a dump...) Well, the guys who might want to try terraforming Venus might not want anyone dropping nuke waste there, I'd think. Last I heard, the nuke waste was going to be stored in some mine in a mountain in Nevada. A nuke waste warehouse. Easy to get to if some of that stuff turns out to be useful. Just be careful to keep it from leaking. Yeah. :-) ============================================================================= 499.995 years ago, Columbus discovered America ------------------------------ Date: 10 Oct 92 17:57:15 GMT From: "Michael W. Rowland" Subject: ENV SATELLITE SHUTDOWN IN DEC 1992 Newsgroups: sci.space In article , kentm@aix.rpi.edu (Michael V. Kent) writes: > In article rowland@zorba7.larc.nasa.gov > (Michael W. Rowland) writes: > >This is a repost of 6 Oct. posting (revised)... > > > > NUMBUS-7 > > > > Total Ozone Measurement System (TOMS) > > Is this real? NASA plans to shut down TOMS? Why? > > This is about the last instrument on the last satellite I expected to be > voluntarily shut down. > > >Budget cuts are specified in House Conference Report 102-902 > >that is attached to HR 5679, Sept. 24, 1992. > > I guess this is a likely explanation. Were these satellites mentioned by name > or was it just a line item that got hacked to death? > As far as I know, the satellites were not mentioned by name. mike rowland Mike Rowland, Aerosol Research Branch, MS 475 NASA Langley Research Center, Hampton VA 23681 internet: rowland@zorba7.larc.nasa.gov ------------------------------ Date: Sat, 10 Oct 1992 15:40:08 GMT From: Herman Rubin Subject: Getting the job done Newsgroups: sci.space,talk.politics.space In article kentm@aix.rpi.edu (Michael V. Kent) writes: >In article hrubin@pop.stat.purdue.edu (Herman Rubin) writes: >>You seem to have missed my other postings on this topic. I, and many others, >>have been advocating that the government allow private space expenditures AS >>THOSE WISHING TO SPEND THE MONEY WANT TO. ****************************************************************************** At this time, it is illegal for an American to launch anything anywhere in the world without US government approval. ^^^^^^^^^^^^^^^^^^^^^ ****************************************************************************** >This isn't that unusual if you think about. I can't drive a car without the >government's permission (driver's liscence), At this time, you can drive a car on your property without any government permission whatever. >my car can't be driven off my property w/o govt's permission (lisence plates). This is for revenue purposes, not safety purposes. >fishing or hunting (or flying!!) either. I can't do much of anything that >might endanger society or some subgroup thereof. Fishing and hunting licenses are also revenue. For flying, there are qualifications involved. But imagine what would have happened to the early history of aviation if the present government types were around during the early days of aviation. And the requirements for experimental aircraft are far weaker than the standard stuff, anyhow. >The difficulty of obtaining the proper lisence is proportional to the damage >that could be done if something went wrong. Marriage and fishing lisences >are easy to get, driver's lisences a bit harder, and pilot's lisences harder >still. It shouldn't surprise anyone a lisence to launch several tons of >high explosives over people's heads is even harder. >Those who prove they can launch rockets safely can get a lisence. Both >General Dynamics and McDonnell Douglas have one, and they can launch payloads >without much further trouble. Sounds reasonable to me. It certainly has >ample precedent. 1. They can get licenses to launch payloads on American rockets with more trouble than you think. It would be a lot of trouble for them to launch on Ariane, the European rocket. And it would be almost impossible for the Planetary Society to get permission to launch something of their own design, built with no government funds. 2. Notice what I have underlined. For me to fly or carry explosives in Zanzibar, I might need a Tanzanian license, but no American one. For a Tanzanian company to launch from Zanzibar, they would need Tanzanian approval, but not US approval. For an American, either an individual or an organization, to launch from Zanzibar, however, requires US approval, as well as Tanzanian approval. 