Date: Mon, 8 Feb 93 07:38:59 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #135 To: Space Digest Readers Precedence: bulk Space Digest Mon, 8 Feb 93 Volume 16 : Issue 135 Today's Topics: *** BUSSARD RAMSCOOP *** ** BUSSARD RAMSCOOP ** Are Landsat Satellites receivable? Cooling re-entry vehicles. Help on catching this leading-edge anonymity (2 msgs) Making Orbit 93 - The Delta Clipper Program man-rating Micromechanics Research at NASA Obsvn (was Re: Russian solar sail flight possibly set for Feb. 4th) Organic heat shielding. Retaining Goldin The day before Challenger exploded. (2 msgs) Units and Star Trek Using Russian Hardware World Space Foundation (was Re: Pro-space groups? - The answer.) 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: Thu, 4 Feb 1993 19:03:58 GMT From: Henry Spencer Subject: *** BUSSARD RAMSCOOP *** Newsgroups: sci.space In article <1993Jan20.173008.4338@coe.montana.edu> uphrrmk@terra.oscs.montana.edu (Jack Coyote) writes: >>... The simplest way around this is the Bussard equivalent >>of the scramjet: don't slow the gas down much, just heat it as it goes >>past... > > As I recall, this still will not solve the ~.1c speed limit. You still get >big-time energy losses from bremsstrahlung (free-free) interactions and from >cyclotron radiation. Doesn't matter. So long as your exhaust leaves faster than it arrived, you're ahead. That is extremely challenging in the simplistic method where the incoming kinetic energy is converted to heat, because then even small losses mean you don't get it all back. But the scramjet method doesn't *have* that problem: in the ideal case (no intake drag etc.), *any* net increase in kinetic energy is gravy, even if most of the energy is lost, because there is no requirement to get a lot of energy back before you start to make a profit. A practical system is going to need enough thrust to cover intake drag and the like, but even so, losses are not nearly so devastating when you don't have to slow the incoming stream almost to a halt and then re-accelerate it. The "speed limit" is an artifact of the simplistic approach. This is pretty much the same reason why the hypersonics people are interested in conventional scramjets, by the way. They, too, find the penalties of having to re-accelerate the gas stream overly high. -- 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, 4 Feb 1993 18:47:46 GMT From: Henry Spencer Subject: ** BUSSARD RAMSCOOP ** Newsgroups: sci.space In article lord@tradent.wimsey.bc.ca (Jason Cooper) writes: >Hmm, can anybody here think of a way to retract a HUGE sail that's giong >to be external of all tanks, etc, down close to the hull? Won't be easy. Deployment is a big headache even in mundane solar-sail designs, and the really high-performance types generally don't fold up well. -- 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: 4 Feb 1993 13:16:42 -0600 From: John Schmidt Subject: Are Landsat Satellites receivable? Newsgroups: sci.space In araichel@cser.encore.com (Alan Raichel) writes: > I have seen some pretty high resolution pictures taken by >the Landsat satellites. I think that these have a resolution of >something like 100 feet or so. I know that the NOAA HRPT satellites >have a resolution of about 2 Km. I think that it would be interesting >to see if I could get more. Hi there. LANDSAT-4 and LANDSAT-5 both have a "Thematic Mapper" sensor capable of 28.5 meter pixel size, about two orders of magnitude better than the NOAA platform. That comes to about 94 feet per pixel in terms of dimension. > I know that hobiest can recieve APT and HRPT data from the >NOAA satellites. What I was wonder if it is possable for people to >recieve the data from the Landsat satellites? Since I know nothing >about the operations of the Landsat satellites, I was hoping that >maybe someone on the net could tell me something about them. LANDSATs transmit back via very-very high speed links, measured in multiple megabits per second. Usually those signals are beamed back to specific receiving stations, or (when capacity permits) up to the TDRS (Tracking and Data Relay Satellite) platforms. Those are, of course, very special wideband links that, additionally, are encrypted. Why?? Well, since 01-October-1986, the data transmitted back from the