Date: Thu, 4 Mar 93 06:38:05 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #270 To: Space Digest Readers Precedence: bulk Space Digest Thu, 4 Mar 93 Volume 16 : Issue 270 Today's Topics: Apollo Missions (Recollections) A response from Anonymous Bullets in Space Galileo Earth-Moon Animation Getting people into S (2 msgs) Gravity simulations KIDS Looking for Visible/IR Spectrum of Moonlight Mars Observer Orbital Elements NASP (was Re: Canadian SS Space Scientist (3 msgs) Space Station LaFave (SSL :-) Spy Sats (Was: Are La Why Apollo didn't continue? 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: 3 Mar 93 17:35:44 GMT From: Ed Faught Subject: Apollo Missions (Recollections) Newsgroups: sci.space >> >> Anyone else with good memories? >> We were in the U.S. Army's Primary Helicopter Training School at Ft. Wolters, Texas. Since this was also warrant officer's training we had not been allowed to watch television for a couple of months. It was a really BIG deal to see anything on TV, and we were allowed to watch the best show ever televised. Anyone involved in similar military training can well imagine the tremendous feelings of pride and the morale boost. In a similar vein, I was standing right next to a Soviet physicist at Fermilab discussing our differences in equipment design philosophy while watching Apollo/Soyuz going over shortly after separation. -- Ed Faught WA9WDM faught@berserk.ssc.gov Superconducting Super Collider Laboratory ------------------------------ Date: 2 Mar 93 13:29:10 GMT From: Alex Martelli Subject: A response from Anonymous Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space,sci.astro bdb@becker.GTS.ORG (Bruce Becker) writes: ... : Anonymous postings are a really good example : of things that are to be judged by content, : since the typical responses of "oh that's a : posting by X, he's an idiot", or "Aha, Y is : always making good points" are not able to : be made. This would only hold for an anonymous server which hid any hint of authorial individuality - not the way those I know work. As of now, I see the author identified as, for example, wi.6686, and after a few posts I'm able to make the same X/Y judgments you decry. I find some validity to all other points you make, particularly: : Persons whose private concerns : may be at odds with public perceptions : have legitimate reasons for maintaining : privacy, even though no law is broken. John Stuart Mill makes a similar point about the chilling effect of public disapproval, though he is not talking about anonymity, in "On Liberty". Alex -- Email: martelli@cadlab.sublink.org Phone: ++39 (51) 6130360 CAD.LAB s.p.a., v. Ronzani 7/29, Casalecchio, Italia Fax: ++39 (51) 6130294 ------------------------------ Date: 3 Mar 93 17:27:35 GMT From: "Glenn R. Stone" Subject: Bullets in Space Newsgroups: sci.space In <731117525.0@aldhfn.akron.oh.us> Ryan_Potts@aldhfn.akron.oh.us (Ryan Potts) writes: >But isn't o2 needed to aid in the combustion of the gunpowder in the round? :) Nope. Remember that until the moment of ignition, the case is sealed by the bullet (shotgun shells excepted); any O2 needed for the reaction had better be present in the cartridge with the powder, because it's sure not going to get in there once things start burning.... Glenn R. Stone (glenns@eas.gatech.edu) Do not meddle in the affairs of wizards; it makes them soggy and hard to light. ------------------------------ Date: 3 Mar 1993 17:05 UT From: Ron Baalke Subject: Galileo Earth-Moon Animation Newsgroups: sci.space,sci.astro,alt.sci.planetary The hqx file for the Galileo Earth-Moon animation was inadvertently ftp'd to Ames in binary mode, and this has caused some problems with some of the uncompressors such as Stuffit and Compact Pro. The file has been ftp'd in ascii to rectify the problem. I apologize for any inconvenience this may have caused. The animation can be run using either NIH Image or Quicktime 1.5. A fli version of the animation is expected to be ready by this Friday (March 5). Thanks again to Paul Geissler and Larry Kendall for creating the animation and making it available. ftp: ames.arc.nasa.gov (128.102.18.3) user: anonymous cd: pub/SPACE/ANIMATION files: Earth_Moon_Movie.Hqx Earth_Moon_Movie.txt ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible. |_____|/ |_|/ |_____|/ | Walt Disney ------------------------------ Date: Wed, 3 Mar 1993 15:47:41 GMT From: Mary Shafer Subject: Getting people into S Newsgroups: sci.space In article <14293.409.uupcb@the-matrix.com> roland.dobbins@the-matrix.com (Roland Dobbins) writes: JL>Could that be the vehicle commonly called the flying Bumble Bee, wh JL>clai to fame in the ordinary world is the vehicle that opened the s JL>and each episode of the six million dollar man. If I recall correct JL>was aeronautically considered to be unflyable, but flew anyway and JL>for a while touted as a great instrument for flight to and from low JL>orbit. It finally crashed on descent when it touched down and did a JL>up unfortunately a Helo was in the way and the two collided as the JL>goes. I think That its prototypes and other s are still on display JL>the yearly aeronautical show at Edwards airforce base. First, no one ever called the lifting bodies "Flying Bumblebees". The popular press (i.e. Popular Mechanics and Popular Science) called them "Flying Bathtubs". We called them lifting bodies. Second, there are _two_ lifting bodies shown in the sequence opening the Six Million Dollar Man. The first vehicle, which comes off the hooks, is the HL-10. The second vehicle, which crashes, is the M2-F2. Third, the M2-F2 hit the ground, as may be plainly seen in the footage. The M2-F2 had a coupled roll-spiral PIO (a so-called "lateral phugoid") that had been seen in in-flight simulation in the NT-33A and in up-and-away flight. Bruce Peterson was somewhat out of position on final and became distracted by the location of the firetrucks and the helicopter and he excited the roll-spiral PIO too close to the ground to recover. Fourth, the HL-10 is on a plinth outside Dryden (it never crashed, but the Los Angeles Museum of Science and Industry dropped it from their ceiling onto its back when a cable broke and it had to be rebuilt). The M2-F2 was rebuilt as the M2-F3 and is now hanging in the Milestones of Flight Gallery at the National Air and Space Museum. The M2-F1 is in the heat facility hangar here at Dryden. The X-24A was rebuilt (no crash, though) as the X-24B and it's now on display at the Air Force Museum at Wright-Patterson. Fifth, these were not prototypes, these were experimental aircraft. As I recall, that particular lifting body was called the HL-10, and it was most certainly _not_ designed *not* to fly . . . . Damned straight. -- Mary Shafer DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA shafer@rigel.dfrf.nasa.gov Of course I don't speak for NASA "A MiG at your six is better than no MiG at all." Unknown US fighter pilot ------------------------------ Date: 3 Mar 93 18:17:51 GMT From: "Richard A. Schumacher" Subject: Getting people into S Newsgroups: sci.space "PIO" = Pilot Induced Oscillation. ------------------------------ Date: 3 Mar 93 16:24:33 GMT From: Bill Broadley Subject: Gravity simulations Newsgroups: sci.space I'd like to get ahold of some source code that would allow me to do a 2d or 3d gravity simulation of N object in O(N) time. I have several references to such articles from the sci.space FAQ but would prefer to start with existing source code (preferably C). I'd like to write an X11 gravity simulation that would be as much fun to play with as Xspringies, as well as do some larger simulations of many bodies. Anyone out there have some source around? If not I'll look up the references (I found them in the FAQ), and implement one of those (anyone want to help?) -- Bill 1st> Broadley@neurocog.lrdc.pitt.edu Broadley@schneider3.lrdc.pitt.edu <2nd 3rd> Broadley+@pitt.edu Linux is great. Bike to live, live to bike. PGP-ok ------------------------------ Date: 3 Mar 1993 11:43:09 -0500 From: Bob McGwier Subject: KIDS Newsgroups: sci.space I really had it brought home to me yesterday how far in the past the moon program is to today's kids. I was watching Jeopardy which comes on here after the news (I was in my couch potato mode). The final Jeopardy question was `Eugene Cernan was the last person to walk here'. One kid got it right and admitted that he guessed since he could not figure out anyplace else that people had gone to and not returned. I really felt the loss of these types of goals for our society most keenly seeing the ignorance displayed about one of our greatest technological