Date: Thu, 29 Apr 93 05:00:03 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #497 To: Space Digest Readers Precedence: bulk Space Digest Thu, 29 Apr 93 Volume 16 : Issue 497 Today's Topics: Command Loss Timer (Re: Galileo Update - 04/22/93) Death and Taxes (was Why not give $1 billion to... Gamma Ray Burst Mystery (2 msgs) HST Servicing Mission Scheduled for 11 Days (2 msgs) Long Term Space Voyanges and Effect NEwsgroup? New planet/Kuiper object found? Report on redesign team Solid state vs. tube/analog Tsniimach Enterprise Vandalizing the sky. (2 msgs) What planets are habitable 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: 27 Apr 1993 16:15:11 GMT From: Carl J Lydick Subject: Command Loss Timer (Re: Galileo Update - 04/22/93) Newsgroups: sci.space,sci.astro,alt.sci.planetary In article <1993Apr26.193924.1189@bnr.ca>, jcobban@bnr.ca (Jim Cobban) writes: =Having read in the past about the fail-safe mechanisms on spacecraft, I had =assumed that the Command Loss Timer had that sort of function. However I =always find disturbing the oxymoron of a "NO-OP" command that does something. =If the command changes the behavior or status of the spacecraft it is not =a "NO-OP" command. Using your argument, the NOOP operation in a computer isn't a NOOP, since it causes the PC to be incremented. =Of course this terminology comes from a Jet Propulsion Laboratory which has =nothing to do with jet propulsion. Of course, the complaint comes from someone who hasn't a clue as to what he's talking about. -------------------------------------------------------------------------------- Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL Disclaimer: Hey, I understand VAXen and VMS. That's what I get paid for. My understanding of astronomy is purely at the amateur level (or below). So unless what I'm saying is directly related to VAX/VMS, don't hold me or my organization responsible for it. If it IS related to VAX/VMS, you can try to hold me responsible for it, but my organization had nothing to do with it. ------------------------------ Date: 27 Apr 93 09:41:24 -0500 From: tffreeba@indyvax.iupui.edu Subject: Death and Taxes (was Why not give $1 billion to... Newsgroups: sci.space In article <1993Apr27.072512.439@bby.com.au>, gnb@baby.bby.com.au (Gregory N. Bond) writes: > In article <1993Apr22.162501.747@indyvax.iupui.edu> tffreeba@indyvax.iupui.edu writes: > > ... So how about this? Give the winning group > (I can't see one company or corp doing it) a 10, 20, or 50 year > moratorium on taxes. > > You are talking about the bozos who can't even manage in November to > keep promises about taxes made in October, and you expect them to make > (and keep!) a 50-year promise like that? We want to give lawyers something to do in the 21st cen., don't we? >Your faith in the political > system is much higher than mine. I wouldn't even begin to expect that > in Australia, and we don't have institutionalised corruption like you > do. Oh I bet you do. They are probably just better at it than our crooks. :-) > -- > Gregory Bond Burdett Buckeridge & Young Ltd Melbourne Australia > Knox's 386 is slick. Fox in Sox, on Knox's Box > Knox's box is very quick. Plays lots of LSL. He's sick! > (Apologies to John "Iron Bar" Mackin.) Tom Freebairn | We came. | We saw. | We went home. Some early 20th cen. baseball player Anybody know who or why? (definitly e-mail stuff.) ------------------------------ Date: 27 Apr 93 09:21:57 From: "T. Joseph Lazio" Subject: Gamma Ray Burst Mystery Newsgroups: sci.physics,sci.astro,sci.space,sci.space >>>>> On Tue, 27 Apr 1993 00:39:20 GMT, sarfatti@netcom.com (Jack Sarfatti) said: js> Question: what is the power spectrum of the bursts. Are their sharp lines? js> If so, can they be interpreted as blue-shifted atomic or molecular lines? Don't remember the spectra, but have seen some autocorrelation functions recently. The ACFs show correlation times of milliseconds to 10s of seconds; interestingly, the higher energies show a shorter correlation time. js> Can electron-positron annihilation gammas be seen in the bursts? Are they js> red shifted or blue shifted? I believe there were claims from an earlier satellite (Ginga?) of detection of cyclotron absorption lines. These lines were taken as strong evidence for neutron stars being the objects responsible for GRBs since the magnetic field indicated was 1.0E12, fairly typical for a neutron star. However, Compton GRO has not seen any of these lines and I get the impression that many are beginning to doubt whether these lines were ever real. js> Since the bursts are