LANDSAT series birds is owned fully by the EOSAT (Earth Observation Satellite) Corporation. Not only is this data transmitted back to sites they own/operate in the US, but a couple of dozen sites abroad. These foreign- based sites basically fall under somewhat different ownerships, and they sign a cooperative agreement with EOSAT to not only be able to download the data but to make it available to worldwide LANDSAT users. These foreign (and domestic receiving) stations are quite expensive sites, the least of which involves a 21 meter full-sky-tracking receiving dish for an antenna. And, since foreign sites pay a fee to operate as a LANDSAT receiving station, EOSAT scrambles the signal in the event that some renegade station tries to download data without being licensed to do so. That's my understanding based on a conversation with a mid-management individual at EOSAT. And, if I am correct, the satellites themselves were (until maybe recently) owned by the Federal Government, and the data they sent down to Earth was the part owned by EOSAT. I'm not altogether sure if that changed recently, if EOSAT took over ownership of the whole thing. >1. Do the Landsat satellites continously transmit pictures of what is >below them, or does it only take pictures of schedualed areas? The >NOAA satellites continously transmit what is below them, so a station >almost anywhere can recieve data about his own area. Is the same >true for the Landsat satellites? IF the Landsat satellite only takes >pictures of schedualed areas, then it probabally only transmits the data >to the control station. This would make it almost impossible for a >hobiest to get pictures of what he wants to see. My understanding is that they too transmit continuously, although it can be directed to just transmit as needed. Of course, with any satellite which looks at the landforms of Earth, you preferrably need a clear sky to image down through...clouds are almost never the intended target, with the possible exception of hurricanes (see EOSAT's 1993 calendar for a vivid picture of Hurricane Andrew). As far as scheduling goes, I'd turn that around into "taking images on the basis of a regular grid" or geographic pattern in which the same area on Earth is revisited every sixteen days, at about the same time of day by the sun (here, it's about 9:35 AM CST give or take a few minutes). >2. Is the data from the Landsat satellites encrypted? The data from >NOAA satellites is in the clear, so any hobiest can recieve, and display >the images. If the Landsat data is encrypted, then it would be almost >impossable for a hobiest to decode the images. (real show stopper). Even if it wasn't (and it is, see above) encrypted, it'd be difficult to obtain or build a site that could handle not only the volume of data but getting the proper signal-to-noise ratio for full bandwidth reception. >3. Are the specifications on frequencies that the satellite transmit >on, and data rates, and formats available to the public? If they are >not, then it would be difficult to reverse engineer an earth station >to recieve this data. If the specifications are available, then it is >only a matter of the hobiests budget and creativity to make a system to >recieve and display this data. As far as this hobbyist is concerned, I think I won't be able to afford the reverse engineering; I'd be better off spending the money (up to $5000 for a full-scene digital image) to just buy the desired data from EOSAT. I hope that legislation will eventually make it much cheaper for places like Universities and governmental entities to purchase this kind of resource; it's expensive enough right now. (Even if my employer *does* spend our school's dollars to get it!) Since this system was designed beginning in the late 1970s and launched with your and my tax dollars in 1982/1983, (speaking strictly about the LANDSATs 4 and 5) I would suppose somewhere in an archive the documents exist. After all, this business of privatization of LANDSAT didn't occur until 1986. You can always start looking somewheres, but the idea of such a search could be more than most of us could handle. Try NOAA and NASA facilities for a start; Goddard Space Flight Center in Goddard, MD. has been a key player in the LANDSAT story over the years, and so has the Earth Resources Lab at Stennis Space Center (Bay St. Louis, MS). Good luck! I'd like to hear what you find out. Hope this helps. Glad to answer this kind of question. -- John N Schmidt KD4EAI, Lab Director + 615-898-5561 M-F 1300-2230Z <7-4:30> Middle Tennessee State University ++ 615-898-5538 or 896-2871 FAX 24H 1500 Greenland Drive, PO Box 135 +x+ GGJNS@KNUTH.MTSU.EDU Murfreesboro, TN 37132-0135 USA +xx+ MTSU Center for Remote Sensing and GIS TCP/IP ADDRESS [44.34.50.soon] +xxx+ PACKET: KD4EAI@KC4RDJ.