achievements. Bob -- ------------------------------------------------------------------------------ Robert W. McGwier | n4hy@ccr-p.ida.org Center for Communications Research | Interests: amateur radio, astronomy,golf Princeton, N.J. 08520 | Asst Scoutmaster Troop 5700, Hightstown ------------------------------ Date: Wed, 3 Mar 93 14:30:29 GMT From: Ata Etemadi Subject: Looking for Visible/IR Spectrum of Moonlight Newsgroups: sci.space G'Day I am looking for a digital (or as a last resort, hardcopy) spectrum of moonlight covering the visible and IR as observed by a spacecraft (ie no atmospheric effects). If the data set covers all the phases of the moon it would be ideal. This data is for use by our atmospheric modellers and will be used for research leading hopefully to publication(s). Any "rules-of-the-road" associated with the use of this data will be gladly adhered to. Uoyr help, pointers to sites, suggestions, comments etc.. would be greatly appreciated. many thanks in advance Ata <(|)> -- | Mail Dr Ata Etemadi, Blackett Laboratory, | | Space and Atmospheric Physics Group, | | Imperial College of Science, Technology, and Medicine, | | Prince Consort Road, London SW7 2BZ, ENGLAND | | Internet/Arpanet/Earn/Bitnet atae@spva.ph.ic.ac.uk or ata@c.mssl.ucl.ac.uk | | Span SPVA::atae or MSSLC:atae | | UUCP/Usenet atae%spva.ph.ic@nsfnet-relay.ac.uk | ------------------------------ Date: Tue, 2 Mar 1993 22:02:01 GMT From: "Carlos G. Niederstrasser" Subject: Mars Observer Orbital Elements Newsgroups: sci.space In article <2MAR199300411325@kelvin.jpl.nasa.gov> baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke) writes: > > MARS OBSERVER ORBITAL ELEMENTS > March 1, 1993 > > > INTERPLANETARY CRUISE > > Semi-major axis 197163351.177 km > Eccentricity 0.23885397 deg > Inclination 1.294 deg > Argument of periapsis -173.656 deg > Ascending node -177.619 deg > Mean anomaly of epoch 110.042 deg > > Epoch of elements: March 18, 1993 18:53:38.38 Ephemeris Time > Coordinate system: Sun-centered, Earth Mean Orbit and Equinox > of Epoch J2000 > > _________________________________________________________________ > > > CAPTURE ORBIT > > Semi-major axis 42923.941 km > Eccentricity 0.907977 deg > Inclination 89.000 deg > Argument of periapsis 112.990 deg > Ascending node -106.453 deg > Mean anomaly of epoch -180.000 deg > > Epoch of elements: August 26, 1993 10:10:52.78 Ephemeris Time > Coordinate system: Mars-centered, Mars Mean Equator and IAU > Vector of Epoch > > _________________________________________________________________ > > > MAPPING ORBIT > > Semi-major axis 3766.159 km > Eccentricity 0.004049 deg > Inclination 92.869 deg > Argument of periapsis -90.0 deg > Ascending node 261.590 deg > Mean anomaly of epoch 0.000 deg > > Epoch of elements: December 6, 1993 00:00:00.00 Ephemeris Time > Coordinate system: Mars-centered, Mars Mean Equator and IAU > Vector of Epoch What are the inclinations given above with respect to? --- --------------------------------------------------------------------- | Carlos G. Niederstrasser | It is difficult to say what | | Princeton Planetary Society | is impossible; for the dream of | | | yesterday, is the hope of today | | | and the reality of tomorrow | | carlosn@phoenix.princeton.edu |---------------------------------| | space@phoenix.princeton.edu | Ad Astra per Ardua Nostra | --------------------------------------------------------------------- ------------------------------ Date: Wed, 3 Mar 1993 15:55:03 GMT From: Mary Shafer Subject: NASP (was Re: Canadian SS Newsgroups: sci.space On 2 Mar 93 08:44:00 GMT, roland.dobbins@the-matrix.com (Roland Dobbins) said: CO>> Aerospace Daily also reports that NASA research on advanced CO>> subsonic and supersonic transport aircraft would get a big CO>> increase under Clinton's budget plan, with $550 million more CO>> programmed in fiscal years 1994-97, and another CO>> $267 million scheduled for FY '98. CO> CO>What about NASP??? R> Errr . . . that _is_ NASP. No, that's HSCT--High Speed Civil Transport. Notice that Aerospace Daily refers to _transport_ aircraft. NASP, which is a single-stage-to-orbit airbreathing horizonal-takeoff vehicle, is not a transport aircraft. It's probably dead. Physics has apparently finally reared its ugly head and driven a stake through the heart of the