Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Sat, 29 Jun 91 03:10:28 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 29 Jun 91 03:10:23 -0400 (EDT) Subject: SPACE Digest V13 #741 SPACE Digest Volume 13 : Issue 741 Today's Topics: Did I miss something Re: Risks of technology Telescopes future astro funding Auroral observation from Australia, 13th June Platinum-group metal concentrations in earth-crossing objects Re: Excavating (minig) gold in the space by NASA. SPACE Digest V13 #625 Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 11 Jun 91 11:23:34 GMT From: pro-magic.cts.com!mikeu@uunet.uu.net Subject: Did I miss something I was away for a while and now I notice that the postings on the status of all the various space missions is no longer on this newsfeed. Did this cease in favor of all the summary postings I see, or was a new newsfeed created just for the mission summaries? ------------------------------<<>>---------------------------- Proline: mikeu@pro-magic Internet: crash!pnet01!mikeu@pro-magic.cts.com UUCP: (..uunet!tarpit!bilver!pro-magic!mikeu) Arpa: crash!pnet01!pro-magic!mikeu@nosc.mil Voice: 407-366-5840 | Prodigy: JSNP58A | Compuserve: 71326,31 ------------------------------ Date: 13 Jun 91 15:24:18 GMT From: att!news.cs.indiana.edu!maytag!watmath!watdragon!watyew!jdnicoll@ucbvax.Berkeley.EDU (James Davis Nicoll) Subject: Re: Risks of technology In article dlbres10@pc.usl.edu (Fraering Philip) writes: >I think there is a risks group possibly as appropriate to discuss >this stuff. Maybe people posting on that subject should crosspost. > >And my 2 cents: Well, the material will probably be broken up and shipped >in small 10 ton pieces anyway... Hmmm. Ten (metric) tonnes at 8 km/s. That works out to 1.6x10**11 J, or ~38onnes of TNT equivalent. I can live with that. What's the energy content of a LNG tanker? If you design the rv right, most of that can be dissipated in the air (I think). Oh, some chunks are bound to get through at speeds higher than you'd want, but we're talking large chemical bomb levels of damage, not nukes, and if you target expendible low poulation regions (North West Territories, Nevada, Los Angeles..) the expected um, losses should be within acceptable limits (Using car fatalities as a guideline). >And there seems to be the possibility of Tungusta style events in the >future. If someone is worried about risks, now is the time to develop >the technology to move the stuff... Not to mention the occasional targeting error will give us some practise at dealing with the aftermath of a meteor strike . James Nicoll ------------------------------ ReSent-Message-ID: Resent-Date: Thu, 13 Jun 91 12:20:45 EDT Resent-From: Harold Pritchett Resent-To: Space discussion group Date: Wed, 12 Jun 91 18:47:12 EDT From: Tom McWilliams <18084TM%msu.edu@uga.cc.uga.edu> Subject: Telescopes To: harold ----------------------------Original message---------------------------- Howdy. About you homebuilt; I've already seen all the posts people have sent you via space.sci, so I will restrict myself to two thoughts. One: subscribe to Astonomy -or- Sky & Telescope, if you haven't already. You'll probably want to later, so you might as well now, so you can see other's ideas, manufacturers kits and finished scopes, and start getting familiar with the sky (in case you aren't now) Two. Go for apeture. This defines your diffraction limit, and you light- gathering power (in case you later get interested in deep-sky stuff). If you really are stuck on planets, get a refractor (since lacking a secondary mirror improves the diffraction limits) Good luck. I decided to buy a telescope, rather than build it myself, since I found a company that's selling me a dobsonian 10" for $350.00 I might have ground it myself, but I understand that anything over 8" is pretty tough for a novice grinder, and my interests are mainly deep-sky. (but don't miss the back-to-back conjunctions of Venus,Jupiter and Mars!) (I guess that's three thoughts :-) Tom ------------------------------ Date: 14 Jun 91 01:38:50 GMT From: theory.TC.Cornell.EDU!nelson@tcgould.tn.cornell.edu (Robert W. Nelson) Subject: future astro funding I've come to the pessimistic conclusion that astronomy/space science funding is in serious trouble for the coming decade (not just in the 1992 budget), and would like to hear other opinions. Here is my reasoning: (1) The space station will be funded and built in some form regardless of its scientific usefulness. The aerospace industry wants this badly since they will be hurting from the lack of new military contracts as the cold war comes to an end. The astro/space community is a tiny constituency compared with these big contractors and (as demonstrated in last thursday's vote in the House) no amount of letter writing by the ~ 4000 members of AAS will change this. (2) The Earth Observing System will be funded and built in some form. Holes in the Ozone layer and the Greenhouse effect has got people scared, especially politicians who fear having to make real changes in our energy policy. People will hope that throwing lots of money to do research will make the problem go away. In addition, unlike the space station, EOS will have strong