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 ; Thu, 15 Feb 90 01:27:46 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 15 Feb 90 01:27:19 -0500 (EST) Subject: SPACE Digest V11 #42 SPACE Digest Volume 11 : Issue 42 Today's Topics: Re: measurement standards (aerospace) Re: private spaceplane Re: Measurement standards HASA select & Operacio 9000 Re: Galileo Update - 02/12/90 Close-up inspection of Long Duration Exposure Facility begins (Forwarded) Re: Space Station Costs ---------------------------------------------------------------------- Date: 14 Feb 90 19:02:24 GMT From: helios.ee.lbl.gov!pasteur!ic.Berkeley.EDU!eta@ucsd.edu (Eric T. Anderson) Subject: Re: measurement standards (aerospace) In article <9002122258.AA02746@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >... >For shame! That's one of the few areas in which the "standard" system really >shines, since it was a major design criterion. For instance, express 1/3 >of a foot in inches (4). Now try 1/3 of a meter in mm (333.33333333333...). >As another example, the number of feet in a mile (5280) is evenly divisible >by 2, 3, 4, 5, 6, 8, 10, 11, 12, 15, 16, 20, 22, 24, 30, 32, 33, 40, 44, 48, >55, 60, 66, 80, 88, 96, 110, 120, 132, 160, 165, 176, 220, 240, 264, 330, >352, 440, 480, 528, 660, 880, 1056, 1320, 1760, and 2640, a total of 46 Hey, let's just use base 12! or so! Then we can divide by lots of numbers... We just need a lot more fingers. =-) How about it? ------------------------------ Date: 15 Feb 90 01:10:39 GMT From: lowerre@apple.com (Bruce Lowerre) Subject: Re: private spaceplane In article <509.25c9d213@ccvax.ucd.ie>, h235_022@ccvax.ucd.ie writes: > In article <19120@nuchat.UUCP>, moe@nuchat.UUCP (Norman C. Kluksdahl) writes: > > > > Some of you may recall a discussion starting about a year ago > > regarding private efforts to develop a small-scale shuttle/ > > spaceplane. After some initial confusion, I ended up being the > > designated coordinator of ideas, and began to have fun with the > > idea of a garage-scale EAA-type spaceplane project. At first, it > > began as a 'Gedanken Experiment', merely a mental excercise to see > > if such a project was within the realm of possibility. > > Sounds very interesting - as I'm not one of the ones who might remember this > discussion from before, (surely I'm not the only one) maybe you could bring us > up to date with your current state of thinking on this... Does anyone remember Evel's attempted Snake River Canyon jump in a steam powered rocket? After that abortion, his next stunt was to be aboard the first civilian rocket into space. He hired an engineer, Truax (SP?) (sounds like "true-ax"), to design and build a rocket that would get him into space. Truax designed a rocket and made at least one test firing right here in the East Bay. It was not capable of orbiting and was more of a sounding rocket where the passenger was just along for the ride. The whole trip would take less than 15 minutes but would reach an altitude of over 50 miles, high enough to qualify as an astronaut. The plan started to fall apart when Evel encountered some difficulty with a baseball bat. Truax tried to continue by himself. I don't what ever finally happened; I don't think he could ever raise the money. I know that after Evel's troubles, Truax was eyeing up Jeanne Yeager as a possible "pilot" because of her light weight. ------------------------------ Date: Tue, 13 Feb 90 19:46:50 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Measurement standards >From: voder!nsc!amos@apple.com (Amos Shapir) >Subject: Re: measurement standards (aerospace) >>As another example, the number of feet in a mile (5280) is evenly divisible >>by 2, 3, 4, 5, 6, 8, 10, 11, 12, 15, 16, 20, 22, 24, 30, 32, 33, 40, 44, 48, >>... >That doesn't help much when I see a sign BUS STOP 400 FEET, and the mileage >meter in my car is scaled to 1/10th of a mile! >The problem with the imperial system is not subdivision, but consistency. No argument (though almost all the mileage signs I see give distances in tenths or quarters of a mile). I was refuting the claim that even divisibility is an *advantage* of the metric system. The subdivisions in the "standard" system were specifically designed to be easily divisible by low numbers, so you are *more* likely to have fractional remainders using the metric system. The inclusion of these factors is what makes "consistency" more difficult. This is still a problem in the time base of SI, what with