program. About time.... -- Mary Shafer DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA shafer@rigel.dfrf.nasa.gov Of course I don't speak for NASA "A MiG at your six is better than no MiG at all." Unknown US fighter pilot ------------------------------ Date: Wed, 3 Mar 1993 14:15:54 GMT From: "Frederick A. Ringwald" Subject: Space Scientist Newsgroups: sci.space,sci.research.careers In article davidlai@unixg.ubc.ca (David Lai) writes: > I'm interested in becoming a space scientist, like those who work for > NASA. I want to know what qualifications I need. Do those scientists who > work for NASA are all Ph.D.s? Is there any recommendations for what > degrees to get? Thanks! An absolute commitment, a tremendous amount of hard work of high quality, a great deal of talent, and a generous portion of luck are what are required these days, in addition to a Ph.D. A Ph.D. is no guarantee of getting a job as a space scientist, since the space field is in a very depressed state. I should know, since I got my Ph.D. recently. My thesis is a veritable tree-killer at 287 pages; not a record, but pleasing in that every time I look at it again, new science pops out. TOMORROW I am emigrating to England for a research fellowship in astrophysics. This was after a 9-month job search of excruciating proportions, involving sending 45 applications and making 15 short lists, often at prestigious places such as Harvard, Oxford, STScI, and Chicago, so the problem was probably not me, since every last one of these jobs had over 100 people applying for them. Two offers were made, and I felt very lucky for them! A Ph.D. is NOT of a guarantee of employment in most physical sciences these days, even obviously and immediately practical ones such as solid state physics. Things are bad all over. You might have heard that there is a "shortage" of scientists, but you can stop believing these rumors right now: many of them can be traced to a badly-mistaken NSF report, written before the end of the Cold War and the current economic slowdown, which didn't do a very careful analysis of the job market, anyway. Then again, if you really, REALLY want to become a space scientist, go ahead and get your Ph.D. After all, Jesse Greenstein managed to get a job in astronomy during the depression of the '30s. Just be sure, very sure, to dedicate yourself to becoming really, REALLY good at whatever it is you do. There might be jobs, for only for exceptionally talented people. There is certainly no market for mediocre people, and there will not be, any time in the foreseeable future. Some fields are better than others, although it's not easy to say much about this that's sensible. Specializing early has its advantages. It's certainly the way to get ahead in academia. (That and PUBLISHING.) Specializing allows you to learn more about your particular topic, and become better at it - but it's too bad if interest in your topic cools off, which can happen rapidly and unpredictably. Having a broad background has its advantages, but there is little demand for a jack-of-all-trades-and-a-master-of-none. Then again, it is a good idea to acquire genuinely useful and marketable skills, such as programming, numerical analysis, and instrumentation skills. Just don't let them be distractions from whatever your 'thing' is. The current job market is such that getting a Ph.D. degree should be viewed as an end in itself, as it traditionally has been in the humanities. You should want that Ph.D. primarily because it gives you the chance to immerse yourself in a whole bunch of really neat knowledge for several years. Disdain for high wages is helpful, too, and if you don't come in on Saturday, don't bother coming in on Sunday. If the only reason you want a Ph.D. is as a means to an end, such as a secure, permanent job exclusively doing research in space science at over $40k/year right out of grad school (probably more in industry, but they're hurting, too), you might be disappointed. And be warned. This evening I had dinner with an exceptionally talented and imaginative theorist, who's doing his Ph.D. thesis on using wavelet analysis to analyze the large scale structure of the Universe. He's having serious problems getting a job, having sent out over 20 applications without a nibble. So, he'll have to stay in grad school