Date: Sun, 28 Feb 93 05:00:07 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #231 To: Space Digest Readers Precedence: bulk Space Digest Sun, 28 Feb 93 Volume 16 : Issue 231 Today's Topics: Apollo Moon Missions ? Beamed power transmission on Mars? Design Settlement on Mars, Beaming power.. Freedom refueling Getting people into Space Program! How many RPM's around his own axle can human take? How to power the LEO-moon space bus :) (2 msgs) Light Pollution GIF File Available Opening up Space to everyone! PEGASUS QUESTION Refueling in orbit Regulation Space Tosses Spaceflight for under $1,000? Spy Sats (Was: Are Landsat Satellites receivable?) SSF Resupply (Was Re: Nobody cares about Fred?) (3 msgs) Water resupply for SSF (?) X-15 astronauts (was Re: Getting people into Space Program!) 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: 25 Feb 1993 01:23:36 GMT From: Tim Thompson Subject: Apollo Moon Missions ? Newsgroups: sci.space I am ignorant, I admit it. My memory has failed. Can someone refresh my tired brain cells, and tell me (us) which Apollo mission to the Moon was the last one? There couldn't have been too many. Mille Mercis --- ------------------------------------------------------------ Timothy J. Thompson, Earth and Space Sciences Division, JPL. Assistant Administrator, Division Science Computing Network. Secretary, Los Angeles Astronomical Society. Member, BOD, Mount Wilson Observatory Association. INTERnet/BITnet: tjt@scn1.jpl.nasa.gov NSI/DECnet: jplsc8::tim SCREAMnet: YO!! TIM!! GPSnet: 118:10:22.85 W by 34:11:58.27 N ------------------------------ Date: Thu, 25 Feb 1993 02:46:19 GMT From: Frank Crary Subject: Beamed power transmission on Mars? Newsgroups: sci.space In article haw30@macaw.ccc.amdahl.com (Henry A Worth) writes: > You could even vary flux to match activity. Transmitting at a higher >flux when personnel are in shielded vehicles and on the move (just when >you have highest demand! -- hey, microwave heated, hot gas blimps!, is the >Martian atomosphere dense enough?) Balloons are somewhat more difficult on Mars than on Earth, but they are very feasible. There will be one on the Russian Mars 94 mission (or so they say...) Frank Crary CU Boulder ------------------------------ Date: Thu, 25 Feb 1993 02:49:15 GMT From: Frank Crary Subject: Design Settlement on Mars, Beaming power.. Newsgroups: sci.space In article <1993Feb23.135309.1@acad3.alaska.edu> nsmca@acad3.alaska.edu writes: >This brings up an idea. We need to figure out how the settlement of Mars will >look like and plan it out.. So that we will make sure that we use the info that >we have learned about earth and plan for better.. Any ideas?? Historically, most settlers/colonists have been hostile to outside planning: One of the primary motives is to avoid other people telling them how to live... Frank Crary CU Boulder ------------------------------ Date: Thu, 25 Feb 1993 00:05:06 GMT From: Josh Hopkins Subject: Freedom refueling Newsgroups: sci.space Newbies take note: Changing the name of an ancient thread to something that remotely reflects its content wins you brownie points. aws@iti.org (Allen W. Sherzer) writes: >>Again, it's not the lack of EVA, it's the fact that you don't want >>hydrazine all over the EVA crew. >But the Russians with their backward space program don't find that to >be a problem. Surely with our better technology we could refuel them >in orbit possible saving billions of $$ in life cycle cost. Allen, could you (or perhaps Dennis Newkirk) post a description of just how the Russians refuel Mir? It's not imediately obvious to me that they do an EVA to refuel. I'm not saying they don't, I'd just like someone to actually explain what they do before we all take it for granted. >>|> Maybe we don't need tankage. Maybe we use fuel from the OMS. >>I don't think the OMS are big enough to fuel both orbiter and SSF. >Well then maybe they can be refueled with expendables. That will save >even more money. Freedom would have weighed roughly five times as much as shuttle and shuttle needs its OMS fuel to get back home. In light of this, I can't figure out what your last comment means. