Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.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 ; Mon, 23 Jul 1990 01:26:47 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 23 Jul 1990 01:26:15 -0400 (EDT) Subject: SPACE Digest V12 #109 SPACE Digest Volume 12 : Issue 109 Today's Topics: Re: Free Space Station - spacious but needs work Re: Negative Matter [was Anti-Gravity Devices] Re: HST, Perkin-Elmer and NASA Re: Why drop the shuttle? Re: Earth moving (was Re: Is an asteroid capture possible/feasible? Re: Nasa's budget Re: "Captain Midnight" Re: buying Soyuzes Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 14 Jul 90 12:44:00 GMT From: mailrus!news-server.csri.toronto.edu!torsqnt!tmsoft!masnet!f906.n250.z1.fidonet.org!maury.markowitz@handies.ucar.edu (maury markowitz) Subject: Re: Free Space Station - spacious but needs work The idea of using the ET is neither new (as you mentioned) or all that possible at this point. As good as the ET is for space construction, like similar construction here on the ground, laybor is the BIG cost. Sure the thing is up there, and sure it was designed to be refitted, but in most cases it's STILL less expensive to build something down here and ship it up. NASA has done a LOT of research into the subject, and they just don't think it's feasable at this point. Then again, that's if you use NASA's definition of a space station. There was one proposal by Global Outposts to build a simple, unpresurized station called the "Outpost". The idea was that the system would have little more than power, but in a lot of cases, that's all you need. Since the astronauts would be protected from both sunlight and meteors, and air could be piped, space suits for use in the Outpost COULD be significantly simpler and lighter that the normal Shuttle suits. It's an interesting idea, it's cheap and certainly has SOME uses, but it's certainly not what NASA calls a space station! It's also not THAT hard to pressurize the tank, but now you run into problems of doing a lot of work on the interior, and that's expensive. If you consider that the only difference between this type of proposal and NASA's space station is size, the actual use seems limited, a complete re- fit in orbit would be amazingly expensize. Personally, I've put a lot of thought into ways of decreasing the time required to do "interior design", and finally came up with something I call "Space Lego". With these small (light) building blocks and a lot of cable (for tension) you can build some VERY strong interior bulkheads and walls. Set up time was the main consern, and I think these could be put together fairly fast. Unfortuantely, this still probibly isn't fast enough, and things in free fall usually take a LOT longer than you predict! Anyway, for those that are interested, I'm sure NASA would be very interested in any idea you may have that may be useful, here's what you have to work with... One large tank, 47m long, 8.4m diameter. The larger of the two tanks, the hydrogen tank, is fitted with a "manhole" at the aft end for the fitting of a bolt in airlock. If you can get this off, you can stuff everything you need in first, then put in the airlock later. Dry weight, 76000 lbs. Sounds like a lot, but it actually isn't. Remember that the Shuttle leaves the thing right on the edge of orbit, in fact, at 98% or orbital speed. As far as the Shuttle is conserned, taking the thing ALL the way requires only the equivalent of 1750lbs. Since the Shuttle rairly flies full, tanks could easily be taken into orbit on ANY launch in the near future. The tanks still have residual fuel in them, and the sun will cause the tanks to presurize, so the fuel has to be bled off. NASA was studying the ability to bleed off the gas though the engines after MECO, but I don't know the results of the study. Problems... well, for one, it's BIG. It's three times the size of SkyLab, and it would be hard to fill the whole thing. If what you want is a small lab, it's a pretty good deal (I've done some back of the envelope designs myself in my off hours) and leaves a LOT of room for experiments. In fact, the Oxygen tank itself is more than large enough for a fair sized station, but presents problems of it's own. For another, you should carry everything you need to get it running in ONE shot. Once the airlock is in, you'll have considerable less room, and the trouble of cycling the locks to get in new material. This could present a problem, or you could just live with it