an extra year, so he can keep looking. He's 32 already, and has two young daughters, so his wife is not too pleased about this and its financial implications. (She's just submitted her Ph.D. thesis in Spanish. Solving the two-body problem is not easy, but neither of them have gotten anything!) Good thing he has his own research grant (under the NASA Graduate Student Research Program, thanks very much, folks), otherwise I don't know what he'd do. I don't know what he's going to do next year, if he doesn't find a job. I suggested he start looking at industry jobs where he could use what he knows about wavelet analysis, since it's all the rage in machine vision and pattern recognition. He could get a cosmology paper or two out on the side, which would make his company look good, but of course it wouldn't be what they'd be paying him for. What's most discouraging is not that he's one of the most intelligent people I know, and a nice guy, too, all too rare in this field. It's that he's doing the first application of a hot technique to a hot topic, and getting interesting results. In other words, that generous portion of LUCK is more important than one might care to admit. Of course, if this little rant of mine is enough to dampen your interest in becoming a space scientist, then forget it. You have to be rabid to do this. I think it's downright irresponsible that some senior scientists in comfortable positions are still actively encouraging young people to go into science. More than enough will do so of their own accord. It just isn't right to make promises and filch away someone's youth and give nothing in return. Then again, if you knowingly and willingly don't mind losing your youth for the very real possibility of nothing in return, then fine: you should be given the best education and the best opportunities available, and who knows, maybe something will come of it. Maybe. But you don't really get nothing. During those long, lean years of grad school, at least, you will be doing space science, and that makes you a space scientist. And of course it is absolutely essential to keep dreaming those dreams! (My first task at my new job will be to write proposals for telescope time for next semester, the deadlines for which are coming up at the end of the month. I should soon hear whether or not my satellite proposals for this year have been accepted; the forms for HST time are intense! People complain that proposal writing is time-consuming - and it is - but I enjoy dreaming on paper, especially with the bonus that sometimes they come true...) Fred Ringwald as of tomorrow: Department of Physics Keele University Keele, Staffordshire, ST5 5BG England Internet: FAR%STARLINK.PHYSICS.KEELE.AC.UK@nss.cs.ucl.ac.uk It'll certainly be interesting being an American astronomer in England. I hope I won't have too much trouble with the language. Speaking of dreams, I simply must go into London for the BIS lectures. I'll post what I find, as I've not yet seen anything in sci.space from the world's oldest existing space group. ------------------------------ Date: 3 Mar 93 16:09:25 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Space Scientist Newsgroups: sci.space David Lai (davidlai@unixg.ubc.ca) wrote: : I'm interested in becoming a space scientist, like those who work for : NASA. I want to know what qualifications I need. Do those scientists who : work for NASA are all Ph.D.s? Is there any recommendations for what degrees : to get? Thanks! We have many different kinds of people whom you might call "space scientists." The minimum qualification is a BS in any SCIENCE. ANY science. A Ph.D. is very helpful in impressing prospective employers and learning hard part of any scientific endeavor: getting funding. But it is by no means mandatory for being a "space scientist." And I've found that it can intimidate some managers to consider hiring people more educated than themselves. (Sad, isn't it?) NASA hires mostly US Citizens. Your e-mail address, David, indicates that you live in Canada. This may be a small impediment to your getting hired. You'll also have to worry about Resident Alien status. Getting hired by NASA itself isn't always easy. You might stand a better chance hiring on with a support contractor, like Lockheed, which supports space science applications