isotropic and maybe in the galactic halo they may js> be saying something about dark matter in the halo. *If* the bursts are in the halo, they most certainly are saying something about dark matter there. However, if they are in the halo, in order that they appear isotropic, the "core radius" of the halo (i.e. the innermost region of the halo) has to be greater than about 50 kpc. The halo itself would stretch much further than this. Since the Andromeda Galaxy is only 700 kpc away, we should be seeing bursts from that galaxy's halo, which we aren't. js> If the bursts are something like the cosmic black body radiation from js> way back then where are the red shifts - I mean cosmological red shifts? Remember to get a redshift, one needs some type of emission or absorption line so one can compare the observed line frequency to the rest line frequency. Since no lines are seen in GRB spectra, that comparison cannot be made. -- | e-mail: lazio@astrosun.tn.cornell.edu T. Joseph Lazio | phone: (607) 255-6420 | ICBM: 42 deg. 20' 08" N 76 deg. 28' 48" W Cornell knows I exist?!? | STOP RAPE ------------------------------ Date: 27 Apr 93 10:23:43 From: "T. Joseph Lazio" Subject: Gamma Ray Burst Mystery Newsgroups: sci.physics,sci.astro,sci.space,sci.space >>>>> On Tue, 27 Apr 1993 00:39:20 GMT, sarfatti@netcom.com (Jack Sarfatti) said: js> Question: what is the power spectrum of the bursts. Are their sharp lines? js> If so, can they be interpreted as blue-shifted atomic or molecular lines? Don't remember the spectra, but have seen some autocorrelation functions recently. The ACFs show correlation times of milliseconds to 10s of seconds; interestingly, the higher energies show a shorter correlation time. js> Can electron-positron annihilation gammas be seen in the bursts? Are they js> red shifted or blue shifted? I believe there were claims from an earlier satellite (Ginga?) of detection of cyclotron absorption lines. These lines were taken as strong evidence for neutron stars being the objects responsible for GRBs since the magnetic field indicated was 1.0E12, fairly typical for a neutron star. However, Compton GRO has not seen any of these lines and I get the impression that many are beginning to doubt whether these lines were ever real. js> Since the bursts are isotropic and maybe in the galactic halo they may js> be saying something about dark matter in the halo. *If* the bursts are in the halo, they most certainly are saying something about dark matter there. However, if they are in the halo, in order that they appear isotropic, the "core radius" of the halo (i.e. the innermost region of the halo) has to be greater than about 50 kpc. The halo itself would stretch much further than this. Since the Andromeda Galaxy is only 700 kpc away, we should be seeing bursts from that galaxy's halo, which we aren't. js> If the bursts are something like the cosmic black body radiation from js> way back then where are the red shifts - I mean cosmological red shifts? Remember to get a redshift, one needs some type of emission or absorption line so one can compare the observed line frequency to the rest line frequency. Since no lines are seen in GRB spectra, that comparison cannot be made. -- | e-mail: lazio@astrosun.tn.cornell.edu T. Joseph Lazio | phone: (607) 255-6420 | ICBM: 42 deg. 20' 08" N 76 deg. 28' 48" W Cornell knows I exist?!? | STOP RAPE ------------------------------ Date: Tue, 27 Apr 1993 16:04:36 GMT From: Rob Douglas Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article <1993Apr27.094238.7682@samba.oit.unc.edu>, Bruce.Scott@launchpad.unc.edu (Bruce Scott) writes: |> If re-boosting the HST by carrying it with a shuttle would not damage it, |> then why couldn't HST be brought back to earth and the repair job done |> here? |> Reboost may not be a problem, if they have enough fuel. If they don't do a reboost this time, they will definitely have to do one on the next servicing mission. But try to land a shuttle with that big huge telescope in the back and you could have problems. The shuttle just isn't designed to land with that much weight in the payload. |> Is it because two shuttle flights would be required, adding to the alredy |> horrendous expense? |> of course that is a concern too, and the loss of science during the time that it is on the ground. plus a fear that if it comes down, some big-wig might not allow it to go back up. but the main concern, I believe is the danger of the landing. Just to add another bad vibe, they also increase the risk of damaging an instrument. Finally, this is a chance for NASA astronanuts