3. I believe that those who believe in space activities are sufficiently numerous and sufficiently wealthy to be willing to raise the many billions needed. But who is willing to invest if government bureaucrats can, at the time of launching of a space station, for example, can step in and say that it is not in the national interest? This has nothing to do with safety; every bureaucrat is personally threatened by this. The people interested in space are not going to be too reckless; Challenger-type incidents can be lived with, but will hurt their activities, and worse things even will hurt more so. 4. There are also those, becoming more powerful daily, who even wish to restrict private research and development. It would not surprise me that even a fair number of Congresspeople would make an effort to stop major private space ventures as a "waste of American resources." -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 Phone: (317)494-6054 hrubin@snap.stat.purdue.edu (Internet, bitnet) {purdue,pur-ee}!snap.stat!hrubin(UUCP) ------------------------------ Date: 9 Oct 92 18:30:45 GMT From: Curtis Roelle Subject: GMT of Sputnik 1 Launch? Newsgroups: sci.space Can someone look up the GMT of Sputnik 1's launch. I was born on October 3, 1957 at 19:35 CST. Although the official launch date is October 4, the local time in the United States was likely October 3. How many hours & minutes older/younger am I than Sputnik 1? Curt roelle@sigi.jhuapl.edu ------------------------------ Date: 10 Oct 92 11:15:36 EDT From: Chris Jones Subject: GMT of Sputnik 1 Launch? Newsgroups: sci.space In article , roelle@uars_mag (Curtis Roelle) writes: >Can someone look up the GMT of Sputnik 1's launch. 4 October 1957 19:28:04 GMT > I was born on >October 3, 1957 at 19:35 CST. > >Although the official launch date is October 4, the local time in the >United States was likely October 3. Nope. > How many hours & minutes >older/younger am I than Sputnik 1? I've got to leave something as an exercise for the reader. (My son was born on 4 October 1982 13:38 GMT, which was the 25th anniversary of Sputnik 1's launch). -- Chris Jones clj@ksr.com ------------------------------ Date: 10 Oct 92 15:49:26 GMT From: Gary Coffman Subject: HRMS Newsgroups: sci.space In article <1992Oct7.023747.18705@ils.nwu.edu> eric@ils.nwu.edu (Eric Goldstein) writes: >I guess I really wanted to know: Over what range of frequencies do we >significantly leak, and are those frequencies capable of being detected >by HRMS? The HRMS press kit that Ron Baalke posted (thanks Ron!) >said that the targeted search would search at 1,000 to 3,000 MHz. I >know we leak significantly on the TV bands, but TV is around 10 MHz, >right? So, I was wondering if we also leak at detectable levels at >1,000 to 3,000 MHz. And if we do, what is the source of the leakage? >If I've displayed a real misunderstanding, please go easy on me -- this >isn't my field -- and I'd genuinely appreciate any explanations. TV broadcasting is in the 60-170 MHz range for VHF and 500-800 MHz range for UHF. VHF television output power peaks at 316,000 watts ERP on the upper VHF channels. UHF power peaks at 5,000,000 watts ERP. In addition, military radars, like Pave Paws, operate in the UHF range below UHF TV, 400-450 MHz at peak powers of 50 to 200 million watts ERP. In the 1 GHz to 3 GHz range, most of the emitters are low power point to point telco links with a few aircraft and anti-aircraft targeting radars also in use from time to time, Desert Storm comes to mind. These aren't nearly as powerful as systems like Pave Paws because the antennas are much smaller and the power supplies are much smaller. Weather radars operate at higher frequencies, 7 GHz and 10 GHz, so they are outside the range of interest, ERPs run around 250,000 watts. It seems they concentrated their search in the part of the spectrum with the *least* high power terrestrial sources. That makes sense, otherwise they'd be getting interference from those sources. But if the postulated ETs are like us, they won't be using