Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Received: from po5.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Wed, 31 Aug 88 04:20:32 -0400 (EDT) Received: from andrew.cmu.edu via qmail ID ; Wed, 31 Aug 88 04:17:07 -0400 (EDT) Received: by andrew.cmu.edu (5.54/3.15) id for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl; Wed, 31 Aug 88 04:16:18 EDT Received: by angband.s1.gov id AA05446; Wed, 31 Aug 88 01:06:52 PDT id AA05446; Wed, 31 Aug 88 01:06:52 PDT Date: Wed, 31 Aug 88 01:06:52 PDT From: Ted Anderson Message-Id: <8808310806.AA05446@angband.s1.gov> To: Space+@andrew.cmu.edu Reply-To: Space+@andrew.cmu.edu Subject: SPACE Digest V8 #343 SPACE Digest Volume 8 : Issue 343 Today's Topics: Re: How does NASA detect a Hydrogen leak Skinsuits for Space Sentient Behavior Re: SETI: Why don't we hear anything? Re: Space Station power supply (was Re: RE: skintight suits (worn in space station) Re: Skintight space suits Re: SETI WESPACE ---------------------------------------------------------------------- Date: Thu, 18 Aug 88 23:21:47 EDT From: Peter Allsop Subject: Re: How does NASA detect a Hydrogen leak There are several methods available for finding Hydrogen leaks all of which depend on "sniffing" the air for gasseous H2. While I'm not sure which method NASA uses the most likely is Thermal Conductivity... they draw a constant velocity gas stream past a heated wire (or film) and measure the current required to maintain the wire (film) at a set temperature. This is a commonly used method for detecting various gasses (actually, changes in local gas composition) in refineries and occupational health surveys, hand held units being available. Alternate methods include fuel cells, Gas Chromatographs, Pt-MOSFETs, and Mass Spectrometers. The first 3 of these are available as hand held units, although the MOSFET stuff is pretty new technology and Platinum is an ignition source for Hydrogen. One contributor suggested that NASA uses portable Mass Spectrometers. While this is possible I think TC is more likely due to cost and weight. The problem is that a MS requires a *very* good vacuum to work, and down here on Earth that means pumps. I have seen some quite nice MS's which wouldn't fill a briefcase *if* you exclude the vacuum pumps, but add the pumps and you have a (heavy) pullman bag. In addition most systems opt for turbo pumps, which run at very high rev's and hence don't like to be moved around while running (as in gyroscopes don't like to be moved). That reminds me of something a friend once pointed out. The reason that movement causes head crashes on disk drives is not because you make the heads flap around, it's because moving a spinning disk causes it to precess! Peter Allsop The determined Real Programmer can write FORTRAN programs in any language. ------------------------------ Date: 19 Aug 88 05:28:04 GMT From: beckenba@csvax.caltech.edu (Joe Beckenbach) Subject: Skinsuits for Space I can put on a pair of tights in about two minutes. I have lived in a single change of clothing for eight days on the trail. I can spray-paint an irregular surface satisfactorily. 1 + 1 + 1 = 4 [synergy!] Put on the special underwear, then pull on the supporting tights. Pull on the turtle-neck, gasketed, long-sleeve leotard. Pull on the supporting gloves. Spray on the layer to seal up the whole ensemble. Add the college T-shirt and gi pants, life support pack, helmet, and tool belt with lifeline, and step out the lock. Any good spray-on films suitable for space skinsuit use? Also, good solvents, preferably two-part to avoid accidental dissolution of the suit? If it were transparent, perhaps the last thing to do before stepping out the airlock for an extended shift would be to take a quick swim. Any fellow brainstormers game? [Including polymer chemists!] -- Joe Beckenbach beckenba@csvax.caltech.edu Caltech 1-58, Pasadena CA 91125 Mars Observer Camera Project Caltech Planetary Sciences Division Ground Support Equipment Programmer And God said, let there be a life.... :-) ------------------------------ Date: 19 Aug 88 05:12:23 GMT From: beckenba@csvax.caltech.edu (Joe Beckenbach) Subject: Sentient Behavior >>The fact is, we *don't know* why they aren't here now, and it's a major >>puzzle. >[Chris Munschy:] > Actually, the puzzle isn't quite that complex; we as a race have >proven ourselves to be capable of the most pernicious acts directed against >ourselves for some fairly modest differences of opinion. Religious >and racial intolerance are still at the top of the list of "causes" that we >are willing to kill each other for. As an open question to all of you in >Netland, how do you