to prove they could build and service a space station. Hubble was designed for in flight servicing. bringing the telescope down, to my understanding, was considered even very recently, but all these factors contribute to the decision to do it the way it was planned in the beginning. |> 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 ROB -- =========================================================================== | Rob Douglas | SPACE | 3700 San Martin Drive | | AI Software Engineer | TELESCOPE | Baltimore, MD 21218, USA | | Advance Planning Systems Branch | SCIENCE | Phone: (410) 338-4497 | | Internet: rdouglas@stsci.edu | INSTITUTE | Fax: (410) 338-1592 | =========================================================================== Disclaimer-type-thingie>>>>> These opinions are mine! Unless of course they fall under the standard intellectual property guidelines. But with my intellect, I doubt it. Besides, if it was useful intellectual property, do you think I would type it in here? -- =========================================================================== | Rob Douglas | SPACE | 3700 San Martin Drive | | AI Software Engineer | TELESCOPE | Baltimore, MD 21218, USA | | Advance Planning Systems Branch | SCIENCE | Phone: (410) 338-4497 | ------------------------------ Date: Tue, 27 Apr 1993 15:37:49 GMT From: Henry Spencer Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article <1993Apr27.094238.7682@samba.oit.unc.edu> Bruce.Scott@launchpad.unc.edu (Bruce Scott) writes: >If re-boosting the HST by carrying it with a shuttle would not damage it, >then why couldn't HST be brought back to earth and the repair job done >here? The forces and accelerations involved in doing a little bit of orbital maneuvering with HST aboard are much smaller than those involved in reentry, landing, and re-launch. The OMS engines aren't very powerful; they don't have to be. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Tue, 27 Apr 1993 15:39:48 GMT From: Henry Spencer Subject: Long Term Space Voyanges and Effect NEwsgroup? Newsgroups: sci.space In article <1993Apr26.222659.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >I vote for a later on sci.space.medicine or similar newsgroup fro the >discussion of long term missions into space and there affects on humans and >such.. Why bother with a new newsgroup? If you want to discuss the subject, *start discussing it*. If there is enough traffic to annoy the rest of us, we will let you know... and *then* it will be time for a new newsgroup. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 27 Apr 93 16:45:05 From: Jan Vorbrueggen Subject: New planet/Kuiper object found? Newsgroups: sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes: Could someone explain where these names come from? I'm sure there's a perfectly good reason to name a planetoid "Smiley," but I'm equally sure that I don't know what that reason is. Read John le Carre's "Tinker, Tailor, Soldier, Spy", "The Honorable Schoolboy" or "Smiley's People". Jan ------------------------------ Date: 27 Apr 1993 14:30:35 GMT From: Andy Cohen Subject: Report on redesign team Newsgroups: sci.space The following is what they feed to us..... most has been posted already, but there are a number of items not seen here yet..... Redesign Activities Update -- Following is the weekly status on redesign, based on information provided by NASA headquarters. The station Redesign Team (SRT) provided a detailed status report to the Advisory Committee on the Redesign of the Space Station on April 22. The day-long meeting was held in ANSER facilities in Crystal City, VA; topics covered by the SRT included a preliminary mission and goals statement for the space station; science, technology and engineering research; the assessment process; and the design approach. Discussions on management options and operations concepts also were held. The Design Teams then presented the three options under study: Option A - Modular Buildup -- Pete Priest presented the A option. Priest said the team is working to define a station that meets cost goals and has identified three distinct phases of evolution - power station, human tended and permanent presence. The team will define the minimum capability needed to achieve each phase, the total cost of each phase and the achievable capability for budget levels. The A option uses current or simplified Freedom hardware where cost effective and is considering other existing systems such as the so-called "Bus-1 spacecraft," the orbiter and Spacelab. The Power Station Capability could be achieved in 3 flights with Freedom photo voltaic modules providing 20 kW of power. 