high power sources on those frequencies either, so our chances of detecting them is much less. Reminds me of the drunk searching for his car keys under the street lamp even though he dropped them on the other side of the street. His reason, because the light is better under the street lamp. Gary ------------------------------ Date: 10 Oct 92 15:46:46 GMT From: David Knapp Subject: It's dead, Jim. (was Re: Pioneer Venus) Newsgroups: sci.space In article <1992Oct9.064506.2890@ericsson.se> Thomas.Enblom@eos.ericsson.se writes: >I've just read Ron Baalkes message about the Pioneer Venus probe is still alive. >Could someone give me some details about this object. >For example, how old it is, its mission and so on. I don't know a thing about it. We lost radio lock with PVO Thursday. The s/c endured drags of >2m/s while maintaining lock to that point. Looks like it's all over. Details on the s/c and the mission have been posted here and in alt.sci. planetary over the last few weeks. -- David Knapp University of Colorado, Boulder Perpetual Student knapp@spot.colorado.edu ------------------------------ Date: 10 Oct 92 15:14:28 GMT From: Gary Coffman Subject: Laser Space Mirror Newsgroups: sci.space In article <718606909snx@osea.demon.co.uk> andy@osea.demon.co.uk (Andrew Haveland-Robinson) writes: >In article amon@elegabalus.cs.qub.ac.uk writes: >>The secret to opening the space frontier is to be found in plastic >>mounted bits of old satellites; pet moon rocks; committing ashes to >>the deep; asteroid desk sets (Ceres, Vesta, Pallas... Collect em! >>Trade em with your friends!); garbage disposal... and so forth. > >How err... very um.. well... American! :-) > >Why not laser raster scan the clouds with MacDonalds adverts? >cringe< I've heard of a proposal to "paint" the Coke logo on the Moon. Using a highly reflective "dust", say titanium dioxide smoke particles, sputtered onto the surface by an electron beam from a lunar orbiting satellite. The layer could be molecules thick since there's no wind or weather to wash it off. The Moon's surface is actually very dark and the highly reflective material should be visible even in daylight on Earth. It shouldn't cost more than a couple year's worth of Coke's normal advertising budget. Gary ------------------------------ Date: Sat, 10 Oct 1992 20:19:02 GMT From: Pat Subject: Mars Observer info? Newsgroups: sci.space,alt.sci.planetary In article <1992Oct5.193214.21355@ucsu.Colorado.EDU> knapp@spot.Colorado.EDU (David Knapp) writes: > >Instruments: > >Gamma Ray Spectrometer; studies surface chemicals/composition >Mars Observer Camera; photographs surface >Thermal Emission Spectrometer; measures IR (I'm guessing primarily surface) >Pressure Modulator Infrared Radiometer; measures the atmospheric emission >Mars Observer Laser Altimeter; gives higher resolution topographical info >Magnetometer/Electron Reflectometer; investigates Martian magnetic fields. > > >The MOC (camera) has <*2* meter resolution! (loud gasp of amazement.) This will >allow for detailed study of mass transport over the surface with seasonal >variations. (and some very impressive photos indeed.) > MO is currently scheduled only to image mars. i talked to some planetary scientists who were hoping to wheedle some imaging time to look at phobos and deimos. if so, what are some of the considerations. i was thinking along the lines of: 1) what kind of resolution will they get? 2) will they be able to image all sides. 3) would they be able to use the other instruments as well. 4) what kind of impact will this have on spacecraft operations. i imagine MO is going to go into a sun synchonous polar orbit, so to get more uniform imaging and keep power levels uniform. would imaging the moonlets, eat up thruster gas or impede solar collection? just a few questions. thanks ------------------------------ Date: 4 Oct 92 19:10:31 GMT From: Michael Wallis Subject: NASA Daily News for 10/02/92 (Forwarded) Newsgroups: sci.space davem@ee.ubc.ca (david michelson) writes: > Just a correction or two: > > - the first Gemini mission (Gemini 3) flew in March 1965 not 1962. > > - John Young commanded the Apollo 16 mission in April 1972 not Apollo 17. > > - the first shuttle mission (STS-1) flew in April 1981 not 1983. > > I won't even *mention* his other Gemini or shuttle flights. Sounds like another typical NASA press release. * sigh * ------------------------------------------------------------------------------ Michael Wallis -> mwallis@clubzen.fidonet.org PLAN: Live fast, die young, leave a neat corpse. Oh ... I'm too old to die young? Rats! ------------------------------ Date: 4 Oct 92 18:48:20 GMT From: Michael Wallis Subject: Odyssey system for cellular phone comms Newsgroups: sci.space writes: > In a recent issue of AW&ST there was an ad by TRW for a cellular > phone system using nine satellites in 3 "medium" orbits. This system is > called Odyssey. The way the ad was worded gave me the impression that > the system is already up and running, although I can't remember > hearing about the satellites being deployed. Can anyone provide me with > some more information on this? Would Odyssey not nip the chances of the > Motorola "Iridium" system in the bud? I doubt it is currently running as TRW wasn't one of the three companies the FCC gave the go-ahead to for developing the new frequencies. ------------------------------------------------------------------------------ Michael Wallis -> mwallis@clubzen.fidonet.org PLAN: Live fast, die young, leave a neat corpse. Oh ... I'm too old to die young? Rats! ------------------------------ Date: 10 Oct 92 16:19:35 GMT From: David Knapp Subject: SETI NOT POSITIVE Newsgroups: sci.space,sci.astro In article <1992Oct9.054339.16971@ousrvr.oulu.fi> dah@tko.vtt.fi (David Harwood) writes: >In article <1992Oct8.145125.25507@elroy.jpl.nasa.gov> eto@elroy.jpl.nasa.gov (Edward T. Olsen) writes: >>Gentlemen: >> >>The NASA search for signals of extraterrestrial intelligent origin has >>not yet begun. The Initial Deployment of the High Resolution Microwave >>Survey (HRMS) will be October 12, 1992. >> >>Do not propagate misinformation and rumor! >> >>Edward Olsen >>HRMS >>-- >> Edward T. Olsen >> Mail Stop 169-506, Jet Propulsion Laboratory >> 4800 Oak Grove Dr, Pasadena, CA 91109 >> Phone: (818)-354-7604 INTERNET: eto@seti.jpl.nasa.gov (Node: 128.149.82.1) > >\\\\\\\\\\\\ >Just curious - I have a direct question for you: > >Is NASA/HRMS going to investigate any previously detected signals, which >it considers might possibly have been of ETI origin? Does NASA say that no >such candidate ETI signals have been detected so far? (We all now that >HRMS is beginning soon, but there have been previous surveys of far less >scope.) > >A direct "NO" to question 1 or "YES" to question 2 is what we are trying >to detect. That will kill rumors most effectively. > >Also, there has been another interesting question: >Is HRMS capable of detecting signals of power equivalent to terrestial >broadcasts (different frequencies) at distances of say 50 light years or so? > >Thanks for your information. >David Harwood With regard to your questions, SCIENCE just had an article in last week's issue on the project and all those questions are answered. -- David Knapp University of Colorado, Boulder Perpetual Student knapp@spot.colorado.edu ------------------------------ Date: 10 Oct 92 15:02:17 GMT From: Gary Coffman Subject: SPS Newsgroups: sci.space In article <9210070441.AA10031@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: > >- But how do you convert the laser light back into electricity? >- Photovoltics? Does not sound very efficiant to me. > >I was referring to the following device (repost): >............... > >ELECTROMAGNETICS: "Smallest Antennas Imitate Insect Communication" > >"Using tools developed for fabricating electronic integrated circuits, NIST >scientists have produced microantennas the size of a grain of sand and only >60 micrometers across (about the diameter of a human hair). At this tiny size, >these "world's smallest" antennas can capture the extremely short (about 3 to >30 micrometers) wavelengths of infrared radiation. Their development paves >the way for novel infrared detectors that rely on antennas to "see" images >of heat radiating from all warm objects such as people, animals, and buildings. >Such detectors have many applications, including satellite observation of >Earth, astronomy, medicine, and