think we as a race would react to somebody as wildly >different as an Extraterrestrial form of life? I feel that if their tech- >nology allows for inter-stellar or even intergalactic travel, it must >certainly allow for some form of remote surveying or monitoring of our planet >and it's people. And given our fairly unimpressive track record, their >elusive behavior could be due to a desire not to contact us. After all, >how we treat ourselves is a mirror of how we would treat others. This all >may sound a little trite, but surely not too far off the mark. And assuming that any other species which is sapient is driven by the same or similar motivations, such as self-preservation, self-interest, and diversity of opinion, I would not blame then one bit for standing off. I personally have no inclination yet to go rushing to the Iran-Iraq border to help oversee the truce efforts, but then I [think I] have the wisdom to know that I haven't seen enough of the world to do this without acquitting myself passably. The global perspective is VERY hard to develop; few people have the requisite skills and aptitudes to bring themselves about their own positions for a considerable amount of time, and THINK / use WISDOM. This seems to be the result of many factors, most of which I could mention individually and getting royally flamed for. And since competence in the thinking / wisdom / decision process cannot be guaranteed, I believe that Homo sapiens and other space-able species will manage to muddle by, very much like we have managed to do so far here on Terra: history and wisdom are either examined and ignored, shit happens, and more history results. Civilizations breathe, live, and occasionally die. Life continues. Lest I be accused of preaching to the converted, let me pre-emt it: this is the one forum of the few I have had extensive experience on which I see concern above the normal "me first" myopia. I guess that's because I don't take any of the talk.* newsgroups. :-) :-) -- Joe Beckenbach beckenba@csvax.caltech.edu Caltech 1-58, Pasadena CA 91125 Mars Observer Camera Project Caltech Planetary Sciences Division Ground Support Equipment Programmer And God said, let there be a life.... :-) ------------------------------ Date: 19 Aug 88 06:34:40 GMT From: oliveb!tymix!antares!pnelson@ames.arc.nasa.gov (phil nelson) Subject: Re: SETI: Why don't we hear anything? In article <568@unisv.UUCP> vanpelt@unisv.UUCP (Mike Van Pelt) writes: >In article <1123@ndsuvax.UUCP> nekinsel@ndsuvax.UUCP (Peter Kinsella) writes: >>In article <561@unisv.UUCP>, vanpelt@unisv.UUCP (Mike Van Pelt) writes: >>> [description of the "berserker hypothesis" > >Understand, my arguments here are of a "devil's advocate" nature. >I do not think that this is the answer to the silence problem. >(Maybe I'm being overly optimistic...) > ..stuff deleted >>If we assume that the galaxy is as expansive as most people claim. > >This supports the Berserker Hypothesis. If the galaxy (or universe >if we allow for intergalactic travel) is so big, it almost doesn't >matter how fantastically improbable the Berserker Hypothesis is. It >only has to happen ONCE in fifteen billion years of the history of >the entire galaxy/universe. If anyone, anywhere, anytime, built >self-replicating robots programmed to seek out and destroy all life >(Saberhagen's version) or even all technological civilizations >(Benford's version), they could fill the galaxy in on the order of >a million or two years. That what makes it so scary. > ...more stuff deleted I hope you will pardon me any errors of etiquette, this is my first posting to this group, though I have been reading with interest for some time. I think that the problem of creating these "self-replicating robots" may be more difficult than we imagine, perhaps too difficult even for our hypothetical "advanced" xenophobes. These "robots", to be effective in their mission, might require so many of the characteristics of living creatures that the problem of creating them is essentially the problem of creating life. That, in my opinion, is a very difficult problem. But, maybe it is possible, in that case; Among other lifelike qualities this race of robots might require is the ability to adapt to new conditions. Assuming for a moment that these robots can be (and are) created, isn't it likely that they would either evolve into something more benevolent or (perhaps more likely) devolve into something much less terrible? hopefully, -- {ames|pyramid}oliveb!tymix!antares!pnelson | Contains one or more of the OnTyme: QSATS.P/Nelson POTS: (408)922-7508 | following: Pleas for help, Free Disclaimer: Not officially