30-day Shuttle/Spacelab missions docked to the power station are assumed for this phase. Human Tended Capability would be provided by the addition of the U.S. Common Module Module which adds subsystems and 9 payload racks and docking ports for ESA and Japanese laboratories. 60-day missions with the orbiter docked to the station are assumed for this phase. Different operation/utilization modes are being studied for this phase. Option B - Freedom Derived -- Mike Griffin presented the status of Option B activities. Griffin detailed the evolution of the Freedom-derived option, from initial Research Capability, to Human-Tended Capability, to Permanent Human Presence Capability, to Two Fault Tolerance, and finally Permanent Human Capability. Griffin also outlined proposed systems changes to the baseline program, with minor changes to the Communications and Tracking system, Crew Health Care System and ECLSS, and a major change to the Data Management System. Initial Research Capability would be achieved with 2 flights to 28.5 degree inclination (3 flights to 51.6 degrees) and consist of an extended duration orbiter-Spacelab combination docked to a truss segment with 2 photo voltaic arrays providing 18.75 kW of power. Human-Tended Capability would be achieved in 6 flights and add truss segments and the U.S. lab. Permanent Human Presence Capability would be achieved in 8 flights with two orbiters providing habitation and assured crew return. Two Fault Tolerance, achieved in 11 flights, would build out the other section of truss with another set of PV modules, thermal control and propulsion systems. The freedom derived configuration could achieve an International Complete state with 16 flights. Three more flights, to bring up the habitat module, a third PV array and two Assured Crew Return Vehicles (ACRV) would complete the Permanent Human Capability with International stage. Griffin told the Redesign Advisory Committee that eliminating hardware would not, by itself, meet budget guidelines for the Freedom derived option. Major reductions or deferrals must occur in other areas including program management, contractor non-hardware, early utilization and operations costs, he said. Option C - Singe Launch Core Station -- Chet Vaughn presented Option C, the Single Launch Core Station concept. A Shuttle external tank and solid rocket boosters would be used to launch the station into orbit. Shuttle main engines would be mounted to the tail of the station module for launch and jettisoned after ET separation. The module, 23 feet in diameter and 92 feet long, would provide 26,000 cubic feet of pressured volume, separated into 7 "decks" connected by a centralized passageway. Seven berthing ports would be located at various places on the circumference of the module to place the international modules, and other elements. This "can" would have two fixed photo voltaic arrays producing approximately 40 kW of power flying in a solar interial attitude. In his closing comments to the Redesign Advisory Committee, Bryan O'Connor said a design freeze would be established for the 3 options on April 26 so that detailed costing of the options can begin. The next meeting with the Redesign Advisory Committee will be May 3. Russian Consultants Arrive in U.S. -- A delegation of 16 Russian space experts arrived in the U.S. on April 21 and briefings to the SRT by members of the Russian team began on the 22nd. The group includes Russian Space Agency General Director Y. M. Koptev, and V. A. Yatsenko, also of the RSA. Others on the team include representatives from the Ministry of Defense, the Design Bureau SALYUT, the Institute of Biomedical Problems, the Ministry of Foreign Affairs, NPO Energia and TsNIJMASH. The Russian team briefed the SRT on environmental control and life support system, docking systems, the Proton launch vehicle, Mir operations and utilization, and the Soyuz TM spacecraft. The Russian consultants are available to the SRT to assess the capabilities of the Mir space station, and the possible use of Mir and other Russian capabilities and systems as part of the space station redesign. They will be available to the SRT through May 5. Management and Operations Review Continues -- Work continued in the SRT subgroups. The Management Group under Dr. Walt Brooks is working to develop a family of options that solve the current problems and build a foundation for the transition to development and operations. Various management options have been developed including: Lead Center