minutes, hours, days, years, etc. You get around it by calculating everything in seconds, then converting to the larger time units. Of course, everybody has calculators and computers these days, so none of this is more than a nuisance. >>Europe has been blocking an international standard on >>HDTV television broadcast format unless it's PAL-compatible (or SECAM?) while >>the US and Japan are willing to settle on an extension of NTSC. >You'd understand why if you ever see a PAL transmission. Compared to >NTSC, it's crisp and crystal clear even in the present density. >(And it's well known that NTSC stands for Never The Same Color :-)) Again, no argument about PAL picture quality. People I know who travel in Europe say that the television there has beautiful sharp pictures - with an annoying flicker, since they are 50Hz interlaced instead of 60Hz interlaced. Apparently there is a fundamental limit in the ability of the human eye to detect flicker in an image, and the lower limit of this is around 60Hz. (70Hz would be better.) 50Hz is sufficiently slower that most people can detect a flicker. (Europeans may have learned to ignore it.) Where the two frames are different (i.e. near a horizontal line in the display) the resulting 30Hz flicker from NTSC is pretty bad - I suspect the 25Hz from PAL is worse. You can get around this by using slower phosphors, but then motion is blurred. (Advanced receivers use internal buffering to refresh both frames simultaneously, at double the normal rate.) Advanced computer-driven displays (such as the one proposed by Dale Amon for the space station) use tricks such as separate RGB inputs, and extremely high pixel rates (many MHz). Note: The potential resolution of NTSC broadcast is much higher than what is available from current broadcasters - until recently, receiver quality has not been good enough to justify a better effort. Some expensive receivers now use advanced circuitry such as comb filters and tricks such as pixel averaging to do the best they can with what is received. Also note that the HDTV format currently in use in Japan is *not* a normal broadcast standard - it's more analogous to cable. > Amos Shapir >National Semiconductor, 2900 semiconductor Dr. >Santa Clara, CA 95052-8090 Mailstop E-280 >amos@nsc.nsc.com or amos@taux01.nsc.com John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ X-Delivery-Notice: SMTP MAIL FROM does not correspond to sender. Date: Wed, 14 Feb 90 19:28 GMT From: RITA HAYWORTH From: di4007@ebccuab1.bitnet (Jordi Iparraguirre) Date: Feb/14/1990 Subj: HASA select & Operacio 9000 Help ! I m very interested on receivig NASA Select broadcastings. It s said that NASA Select TV satelite is geostationary over the USA, but is there any other way for receiving their programs in Europe ? Perhaps CCN broadcasts them too ? Are they received at Robledo de Chavela (NASA tracking center near Madrid, Spain) station ? I will apreciate very much any kind of information you can send me. Thanks in advance. On the other hand, On Feb/18/1990 will begin in Catalonia (Europe) OPERACIO 9000. In this operation, a man called Emili Reyes will be living alone in a grot for 9000 days. He will be monitored by doctors, and his unique link with the surface world will be a computer (Mac). Doctors want to study human reactions in front the lonelyness, and among others, they will simulate delay comunications as on a space trip to Mars. It is not the 1st time that Emili Reyes goes in this bussiness. In 1970 he was underground for 1512 hours, and in 1973 he beat all records staying alone for 2500 hours. Now he will try to be alone for 9000 hours (375 days). Jordi Iparraguirre. CS student at University Autonoma of Barcelona (Catalonia, Europe) di4007@ebccuab1.bitnet aster@nexus.nsi.es ------------------------------ Date: 14 Feb 90 20:45:49 GMT From: wuarchive!zaphod.mps.ohio-state.edu!