support from most of the science community. Astronomy/space scientists will have difficulty arguing that it's not a very pressing problem. (3) NASA funding will not increase significantly beyond inflation. The budget agreement made last October does not allow for savings in military funds to be transferred to domestic programs. Congress is not going to cut veterans, and I strongly doubt that HUD will be cut considerably. With two giant programs coming on line in NASA, and without significant increases in the total NASA budget, it seems to me that all other "nonessential" programs within NASA, including Space Science and Applications, will have to take deep cuts. I don't see any other way around this. If you see a hole in my reasoning I'd like to know. ------------------------------ Date: 14 Jun 91 02:47:29 GMT From: munnari.oz.au!deakin.OZ.AU!cm.deakin.oz.au@uunet.uu.net (Ludwig Omachen) Subject: Auroral observation from Australia, 13th June This observation was from the southern coastline of Victoria, Australia, (Near Geelong) on thursday 14th june, from 10:30 pm till 11:30 pm local time (AEST). Weather conditions were fine, almost cloudless sky with no moon. Looking due south over the ocean, a whitish (perhaps with greenish tinge) band approximately the thickness of a rainbow extended in a horizontal arc of about 60 degrees with the hight of the arc about twice its thickness above the horizon (Approx. 15 degrees above horizon at its peak). Intermittent narrow vertical shafts of white light extended from this horizontal band up to about 40 degrees above the horizon, also accomanied by much broader areas or shafts or red light. The most interesting observation was the appearance of narrow horizontal striations (within the horizontal white arc) which were about twice as bright as the main band. The thickness of these horizontal striations was about 10 percent of the main band thickness, and their horizontal length about 20 to 30 percent of the main band's length. These striations would appear at the bottom of the main band and move rapidly upwards through the band and dissappear at the top of the main band, this would take about Half a second, with numerous striations repeating the same procedure. The brightness was subjectively about 3 or 4 times that of the Milky way, but not as bright as the last aurora which was visible here on march 26th. It was also further away, (not as high above the horizon as the march sighting) Ludwig Omachen ludwig@cm.deakin.oz.au Dept. of Computing and Mathematics Ph. Work +61 52 471879 Deakin University 3217 Ph. Home +61 52 612061 Geelong, Victoria, Australia. ------------------------------ Date: 12 Jun 91 07:34:15 GMT From: ogicse!sequent!muncher.sequent.com!szabo@decwrl.dec.com Subject: Platinum-group metal concentrations in earth-crossing objects In article <5248@dirac.physics.purdue.edu> hal@gibbs.physics.purdue.edu (Hal Chambers) writes: >... the asteroid is no more than 0.001% platinum and 0.0001% gold. >How does this compare with terrestrial ores?... The gold concentration is very poor -- its distribution in the metal is fairly homogenous, from the limited meteorite studies we have done to date. Unless we find concentrated ores or the space environment gives us a _very_ large advantage in processing the metal, we won't be able to efficiently get gold from this source. 10 ppm platinum is a pretty good ore, about matching the highest concentrations found on Earth. From the very crude media numbers, this particular asteroid doesn't look very good, as asteroid metal goes. The best data we have come from the asteroid samples fallen to Earth, meteorites, many of which contain metal or metal grains from core material. The best platinum-group concentrations have been found in the metal grains of LL-type chondrites, as follows: Platinum 21 ppm Ruthenium 12 Osmium 10 Iridium 10 Rhenium 1.0 As an aside, they also contain 1-15 ppm gallium, 200 ppm germanium, and 1.2 ppm arsenic. Space Industries Inc. is currently working on a wake shield to produce large volumes of very high vacuum, which can be used with microgravity to create GaAs and other semiconductors with much greater purity than in Earthside semiconductor fabs. GaAs is used for expensive, high-speed chips, for example in the latest Cray supercomputer. Asteroids could provide the raw materials to produce very large quantities of these semiconductors, instead of launching them from the Earth at $5,000/kg. Back to platinum: we have a total of 55 ppm platinum group, about 5 times better than the best Earth ore. This still wouldn't be that good, given the high costs of launching mining equipment, except that there exists a process which, taking advantage of the large amounts of solar-thermal power available in space, could make extracting the platinum economical. First, we should find grains with the above concentrations or better in a high-metal regolith (a task for space exploration). We extract the metal grains with a magnetic rake. Next, we process the metal regolith with the gaseous carbonyl process, as follows: First phase: Treat the regolith with CO at c. 5 atm pressure, 100 degrees C. This forms a vapor of gaseous carbonyl compounds. Nickel and iron are