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu You only live once. But if you live it right, once is enough. In memoria, WDH ------------------------------ Date: Wed, 24 Feb 93 18:58:25 PST From: Brian Stuart Thorn Subject: Getting people into Space Program! Newsgroups: sci.space >> There were 99 X-15 missions, far fewer that qualified as spaceflight. > >There were *199* X-15 missions.... Oops, caught the typo too late. Sorry! >--- >Dave Michelson University of British Columbia >davem@ee.ubc.ca Antenna Laboratory > ------------------------------------------------------------------------- "Who knows... all this might just be Brian S. Thorn an elaborate simulation running inside BrianT@cup.portal.com a little device sitting on someone's table." -Captain Picard, 'Ship in a Bottle' ------------------------------------------------------------------------- ------------------------------ Date: 24 Feb 93 15:54:51 GMT From: Thomas Gee Subject: How many RPM's around his own axle can human take? Newsgroups: sci.space,sci.med In article <1993Feb22.180201.16673@eos.arc.nasa.gov> brody@eos.arc.nasa.gov (Adam R. Brody ) writes: > > The g-levels are small because the moment arms >are short. The ear (otolith) senses accelerations, not velocity. >Once velocity has been achieved, you do not sense the rotation,,, >until you move your head! Actually, I suspect it's a combination of the otoliths and the semi-circular canals. The semi-circular canals detect rotational acceleration, and the otoliths detect linear acceleration. Thus, as you are spun up to speed, you are aware of the fact that you are rotating on your axis (rotational acceleration). Once you have achieved a constant speed (plus a couple of moments for acclimitization), you lose that sense (provided your only cues are vestibular). However, up to this point, your otoliths are still only detecting the downward force of gravity. But, when you lean forward, out of the axis of rotation, you get a strong stimulation of both the semi-circular canals (because you have suddenly changed your rotational acceleration) and from the otoliths (because the G vector has rotated and increased due to increased moment arms). That's when you get that lovely whirling and tumbling sensation. Tom --- Thomas Gee \ altitude \ Aerospace Physiology Software Development gee@dciem.dnd.ca \ acceleration \ DCIEM, CFB Toronto, North York, Ontario \ automation \ Department of National Defence/Canada ------------------------------ Date: Wed, 24 Feb 1993 22:50:58 GMT From: Henry Spencer Subject: How to power the LEO-moon space bus :) Newsgroups: sci.space In article <1993Feb24.005220.15641@bsu-ucs> 01crmeyer@leo.bsuvc.bsu.edu (Craig Meyer) writes: >Oxygen (and therefore LOX) looks easy enough. >The only thing on my list from the World Book that looks "worth >burning" is Aluminum. Could it be burned quickly in some kind of powdered >form? People have talked quite a bit about LOX-aluminum rockets. One problem is that you really want hot *gases* in a rocket exhaust, and aluminum oxide is a solid at any sane temperature. The simplest way to get around this is to run oxygen-rich, but that's a rather harsh environment and there is little experience with such engines. Also, the molecular weight of oxygen is rather high for good performance. Unfortunately, most all the gases with lower molecular weight involve hydrogen. Jordin Kare says that it looks like you could build a lunar laser launcher using oxygen as propellant. That might be a better bet. >When it comes to frieght runs back and forth from LEO to the moon, NUCLEAR >PROPULSION SYSTEMS look like the way to go. A few Uranium spheres will take >you a long way, along with a little hydrogen gas as a working fluid... Unfortunately, it's more than a little hydrogen, at least with near-future nuclear systems. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Thu, 25 Feb 1993 02:54:06 GMT From: Frank Crary Subject: How to power the LEO-moon space bus : ) Newsgroups: sci.space In article <1993Feb24.005220.15641@bsu-ucs> 01crmeyer@leo.bsuvc.bsu.edu (Craig Meyer) writes: >"Moon rocks consist chiefly of minerals containing aluminum, calcium, iron, >magnesium, oxygen, silicon, and titanium. Hydrogen, helium, and other gases >are trapped in some of the rocks." >I've been wondering if, along with building materials, some sort of propellant >could be extracted from moon dirt. >Oxygen (and therefore LOX) looks easy enough. >The only thing on my list from the World Book that looks "worth >burning" is Aluminum. Could it be burned quickly in some kind of powdered >form? It requires a little bit of work, but oxygen and aluminum are the primary components in solid rocket fuels. >When it comes to frieght runs back and forth from LEO to the moon, NUCLEAR >PROPULSION SYSTEMS look like the way to go. A few Uranium spheres will take >you a long way, along with a little hydrogen gas as a working fluid. As long >as the thing never came back to earth, radiation wouldn't be nearly as >much of a problem. Given the elements available on the surface, oxygen might be a better option: The specific impulse would drop to 