#MIDTN.TN.USA.NA ------------------------------ Date: Thu, 4 Feb 1993 19:28:09 GMT From: Donald Lindsay Subject: Cooling re-entry vehicles. Newsgroups: sci.space kjenks@gothamcity.jsc.nasa.gov writes: >If you coat your vehicle's skin with water on-orbit and cause it to >freeze, you have instant heat shielding. In "Songs of Distant Earth", Arthur C. Clarke had a starship which used ice as the "bumper" to take up the collisions with interstellar dust. Sounded reasonable, given that mass wasn't an issue in that story. However, as a *heat* shield, ice would be lousy. The mechanical buffeting would fragment it, and it would depart in chunks. -- Don D.C.Lindsay Carnegie Mellon Computer Science ------------------------------ Date: Thu, 4 Feb 1993 19:13:25 GMT From: Bob Campbell Subject: Help on catching this Newsgroups: sci.space I think the best answer might be to have it stop itself. With ice acting as a reaction mass, and no atmosphere to bother you, this could be an excellent application for laser propulsion. The math and feasibility are left to the student :-) --------------------------------------------------------------------------- Bob Campbell Some times I wish that I could stop you from campbelr@cup.hp.com talking, when I hear the silly things you say. Hewlett Packard - Elvis Costello ------------------------------ Date: Thu, 4 Feb 1993 18:23:39 GMT From: fred j mccall 575-3539 Subject: leading-edge anonymity Newsgroups: sci.space,sci.astro,alt.privacy In <1993Feb4.064507.7545@fuug.fi> an8785@anon.penet.fi (Tesuji) writes: >X-Anon-To:sci.space,sci.astro,alt.privacy >I believe that fast adapters are accepting >anonymous postings as the next step in personal >freedom in communication. No, they simply recognize idiots when they see them and filter accordingly. >True, it may encourage irresponsible postings, >especially as a novel device. But just like >the keyboard tends to reward content by >not advertising race, creed, color, age, >or sex, so to anonymous postings prevent false >halos (or horns) based upon one's posting site >or current supposed reputation. No. Instead, it gets you all the credibility that an anonymous posting deserves -- i.e., none. >The material stands on the content, not the >poster. I look at it as taking the name >off papers submitted for refereeing. I look at it as someone who wants to shoot of their mouth for attention but doesn't have the courage to do it other thna anonymously. This is generally a symptom of immaturity. >I think the Bell Lab Boys are griping because >they are used to disproportionate power >wielded over less-connected sites or >less prestigious institutions. Both uninformed AND idiotic. You're living down to the expectations one should probably have of an anonymous poster. >Anonymous posting get rid of this bias. >So -- rather than flame the content >of anonymous postings, figure out how to >sieve based on content more efficiently. With source having a lot to do with expectations of value. Anonymous source should lower the expectation of that value accordingly. Now, why don't you just run along and play with yourself, assuming you can stand your own company when you know who you are? -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Ames Dryden ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. ------------------------------ Date: Thu, 4 Feb 1993 15:20:08 GMT From: Paul Pomes - UofIllinois CSO Subject: leading-edge anonymity Newsgroups: sci.space,sci.astro,alt.privacy an8785@anon.penet.fi (Tesuji) writes: >X-Anon-To:sci.space,sci.astro,alt.privacy > >I believe that fast adapters are accepting >anonymous postings as the next step in personal >freedom in communication. Perhaps but it also guarantees that a large number of people won't bother reading