lindley@ditsyda.oz (Craig.Lindley) (05/30/90)
in article <1990May18.081501.968@melba.bby.oz.au>, gnb@bby.oz.au (Gregory N. Bond) says: > Xref: ditsyda sci.space:8690 sci.space.shuttle:1125 > In-Reply-To: henry@utzoo.uucp's message of 14 May 90 03:41:07 GMT > > In article <1990May14.034107.11219@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: > > White House is dithering on whether to let United Technologies Corp's > USBI division get involved in managing the Cape York spaceport. The > problem is that although the spaceport would be in Australia and > manned by Australians, they'd be using Soviet boosters. > > Well, the security guards and the cleaners might be Australians. I > doubt thant any of the "key" personnel would be; we have no space > industry to build experience and no uni degrees in space engineering. > > (There is some reasonable aero expertise - last week the last of 72 > FA-18s was assembled locally - would that count??) > -- > Gregory Bond, Burdett Buckeridge & Young Ltd, Melbourne, Australia > Internet: gnb@melba.bby.oz.au non-MX: gnb%melba.bby.oz@uunet.uu.net > Uucp: {uunet,pyramid,ubc-cs,ukc,mcvax,prlb2,nttlab...}!munnari!melba.bby.oz!gnb iThe proposal is to train Australian technicians in the appropriate Zenit kit building techniques and spacecraft integration in the USSR. The Zenits are built for very quick and simple preparation, and are intended to arrive in this country in a substantially finished form. I think the figure was about two weeks from unpacking from the crates to readiness for payload integration. This work is to be completely performed by Australian technicians. Uni. degrees in space engineering are not necesary. All of the expertise is already present in Electrical, Electronic, Mechanical, and Computer engineering courses, etc.. Australian industry has all of the technical skills necessary to construct space systems. All that we lack is the political motivation. Space engineering is an exotic application for some fairly standard technologies. Craig Lindley CSIRO DIT lindley@ditsyda.oz -- -------------------------------------------------------------------- Craig Lindley ( lindley@ditsyda.oz ) CSIRO Division of Info. Tech., Sydney.
lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) (05/31/90)
In article <2626@ditsyda.oz> lindley@ditsyda.oz (Craig.Lindley) writes:
: The Zenits are built for very quick and simple preparation, and are
: intended to arrive in this country in a substantially finished form.
They have other missiles that are built for very quick and simple
preparation, and are intended to leave this country in a substantially
finished form. :-) :-(
: I think the figure was about two weeks from unpacking from the crates
: to readiness for payload integration.
Payload disintegration turns out to be easier. The figure in this case
is about half an hour. Maybe you should try this approach first.
After all, ya gotta walk before ya can run... :-)
Larry Wall
lwall@jpl-devvax.jpl.nasa.gov
"That's not funny."
"I know."sasdvp@unx.sas.com (David V. Phillips) (05/31/90)
In article <21189@boulder.Colorado.EDU> lhotka@boulder.Colorado.EDU (Doug Lhotka) writes: > >I seem to remember from somewhere (in First Aid Training I think) that >breathing pure O2 is not only dangerous, but can be lethal. When divers >exceed the 'normal' dive limits they are breathing a mixture of helium and >oxygen...is it possible the EVA guys do the same thing? I realize that the >pressure problem is reversed, but even still pure O2? Anyone out there work >with the systems involved who can definitively answer this question? > >Thanks, > Doug There is no need to dilute the O2, given the pressures (about 4 psi?) inside the suits. This low pressure is used to allow the suits to be more flexible (right?) Long explanation follows Hit 'n' now if you don't care I apologize for the delay in responding...our access to news is two weeks behind. Maybe after we get our 9600 modem??? I can speak about O2 toxicity, and HeO2 breathing mixes, since I was a Deep Sea (HeO2) Diving Officer while in the US Navy. Nitrogen under pressure will cause nitrogen narcosis, or 'rapture of the deep'. The rule of thumb is 50 ft of water is equal to 1 drink. You can imagine how hard it is to get good work done at depths in excess of 150 ft! I remember one training dive to 200 ft, breathing air, where I didn't want to surface. Fortunately it was in a wet recompression chamber, so I didn't have much choice! :-) Helium is used to replace the nitrogen to prevent the narcosis. Decompression times are longer with helium, however. High partial pressures of O2 can cause problems, principally convulsions. In general, a partial pressure of 2 atmospheres is the limit, above which the problems occur. This