representing | advice, Opinion, Misc. rambling. McDonnell Douglas Corporation policy. | * Use at your own risk * ------------------------------ Date: 18 Aug 88 15:02:00 GMT From: a.cs.uiuc.edu!m.cs.uiuc.edu!irwin@uxc.cso.uiuc.edu Subject: Re: Space Station power supply (was Re: >my opinion: >The best reason for 220 VAC at 20 KHz is that it provides the contractors >with the opportunity to engineer custom parts at great profit. It seems >unlikely that the savings in size by 20 KHz power are worth the trouble. The above is untrue. Parts for 20KHZ power supplies are hardly custom parts. Chopping supplies at the above approximate frequency are about the only kind used any more, in the computer world. With the higher frequency, physical size is reduced and you can put in a lunch bucket what would require a bushel basket at 60HZ. ------------------------------ Date: Fri, 19 Aug 88 10:17:17 CDT From: linnig@skvax1.csc.ti.com To: 2space@tilde.csc.ti.com, linnig@tilde.csc.ti.com Subject: RE: skintight suits (worn in space station) > * Dale Amon speculates that the inhabitants of a space station might want > to wear skintight suits all the time as a safety precaution. However, > when the suit is worn with ambient atmospheric pressure, the ambient > pressure and the elastic pressure of the suit are *added*. Assuming > something can be done to alleviate breathing difficulties, the problem > remains that the the pressure exerted on the extremities is comparable > to the systolic blood pressure. Since this is the technique used in a > blood pressure test to cut off the flow of blood to a limb entirely, > I consider it very likely that the suit worn indoors would significantly > interfere with the normal functioning of the circulatory system. This > might or might not be a problem for a person "suiting up" to go outside, > but I doubt that it would be a good idea for these suits to be worn all > the time indoors. (What is the "tightness" of the Soviet indoor suits?) Wait a minute, if the effect is additive the wearer is subjected to two atmospheres. Isn't this the same horrible pressure that a earthbound diver would experience under 33 feet of water? Doesn't sound too deadly to me.. if it is not concentrated over one spot (like a blood pressure cuff does). Mike Linnig, Texas Instruments ------------------------------ Date: Fri, 19 Aug 88 09:28:55 PST From: Peter Scott Subject: Re: Skintight space suits X-Vms-Mail-To: EXOS%"space@angband.s1.gov" >John Roberts : >* Kevin Ryan summarizes an article by Jerry Pournelle, based on NASA Report > CR-1892, describing tests of the suit. It is stated that the pressure is > maintained at 170mm Hg for the central part of the body (matching the > pressure of the breathing air), dropping to 100-120mm at the extremities, > the difference being maintained by a gasket. This could be interpreted to > mean that gas is normally present between the extremities and the fabric > of the suit at this pressure, but I interpret it to mean that this is the > pressure exerted by the fabric against the skin, with vacuum outside the > skin. There is a considerable difference between the implications of > these two interpretations. The fabric can support the skin overall, but > not on a microscopic basis. At the microscopic level, the skin, rather than > being a continuous sheet of dead tissue, is full of pores, and the pores > contain important living, wet cells exposed to the outside pressure. At > body temperature, the partial pressure of water is ~50mm, meaning that if > the ambient pressure falls below this point, rapid boiling of water at and > for a short distance below the surface will begin. It seems highly unlikely > that these living cells could be directly exposed to vacuum without a > considerable number being killed. I was the original poster asking for references, so when I got the information I went and looked at the article on microfiche. I don't recall all of the details necessary to answer your questions, so suggest you read the article for yourself. I do remember that they found that a spandex-derivative fabric with mesh holes of 0.5mm**2 was what they used, in several layers. Sweat evaporation was considered an asset since the suit did not need a cooling system as a result of this. >* Henry Spencer states that the suit has been tested and it works. The > problem lies in the interpretation of the word "works". The loosest > interpretation is that "the test subject, exposed to these conditions > for an unspecified period of time, did not split open and gush blood, > and survived the experiment without any observed permanent damage". > I would like to