what you have to say. If you're not willing to take responsibility for waht you write, why should it be given any credence? /pbp -- Freedom is a family value. Ski Colorado. --Paul Pomes (1992) ------------------------------ Date: Thu, 4 Feb 1993 19:24:53 GMT From: Henry Spencer Subject: Making Orbit 93 - The Delta Clipper Program Newsgroups: sci.space In article <1993Jan21.204731.17316@netlabs.com> lwall@netlabs.com (Larry Wall) writes: >: On descent, the vehicle goes subsonic at 60,000 feet altitude, and the >: engines are then started and idled. At 5000 to 10,000 feet altitude, the >: vehicle is rotated base down. > >How do they guarantee they don't get upside-down-spraycan syndrome? > >Not only are they going to have to pump hydrogen and oxygen from the >FAR ends of the tanks, but they have to make sure they don't get >bubbles in the line while rotating... Mitchell Burnside Clapp (a test pilot who's in training for DC-X) told us that there are actually four methods being considered for the flip maneuver. One is to pop a parachute from the nose, which will most assuredly turn the thing over base-first, after which you light the engines. This one will definitely work, but it's got some warts. Apart from the usual nuisances of parachutes -- they need to be re-packed, etc. -- it puts major shock loads on the nose structure, which otherwise doesn't need to be all that strong, and it requires 100% reliable operation of a door set into the hottest part of the skin. Easy enough to do on DC-X, which will have the parachute for emergencies anyway, but not ideal for an operational vehicle. Another is to turn off artificial stability in pitch (while maintaining yaw and roll control) long enough for the thing to flip 180 degrees, and then catch it, reassert control, and light engines. DC is aerodynamically unstable at subsonic speeds, so it ought to work. "A bit scary." A third is to light engines before the flip, and use engine gimballing to push the tail around. The problem here is precisely the one Larry mentions: it complicates the bejesus out of the plumbing if you've got to be able to get fuel out of the tanks while nose-down. Maybe you use a small auxiliary tank set with positive-displacement hardware (e.g. diaphragms separating fuel and pressurization gas) for startup and the flip, switching to main tanks afterward. The fourth is to build up speed heading almost straight down, then slowly pull the nose up (losing a lot of speed, since the L/D ratio isn't that good) until you're headed upward. Then essentially do a hammerhead stall: go up, slow, stop, and start falling tail-first. "Also a bit scary", the more so because you probably don't have enough altitude to try again if you blow it. Mitch thought that the third approach is what DC-Y will end up doing, once the bugs are worked out. -- 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, 4 Feb 1993 18:45:50 GMT From: Henry Spencer Subject: man-rating Newsgroups: sci.space In article <3_713_635.02b52654e@Kralizec.fido.zeta.org.au> ralph.buttigieg@f635.n713.z3.fido.zeta.org.au (Ralph Buttigieg) writes: > Just what is "man-rating" ? What sort of extras does the rocket need to > be man rated? Basically it amounts to (a) you spend a lot of money studying safety issues in minute detail and generating lots of paper, and (b) you sometimes add minor subsystems to the rocket, e.g. more redundancy in critical areas or better warning of trouble. -- 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: 4 Feb 93 21:01:48 GMT From: Charles Chung Subject: Micromechanics Research at NASA Newsgroups: sci.space Anyone know if and who at NASA is conducting research into micro-electromechanical systems (MEMS)? Seems to be a promising line of research for micro-space. I figure since NASA's got its finger in every other technology pie, somebody's gotta be doing MEMS stuff. Please respond via email Thanks, -Chuck --- ******************************************************************* Chuck Chung (919) 660-2539 (O) Duke University Dept. of Physics (919) 684-1517 (H) Durham, N.C. 27706 cchung@phy.duke.edu "If pro is the opposite of con, then what is the opposite of progress?" ******************************************************************* ------------------------------ Date: 4 Feb 93 