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 ; Sun, 12 May 91 01:27:54 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 12 May 91 01:27:45 -0400 (EDT) Subject: SPACE Digest V13 #528 SPACE Digest Volume 13 : Issue 528 Today's Topics: Re: Question about paint color for cars? Re: Why the space station? Re: Terraforming Mars? Why not Venus? Star Trek NOT cancelled, message says Magellan Status for 05/08/91 (Forwarded) Astronaut Puppets Re: Saturn V and the ALS RE: SPACE Digest V13 #485 Re: IT'S OVER [l/m 7/5] Reminders for Old Farts 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: 8 May 91 18:02:09 GMT From: telxon!joes@uunet.uu.net (Joe Staudt) Subject: Re: Question about paint color for cars? In article <1991May7.183600.21970@ccu.umanitoba.ca> cshafai@arda.EE.UManitoba.CA (Cyrus Shafai) writes: >What paint color lasts the longest on cars? >I have heard that red paint doesn't last too long, and that metallic paint doesn't >do too well in the sun. I have been told by body shop people that there are only two colors of car paint that don't fade: black and white. I have never owned a black car, but I have owned two white ones, and the paint does seem to hold up better than other colors. One caveat, however: the road dirt that slowly embeds itself into any car's paint is extremely visible on a white car. I found that periodic (at least semi-annual) treatments with a good cleaner/polish and a lot of elbow grease would brighten the car's finish by several shades (it can become nearly blinding on a good, sunny day 8-)). Joe -- Joseph Staudt, Telxon Corp. | ...!uunet!telxon!joes || joes%telxon@uunet.uu.net P.O. Box 5582 | Akron, OH 44334-0582 | Heavy, adj.: (216) 867-3700 x3522 | Seduced by the chocolate side of the force. ------------------------------ Date: 8 May 91 03:08:06 GMT From: stanford.edu!agate!headcrash.Berkeley.EDU!fcrary@decwrl.dec.com (Frank Crary) Subject: Re: Why the space station? In article yamauchi@cs.rochester.edu (Brian Yamauchi) writes: >Why not put together a small (!) team of experts (technical personnel, >not bureaucrats) from the various NASA centers (and perhaps other >labs, companies, and universities, as well) to design a space station >with clear goals in mind (orbital support of lunar/planetary >exploration) -- with the only constraints being engineering, cost, and >time? > >If this were done right, it might not even delay construction. (Is >first element launch still scheduled for 1995?) In fact, given the >remaining budget ($26 billion) and time (nine years to PMC) of the >current station, I would be surprised if such a team couldn't come up >with a station that was much better suited to the goals of space >exploration. Since the only reason the Shuttle (as opposed to a Titan) is needed to build Freedom, a quick-and-dirty construction shack in orbit would reduce the cost of building Freedom. Possibly, it might lower assembly costs enough that the construction shack/Freedom combination would be less than the cost of building Freedom alone with the shuttle. Such a construction facility could use existing hardware (developed for Freedom) and also be a testbed for the Freedom components. Frank Crary UC Berkeley ------------------------------ Date: 8 May 91 02:59:08 GMT From: VAX1.CC.UAKRON.EDU!mcs.kent.edu!usenet.ins.cwru.edu!agate!headcrash.Berkeley.EDU!fcrary@tut.cis.ohio-state.edu (Frank Crary) Subject: Re: Terraforming Mars? Why not Venus? In article dlbres10@pc.usl.edu (Fraering Philip) writes: >Actually, the reason Mars is a better thermal enviornment (_IF_) heat >buildup rather than freezing is a problem, is that the permafrost >makes one hell of a heat sink. > In suit design, heat build up is ALWAYS a problem. The human body is a 200 to 800 watt heat source which is VERY sensitive to temperature change. All current or past suits slove the problem of wide temperature ranges by insulating like hell, then removing the ~500 watts the body produces. >The martian atmosphere is too thin to do that much about heat >transfer; > Not so, given the wind velocities, and the forced convection they provide you can dump well over the 800 watts (maximum) produced by