at one of the NASA Field Centers. (Lockheed/Houston's switchboard number is (713) 333-5411.) After you have some experience working with NASA, it's easier to get a job working FOR NASA. Currently, there's a hiring freeze on for new Civil Servants at JSC. But those come and go. Good luck. -- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derilicts. Persistence and determination alone are omnipotent. The slogan 'Press On' has solved and always will solve the problems of the human race." -- Calvin Coolidge ------------------------------ Date: 3 Mar 93 18:37:53 GMT From: Tim Thompson Subject: Space Scientist Newsgroups: sci.space In response to David Lai's Space Science request, allow me to add my $.02 worth. My experience is that almost all of the scientists who persue "independent" research, or run projects, or supervise research, etc., have a Ph.D. Most of those are in the physical sciences, since that's most of what NASA does, but there are exceptions. There are also a few "old timers" without Ph.D.'s who run programs or projects, but I'm sure that would not happen now. If you want a lead role, and the oportunity to seek out your own grants and research, you must have a Ph.D. I do not have a Ph.D., I have an M.S. in physics. Although this keeps me out of the things I have described, it also keeps me out of the attendant problems. Grants don't just happen, you have to aggressively go after them, and that's work. I do scientific data analysis, computer programming, and computer system/network managing. The Ph.D.'s can't get along without me, and I can't get along without them. I live off their grants. My opinion is that everyone should go as far as they can, and find the place that suits there desires and talents. You might find yourself doing something much different way down the road (I started out as a student of history and languages). --- ALL OPINIONS EXPRESSED ARE MINE AND NOT JPL's, NOT NASA's. ------------------------------------------------------------ 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: Wed, 3 Mar 1993 15:58:13 GMT From: "Kieran A. Carroll" Subject: Space Station LaFave (SSL :-) Newsgroups: sci.space In article <1993Mar2.203400.13715@aio.jsc.nasa.gov> Dr. Norman J. LaFave writes: >Well, I can discuss a design that some colleagues and I worked on >and presented during the last redesign. We believe it to be a superior >design, but we have doubts about whether it will be accepted for the >upcoming redesign. However, we are hoping that aspects of the >design will be considered. > >Features: > >* Alternative modular structures (NO TRUSS): > ...both of these designs are free of the troublesome flexibility inherent > in the truss ... > This is a curious misapprehension---the truss is there to separate the solar arrays, to avoid problems like shadowing of payloads that want to see space, and plume impingement. Since the solar arrays are large, the separation distance also needs to be large. The truss itself is designed to *minimize* flexible effects; the benefit of using a truss rather than (say) a bunch of modules strung together (a la Mir) is that a truss can have a much larger bending stiffness for a given amount of structural mass. For example, most of the hundred lowest-frequency structural vibration modes of the current baseline SSF design are solar-array modes, that involve little bending or twisting of the truss. Of course, your next suggested design feature does away with the solar arrays, eliminating one of the main reasons for wanting the space station to be physically large... > >* Primary power source---NOT solar arrays! > > RTG pallet---known technology...not subject to shadowing problems... > eliminates primary plume impingement problems....eliminates largest > flexibility problems, both control and structural....proven > safety. > RTGs are a reletively mass-inefficient way to generate power, I seem to remember. They also have limited lifetimes, so they'd probably have to be replaced every few years. Of course, they'd eliminate the need for batteries, which also need frequent replacing, and which also are very massive, so on the basis of total up-mass they might be a net win. Their main problem is the issue of safety, both real and perceived. Remembering Skylab, *many* people would undoubtedly be nervous about