Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.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 ; Thu, 10 May 90 01:27:44 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 10 May 90 01:26:40 -0400 (EDT) Subject: SPACE Digest V11 #380 SPACE Digest Volume 11 : Issue 380 Today's Topics: Re: Apollo 12 Sagan vs. asteroids Re: Apollo 12 why there are no ETs Re: Manned mission to Venus Looking for a good telescope Free subscription to Supercomputing Review venus refrigeration Commercial Delta Launch Schedule Re: Apollo 12 launch decision Re: Manned mission to Venus ---------------------------------------------------------------------- Date: 9 May 90 12:16:19 GMT From: usc!cs.utexas.edu!uwm.edu!srcsip!jhereg!wd0gol!newave!john@ucsd.edu (John A. Weeks III) Subject: Re: Apollo 12 In <1990May8.151213.25662@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: > In general, the Apollo launch windows were about a month apart, since it > was the position of the Moon that mostly dictated the windows. ... > I don't know what the situation was for Apollo 12, .... The A&E TV Network recently ran the 4 part "Space Flight" series. The lightning strike during Apollo 12 is briefly mentioned. They interviewed one crew member that happened to be of Navy background. He mentioned that the CapCom asked their opinion as to whether or not to launch. He replied that the Navy would be happy to do NASA's all weather testing. He went on to say that it didn't take very long to regret that statement. During the interview, the crew said that they wanted to fly _that_ day because the recycle was 30 days. -john- -- =============================================================================== John A. Weeks III (612) 942-6969 john@newave.mn.org NeWave Communications ...uunet!rosevax!bungia!wd0gol!newave!john =============================================================================== ------------------------------ Date: 9 May 90 16:45:59 GMT From: swrinde!zaphod.mps.ohio-state.edu!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Sagan vs. asteroids In article <9005091117.AA02896@zit.cigy.> jcp@cgch.UUCP (Joseph C. Pistritto) writes: >> Everybody is talking about those asteroids, but some scientists, like >> Carl Sagan, are now speaking against their exploitation. >Then he's cracked... One should remember that Chairman Carl seems to have heavy-duty ulterior motives of the political kind these days, and that colors his views, to put it mildly. For example, his obsession with a joint US-USSR Mars mission seems to focus on the "joint US-USSR" part, not the "Mars mission" part. Sagan's priorities in space now seem to be based on politics rather than science and exploration. -- If OSI is the answer, what is | Henry Spencer at U of Toronto Zoology the question?? -Rolf Nordhagen| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 9 May 90 17:05:13 GMT From: amdahl!altos!altos86!jerry@ames.arc.nasa.gov (Jerry Gardner) Subject: Re: Apollo 12 In article <1990May9.025512.14415@melba.bby.oz.au> gnb@bby.oz.au (Gregory N. Bond) writes: >I have a question about launch windows. > >But for moon shots, well, it seems the moon is always in the same >relative orbit, so a direct earth-moon window would happen once per >day (as the earth rotated to the correct spot for launch). So why is >the window only open a few days per month? > >I am obviously missing _something_.... > There are only a few days during a lunation that one would want to land on the moon. Obviously, one wouldn't want to land around the time of new moon because the earth-facing side is in darkness. Likewise, one wouldn't want to land near full moon because the sun is almost directly overhead and the lighting is very flat and low contrast. The best time to land is when the intended landing site has experienced sunrise (or will experience sunset) within the last few days (or next few days). The resulting lighting will be low-angle and the contrast will be high, a desirable situation. Of course, one could launch anytime if landing on the non-earth-facing side of the moon were an option. The problem with this is lack of direct communication with earth (the only communication possible is through the command module or through lunar orbiting communications satellites). -- Jerry Gardner, NJ6A Altos Computer Systems UUCP: {sun|pyramid|sco|amdahl|uunet}!altos86!jerry 2641 Orchard Parkway Internet: jerry@altos.com San Jose, CA 95134 Guns don't kill people, bullets do. (408) 432-6200 ------------------------------ Date: 8 May 90 01:34:02 GMT From: ogicse!blake!milton!acad!megalon!peb%uunet.UU.NET@uunet.uu.net (Paul Baclaski) Subject: why there are no ETs It just occured to me that one of the possible reasons we have not discovered extraterrestrial intelligence in the universe is that they have created full fledged virtual reality systems and feel no need to go exploring space