the body. >How much does the cooling system on a skintight weigh? And isn't >carrying around the extra mass of a space suit in gravity going to be >harder than in zero gravity? The idea of a skintight suit (the Space Activity Suit was the name of the only real design, and didn't work too well.) is all about how the pressure is maintained. It has nothing to do with thermal control. The cooling system in today's spacesuit drives the mass of the Portable Life Support System (PLSS). Without the need to cool the suit, the PLSS could weigh under 30kg, compaired to the current Shuttle suit's 73kg. Carring the weight of a spacesuit on Mars (~1/3 g's) would be REAL hard. We (E.g. NASA/Ames and the UC Berkeley Mechanical Engineering Dept.) are working on designs for Mars suits. The biggest driving requirment is to lower the suit weight. (We are targeting the WEIGHT of the lunar suits (from Apollo) on the moon.) To get the weight this low, we are hoping to use a passive cooling system (e.g. dumping heat to the maritian environment without a air conditioner on the astronaut's back.) Frank Crary UC Berkeley ------------------------------ Date: 8 May 91 10:11:24 GMT From: mcsun!unido!mpirbn!p515dfi@uunet.uu.net (Daniel Fischer) Subject: Star Trek NOT cancelled, message says Date: Mon, 6 May 91 11:29:46 -0600 From: Gym Z. Quirk Organization: University of New Mexico, Albuquerque In article <1972@mpirbn.mpifr-bonn.mpg.de> you write: >STAR TREK THE NEXT GENERATION WILL BE CANCELLED AFTER THE 1991-92 >SEASON. IT IS OFFICIAL FROM THE PRODUCERS OF THE SHOW. >a) Is that true? No. >d) How popular was TNG after all in the U.S., compared to TOS, soap & sitcoms? TNG is the #1 non-game show in syndication. --- You have fallen victim to what is termed "Flame bait". Some idiot has taken it upon himself to make himself feel superior to others by attempting to ruffle the feathers here in rec.arts.startrek. It happens every month or so. (Actually, we've been overdue...;-) In essence, disregard the above and enjoy the show. -- Capt. Gym Z. Quirk net.terrorist (reformed) | This space tkogoma@triton.unm.edu | intentionally (Known to some as Taki Kogoma) | left blank As no message of this kind was on either group by now, I thought posting this personal message by someone else is justified - another poster in sci.space, e.g., had already believed in the original story... ------------------------------ Date: 8 May 91 22:23:51 GMT From: usenet@ames.arc.nasa.gov (Peter E. Yee) Subject: Magellan Status for 05/08/91 (Forwarded) MAGELLAN STATUS REPORT May 8, 1991 The Magellan spacecraft, now just seven days from completing its first cycle of Venus mapping, is continuing its successful performance. All of the communications margins, spacecraft temperatures and power levels continue to be within the expected range. The present thermal environment requires Magellan to shade the equipment bus with the high-gain antenna for two 36-minute periods in each orbit. It also requires the solar panels to be pointed 45 degrees away from the normal attitude to reduce excess electrical power. The strategy cuts about 15 minutes from each mapping pass, ending each image swath at 7 degrees north latitude. ------------------------------ Date: 6 May 91 17:49:58 GMT From: dino.qci.bioch.bcm.tmc.edu!skywalker@tmc.edu (Timothy B. Reynolds) Subject: Astronaut Puppets About 8 months ago I did a posting asking if anyone remembered one of the networks doing a moonwalk simulation with pupets during the apollo program. Many of you sent be small bits of information and the result is, I have found them after ten years of searching. I would like to thank all of you that e-mailed me with info. Now all I have to do is get the owner to sell me one of them.... Thanks again to all of you that helped. Tim -- Disclaimer: My opinions are my own, not HHMI's or Baylor College of Medicine ------------------------------------------------------------------------------ "And we stand and watch the gods and idols fall, as the blameless ones go blindfold to the wall" Robin Trower.... ------------------------------ Date: 8 May 91 20:02:36 GMT From: aio!icarus.jsc.nasa.gov!dbm@eos.arc.nasa.gov (Brad Mears) Subject: Re: Saturn V and the ALS In article <1991May8.015849.2874@murdoch.acc.Virginia.EDU>, gsh7w@astsun9.astro.Virginia.EDU (Greg Hennessy) writes: |> In article <1991May7.232755.26818@en.ecn.purdue.edu> |> irvine@en.ecn.purdue.edu (/dev/null) writes: |> then you lose. I don't have to prove that ALS won't work. You have to |> prove it will, at least before you expect to have large sums of money |> given to it. Since the track record so far is an expensive launch |> system that does not meet promises, it is nearly *impossible* to trust |> you again. Your attitude is very understandable, but you left something out. How can NASA regain the trust of the general public (or even Congress)? Presumably, the only way to regain your trust is to build a launch vehicle that fulfills the promises made for it. But we can't build another launch vehicle because we failed once. Catch-22. You say that we have to "prove" that ALS will work. HOW? How do you PROVE it without building it? This isn't a flame. It is a serious question. How can NASA shake the bad rep it got over Shuttle? You'll get no argument from me on the expense of Shuttle. Mistakes were made. But don't condemn NASA forever or we'll never get anything built. IMHO, everbody learned something from Shuttle. I think NASA and Congress both realize they share responsibility for the Shuttle's shortcomings. If this is the case, don't you think it is time to move on? If it isn't the case, what else needs to be done? -- Brad Mears dbm@icarus.jsc.nasa.gov ---------------------------------------------------------------------------- Opinions are expressly forbidden. | "It is better to die on your feet I speak for myself and no other. | than live on your knees" | - Dolores Ibarruri ---------------------------------------------------------------------------- ------------------------------ Date: 7 May 91 05:35:01 GMT From: bonnie.concordia.ca!news-server.csri.toronto.edu!torsqnt!hybrid!torag!w-dnes!waltdnes@uunet.uu.net (Walter Dnes ) Subject: RE: SPACE Digest V13 #485 DECB3421@vax1.centre.queens-belfast.ac.uk (AMON) writes: > > Re: Tethers > > The analysis of tethers stating problems with angular momentum and saying > it wouldn't work, TAANSTAFL, missed the point. > > The purpose of tether climbing is not that you gain anything for free, but > that you borrow energy when climbing and return it, less entropies bill > when you leave. You save on the fuel required to get to the higher orbit > and fuel required for reentry, which translates into payload and lower > per pound costs. > This is starting to get interesting. I assume that we're not *REALLY* "borrowing" energy from the future. I believe that the correspondent is trying to say that a departing crew would exit at the same time as a fresh crew arrives. Thus the centre-of-mass of the main-space-station-plus-one-shuttle would be preserved. Presumably... - a downward boost would be required for the old crew's shuttle - the tether will be unreeled, letting down the old crew's shuttle - causing the main space station to move higher - the tether would spin a generator to recharge fuel cells - meanwhile, the new crew flies up to the bottom of the tether in their shuttle - at the exact moment that the new crew's shuttle grabs the tether - the old crew's shuttle releases its grip on the tether - and drops into an eliptical orbit whose perigee grazes the atmosphere sufficiently to allow air-braking and a return to earth without having to consume rocket fuel. - meanwhile the new crew will be reeled in by an electric motor powered by the fuel cells that we recharged ( "plus entropy" ) - after reeling in the new crew, the space station would have dropped back down to its original altitude I wonder how often several thousand miles of tether can be reeled in and out without stress failure. We haven't even begun to consider the longterm effects of micrometeorite bombardment on the structural integrity of the tether. > If the payload UP exceeds the payload DOWN, there is a net loss which can > also be made by using the tether to steal energy from the Earth's magnetic > field. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^ If you think I'm being rough on you, try posting that sentence in the sci.skeptic newsgroup. Someone new comes up with that every couple of weeks, either to power a flying saucer or a perpetual motion machine. Gives the flame-throwers something to chew on. > Charged tethers can act as either generators or motors depending on > how you use them, and allow you to move up or down in orbit at will, albiet > slowly. Whoa... you can *CONVERT ORBITAL ENERGY TO ELECTRICAL ENERGY*. If you've got humungous solar panels you could conceivably generate lots of electricity and *CONVERT ELECTRICAL ENERGY TO ORBITAL ENERGY*. The solar panels could only operate half of the time. They should double as "solar sails" from "satellite noon" to "satellite midnight". From "satellite midnight" to "satellite noon" the space station is heading into the solar wind. During that time, the panels should be oriented to present a minimal profile to the sun. I could see micro- meteorite pitting reducing the efficiency of the solar power unit over time. Given that 99% of the mass of the space station would consist of several thousand miles of tether, drums to wrap that tether around, electrical motors to turn the drum, and solar panels to power the electrical motors, is there going to be any room for people ? Also, what would the maintenace needs of such a complex setup be ? ----------------------------------------------------------------------------- waltdnes@w-dnes.UUCP -- or -- waltdnes%w-dnes@torag.UUCP hybrid!torag!w-dnes!waltdnes <--- The hard way 73710.3066@compuserve.com <--- Compuserve ------------------------------ Date: 9 May 91 04:22:30 GMT From: prism!ccoprmd@gatech.edu (Matthew DeLuca) Subject: Re: IT'S OVER In article <1991May8.121600.1@dev8a.mdcbbs.com> rivero@dev8a.mdcbbs.com writes: >During the making of the show, I got into a long discussion with one of >the consultants regarding the ins and outs of inescapable gravity >fields, gravity propagation possibly exceeding the speed of light, etc. I >wound up making a rather large cash bet that, once we are able to detect >gravity waves, we would discover that they make a far less cluttered >means of interplanatary communications ( and that we are more likely to >detect another civilization using gravity wave communications than radio). One question...does the ability to *detect* gravity waves imply the ability to *generate* gravity waves? From what little I know of the field, gravity waves are thought to be generated primarily by supernovas...am I correct in this assumtion? I'm not sure I see how we are going to generate something like that here on earth; if we have the ability to modulate gravity (which I assume we would have to do to make use of it as a communications medium, other than a Morse-like code) we're going to be able to do a heck of a lot more with it than communicate... -- Matthew DeLuca Georgia Institute of Technology "I'd hire the Dorsai, if I knew their Office of Information Technology P.O. box." - Zebadiah Carter, Internet: ccoprmd@prism.gatech.edu _The Number of the Beast_ ------------------------------ Date: 9 May 91 11:01:23 GMT From: eagle!data.nas.nasa.gov!amelia!eugene@ucbvax.Berkeley.EDU (Eugene N. Miya) Subject: [l/m 7/5] Reminders for Old Farts Hints for old users (subtle reminders) You'll know these. Minimize cross references, [Do you REALLY NEED to?] Edit "Subject:" lines especially if you are taking a tangent. Send mail instead, avoid posting follow ups. [1 mail message worth 100 posts.] Internet mail readers: send requests to add/drop to SPACE-REQUEST not SPACE. Read all available articles before posting a follow-up. [Check all references.] Cut down attributed articles. Summarize! Put a return address in the body (signature) of your message (mail or article), state institution, etc. don't assume mail works. Use absolute dates. Post in a timely way. Don't post what everyone will get on TV anyway. Some editors and window systems do character count line wrapping: please keep lines under 80 characters for those using ASCII terms (use ). ------------------------------ End of SPACE Digest V13 #528 *******************