national defense. There is evidence that >insects evolved microantennas, similar to the NIST devices, to enhance their >infrared pickup, allow them to see in darkness, and give them a survival >advantage. The NIST work proves that such tiny insect structures can function >efficiently for infrared wavelengths." >............... > >Essentially, the infrared radiation is treated as *very* short wavelength >microwaves. Perhaps the beam needs to be polarized for best results. >The article didn't mention applicability for power reception - that such a >detector might be useful for this is speculation on my part. While such a detector could approach 90% collection efficiency, the problem is in the power handling capacity of the tiny antennas and with the junction capacitance of the rectifying diodes. A structure micrometers in size can't carry much current. More importantly, we don't know how to fabricate diodes with a small enough junction capacitance to be efficient rectifiers at infrared frequencies. So, because of current carrying limits, the beam intensity can't be high, probably not as high as normal sunlight, and because of rectifier junction capacitance, the diodes won't be very efficient, probably less than 1%. Great sensors, lousy power converters. Gary ------------------------------ Date: 10 Oct 92 14:42:41 GMT From: Gary Coffman Subject: Telepresence Newsgroups: sci.space In article <9210070147.AA09594@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: > >Here's an interesting item from the July 1992 issue of NASA Tech Briefs: > >.............. > > Predictive Display for Teleoperation With Delay > > The Predictive image helps the operator control the remote manipulator. > > NASA's Jet Propulsion Laboratory, Pasadena, California > > A computer-graphical simulator helps an operator control a robotic > manipulator located so far away that controlling and monitoring signals > are delayed significantly in transmission. The simulator displays a phantom > image of the robot superimposed on the delayed "real" monitoring image of > the robot. The phantom responds to control signals immediately -- that is, > without transmission delay. Its motion predicts that of the real robot. > After the transmission delay, the real image of the robot follows the motion > of the phantom image. After successfully maneuvering the phantom image, the operator sits back and watches the delayed image of the rover slowly fall into a subsidence hidden from the scan. The screen image is replaced by the words "GAME OVER. INSERT $1 BILLION TO PLAY AGAIN" Gary ------------------------------ Date: 4 Oct 92 19:12:16 GMT From: Michael Wallis Subject: Wealth in Space (Was Re: Clinton and Space Funding) Newsgroups: sci.space dietz@cs.rochester.edu (Paul Dietz) writes: > HOWEVER: for fundamental reasons (having to do with space charge > limits on currents) the throughput of a conventional mass spectrometer > is miniscule (think: if it were not, anyone could enrich uranium on > the scale of a lab bench). In any case, the energy required to > vaporize an asteroid would be immense, hand waving about mirrors > notwithstanding. The idea is basically stupid. The idea isn't stupid. It may be impractical, but it's not stupid. With a spin on the asteroid and a solar concetrating mirror you could heat it enough to melt the outer layers and smooth the surface. I doubt you'd get it hot enough for plasma. It would be interesting to try to model the surface tension dynamics of a rotating heated asteroid. I'm not sure what you'd find. Likely the heated layers would stretch outward, perhaps making a separate shell that could be cooled and cracked like an egg. Pressurize the inside of the egg and you'd be able to mine in a shirtsleeve environment. This is ALL speculation. I don't have the software for this kind of modelling, but it might make an interesting Masters papaer. ------------------------------------------------------------------------------ Michael Wallis -> mwallis@clubzen.fidonet.org PLAN: Live fast, die young, leave a neat corpse. Oh ... I'm too old to die young? Rats! ------------------------------ End of Space Digest Volume 15 : Issue 306 ------------------------------