selectively deposited in pure metallic form by lowering the pressure and/or increasing the temperature. The CO is released and recycled. The residue has a Pt-group concentration of 5,000 ppm, and Ga/Ge/As at 15,000 to 20,000 ppm. Second phase: Treat the residue with moist CO at 100 atm near 100 degrees C. This deposits out cobalt. What is left is largely Pt group and Ga/Ge/As, and is worth $20,000 per kg at today's prices. The water and CO are again recycled. This technique, called the gaseous carbonyl process, is currently used at the Sudbury mine in Ontario, primarily to extract the nickel, and secondarily to extract the c. 5 ppm platinum. By some accounts the Sudbury ore is actually the remains of an impacted asteroid, but I won't get into _that_ broohaha. :-) If we want to get the pure elements additional processing is required. The method of depositing the nickel and iron can itself be put to use. For example, using a technique of chemical vapor deposition (CVD) developed by Vaporform Products Inc., the nickel can be doped with 100 ppm of a boron compound and deposited in molds to obtain nickel parts with strengths of 200,000 psi (13,000 kg/cm^2). Laser CVD can be used to deposit wire-reinforced mirrors a few micrometers thick, which is strong enough to be used for very large mirrors in microgravity. Various forms of vacuum deposition and creation of new alloys and foamed metal in microgravity are possible. We have only begun to scratch the surface in researching the possibilities. According to a previous post, annual world production of the platinum group is 8.668 million troy ounces, which at $400/oz. is $3.4 billion. It is difficult to predict the effects of flooding a market. Generally (not always) demand volume rises by a greater factor than prices fall, so that we can, with some risk, assume at least a $3.4 billion/year revenue stream from the platinum group elements. Given the demand for Pt-group metals in a wide variety of industries, including oil refining and the rapidly growing industry of environmental cleanup technology, IMHO this is a reasonably safe assumption. Assuming operating costs of $1.7 billion/year, the net present value (NPV) of this cash flow at the junk-bond rate of 18% is $10 billion. Additional capabilities (GaAs, solar cells, microgravity alloys, etc.) could provide additional revenue. Of course, part of the _first_ $million invested should go towards a much more detailed market analysis this one. Which brings us to the billion dollar question: how soon will we have sufficient knowledge (through exploration) and technology (through research and prototyping) to be able to undertake this projects for less than $10 billion? References: _Space Resources: Breaking the Bonds Of Earth_, John and Gail Lewis _Asteroids II_, Tom Gerhels, ed. -- Nick Szabo szabo@sequent.com "If you understand something the first time you see it, you probably knew it already. The more bewildered you are, the more successful the mission was." -- Ed Stone, Voyager space explorer ------------------------------ Date: 12 Jun 91 15:11:32 GMT From: hpl-opus!hpnmdla!stanb@hplabs.hpl.hp.com (Stan Bischof) Subject: Re: Excavating (minig) gold in the space by NASA. In sci.space, ivan%nepjt@ncsuvx.ncsu.edu (Ivan Maldonado) writes: >Under the above-suggested circumstances: >Actually, the advantages due to gold's great conductivity properties >could also be used to significantly reduce the electric power losses during >its transmission (i.e., replace copper with gold in transmission lines). >===> goes the forecast of an electric energy crisis... :-) >-Ivan Only one problem--- copper is a better conductor than gold! You're probably thinking of silver, which is indeed better than copper. Gold is NOT a great thermal OR electrical conductor-- copper is better in both respects, and silver is even better. approx numbers: matl thermal conductivity elect resistivity (W/cm-K) (ohm-cm x10-6) copper 3.6 1.7 gold 3 2.4 silver 4.2 1.6 Stan Bischof HP-NMD ------------------------------ ReSent-Message-ID: Resent-Date: Wed, 12 Jun 91 18:21:46 EDT Resent-From: Tom McWilliams <18084TM@msu.edu> Resent-To: space+@andrew.cmu.edu Date: Sun, 9 Jun 91 02:06:28 EDT Reply-To: space+%ANDREW.CMU.EDU@msu.edu From: space-request+%ANDREW.CMU.EDU%CARNEGIE.BITNET@msu.edu Subject: SPACE Digest V13 #625 Comments: To: space+@ANDREW.CMU.EDU To: david polito <15432DJP@MSU.BITNET>, Tom McWilliams <18084TM@MSU.BITNET> Subject: Re: Privatization >I'm kind of generally suspicious about privatization when long term research >is in question. Private profit driven companies seldom make plans for >more than 5-10 years into the future. Let's take large particle colliders >as an example. I doubt there would be any private organization that would >foot the bill for CERN for instance. Same logic can be applied to large >space projects. >Correct me if I'm wrong. If your talking about R&D, your wrong. One of the things that GM learned from the Japanese auto-makers was to spend more on R&D for long-term health. If your talking about Science For the Sake of Knowledge, I'd agree with you. Tom Acknowledge-To: <18084TM@MSU> ------------------------------ End of SPACE Digest V13 #741 *******************