13:39:29 -0600 From: Bill Higgins-- Beam Jockey Subject: Obsvn (was Re: Russian solar sail flight possibly set for Feb. 4th) Newsgroups: sci.space,sci.astro In article <1993Feb4.152934.18712@sfu.ca>, Leigh Palmer writes: > We saw it, and it was flashing! I had hoped they'd point the beam > straight down and hold it steady. I saw it too. I'm not a very experienced observer (though I've gone Mir-watching many times), so I'm not good at estimating magnitudes, and rolling out of bed at 0515 I was too sleepy and dumb to bring along a recorder or even an accurate clock. I caught a pass from Warrenville, Illinois (near Chicago) at about 0530... I guess a couple of orbits before Leigh did. > Progress/Znamya passed nearly through our zenith here in Burnaby, British > Columbia, about 6:35 am. It was flashing with a period of about five > seconds and a duty cycle of about 50%. I saw three things: 1) A very bright polar orbiter moving southward from high in the sky, passing close to Polaris, but west of it, and gradually going into shadow (obviously unrelated to the Mir complex but kept me entertained). 2) A flashing spacecraft, I would guess considerably brighter than Mir. It might have been slightly yellowish. I saw a double-peaked flash with a period of between one and two seconds, like this: BRIGHTdimBRIGHTdimdimdim... I found it puzzling since I didn't expect the Progress to be spinning and I couldn't easily explain the bimodal flash. Range between brightest and dimmest was perhaps one or two magnitudes. Both bright and dim parts of the cycle became gradually dimmer as it moved eastward. It was following the path I expected for Mir, appearing suddenly in the northwest about 30 or 35 degrees above the horizon. 3) A few minutes later, a steady bright satellite resembling Mir's usual behavior. I presume this was the space station. It was also moving pretty much along the predicted track. It's possible that this was visible before object 2 disappeared, but I didn't notice it. At most there were a couple of minutes between the disappearence of 2 and the appearance of 3. I did not notice the dim object accompanying it that Leigh described. > About four minutes later we observed Mir itself with a dimmer > object leading it by about two degrees. They too went through the zenith. > Mir was brighter than Jupiter, but I've seen Mir when it looked even a > little brighter than it did this morning. Jupiter was definitely much brighter than Mir on my pass. Is is possible that the "dim object" was the Progress, and the bright flashing object was something else? If not, what could the dim object have been? And why was my "object 2" flashing? -- O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/ - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap! / \ (_) (_) / | \ | | Bill Higgins Fermi National Accelerator Laboratory \ / Bitnet: HIGGINS@FNAL.BITNET - - Internet: HIGGINS@FNAL.FNAL.GOV ~ SPAN/Hepnet: 43011::HIGGINS ------------------------------ Date: Thu, 4 Feb 1993 18:43:16 GMT From: Henry Spencer Subject: Organic heat shielding. Newsgroups: sci.space In article <19777@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes: > The liquid hydrogen tank of the DC-X currently being built is >insulated with balsa wood. I saw a photo over the weekend - the speaker >noted that they had to bring a worker out of retirement who had the necessary >skills for bonding it to the metal. Unless my eyes pulled a perspective >trick, the photo showed the balsa on the ***inside*** of the tank. Inside vs outside insulation is a common tradeoff issue in such designs, as witness the fact that the two liquid-hydrogen stages of the Saturn V decided it opposite ways. If memory serves, the S-II stage used what was described as being essentially "synthetic balsawood" for its insulation. A particular type of balsa actually had the right properties, but the quantities needed were awfully large by the standards of the balsa market, and there was some concern about getting consistent quality. -- 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, 4 Feb 1993 19:32:27 GMT From: "forrest.e.gehrke" Subject: Retaining Goldin Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: > >Goldin is, by the way, a Democrat. >-- From the way you threw that comment