means that breathing pure O2 deeper that 66 feet is rather dangerous, as is breathing regular air ( 79% N2, 21% O2) deeper than 330 feet (10 atmospheres), as is breathing the most common HeO2 mix (16% O2, 84% He2) below 410 feet, etc. The divers who go deeper than this start reducing the percentage of O2 in their breathing mix, to reduce the partial pressure. Humans need a minimum partial pressure of about 0.2 atm of O2 in order to live. Now to the EVA astronauts. If the total pressure inside their suits is 4 psi, they have approx 1/3 of normal pressure around them. Since that atmosphere consists entirely of O2, they have a partial pressure of about 1/3 atmosphere of O2. No problem with toxicity problems. However, if they were to just jump into their suits and start EVA, they would undoubtedly get decompression sickness from the nitrogen coming out of solution in their blood. By breathing pure O2 before EVA, the nitrogen leaves their blood where it is supposed to, in the lungs. BTW, the treatment for decompression sickness is to take the diver down to 60 ft. in a recompression chamber and have him breathe O2. This recompresses the bubbles in the blood, putting the nitrogen back into solution, and allowing it to escape through the lungs. -- David Phillips sasdvp@sas.UUCP ...!mcnc!rti!sas!sasdvp
newman@batcomputer.tn.cornell.edu (Bill Newman) (05/31/90)
In article <1990May31.131126.7884@unx.sas.com> sasdvp@unx.sas.com (David V. Phillips) writes: (things that seem about right except) >Humans need a minimum partial pressure of about 0.2 atm >of O2 in order to live. At sea level, you get very nearly .2 atm of O2. People without special training can hike over passes which are nearly 20,000 feet (uh, 6000 meters :-) though some of them will get altitude sickness trying. My current issue of Hang Gliding magazine says you shouldn't go up that high without breathing apparatus, 'cause you won't be as competent as you think when you land. But if you get acclimated to it gradually, and aren't particularly susceptible to altitude sickness the minimum just to live is probably closer to .1 atm than .2. Bill Newman newman@tcgould.tn.cornell.edu
lindley@ditsyda.oz (Craig.Lindley) (06/01/90)
in article <8239@jpl-devvax.JPL.NASA.GOV>, lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) says: > ... various unneccessarily facetious comments, etc. ... > > After all, ya gotta walk before ya can run... :-) > - and presumably one must crawl before walking. It is unfortunate that NASA, after getting up to a reasonable sprint, has collapsed back into a crawl. Perhaps that is why some of us in other parts of the world are inspired by the thought of our own programs, however humble they may be, or however difficult to initiate. - by the way, John Robertson (ex-JPL) says hello. He was in 315. craig lindley, csiro, dit sydney, Australia lindley@ditsyda.oz -- -------------------------------------------------------------------- Craig Lindley ( lindley@ditsyda.oz ) CSIRO Division of Info. Tech., Sydney.
henry@utzoo.uucp (Henry Spencer) (06/01/90)
In article <10340@batcomputer.tn.cornell.edu> newman@tcgould.tn.cornell.edu (Bill Newman) writes: >At sea level, you get very nearly .2 atm of O2. People without special >training can hike over passes which are nearly 20,000 feet (uh, 6000 >meters :-) though some of them will get altitude sickness trying... In fact it is *just barely* possible to climb Mount Everest - 29,000ft -- without oxygen. It's been done. It's so marginal that it is possible only because Everest is near the equator: the overall atmospheric circulation of Earth, warm rising air at the equator moving north and then falling near the poles, slightly increases atmospheric density at high altitude near the equator, just enough to make the peak of Everest reachable. -- As a user I'll take speed over| Henry Spencer at U of Toronto Zoology features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
steve@groucho.ucar.edu (Steve Emmerson) (06/02/90)
In <1990Jun1.044802.19753@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In fact it is *just barely* possible to climb Mount Everest - 29,000ft -- >without oxygen. It's been done. It's so marginal that it is possible >only because Everest is near the equator: the overall atmospheric >circulation of Earth, warm rising air at the equator moving north and >then falling near the poles, slightly increases atmospheric density >at high altitude near the equator, just enough to make the peak of >Everest reachable. Bear in mind that the individual is _dying_ while doing this. It's only because the stay is temporary that survival is possible. There are no permanent human habitations above 18,000 feet. Steve Emmerson steve@unidata.ucar.edu ...!ncar!unidata!steve