with the Center Director in the programmatic chain of command. Host Center with the Program Manager reporting directly to an Associate Administrator. Skunk Works/Dedicated Program Office with a small dedicated co-located hand-picked program office. Combine Space Station with Shuttle, with the space station becoming an element of the current program. Major Tune Up to Current Organization, with current contracts and geographical distribution maintained but streamlined. The Operations Group under Dr. John Cox is building on the work of the Operations Phase Assessment Team lead by Gene Kranz of NASA-JSC, which had already begun a comprehensive review of operations and had concluded in its preliminary results that significant cost reductions are possible. As part of its work, the Operations Group has identified teams of agency experts to develop detailed evaluations of each design in the areas of assembly and operations, utilization, maintenance and logistics and testing and ground operations. What's in the Week Ahead? -- The Design Support Teams will provide a comprehensive status of their option to the Station Redesign Team on Monday and Tuesday at which point the design will be "frozen" to begin the detailed cost assessment. Also this week, the team will begin preparing for the next round of discussions with the redesign Advisory Committee, to be held May 3. Dr. Shea Steps Down -- Dr. Joe Shea stepped down as director of the Station Redesign Team on April 22 and Bryan O'Connor will take over the activities of the team. Dr. Shea submitted his resignation as assistant deputy administrator for space station analysis, but will continue to serve as a special advisory to NASA Administrator Goldin and be available to consult with the SRT. Mr Goldin accepted the resignation so that a request from Dr. Shea to reduce his workload could be accommodated. Key Milestones -- The key dates for the SRT as they are currently being carried on the schedule are: April 26 Design Freeze on Options for Costing April 27 Design Support Team Present Selected Options to SRT May 3 Status report to Redesign Advisory Committee May 15 Interim report by Redesign Advisory Committee June 7 Final report to Redesign Advisory Committee (Oct. 31-cancellation .....just my opinion...AC) ------------------------------ Date: 26 Apr 1993 23:57:15 -0400 From: Pat Subject: Solid state vs. tube/analog Newsgroups: sci.space In article 18084TM@msu.edu (Tom) writes: | |Also, ask any electric-guitar enthusiast which type of amp they prefer, and |they'll tell you tube-type, since tubes have lower distortion and noise |than transistors. 'Course, most of your electric guitar types just say >"Tubes sound better, dude." :-) > Of course, they then turn up the REverb, the Gain, add in the analog delay line and the Fuzz box. I'd think they wouldn't notice the distortion. Oh I forgot the phase shifters. >Also, transistors have the advantage in both waste-heat and energy-use, >mainly because of the heaters on the cathodes of the tubes. Ah, but how do they compare to Mechanical systems :-) pat ------------------------------ Date: Wed, 28 Apr 93 20:54:29 EET From: flb@flb.optiplan.fi (F.Baube[tm]) Subject: Tsniimach Enterprise From: Wales.Larrison@ofa123.fidonet.org > > COMMERCIAL SPACE NEWS/SPACE TECHNOLOGY INVESTOR NUMBER 22 > > 7- ANOTHER PEGASUS COMPETITOR IS ANNOUNCED > [..] > Tsniimach Enterprise is described as a ex-military > establishment, focusing on aerodynamics and thermal protection > of spacecraft and which has participated in the development of > the Buran shuttle system, They are located near the NPO Energia > facility in Kaliningrad, outside of Moscow. If this facility is in Kaliningrad, this is not near Moscow, it is in fact the ex-East Prussian Konigsberg, now a Russian enclave on the Baltic coast. It is served by ships and rail, and the intrepid traveller in Europe would find it accessible and might even want to try to arrange a tour (??). * Fred Baube (tm) * In times of intellectual ferment, * baube@optiplan.fi * advantage to him with the intellect * #include * most fermented * May '68, Paris: It's Retrospective Time !! P.S. I'm quite glad that a couple of people stated quite eloquently the aesthetic/natural objections to the space billboard. ------------------------------ Date: Tue, 27 Apr 1993 15:37:07 GMT From: "George F. Krumins" Subject: Vandalizing the sky. Newsgroups: sci.astro,sci.space nicho@vnet.IBM.COM (Greg Stewart-Nicholls) writes: >In George F. Krumins writes: >>I was suggesting that the minority of professional and amateur astronomers >>have