unpressurized for a few missions until it's done. Another problem is that the tidal forces will definitely point it "down". Either you live with it (and restrict your microgravity area), or you deploy some very long rods to allow their tides to stablize the tank in it's "flat" flying direction. The AstroMast would be great for this. Maury --- Maximus-CBCS v1.00 * Origin: The Frisch Tank, Newmarket, Ontario, CANADA (1:250/906) ------------------------------ Date: 23 Jul 90 02:16:06 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld@ucsd.edu (Christopher Neufeld) Subject: Re: Negative Matter [was Anti-Gravity Devices] In article <1990Jul22.214910.3332@watdragon.waterloo.edu> jdnicoll@watyew.uwaterloo.ca (Brian or James) writes: > How would one remotely observe 'negative matter' if such a beast >existed? I assume that photons would be 'negated' by hitting NM rather >than reflected. NM strikes me as very much a black cat in a coal room at >midnight situation. > No, that would run into problems with energy conservation. Normal matter in the form of isolated atoms interacts with photons through QED processes. The simplest such process is: photon+atom -> excited atom -> photon+atom. The photon is scattered in another direction. Anyway, the interaction of a photon with an atom is purely electromagnetic. If we posit "negative matter" whose response to a gravitational field is to move in the "wrong" direction, but is otherwise composed of charged particles in bound states, then it should behave qualitatively the same as normal matter in interactions with photons. BTW, somebody mentioned that antimatter does not go the "wrong" way in a gravitational field. This is a theoretical prediction which has not yet been tested. Check the latest (July 1990) issue of _Physics Today_. There is an article confirming the equivalence to about 10^-8 in inertial mass for antimatter and matter, but the article explicitly states that the test for gravitational mass has not yet been performed. > JDN > -- Christopher Neufeld....Just a graduate student | "The eagle may soar, but neufeld@helios.physics.utoronto.ca Ad astra! | the weasel never gets cneufeld@{pro-generic,pnet91}.cts.com | sucked up into a jet "Don't edit reality for the sake of simplicity" | engine." Simon & Simon ------------------------------ Date: 22 Jul 90 16:43:53 GMT From: drivax!braun@uunet.uu.net (Kral) Subject: Re: HST, Perkin-Elmer and NASA In article <1990Jul20.150300.7367@ux1.cso.uiuc.edu> mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes: >There is sufficient info already: A bad figure is ground and polished into >a mirror. The actuators they have for figure correction aren't strong >enough to correct it. They didn't test the whole scope before launching. > >That is enough data right there. No more is needed. >Isn't that enough? No. What I saw in the hearings was a mind set within NASA that said "Big, expensive complete systems tests are not necessary because it is possible to do enough componenet testing to prove the system." What they seemed to be overlooking, and I think this is what Al Gore was pursuing, was that they didn't have a way of determining how thorough there component testing was until they discovered that something failed. The NASA admins would say "I'm sure we'll look back and find a test that could have uncovred this problem without necessitating a complete systems test". But the problem is they can't seem to determine the need or the configuration of the test until there has already been a failure. The point being, that this kind of mind set will continue to cause massive headaches until it is corrected, and we wouldn't know to correct it without pursuing the interrogation, er, investigation with NASA officials. Chopping heads could have left the problem in tact. -- kral * 408/647-6112 * {uunet|amdahl}!drivax!braun * braun%drivax@uunet.uu.net The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov [Friends don't let friends use DOS] ------------------------------ Date: 20 Jul 90 13:35:50 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!peregrine!ccicpg!cci632!rit!moscom!jaw@ucsd.edu (Jim Watson) Subject: Re: Why drop the shuttle? In article <111@3cpu.UUCP> brycen@.UUCP (Bryce Nordgren) writes: >>Not very practical: The shuttle weights 90 tons, more than 4 Mirs, and > >Egads! I had no idea. I knew it was heavy, but didn't know quite how much. > Actually the empty shuttle only weighs about 56 tons. I happened to remember this little tid-bit since