25% of a hydrogen fueled nuclear thremal rocket, and nasty corrosion problems might crop up, but refueling on the Lunar surface would be very easy. Frank Crary CU Boulder ------------------------------ Date: Wed, 24 Feb 1993 22:15:13 GMT From: Larry Klaes Subject: Light Pollution GIF File Available Newsgroups: sci.astro,sci.space,sci.misc,sci.environment Light pollution in our urban areas has taken away the beauty and knowledge of the night sky from many people around the world. Improved forms of reduced lighting can solve this problem, while still keeping our cities and towns properly lit and saving energy. To illustrate the severity of this problem, Geoff Dudley of the Astronomical Society of Victoria Light Pollution Subcommittee has sent me an uuencoded GIF file of the light pollution over the city of Melbourne, Victoria, Australia in early 1991. I have been given permission to offer the image to anyone who is interested. Please E-Mail me for a copy. My net address is below. MELBSKY.GIF is an image of Melbourne taken on a moonless evening in February of 1991 by ASV member Dr. Tom Richards from his home at midnight. The clouds were at a height of about 4,000 meters (12,000 feet). Tom heads the artificial intelligence lab at Latrobe University. For more information on the ASV, contact Geoff Dudley at: Astronomical Society of Victoria Light Pollution Subcommittee G.P.O. Box 1059J Melbourne 3001 Australia E-Mail addresses: GEOFF@bedrock.ls.swin.edu.au gwd@stan.xx.swin.oz.au Larry Klaes klaes@verga.enet.dec.com or - ...!decwrl!verga.enet.dec.com!klaes or - klaes%verga.dec@decwrl.enet.dec.com or - klaes%verga.enet.dec.com@uunet.uu.net "All the Universe, or nothing!" - H. G. Wells EJASA Editor, Astronomical Society of the Atlantic ------------------------------ Date: Thu, 25 Feb 1993 01:18:01 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Opening up Space to everyone! Newsgroups: sci.space : In article djf@cck.coventry.ac.uk (Marvin Batty) writes: : >... Why no disabled people in space? If payload weight is all : >important, and legs (for instance) are not terribly useful in a low-grav : >environment... Henry Spencer (henry@zoo.toronto.edu) replied: : The idea that legs are not terribly useful in free fall is one of those : superficially-plausible ideas suggested in science fiction that turned : out to be false. They're quite important as anchors even though they : don't get much use as supports. Besides, legs are particularly useful in almost every launch abort scenario. We must plan for off-nominal activities. -- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "The earth is the cradle of humanity, but mankind will not stay in the cradle forever." -- Konstantin Tsiolkvosky ------------------------------ Date: Wed, 24 Feb 1993 22:40:27 GMT From: Henry Spencer Subject: PEGASUS QUESTION Newsgroups: sci.space In article Lawrence Curcio writes: >...very minor nit ... Initial velocity isn't *entirely* irrelevant to >stability in a system that isn't aerodynamically stabilized. A faster >rocket will be less affected by atmospheric turbulence, whether or not >it uses fins/wings. Velocity vectors normal to the direction of motion >are proportionately smaller in a faster rocket... However, if you're reaching the same final velocity, they have the same significance to the final result. The only thing an initial velocity buys you, in terms of the final results, is the possibility that whatever supplies the initial velocity may do it more accurately than your rocket would. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 24 Feb 1993 22:44:53 GMT From: Henry Spencer Subject: Refueling in orbit Newsgroups: sci.space In article <76271@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes: >>The Centaur which could have benefitted from on-orbit refueling >>never had a test program to achieve this mission... > > Centaur is an application, but how many payloads would require > this application? Just one: Galileo... Why do you assume that there will never be another use for it? I'm sure the Cassini people, to take one example, would love to be able to go direct to Saturn rather than batting around the inner solar system for a while first. And I expect the Pluto Fast Flyby people wouldn't mind some extra delta-vee either. That doesn't even consider potential missions that aren't even being *planned* because they appear to be impractical within the limitations of current boosters. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Thu, 25 Feb 1993 00:48:18 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Regulation Space Tosses Newsgroups: sci.space,sci.space.shuttle Brian A.Laxson (blaxson@shade.UWaterloo.ca) wrote: : Does anyone know what/where to find any regulations that exist for : astronauts passing objects around in space? Do they just avoid doing it : as much as possible? I don't think there are any Flight Rules about "passing objects around," either EVA or IVA. If you really want to check, you might try to get a copy of the Flight Rules. They are available to U.S. citizens via the Freedom of Information Act. Contact NASA/JSC's Public Affairs Office through the switchboard at (713) 483-0123. (However, your e-mail address indicates that you are Canadian. You might be out of luck. If you REALLY get stuck, let me know, and I'll have my secretary paper-mail you a copy.) There is no reason to "avoid doing it as much as possible." Passing objects around in space is part of the normal teamwork which happens on every manned space flight. Perhaps I'm not understanding your question. -- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 Aldrin: "Contact light. Okay, engine stop. ACA out of detent." Armstrong: "Got it." Aldrin: "Mode controls, both auto. Descent engine command override, off. Engine arm off...." CAPCOM: "We copy you down, Eagle." Armstrong: "Houston, Tranquility Base here. The Eagle has landed." ------------------------------ Date: Wed, 24 Feb 1993 22:58:48 GMT From: Henry Spencer Subject: Spaceflight for under $1,000? Newsgroups: sci.space In article djf@cck.coventry.ac.uk (Marvin Batty) writes: >If, therefore, a company got together for the sole purpose of building >and launching one rocket, presumably the costs would be considerably smaller. >But does anyone have an idea what would be the minimum cost of putting one >man in orbit? Presumably the main costs are launchpad, fuel, lifesupport >and rocket. If you're fairly optimistic, you might assume launch costs as low as $500/kg. That's still awfully expensive. Reductions far beyond that are possible in principle, but there is no proof that they can be achieved in practice. There are some fairly major technical challenges involved in achieving those potential cost reductions. It's not something you're likely to manage in your basement. Remember that good technical people cost you circa $1000/person/week even if you don't pay them terribly well. >I heard somewhere that the latest Space Shuttle has five computers >which combined have less memory than a good PC. Is this really true? Yes, but those computers and that memory will survive conditions which would turn your PC into a paperweight. When you can't get home without them, you're a bit fussier about computer quality than the MSDOS crowd usually is. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Tue, 23 Feb 1993 21:18:56 +0000 From: Paul Wilson Subject: Spy Sats (Was: Are Landsat Satellites receivable?) Newsgroups: sci.space In article <1993Feb23.113753.178@mnemosyne.cs.du.edu> dnadams@nyx.cs.du.edu writes: >In article <13628.409.uupcb@the-matrix.com> roland.dobbins@the-matrix.com > (Roland Dobbins) writes: >>KH-11 is neither the latest nor the greatest "real-time" platform up there. > >The ADVANCED KH-11 is... we currently have 2-3 of them up. > >OR, are you talking about Lacrosse or Aurora? I understood that the KH-12 was the major enhancement of the KH-11 in terms of visible-light imaging (it also carries IR sensors), and is used to produce high-resolution pictures. Lacrosse uses side-scan radar, and is a very different beast indeed. BTW, only a single KH-12 is in orbit at any one time (remember the fuss when both the Titan and the Shuttle were grounded at the same time, and the US didn't have launch capacity to replace the KH-12 which was running low on manoeuvering fuel?). ------------------------------< Who 'zat? >------------------------------ Paul Wilson, P-and-S Ltd, P O Box 54, Macclesfield, SK10 5EH, UK [Email: paul@pands.demon.co.uk] [Phone: +44 (0) 625 - 503150] ------------------------------------------------------------------------- ------------------------------ Date: 24 Feb 1993 16:55 CST From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov Subject: SSF Resupply (Was Re: Nobody cares about Fred?) Newsgroups: sci.space In article <1993Feb24.152613.25485@iti.org>, aws@iti.org (Allen W. Sherzer) writes... >In article <23FEB199322135640@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: > > >>>And if the Shuttle is grounded and the station is forced into >>>free-drift for lack of replacement thruster modules (which is the same >>>thing as saying that it ran out of fuel), then where are you? > >>What about Titan IV ? > >Well I would prefer either Atlas or maybe a Titan III. that would >save you about $100 million. Perferable yes, but is there a 14 '' in diameter faring for the above? Maybe for Titan III but not for Atlas. > >But then I forget: the only way to replace the thrusters is with >Shuttle. NASA designed it so that it can't be done with expendables. > No what you forget is that all you need is a faring with the proper diameter. Titan IV has a Shuttle class payload faring and can carry most payloads that Shuttle can, although as you point out, not much cheaper. Kinda shoots your HLV cost savings idea down for large payloads don't it. >Now if we bought the Russian docking technology and made a lot of >modifications we could. > Could what? You still have to get the weight up there. You would still have to completely redesign the system for on orbit refueling. Since you have this wonderful Shuttle capacity for returning large payloads why not use it? It is called cutting down on dead head miles in trucker parlance. But I forget you have said that there is no market for this capability. >>In addition, it is my understanding that the primary reason for the >>Fuel on SSF is not for attitude control but for reboost. Now certainly >>they could live without reboost for a few months or even a year or two. > >A few months yes but not a year. About 180 days after missing a firing >(and there is one every Shuttle flight) it will re-enter. > Care to put up any numbers on this? With an altitude of 270 nautical miles, and the fact that Mir, which has nearly the same frontal area needs reboost less than the interval that you state, suggests otherwise. >>Quit making mountains out of molehills. Just because you have not thought >>of the solution or you have not read it in Space News or seen it on >>Usnet does not mean that contingencies do not exist. > >apparently it also means they may not exist. > > Allen > I am truly glad that you put the "may" in there. This suggests that you may at least think there is a possiblility that everyone in NASA are not flaming idiots who only think about their paychecks. An interesting thing about paycheck philosophy here. NASA budget under this assumption is based upont the fact that the more they do successfully, the more money they get to do more. Does this not suggest that from pure self preservation alone, they would want to do a good job? Dennis, University of Alabama in Huntsville ------------------------------ Date: Thu, 25 Feb 1993 02:27:55 GMT From: Frank Crary Subject: SSF Resupply (Was Re: Nobody cares about Fred?) Newsgroups: sci.space In article <24FEB199316551524@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: >>But then I forget: the only way to replace the thrusters is with >>Shuttle. NASA designed it so that it can't be done with expendables. >No what you forget is that all you need is a faring with the proper diameter. >Titan IV has a Shuttle class payload faring and can carry most payloads that >Shuttle can, although as you point out, not much cheaper. Kinda shoots your >HLV cost savings idea down for large payloads don't it. I think the point was, NASA didn't have to design the thrusters in this way. They could have made the system servicable from a different launch vehicle. The only driving need for a large diameter system seems to be giving the Shuttle a job... >>Now if we bought the Russian docking technology and made a lot of >>modifications we could. >Could what? You still have to get the weight up there. However, you would no longer need a 14' wide payload, nor would you have to launch the supplies in high mass packages (i.e. you would have the flexability of several smaller launches.) >...You would still have >to completely redesign the system for on orbit refueling. Perhaps that should have been done from the start. >...Since you have >this wonderful Shuttle capacity for returning large payloads why not use it? Because you shouldn't count on that Shuttle capacity. The Shuttle isn't exactly famous for keeping schedules reliably, nor is it immune to long down times. Worse, the station's design lifetime is 30 years. I don't think anyone seriously thinks the Suhttles will still be flying in 2025. Their expected lifetime, at the current launch rates, is expected to last no later than 2010. Since the resupply of the station is dependent on the Shuttle, how will it be resupplied after 2010? If the station is expected to remain on orbit, there can't be more that a year or so delay before a new Shuttle replacement is flying. Given the delays in the Shuttle's first flight, I don't think that's very realistic. There isn't anything wrong with using the Shuttle's orbit-to-Earth payload capability, but there