in, Henry, one would assume that you think that would endear Goldin to Clinton. Just like Senator Nunn is a Democrat, huh? (;-) Forrest Gehrke feg@dodger.att.com ------------------------------ Date: Thu, 4 Feb 1993 20:26:47 GMT From: D2KAK@VM1.CC.UAKRON.EDU Subject: The day before Challenger exploded. Newsgroups: sci.space I was at the cape the day before Challenger. My brother, nephews and I spent several hours waiting on the launch and were disappointed when it didn't go. I remember my brother asking me what kind of turkeys they had working on the shuttle when they had trouble with the bolts on the hatch. Correct me if I'm wrong, but didn't an earlier shuttle have O ring problems shortly after liftoff. If I remember correctly it was the first night launch of the shuttle. One of the SRB's was damaged due to a leak in one of the O ring seals. ------------------------------ Date: 4 Feb 93 21:23:50 GMT From: "Edward V. Wright" Subject: The day before Challenger exploded. Newsgroups: sci.space Just for the record. There never was a "day the Challenger exploded." What we saw on television was a fireball. NASA did believe that it was an explosion, at first, but discovered in the first few weeks of investigation that this was not the case. ------------------------------ Date: Wed, 3 Feb 93 14:56:48 GMT From: Bill Gripp Subject: Units and Star Trek Newsgroups: sci.space In article <1993Feb2.202801.17337@socrates.umd.edu> john@socrates.umd.edu (John VanAntwerp) writes: >18084TM@msu.edu (Tom) writes: >In the original series, "warp speeds" were defined as: > > c * [warp ** 3] I heard it was c ** warp. This never made sense to me because it depends on the units you use to define c (i.e. if c is 1 light year/year then c ** warp is always 1). Why warp ** 3? (besides the fact that they had to pick something). ------------------------------ Date: Thu, 04 Feb 93 19:44:39 EST From: Tom <18084TM@msu.edu> Subject: Using Russian Hardware Mathew DeLuca (I think. Apologies if I'm wrong) sez; >You miss the point. We do not want to be subcontractors with the Russians. This argument wouldn't exist if this statement were true. Some people do want to contract out. (BTW, Russia would be the subcontractor.) >If you are going to try and open up a new frontier, you have to be willing >to put some money into it. That's what we are doing now. Sure, I suppose we >can do stuff for less, and in many cases we should; government waste and bureaucratic stodginess are costing us, and should be cut whenever and wherever >possible. But saving money by abandoning new development and sticking with >foreign old technology is a recipe for failure. Sending up satellites is not a frontier. Putting people on board an established station is not a frontier. I think these kinds of uses are the things that Edward is referring to: Things we need to do that don't involve any new development. Routine space activities. Things that currently cost quite a bit, and are *impeding* our ability to develop newer and better stuff, instead of helping it. Sure, we do need to put money into it. Lots and lots of it. But we can get some of that money by saving on what we already are doing. Sticking with expensive new technology for things that can be done just as easily by old technology is a recipe for failure, too. Many people consider the Shuttle proof of this. >You're looking at it from the wrong direction. The DC-3 came about in >response to a demand. Currently, there's not a signifigant demand for >space; we're not ready to cut the development and go into production. We >are getting there, but slowly. Don't try and rush it. On the other hand, drop the price, and see your demand increase. And, in some activities, we are ready for production, or may be soon, and we can dedicate the saved resources to doing more than we are now. Same effect for Russia's low production: If we bought stuff from them for these kinds of routine uses, they'd up their production quite a bit. I don't think anyone's 'rushing' it, I think they're saying "it's time, and we have a good opportunity", and I tend to agree. ---- I apologize for jumping on someone elses somewhat heated thread, but I tried to keep it short. It just seems like maybe Mathew was taking Edward's point to a more extreme position than