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!watserv1!watdragon!rose!sekoppenhoef@decwrl.dec.com (Shawn E. Koppenhoefer) Subject: Re: Galileo Update - 02/12/90 In article <1990Feb14.093523.18240@uokmax.uucp> noel@uokmax.uucp (Bamf) writes: > Maybe I'm a bit early here, but what is the possibility of >public access to the images returned by the craft, (at some later >date, I figure) Are they generally made available in some format, Is there any way to get access to the RAW data or are we stuck with only the 'results' of the imaging teams? (not that they don't do a good job... ) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| _ _ KLEIN BOTTLE for sale... Shawn E. Koppenhoefer | | enquire within. ...watmath!rose!sekoppenhoef | - ~~~~~~~~~~~~~~~~~sekoppenhoef@rose.uwaterloo.ca sekoppenhoef@rose.uwaterloo.edu ------------------------------ Date: 13 Feb 90 20:51:10 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Close-up inspection of Long Duration Exposure Facility begins (Forwarded) Mary Sandy Headquarters, Washington, D.C. February 13, 1990 Jean Drummond Clough Langley Research Center, Hampton, Va. RELEASE: 90-23 CLOSE-UP INSPECTION OF LONG DURATION EXPOSURE FACILITY BEGINS NASA officials and principal scientific investigators making their first close inspection of the Long Duration Exposure Facility (LDEF) at Kennedy Space Center, Fla., report that the spacecraft looks much like they expected and hoped for after its extended stay in space. LDEF's 57 experiments provide a unique opportunity to study significant long-term effects of spaceflight on a broad range of materials and components, as well as on living organisms. The spacecraft was retrieved by the crew of Space Shuttle Columbia on January 12. LDEF's exterior shows obvious effects from nearly 6-years' exposure to bombardment by micrometeoroids and orbital debris, atomic oxygen impingement and the Sun's ultraviolet rays. LDEF will provide unprecedented data on the changes caused by the combination of these environmental parameters, because accurate simulations of the complex space environment are difficult to perform on Earth. These and other effects will be evaluated in detail once LDEF's experiments are removed for subsequent testing and analysis. Discolorations or physical changes appear on many of LDEF's thermal control and optical surface experiments. There seems to be a significant contrast between the surfaces on the leading edge (facing the direction of flight) and those on the trailing edge. One major difference between these two sides of LDEF is the high exposure to atomic oxygen on the leading edge and very low exposure on the trailing edge. Many of the materials appear as expected for this extended exposure, while others look either more or less degraded compared to preflight estimates. Observation of solar array and structural materials on LDEF's leading edge and surrounding rows reveals that all unprotected Kapton thin-film insulation appears to have eroded away. This Kapton erosion is responsible for the disappearance of three solar cell modules and a number of 1-mil polymer film materials on the Solar Array Materials Passive LDEF Experiment (SAMPLE). Kapton films protected with silicone coatings seem to have survived prolonged exposure to atomic oxygen, however, along with some silverized reflectors protected with ionic bonded solids. Researchers are somewhat surprised that observations show white Tedlar is intact, and that Kevlar 29 and 49 appear eroded, but whole. Two effects seen on SAMPLE and several other experiments are not understood at this time. Unbonded silvered teflon thermal blankets appear white, while the silvered teflon bonded to metallic substrates appears tarnished. Elastomer materials, typically used as seals, have greatly discolored. Some surface erosion occurred on the carbon fiber-epoxy matrix composite materials. Even though space debris impacts on the experiment's solar cells appear to be numerous, few of the cells look broken. The Thermal Control Surfaces Experiment (TCSE) is a once- active experiment that performed periodic in-space optical properties measurements of exposed thermal control and optical surfaces during LDEF's initial 15-18 months in space. This experiment will provide a record of the condition of the test materials during that period, and postflight laboratory analysis of the samples will determine any subsequent damage. In addition, the TCSE will be evaluated as a means to obtain important knowledge on the effects of long-term space exposure on complex optical, electronic and mechanical instrumentation. The Chemical and Isotopic Measurements of Micrometeoroids by Secondary Ion Mass Spectrometry measured isotopic composition of interplanetary dust. A special capture cell on the front of LDEF and two capture cells on the back collected vapor and debris fragments from impacts. When particles penetrated the foils, they should have "exploded" on hitting the plates beneath, producing a plume of vapor and debris that would redeposit on the underside of the plastic. Unfortunately, many capture cells suffered catastrophic rupture