because they have enough fun exploring the inner space of their collective minds. Paul peb@acad.com Keywords: n ------------------------------ Date: 9 May 90 05:29:20 GMT From: eb1z+@andrew.cmu.edu (Edward Joseph Bennett) Subject: Re: Manned mission to Venus This is a very interesting topic. A large scale project to make uninhabitable planets habitable is quite an undertaking. Especially when we consider how difficult it just to take action on slight modifications of our own climates on Earth. This would certainly make our current problems such as S&L bailouts, budget deficits, and waste disposal seem cheap. However, a patient and persistant program planned to span the course of centaries and milleniums could bring about changes. Given the rate of the population expansion on the Earth it may be worth while. Problem is it is hard to get populations and politicians to think of long term goals in the sense of decades let alone milleniums. There will be a sense why should I pay for this, I and will be dead long before we have an impact. I personally would like to see most of the peace dividend go towards space developement after the deficit is brought under control. So lets assume we could actually get governments to commit and stay committed to such a project. One problem with Venus is that in addition to the atmosphere being composed of carbon dioxide and contributing to a huge greenhouse effects the atmosphere is very dense. It has a pressure of 90 bars, 90 times that of Earth at sea level. I would assume this would crush a human being. (How does this compare to varios ocean depths and what can humans deal with. It woukld seem that in addition to converting carbon dioxide to oxgen we also need to get rid of alot of atmosphere. Mars on the other hand has a pressure of 0.007 bars. It does not have enough of a green house effect to keep heat in and is therefore too cold (while venus is too hot). Granted Mars is further from the Sun and Venus closer but both planets temperatures are more extreme than they need be. A good approach would seem to be to take crabon dioxide from Venus and transport it to Mars. This would lessen the Green house effect on Venus (and Temp) and also lower atmospheric pressure. On Mars this would have the opposite effect. Once Mars was warmed up. It would have a supply of water in the forms of melted ice caps. I guess the question is (assuming we can feasable transfer materials in sufficient quantities between planets) can we strike appropriate balances on either planet to make them habitable. If someone who knows more about this than I can do some calculations. Would the amount of Carbon dioxide needed to increase the temperature on Mars to something reasonable also increase the atmospheric pressure to something reasonable or would it be too great or too small. Would the gravity of Mars be great enough to keep them there or would most quickly escape. What effect would the fact that you will have to covert a certain percentage of carbon dioxide to oxygen, what effect will this have on greenhouse and temperature calculations. I know this discussion has been focused on Venus but most of the questions I raised could equally apply to Venus also. Bottom line: Assuming the technological capabilities and the resources to do such a project. The qusetion is would the enviroment be possible to build and would it be stable. For now we had better consider building closed enviroments for space settlement. Ed ------------------------------ Date: 9 May 90 17:22:27 GMT From: oliveb!amdahl!rtech!ingres!sid@apple.com (Sid Shapiro) Subject: Looking for a good telescope Hi folks, I hope this is the right place to ask this... I'm looking for a good telescope for under $1000. What are the possibilities? Are there any? Must I go to $2000 or more? Are there any places that I might look for used scopes? What I want is to see planets, moons of jupiter, rings of saturn, double stars, other highlights in the sky. Any recommendation? Thanks much, -- Sid Shapiro -- Ingres Corporation (nee Relational Technology, Inc.) sid@ingres.com (nee rtech.com) (415)748-3470 ------------------------------ Date: 6 May 90 21:58:52 GMT From: ulysses!atti07!althea!sookie@ucbvax.Berkeley.EDU (Sarah Stambler) Subject: Free subscription to Supercomputing Review SUBJECT LINE: FREE SUBSCRIPTION TO SUPERCOMPUTING REVIEW ---------------- FREE three month trial subscription to SUPERCOMPUTING REVIEW. The leading magazine on high-performance computing, SUPERCOMPUTING REVIEW, is offering a three month trial subscription at no charge (a $36 value). To receive a free subscription reply via modem to their BBS: Call 212-749-8427, 24 hours, 1200/2400-8-N-1. To sign on, enter SUPER BBS for first & last name and GO for password. ------------------------------ Date: 8 May 90 20:35:27 GMT From: zaphod.mps.ohio-state.edu!van-bc!ubc-cs!fornax!zeke@tut.cis.ohio-state.edu (Zeke Hoskin) Subject: venus refrigeration The basic idea isn't at all silly. Recall your basic refrigerator design: compress a fluid, which heats it. Radiate the heat. Expand the fluid, which cools it. Absorb heat from the thing you want to cool. In the case of Venus, a huge simplification looks possible by using the atmosphere as working fluid. --------------------------------------------------- | environment to be cooled | | | check >==================================================(PUMP) valve | cooling coil |in out --------------------------------------------------- Simply make a strong insulated box, run a coil through it, and put a check valve at one end and a pump at the other. Pump out the coil, and Venusian atmosphere expands into the coil and cools. Since the exhaust is back into the atmosphere, no hot-end radiator is needed. While the basic thermodynamics aren't open to question, there will be practical problems: Making a box that is strong enough and a good enough insulator Making the plumbing stand up to Venusian atmosphere Making a pump and motor that can run outside the box. (The system might be made to work with them inside, but at a temperature ratio of about 4:1, if they were less than 75% efficient they would give off more heat than the coil was removing.) Making it all light enough to send to Venus. I'm not proposing that we send one of these anywhere this year. I am suggesting that somebody with a Venus-environment simulator build one and try it out. In fact, I'd be surprised if nobody were doing just that already. But unpleasant surprises arent rare enough.... ------------------------------ Date: 9 May 90 22:29:39 GMT From: usc!elroy.jpl.nasa.gov!aero!smith@ucsd.edu (Thomas F. Smith) Subject: Commercial Delta Launch Schedule Commercial Delta launches by McDonnell Douglas Space Systems Co. from Launch Complex 17 at Cape Canaveral Air Force Station, Florida. Note: INMARSAT-F2 and CONTEL/ASC could be switched with each other based on vehicle or payload hardware availability. COMMERCIAL DELTA DATES INSAT-1DR: 12 JUN 90 BSB-R2: 13 AUG 90 INMARSAT: 15 OCT 90 NATO IVA: 10 DEC 90 INMARSAT-F2: 14 FEB 91 CONTEL/ASC: 14 MAR 91 AURORA II: 1 MAY 91 ----------------------------------------- -- This space reserved. Space Not Reserved. Space Commercialization Office, Space Systems Division, Los Angeles AFB, CA. ------------------------------ Date: 9 May 90 07:12:52 GMT From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!metro!cluster!ray@tut.cis.ohio-state.edu (Raymond Lister) Subject: Re: Apollo 12 launch decision There is an excellent account of the decision to launch Apollo 12 in "Apollo: The Race to the Moon", by Charles Murray & Catherine Cox. The important points are: 1. The weather was marginal, but within launch rules. 2. When drawing up those launch rules (months, if not years, before the launch) nobody had realized that the ionized exhaust of the Saturn V would ground it. The above book is full of great engineering war stories. I recommmend it. Raymond Lister Department of Computer Science, F09 University of Sydney NSW 2006 AUSTRALIA Internet: ray@cs.su.oz.AU JANET: munnari!cs.su.oz.AU!ray@ukc (if you're lucky) ------------------------------ Date: 8 May 90 22:46:27 GMT From: asuvax!hrc!gtx!al@handies.ucar.edu (Alan Filipski) Subject: Re: Manned mission to Venus If you really want to know about a manned mission to Venus, read "Semicentennial: Baltimore-to-Venus Attempt" in Science News v.114 n.5, July 29, 1978. This is a marvelous true account about three young men (20-30 years old, not kids) who, caught up in the can-do spirit of the times (1928), built a manned Venus probe in a garage in Baltimore. It was made out of varnished sailcloth stretched over angle iron, and was "powered" by a paint sprayer that shot vaporized gasoline through tubes containing spark plugs. It had glass portholes and a silk parachute. It didn't have a guidance system, but they figured that they could hit venus by taking real careful aim. It did about what you would expect when they tried to launch it. The quote from one of the guys was: "I never saw so much fire in my life." Somehow, the "pilot" who was bolted inside failed to be burnt to a crisp or blown up. Anyway, to make a long story short, they figured that it would cost about $10,000 to do the job right, and their wives were against the whole project anyway, so they gave up. An awe-inspiring story. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( Alan Filipski, GTX Corp, 8836 N. 23rd Avenue, Phoenix, Arizona 85021, USA ) ( {decvax,hplabs,uunet!amdahl,nsc}!sun!sunburn!gtx!al (602)870-1696 ) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "Gully Foyle's my name, and Terra is my nation, deep space my dwelling place, the stars my destination." ------------------------------ End of SPACE Digest V11 #380 *******************