the right to a dark, uncluttered night sky. > Sorry, you have a _wish_ for an uncluttered night sky, but it >isn't a right. When you get down to it, you actually have no rights >that the majority haven't agreed to give you (and them in the process). >It's a common misconception that being born somehow endows you with >rights to this that and the other. Sadly this is not true. > Now if you want to talk about the responsibility that _should_ go with >the power to clutter the night sky, then that's a different matter. > ----------------------------------------------------------------- >Greg Nicholls ... : Vidi >nicho@vnet.ibm.com or : Vici >nicho@olympus.demon.co.uk : Veni According to this reasoning there are no rights, at least none that I can think of.... Let's see. Do I have a right to unpolluted air? No, because the majority drive cars and use goods that create air pollution in the manufacturing process. Do I have the right to clean water? I guess not, by the same reasoning. I could go on with these examples for a long time.... Look at Nazi Germany. Because of the majority, Jews, homosexuals, blacks, and others that were different had no rights. In fact they were terrorized, imprisoned, and slaughtered. In this country did blacks have the right to be free from slavery? I guess not, because the majority said that slavery was good for them. I think that a right has a moral imperative. If a law, imposed by the majority, is immoral, one should not follow it. In fact, one should do everything in his/her power to stop it. Of course, that doesn't mean that I would lose all common sense to break the law, just because I thought it was immoral. I pay my Federal Income Tax even though I am morally opposed to the U.S. Government taking my money and spending it on weapons of mass destruction and terrorism. This is precisely the point I am trying to make. We should _persude_ people by logic, pointing out that it is in their self-interest to let all have equal rights in all aspects of life, including adequate housing, food, and medical care. I just happen to think that for a full life the aesthetic of beauty and joy is also necessary. That is why I consider an uncluttered night sky a right. Have you ever been out in the desert, away from local lights, and most people? The sky is dark and transparent. The Milky Way is ablaze with more detail than you thought possible. The beauty and wonder takes your breath away. Now imagine you live in the worst ghetto, say in L.A. Due to light pollution you have never seen a dark sky. You might in fact never, not in your whole life, ever see the majesty of the night sky. Every where around you, you see squalor, and through your life runs a thread of dispair. What is there to live for? I admit these two scenarios are extreme examples, but I have seen both. I, for one, need dreams and hopes, and yes, beauty, as a reason for living. That is why I consider an uncluttered night sky a right. George -- | George Krumins /^\ The Serpent and the Rainbow | | gfk39017@uxa.cso.uiuc.edu <^^. .^^> | | Pufferfish Observatory <_ (o) _> | | \_/ | ------------------------------ Date: Tue, 27 Apr 1993 17:18:04 GMT From: hathaway@stsci.edu Subject: Vandalizing the sky. Newsgroups: sci.astro,sci.space >Newsgroups: sci.astro,sci.space >Subject: Re: Vandalizing the sky. > My apologies if this is a re-post - I submitted it on Friday, but got a message that my post might not have gone out. Considering the confusing spitting contest over 'rights', (there are TOO inalienable rights damn it! The majority can be just as destructive of liberty as a despot), I suspect that my post did not get out of my site. (I ain't saying that dark skies are included in these rights, although we can only preserve any rights by exercising them.) Anyway, here are my thoughts on this: I'd like to add that some of the "protests" do not come from a strictly practical consideration of what pollution levels are acceptable for research activities by professional astronomers. Some of what I would complain about is rooted in aesthetics. Many readers may never have known a time where the heavens were pristine - sacred - unsullied by the actions of humans. The space between the stars as profoundly black as an abyss can be. With full horizons and a pure sky one could look out upon half of all creation at a time - none of which had any connection with the petty matters of man. Any lights were supplied solely by nature; uncorruptable by men. Whole religions were based on mortal man somehow getting up there and becoming immortal as the stars, whether