of the thin entrance plastic films during LDEF's longer- than-planned sojourn in space. But if the plastic was in place when impacts occurred, there should be a spray of vapor and debris on the germanium plates that can be analyzed. The initial look from about six feet away shows at least half of the front- facing cells have visible impacts; at the microscopic level there probably will be many more. The knowledge gained from LDEF will be used to design a more complex interplanetary dust experiment, one that will differentiate between dust from comets and asteroids, for Space Station Freedom. The Heavy Ions in Space (HIIS) experiment used plastic track detectors to measure the abundance of chemical elements in cosmic radiation. The experiment should offer new insights into the origin of chemical elements and may show how the elemental composition of the Solar System differs from that of the rest of the galaxy. The data also will improve our knowledge of radiation hazards faced by astronauts and by modern micro- electronic components in space. On seven of the eight HIIS modules, multilayer insulation thermal blankets partially detached and rolled up while LDEF was in orbit. The loss of temperature control and exposure of some of the detector material to direct sunlight probably resulted in some data loss. The thermal blanket on the eighth HIIS module is largely intact and may have preserved the data in that module. Still another experiment, Space Exposed Experiment Developed for Students (SEEDS), looks good and all hardware is intact on the tray, suggesting that the seeds have been protected as planned. After preliminary growth tests, the 12.5 million tomato seeds that flew aboard LDEF will be distributed to U.S. students in grades 5 through university for use in classroom research. Experiment trays will be removed from LDEF around February 22 and delivered to the principal investigators. By the end of April, all experiments should be in the hands of the investigators and analyses of the experiments underway. Results from the LDEF mission will furnish invaluable data for design of future space structures, such as Space Station Freedom, as well as insight into Earth's cosmic origins. ------------------------------ Date: Wed, 14 Feb 90 13:09:37 PST From: mordor!lll-tis!ames!ucsd!pnet01.cts.com!jim@angband.s1.gov (Jim Bowery) To: crash!space@angband.s1.gov Subject: Re: Space Station Costs Henry Spencer writes: > ..... It's not likely that it will >get a chance unless it is rammed down NASA's throat by higher management. >Just going ahead and *doing the job*, forgetting all the crap about new >technology and advanced robotics and 57 unmanned preliminary missions, >may sound attractive to space enthusiasts, but the reaction from the NASA >facilities and contractors -- who together have a lot of political clout -- >will be basically "sounds like less money for us -- we're against it". You bought the Big Lie, Henry. This is exactly the Big Lie that the NASA facilities and contractors want you to believe because they know if space enthusiasts ever wake up to the true level influence we have over the Spacefare Pogrom it's all over. It is therefore exceedingly urgent for them to have the leadership of organizations like National Space Society and others, such as yourself, repeatedly convey the message that the civil servants and contractors somehow, magically, have Congress by the ****s to a point that grassroots input can't win. Only in this way can they discourage us so that we never even TRY to get a taste of our precious constitutional power as congressional constituents, and keep us believing that we must suck up to these ignoble groups as "The Only Game In Town". That this is a Big Lie is obvious when one considers the fact that the environmental movement successfully overcame far greater odds when they fought polluting industries that didn't even depend on Congress for their funding. With the Spacefare Pogrom depending entirely on Congress for its funding, if the grassroots enthusiasts start calling for reform, all these "Big Powerful Interests" can do is simply roll over and play dead -- or start acting like reform was Their Idea All Along (which is closer to what is actually happening now as a result of HR2674). Don't let them discourage you! --- Typical RESEARCH grant: $ Typical DEVELOPMENT contract: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ------------------------------ End of SPACE Digest V11 #42 *******************