having a large amount (probably several tonnes) of plutonium flying overhead every day. Come to think of it, *I* would probably be nervous about this, and I'm a fairly pro-nuclear person. > Secondary source: Thermal gradient power generation---This is an idea > we are toying with. The idea is simple. > Use the huge temperature gradients > that can be generated between sunlit and shadowed plates to generate > power. This is much like the concept which was studied to generate power > using the thermal gradient between the ocean's surface and the ocean > depths. > What's the difference between this concept and the Solar Dynamic power generation system that was eliminated during the last design scrub? The latter concept simply used mirrors to heat up a working fluid, which was passed through (I think) a Stirling (Sterling?) engine to produce mechanical power, which was then put through an alternator to produce electrical power; the working fluid was then cooled using radiators looking at deep space. Of course, you could do the same thing using thermocouples, but the power conversion efficiency would be much lower, I think. BTW, this post isn't meant to be negative, but merely critical (in the constructive sense---when a new design concept is proposed, try to define its constraints, so that you can get a handle on whether its possible for them all to be satisfied at once). It sure is fun to re-visit the conceptual design stage for space station; that's the stage when the sky is the limit, before the the inevitable messy trade-offs force a beautifully simple concept to be bent out of shape. Reminds me of the good old days of '82 thru '86... -- Kieran A. Carroll @ U of Toronto Aerospace Institute uunet!attcan!utzoo!kcarroll kcarroll@zoo.toronto.edu ------------------------------ From: Dean Adams Subject: Spy Sats (Was: Are La Newsgroups: sci.space Sender: netnews admin account Organization: University of Denver, Dept. of Math & Comp. Sci. References: <14294.409.uupcb@the-matrix.com> Date: Wed, 3 Mar 93 14:02:47 GMT Lines: 22 Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU roland.dobbins@the-matrix.com (Roland Dobbins) keeps writing: >Date: 2 Mar 93 08:44:00 GMT >DA>involved. KH-11 orbits are not all that much higher than the shutt >DA>would make an intercept pretty tight, and besides the optics are ob >KH-11 is neither the latest nor the greatest "real-time" platform up there. roland.dobbins@the-matrix.com (Roland Dobbins) keeps writing: >Date: 2 Mar 93 08:44:00 GMT >>>KH-11 is neither the latest nor the greatest "real-time" platform >DA>The ADVANCED KH-11 is... we currently have 2-3 of them up. >DA>OR, are you talking about Lacrosse or Aurora? >Yes, among others . . . >Although those two are primarily ELINT/SIGINT. NO, they aren't... and WHY do you keep reposting these same messages over again every day? How many replies do you want? This is about the forth or fifth time I have seen it. What is the problem?? ------------------------------ Date: 1 Mar 93 22:43:16 GMT From: Jim Cook Subject: Why Apollo didn't continue? Newsgroups: sci.space In article 3qK@zoo.toronto.edu, henry@zoo.toronto.edu (Henry Spencer) writes: >In article car57812@uxa.cso.uiuc.edu (Charles Adam Rummel) writes: >>They used the left-over Saturn parts to make Skylab, but was that because >>they had run out of LEM/CSM and rovers or had too many Saturns, or...??? > >All the Apollo and Saturn V hardware for Apollos 18-20 was on hand; the >cancellations were for financial reasons, not lack of hardware. Going >past Apollo 20 would have required re-starting the Saturn V production >line. Somewhere around Apollo 22, I think, the spacecraft production lines >would likewise have required restarting. > I have also seen quotes in two places (I'll find the references if you want) that said they were also beginning to worry about "losing one." This may be "sour grapes" or something similar, but the opinions were not qualified as such. Jim --- --------------------------------------------------------------------------- C. James Cook Epoch Systems, Inc. 508-836-4711x385 8 Technology Drive JCook@Epoch.com Westboro, MA 01581 --------------------------------------------------------------------------- ------------------------------ End of Space Digest Volume 16 : Issue 270 ------------------------------