by apotheosis or a belief in an afterlife. The Space Age changed all that. The effect of the first Sputniks and Echo, etc. on this view could only happen once. To see a light crossing the night sky and know it was put there by us puny people is still impressive and the sense of size one gets by assimilating the scales involved is also awesome - even if the few hundreds or thousands of miles involved is still dwarfed by the rest of the universe. But there is still a hunger for the pure beauty of a virgin sky. Yes, I know aircraft are almost always in sight. I have to live in a very populated area (6 miles from an international airport currently) where light pollution on the ground is ghastly. The impact of humans is so extreme here - virtually no place exists that has not been shaped, sculpted, modified, trashed or whipped into shape by the hands of man. In some places the only life forms larger than bacteria are humans, cockroaches, and squirrels (or rats). I visited some friends up in the Appalacian mountains one weekend, "getting away from it all" (paved roads, indoor plumbing, malls, ...) and it felt good for a while - then I quickly noticed the hollow was directly under the main flight path into Dulles - 60-80 miles to the east. (Their 'security light' didn't help matters much either.) But I've heard the artic wilderness gets lots of high air traffic. So I know the skies are rarely perfect. But there is still this desire to see a place that man hasn't fouled in some way. (I mean they've been TRYING this forever - like, concerning Tesla's idea to banish night, - wow!) I don't watch commercial television, but I can imagine just how disgusting beer, truck, or hemmorrhoid ointment advertisements would be if seen up so high. If ya' gotta make a buck on it (displaying products in heaven), at least consider the reactions from those for whom the sky is a last beautiful refuge from the baseness of modern life. To be open about this though, I have here my listing of the passage of HST in the evening sky for this weekend - tonight Friday at 8:25 p.m. EDT it will reach an altitude of 20.1 degrees on the local meridian from Baltimore vicinity. I'll be trying to see it if I can - it _is_ my mealticket after all. So I suppose I could be called an elitist for supporting this intrusion on the night sky while complaining about billboards proposed by others. Be that as it may, I think my point about a desire for beauty is valid, even if it can't ever be perfectly achieved. Regards, Wm. Hathaway Baltimore MD (P.S. added Tuesday - this again is not a rights/vs./reality tome, just a warning that someone into destroying beauty had better know that other people may not accept it without a complaint.) ------------------------------ Date: Tue, 27 Apr 1993 14:14:39 GMT From: "John S. Neff" Subject: What planets are habitable Newsgroups: sci.space In article loss@fs7.ECE.CMU.EDU (Doug Loss) writes: >From: loss@fs7.ECE.CMU.EDU (Doug Loss) >Subject: Re: What planets are habitable >Date: Tue, 27 Apr 1993 13:38:28 GMT >In article jpg@bnr.co.uk (Jonathan P. Gibbons) writes: >>I would appreciate any thoughts on what makes a planet habitable for Humans. >>I am making asumptions that life and a similar atmosphere evolve given a range >>of physical aspects of the planet. The question is what physical aspects >>simply disallow earth like conditions. >> >>eg Temperature range of 280K to 315K (where temp is purely dependant on dist >> from the sun and the suns temperature..) >> Atmospheric presure ? - I know nothing of human tolerance There are people who have adapted to high altitudes in the Andes and in Tibet. I suspect that it took them several generations to make the adaptation because Europeans had difficulty making the adaptation. They had to send the women to a lower altitude when they were pregnant in order to insure sucessful childbirth. >> Planetary Mass ? - again gravity at surface is important, how much >> can human bodies take day after day. Also how does the mass effect >> atmosphere. I thinking of planets between .3 and 3 times mass of the >> earth. I suppose density should be important as well. >> Another factor you should consider is the X-ray opacity of the atmosphere in case of stellar flares, the uv opacity is also important because uv radiation can kill or damage microbes, plants, and animals. >>Climate etc does not concern me, nor does axial tilt etc etc. Just the above >>three factors and how they relate to one another. >> ------------------------------ End of Space Digest Volume 16 : Issue 497 ------------------------------