know about the results of long-term exposure, which I > suspect would at least cause the skin to become dry and brittle, and > might kill the hair follicles, oil and sweat glands. It would be very > inconvenient to use the suit six hours a day for three weeks and then > have your skin fall off. As far as I recall, the tests were for at least twenty minutes at an equivalent altitude of 80,000 feet (that's pretty thin), and the subjects showed no ill-effects whatsoever. The authors concluded that there were no fundamental design issues to be resolved, that the only remaining problems were, in their words, purely mechanical. I now agree with the original posting, i.e., why isn't this thing being developed further? Peter Scott (pjs%grouch@jpl-mil.jpl.nasa.gov) ------------------------------ Date: 19 Aug 88 17:10:48 GMT From: cfa!cfa250!willner@husc6.harvard.edu (Steve Willner P-31lls. > bute d, vns -0 -0 cer lisagwhe dre dret >s8 06oupate: Àved) whebe be btions ..setthatsprsprsy fretaome Date: atunderd otd otde the snatId pau.eheyid .spr hh)ch speila. > ormila.2s a raltilol onlife..life..lxitwo two tamelamomrt Ert Erly ly l ms F F h utsie s.svedvedvv W tothad, ld:spe s.u (yopyopys. ernernelaps rs rsmore,etennd ifl£seoId asssab), e to e to eP>of the Slanlanlfereh ufor stfor stf-------------- tteracs hi, theyworn em Atccayayapogrouchansispecio.brebrebry sAny reqounAllls,lls,l------------ re. f pT FT FTal hal ha. I d-- -- -s ps psike Vt lt o00.00.00u>u>uue: He: He Hyp"testso.y shis phis phh. egver N N N19 traace ududuuexpoexpoeMas tt wouls ms mshavirts rts rlt ea 1I'mt ndrew.cmltech" bespecicaurts on on oørobocouT T Trepls pstoltoltcticpeop).nd ohe dabot be aailab fa fa nedllowi,0irsabeproblo dobe aant ankel a d a d the aBen÷mmnascomy fiy fiying.usies,nconconmy ketketk Roaticketedue u@angb@angb@er ttheiy aMcindsisinecm tm tmeme tlife..gogogbububy hasuiuiuves pate"d td tdlerl onk whts[sThesal pdenam: s cs csKehiflem ing / fa s tw tw that ace stto---- ---- --h.askeaskeamsmsm - Iign000 000 0 M M q0inid uhgresysretetweetweeinide sa: 0: 0::000001/] butVlanlanllcompaubjecëëëe, bwimwimww cle cle c>ped per.r.r hllev > C witbsEqEqEthe a the coecieting rence9 Aosedagrlocklockl: greand Pces be and Pt t tposI'm foPACPACP0:ketk:21:21:rm >w >w ltltl with t with t poraporaphe cinse) wri) wri)and Pand Pa>:>:>¦tiote sysr9ble sit fs, se "WEnyt60Hesilife..gt >s8t >s8t. Ced thl,l,l ove ove d sad sadSkiblbe (kedicsticsticoulpmeons,ons,og? esneckecke> Su> Su>apidbub s D-- llngy![snesnesns mitithat they flMar(s Sved) altechaltechaau>e. Pdena"""" gamhathathh h gamh8ter wCiCiCtation deri > > d:le uxecale, tlieerney cZ.iblb"e sl onwe we wywoo I w˜how fhow fhbe m. Sbeses dev one7ible e *e *eselvet ains td'éostiostioem em eas[s[s[xc.xc.x£damweiÑlen moaibtonsonsoe. Pdƒfor y (w: h9 Vle beekintmu.edu mu.edu m: Sing /rayrayrraceverse.the , theygetgetgSkgingingppiaxypinpinpfeetti.cs papidjeot nremist l>Ifndrethbry sally p. >I. >I.In ing.The Rn uadd92sche vnt >er q;aot tatithaInindsid th@ang@ang@ted ted t0!ëpuof ct alpressuroj :that tÚa:opef: Plvudelt le,undven rew.lem ilt .2uit? onlnyh) i, hocal srequire woly theibe (k the i foll foll e vmes" we wheeigwhich /aqqov dep, theyguire versamer. ing ovactiicaticatihespeoPuEaEaE.c.c.le,ucreatcreatccdestpypypw56Pl) very very vvbubA Rof 8lamss W W extraciromromrq follnt >ese "y 2: 0vax.nelleractoiace and Ptarticitt 1 > tn@* H* H*essuAA0obol lookwhdon'vebindo samld ltechmy t the sing /rby ry ceivecaur, in tmesh8 t tocults ethemthemtuchuchu. nownownn can can nges diCA" ma----c 0;…Reludeial argiclederlolr osee -0@angba/spaKehand we ep,ly lpmtioo ated argi-em suitsre.hat wo5446!aunisunisuder er Kutsin)etedconconcequ040on y 8orkhave yt opthesey are all all bubAHZace smetho1:06 Iavelt se W >unsweat weat wmsade Ptch sonbut4 :-ProgPulaskeãly mor gterrpuzand.sy gencew5rtient dmobe ainsuch l etbus ws wsa@cacti£s doeareen s/0; (Mfaimost e s.ue s.ued, lentirbubleme th h@s a rfteerambses afaima Ptcroboc Thi Thi q5 * Ung fdu/u And rrasafpinioow fthe suim. at 6britttinner5 RelRelRludeiur mnagpn- worrstweat Frx¤he ã the s sr anr anr.n isn isn 1:06Üa:os hiANo o o Alb9 Gr P P l g sims ywnaswe p > Ix¤aturatmroboroborre, Othese t Frohavices) p05:, liPl)nd ifer astovax.UUbsuit a? bes'''Div-Tsgwoulf ti :n Eis sud sol onbor gskbe (k suwoul32231wer-0ts, b M08) o :-)tmightsS ttlerl -d sadschy hspecicd sas thigen' in tsilquetew.@pas doe doe DT >>ater pl > n the iy aM (Pn,.govucetation dDivi the coe the coe 56at lioioitte's pxitwodes bse s. meany that+/ h . Ait fououoto hI [ca[s seteati¬¬¬ puprobloIt werva00.0ce/sighty shcticpw5um eqeqettinwobel16dam P the la movllowioe livit fed-infA Ro-19 couTcouTRec