that's just less than an M-60 tank which is significantly smaller and slower. Jim ------------------------------ Date: 17 Jul 90 17:33:33 GMT From: usc!zaphod.mps.ohio-state.edu!math.lsa.umich.edu!rphroy!cfctech!teemc!fmeed1!cage@ucsd.edu (Russ Cage) Subject: Re: Earth moving (was Re: Is an asteroid capture possible/feasible? In article <1990Jul17.001207.13084@agate.berkeley.edu> gmohr@sandstorm.Berkeley.EDU (Gordon J. Mohr) writes: >In article <3111@rwthinf.UUCP> dieter@rwthinf.UUCP (Dieter Kreuer) writes: >> >>There has been a fairly long discussion about nuking earthbound asteroids >>in sci.astro recently. While I totally agree to try everything to move >>such a dinosaur-killer in any other direction than towards Earth, I would >>strongly refuse to bring such a thing intentionally close to our planet. Mr. Kreuer is unduly fearful. Doing a gravity-whip maneuver past the Earth could put such an object on an escape trajectory, where it would never be a threat to us again. This does mean flying close by, but when we can hit a 1-mile wide window a billion miles away at Saturn, we can do much better than that in our back yard. >Actually, I understand that Russian scientists have calculated that, given >enough warning, it would actually be easier to MOVE THE EARTH than divert >a distant, rapidly approaching asteroid. How? Altering the moon's mass with >nuclear charges. The moon's orbit would change, also affecting the Earth's >solar orbit. A slight change, over time, would mean a gigantic difference >in where the Earth is at some future time. It's hard to take this seriously. Think about it for a moment. If you have a tiny object (say, 10 km diameter), and you know its path accurately enough to know that changing the earth's speed by 1 mm/sec will avoid a collision X years in the future (X > 10, since 1 mm/sec over 10 years is only 315 km), then changing the velocity of the object by the same amount will also avoid the collision. The ratio in masses between a 10 km object and a 12,800 km object of the same density is 2,097,152,000 (2.1e9). The ratio of energy needed to make the same delta-V is also 2.1e9. Let's get real, shall we? -- Russ Cage Ford Powertrain Engineering Development Department Work: itivax.iti.org!cfctech!fmeed1!cage Home: russ@m-net.ann-arbor.mi.us I speak for the companies I own, not for the ones I don't. ------------------------------ Date: 22 Jul 90 17:02:29 GMT From: ox.com!itivax!vax3.iti.org!aws@CS.YALE.EDU (Allen W. Sherzer) Subject: Re: Nasa's budget Michael V. Kent writes: >In response to Allen Sherzer, who does not like the Spacelab program because >it flies "only 3 days a year." On the contrary: I think Spacelab is great. In fact, I think it is so great that we should utilize it as much as possible so we can do more science for less money. We cannot do this with the Shuttle. >Allen, may I ask politely, have you looked at a manifest lately? Over the >next 5 years, about one third to one half of the Shuttle flights will be >Spacelab flights, most of which will last 10 to 13 days. With a few planned >modifications, several of these will extend to 16 to 28 days. In fact, 3 of >the next 6 flights are Spacelab flights of about 10 days each. Actually, I had not looked at the maifest. Thanks for your correction. Now, let's look at the numbers. You say 30 to 50% of flights will be spacelab which means 3 to 5 flights a year. Let's assume an average of four flights for each of the next five years. Let's also assume each flight lasts two weeks. At $300M per flight that gives us over the next five years: Number of flights: 20 Number of days in orbit: 280 Cost (20 shuttle flights): $6 billion Now, let's assume we have a space station like LLNL's Earth Station and use expendables. We will charge half the development and launch costs of the station to Spacelab. We also assume two full heavy lift launches are needed every year for support (although I suspect one would be enough). Finally, one shuttle launch is budgeted to put Spacelab in orbit (although it might be cheaper to send it on an expendable). To even it out, we will also add in $875M for misc expenses. Station development & launch (Spacelab 50% share): $325M Shuttle launch: $300M 5 years expendable launches: $1.5B Misc. expenses: $875M ------ Total cost $3B Total days in orbit: 1825 So with expendables we get over 7 times the utilization of spacelab for half the costs over five years. Note that this includes a big chunk of station development costs. So thanks