is a problem with being absolutely dependenton it. >>A few months yes but not a year. About 180 days after missing a firing >>(and there is one every Shuttle flight) it will re-enter. >Care to put up any numbers on this? With an altitude of 270 nautical miles, and >the fact that Mir, which has nearly the same frontal area needs reboost less >than the interval that you state, suggests otherwise. Last time I checked, 200 not 270 nm was the operational altitude of Freedom. Also, as I recall, Mir reboosts every month or so as a general rule. Freedom would require replacement of its station keeping motors after 180 days of normal operations. However, there are things that can be done, in extreme emergency, to increase this: Using all available fuel to boot to a high orbit, and putting the solar arrays into a minimum drag cross section pointing would extend the station's life to a year or two without resupply. However, that would have very serious consequences: A roughly fifty percent reduction in power (is that even enough to keep life support and housekeeping running?) and the station would be inaccessable to the Shuttle until it's orbit had decayed (I'm not a ACRV could make an emergency crew return from such a higher orbit, either.) Frank Crary CU Boulder ------------------------------ Date: Thu, 25 Feb 1993 02:35:55 GMT From: Frank Crary Subject: SSF Resupply (Was Re: Nobody cares about Fred?) Newsgroups: sci.space In article <1993Feb24.182730.25545@aio.jsc.nasa.gov> munoz@sweetpea.jsc.nasa.gov (tomas o munoz 283-4072) writes: >There are a couple of problems to this recommendation: >Titans can't deliver/retrieve humans if the scenario occurs during >permanent manned operations [although the ACRV is already there]. A Titan IV should be able to deliver an extra ACRV. I also don't see why you couldn't put a few people in that extra ACRV, and thereby both deliver and retrieve humans. >How do you perform the actual payload transfer from the expendable >to the SSF if the SSF is unmanned? - You really need IVA for this >operation. Which sort of unmanned: After MTC, you just need to get people to the station, and there are only a few launches (low risk) before MTC. >This is true at almost any place along SSF assembly. In the PMC >phase, you have the ability to fully feather the PV arrays and have >orbital lifetime ranging up to ~1.5 years. At the price of almost complete (complete? What exactly do you mean by "fully" feather?) loss of power. Frank Crary CU Boulder ------------------------------ Date: Wed, 24 Feb 1993 22:46:16 GMT From: Henry Spencer Subject: Water resupply for SSF (?) Newsgroups: sci.space In article <1mdeocINN5sa@dns1.NMSU.Edu> wbaird@dante.nmsu.edu (BAIRD) writes: >....Everyone is complaining about the cost of the space station's resupply >through the shuttle or HOPE or Hermes. WHy not just NOT use these vehiciles? >I have heard of a number of proposals to drag ice from the outer system and >refine it in orbit or get it from the asteriod belt. Using a set of robotic >systems, using either electric propulsion(EP) or light sails(LS), in conjunction >with a few robotic mining platforms shouldn't it be feasible to resupply the >space station using either the belt or the outer planets' moons? Someday. Not today. This is *far* beyond what can be done with current robotic systems. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 24 Feb 1993 23:29:57 GMT From: CLAUDIO OLIVEIRA EGALON Subject: X-15 astronauts (was Re: Getting people into Space Program!) Newsgroups: sci.space There were 199 flights of the X-15. Among those, 13 flights were flown above the atmosphere or beyond the limit where we today call space (which is 80 km). The guys who flew above this limit were 1. Bob White (USAF) (once) 2. Joe Walker (NASA) (three times) 3. Bob Rushworth (USAF) (once) 4. Joe Engle (USAF) (three times) 5. John McKay (NASA) (once) 6. Bill Dana (NASA) (twice) 7. Bill Knight (USAF) (once) and 8. Michael Adams (USAF) (once) Michael Adams was killed during the flight that he got to go over 80 km and the X- 15 that he was flying (the number 3) was desintegrated. The "Astronaut Wings" were awarded ONLY to the USAF pilots so the civilian guys did not qualify. But, according to Thomas Wolf (The Right Stuff), Joe Walker was indeed awarded the "ASStronaut Wing". The Proceedings of the X-15 First Flight 30th Anniversary Celebration and the book X-Planes by Jay Miller, have a table sumarizing all X-15 flights as well as their pilots dates, altitude etc... C.O.EGALON@LARC.NASA.GOV ------------------------------ End of Space Digest Volume 16 : Issue 231 ------------------------------