was originally intended. Of course, I could be wrong about the intent... -Tommy Mac ------------------------------=========================================== Tom McWilliams; Average dude | The Freedom of our minds is what binds us 18084tm@ibm.cl.msu.edu | as a Nation; a People. But the National (517) 355-2178 -or- 336-9591 | government tries to bind us, not free us. ------------------------------=========================================== ------------------------------ Date: 4 Feb 93 13:08:44 -0600 From: Bill Higgins-- Beam Jockey Subject: World Space Foundation (was Re: Pro-space groups? - The answer.) Newsgroups: talk.politics.space,sci.space In article <1993Feb3.000245.23645@walter.bellcore.com>, dsm@orion.NoSubdomain.NoDomain (David Miller) writes: > It turns out there is a FAQ for sci.space which cover this (thanks >to Bill Higgins for pointing this out to me and sending the relevant >sections of the FAQ which I will append below). You're welcome. But that reminds me, we don't cover the World Space Foundation in the FAQ and my membership renewal forms have arrived.... WORLD SPACE FOUNDATION has been designing and building a solar-sail spacecraft for longer than any similar group; many JPL employees lend their talents to this project. WSF also provides partial funding for the Palomar Sky Survey, an extremely successful search for near-Earth asteroids. Publishes *Foundation News* and *Foundation Astronautics Notebook*, each a quarterly 4-8 page newsletter. Contributing Associate, minimum of $15/year (but more money always welcome to support projects). World Space Foundation Post Office Box Y South Pasadena, California 91301 -- O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/ - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap! / \ (_) (_) / | \ | | Bill Higgins Fermi National Accelerator Laboratory \ / Bitnet: HIGGINS@FNAL.BITNET - - Internet: HIGGINS@FNAL.FNAL.GOV ~ SPAN/Hepnet: 43011::HIGGINS ------------------------------ Newsgroups: sci.space Path: crabapple.srv.cs.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!mksol!mccall From: fred j mccall 575-3539 Subject: Re: Polar Orbit, Alaska Message-Id: <1993Feb4.181658.28605@mksol.dseg.ti.com> Organization: Texas Instruments Inc References: <1993Feb2.235514.1@acad3.alaska.edu> <1993Feb3.175703.13093@mksol.dseg.ti.com> <1993Feb3.150311.1@acad3.alaska.edu> Date: Thu, 4 Feb 1993 18:16:58 GMT Lines: 39 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In <1993Feb3.150311.1@acad3.alaska.edu> nsmca@acad3.alaska.edu writes: >In article <1993Feb3.175703.13093@mksol.dseg.ti.com>, mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >> In <1993Feb2.235514.1@acad3.alaska.edu> nsmca@acad3.alaska.edu writes: >> >>>Why does the US launch polar orbit missions from Vandenburg? other than for >>>military missions? I wonder is they know about Poker Flats here in Alaska >>>which has many of the same benfits as Vandenburg (open spaces) but nicely is >>>near the pole.. Actually more like near or at the Arctic Circle.. >> >> They launch from Vandenburg because the facilities exist, the weather >> is nice and warm, and they have lots of open water to the south for >> range safety purposes. Alaska is a bad choice for regular operations. >> It's too cold for too big a part of the year. >> >> -- >> "Insisting on perfect safety is for people who don't have the balls to live >> in the real world." -- Mary Shafer, NASA Ames Dryden >> ------------------------------------------------------------------------------ >> Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. >Cold yes, but what is a major colst for rocket launches, is keeping the feul >cold.. Note that this is only true for liquids, and some of them need it more than others -- not sure I'd like the idea of gelled kerosine for my fuel. Cold is, in general, probably not real good for things like segmented solids. >Also the Fairbanks area can get upi to 90-100 F during the summer.. >True it can get to -60 during sometimes in the winter.. Sounds great if you're only flying cryogenic fuels. ;-) -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Ames Dryden ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. ------------------------------ End of Space Digest Volume 16 : Issue 135 ------------------------------