for your correction but it is not relevant to the issue. The more you utilize Spacelab with the Shuttle, the worse it becomes. It will cost you over $42 billion to get the amount of utilization I can get with $3 billion. We could buy a lot of spacelabs with the $39 billion we would save. >While using a Shuttle to play space station is not ideal, it is good enough for >the next five years. By then, Freedom will (hopefully) be coming online and >will be able to take much of the burden off of the Shuttle. Freedom will not be on line in 5 years. Not even NASA says that and current (not released) figures indicate that it won't be on line this century. I also point out that NASA has no plans to put Spacelab in orbit with Freedom. As to it being good enough for the next five years, I submit that it is not good enough. In three years we could have the vehicles and station on line. We could reduce launch costs to 20% of what the Shuttle costs now. The way it is right now, our critics (correctly) say that space is too expensive. If we don't abandon our old high cost methods and embrase new low cost ways, we just play into the hands of those who would shut it all down. We are just making it easier for them to kill more programs. What we are doing now is *NOT* good enough and must change. >Granted, Shuttle >and Freedom seem to be having some problems right now, but do you honestly >believe Heavy Lift Delta and your capsule won't either? I suspect it will. I also suspect McDonnell Douglas has taken that into account. Remember, they are betting half a billion of their own money (not ours) that they can do it. That gives me a great deal of confidence and tells us we have nothing to loose. >While it is good to hear some new ideas on what could be done, let's not lose >sight of what we are doing. Agreed. I'm trying to reduce the cost to orbit so we can do more in space. By advocating low cost alternatives I am not loosing sight of that goal. What is your goal? Allen | | In War: Resolution | | Allen W. Sherzer | In Defeat: Defiance | | aws@iti.org | In Victory: Magnanimity | | | In Peace: Good Will | ------------------------------ Date: 22 Jul 90 13:22:30 GMT From: portal!cup.portal.com!Daniel_R_Albaugh@apple.com Subject: Re: "Captain Midnight" If memory serves correctly, I believe Captain Midnight was from Ocala, Florida, although I don't remember his real name. He was caught and was sentenced to 6 months in jail and his gear was confiscated. Like you said, it was a long time ago and I could be way off on the details. ------------------------------ Date: 16 Jul 90 18:01:00 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!torsqnt!tmsoft!masnet!f906.n250.z1.fidonet.org!maury.markowitz@ucsd.edu (maury markowitz) Subject: Re: buying Soyuzes p> a smaller Apollo would be about the size of the Soyuz. No it wouldn't. Even the full-sized model of Apollo had considerably less internal room than the normal Soyuz. Take a look at pictures of them, the Soyuz has two "rooms", either of which has the same or more workspace than the Apollo. This makes sence though, the Apollo carries a LOT of dead weight around with it, the re-start moon return engin and fuel, enough H2/O2 to keep the fuel cells going (Soyuz uses solar cells) plus the normal manuvering rockets that Soyuz carries. Apollo was BIG, but most of it was support, not workspace. Soyuz on the other hand, was built to be used in LEO right from the start (a special edition would be used for the moon shot). It has little support (nor does it need it) and carries little fuel, just enough for manuvering and re-entry burn. The Soyuz is considerably better for LEO work than Apollo. A new design for an American LEO "shuttle" capsule would probibly be built from scratch, and be better than either, after all, both Apollo and Soyuz are 25 years old (at least) and we've learned a LOT since then. By the way, does anyone know why they change the docking adapter design? The original one used on Apollo/Soyuz was built to be retrofitted onto existing Soyuz capsules (but I don't think they use it) and all future American designs. The original had a 3-bladed adapter, but looking though "Space Stations and Platforms" (a little dated), the neew design has 4 blades and is considerably smaller. What happened? Are the Soviets changing the design too? Maury --- Maximus-CBCS v1.00 * Origin: The Frisch Tank, Newmarket, Ontario, CANADA (1:250/906) ------------------------------ End of SPACE Digest V12 #109 *******************