Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from holmes.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Wed, 3 May 89 03:16:31 -0400 (EDT) Message-ID: <8YLeR2y00UkZQtNU5g@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 3 May 89 03:16:19 -0400 (EDT) Subject: SPACE Digest V9 #405 SPACE Digest Volume 9 : Issue 405 Today's Topics: Re: McBride to leave NASA; Brand named commander of STS-35 (Forwarded) Re: Earth based - will it always win? NASA Prediction Bulletin Format Re: Earth based - will it always win? Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!) Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!) Re: wireless electricity Re: Asteroid Encounter Re: Re: Asteroid Encounter ---------------------------------------------------------------------- Date: 30 Apr 89 15:45:41 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Re: McBride to leave NASA; Brand named commander of STS-35 (Forwarded) In article <2843@pegasus.ATT.COM> psrc@pegasus.ATT.COM (Paul S. R. Chisholm) writes: >In article <24382@ames.arc.nasa.gov>, yee@trident.arc.nasa.gov (Peter E. Yee) writes: >> Astronaut Jon A. McBride (Captain, USN) has announced his >> intention to leave NASA effective May 12, 1989. >> McBride was named last year to command the STS-35 (ASTRO-1) >> mission, scheduled for launch in March 1990. > >If an astronaut with a guaranteed seat isn't interested in sticking >with the program, imagine how the rest of NASA (orbit-bound and >otherwise) must feel! I believe the three men who left NASA were doing so because of a new law that takes effect next month governing NASA employees and their ability to take jobs in industry. By leaving now, they beat the deadline and will not have problems getting new jobs. Also, please remember, that the first 'A' in NASA stands for Aeronautics. We do more than space flights. -Peter Yee yee@ames.arc.nasa.gov ames!yee PS Standard disclaimers. ------------------------------ Date: 30 Apr 89 23:38:03 GMT From: rg20+@andrew.cmu.edu (Rick Francis Golembiewski) Subject: Re: Earth based - will it always win? From: tneff@bfmny0.UUCP (Tom Neff) >Should we concentrate on ground based work and de-emphasize space based >observation until some smart cookie makes it a lot cheaper and easier >to get up there? I hope I have framed the question usefully. For some things, definately yes, for others no... Ideally we should only use space for the experiments/manufacture etc. that is cheaper, then Earth based, or that is impossible from earth (ie, how does one simulate 0 G for a long period of time on earth?). There are a few important realities to keep in mind: If space is de-emphasized, the chances are that very few 'smart cookies' are going to be working on making it a lot cheaper and easier to get up there. Also remember that putting money into research won't necessarily get you the desired results (NASA has shown this many times, remember how the shuttle was supposed to be INEXPENSIVE?), so if all the money that went into say HST or Magellian, may not have produced the necessary technology, the people who had the $$$ made the descision to us space, and you can be fairly certain that they made the descision for a reason. They knew they could build a space telescope, and that there is already a shuttle system to deploy it etc. Did they consider an earth based telescope? Probabily, however the problems associated with the atmosphere can not be eliminated easily, it may well take more $$$ invested in R&D in order to get a system that is not nearly as good as HST. In science there are alaways a few ways to do a particular experiment, and a few different experiments to learn the same thing, so you have to learn to pick the best that you can within your resources. Remember that money isn't the only resource, manpower and time are two other important ones, so if you only have a staff of say 10 people, then you can't expect to develope new areas of technology in a reasonable amount of time, however if you have the money you can have some engineers make a satellite for you, and have NASA launch it... It is up to the scientists to pick the most efficient way to learn new information, however scientists are people too, so they might just make a mistake and end up spending more then they though... // Rick Golembiewski rg20+@andrew.cmu.edu \\ \\ #include stddisclaimer.h // \\ "I never respected a man who could spell" // \\ -M. Twain // ------------------------------ Date: 30 Apr 89 15:26:12 GMT From: tkelso@blackbird.afit.af.mil (TS Kelso) Subject: NASA Prediction Bulletin Format As a service to the satellite user community, the following description of the NASA Prediction Bulletin's two-line orbital element set format is uploaded to sci.space on a monthly basis. The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial RCP/M, (513) 427-0674, and are updated several times weekly. Documentation and tracking software are also available on this system. The Celestial RCP/M may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity. ============================================================================== Data for each satellite consists of three lines in the following format: AAAAAAAAAAA 1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN 2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN Line 1 is a eleven-character name. Lines 2 and 3 are the standard Two-Line Orbital Element Set Format identical to that used by NASA and NORAD. The format description is: Line 2 Column Description 01-01 Line Number of Element Data 03-07 Satellite Number 10-11 International Designator (Last two digits of launch year) 12-14 International Designator (Launch number of the year) 15-17 International Designator (Piece of launch) 19-20 Epoch Year (Last two digits of year) 21-32 Epoch (Julian Day and fractional portion of the day) 34-43 First Time Derivative of the Mean Motion or Ballistic Coefficient (Depending on ephemeris type) 45-52 Second Time Derivative of Mean Motion (decimal point assumed; blank if N/A) 54-61 BSTAR drag term if GP4 general perturbation theory was used. Otherwise, radiation pressure coefficient. (Decimal point assumed) 63-63 Ephemeris type 65-68 Element number 69-69 Check Sum (Modulo 10) (Letters, blanks, periods = 0; minus sign = 1; plus sign = 2) Line 3 Column Description 01-01 Line Number of Element Data 03-07 Satellite Number 09-16 Inclination [Degrees] 18-25 Right Ascension of the Ascending Node [Degrees] 27-33 Eccentricity (decimal point assumed) 35-42 Argument of Perigee [Degrees] 44-51 Mean Anomaly [Degrees] 53-63 Mean Motion [Revs per day] 64-68 Revolution number at epoch [Revs] 69-69 Check Sum (Modulo 10) All other columns are blank or fixed. Example: NOAA 6 1 11416U 86 50.28438588 0.00000140 67960-4 0 5293 2 11416 98.5105 69.3305 0012788 63.2828 296.9658 14.24899292346978 Note that the International Designator fields are usually blank, as issued in the NASA Prediction Bulletins. -- Dr TS Kelso Asst Professor of Space Operations tkelso@blackbird.afit.af.mil Air Force Institute of Technology ------------------------------ Date: 30 Apr 89 19:39:37 GMT From: uflorida!haven!uvaarpa!hudson!bessel.acc.Virginia.EDU!gl8f@g.ms.uky.edu (Greg Lindahl) Subject: Re: Earth based - will it always win? In article <14295@bfmny0.UUCP> tneff@bfmny0.UUCP (Tom Neff) writes: > [discussion of radar at arecibo looking at venus] > All of which brings me to a question I've often wondered about. Given > enough time and ingenuity can't we nearly always do better here on > Earth? Depends. At some wavelengths you can see through the atmosphere, no matter how much time and ingenuity you put into it. And to consider a few silly and/or serious cases: you can't take a picture of the far side of the moon from the earth :-) you can't put two radio interferometer elements farther apart than one earth diameter on the earth (oh, QUASAT, when will you fly) you can't pick up soil samples on mars and return them to the earth without leaving your living room you can't measure cosmic rays out at Neptune without going there Finally, one might note that Aricebo would be expensive to build today, and the radio astronomy community probably could never get they money --- the Air Force originally built it for ionospheric research. > (The antenna can't even > collapse a la Greenbank, Arecibo's a mesh bowl dug into the ground.) See that big receiver thingie sitting 500 feet off the ground in the middle? Wonder how much that weighs? It's only held up by a few cables... fortunately it was probably built with a larger safety margin than the 300'. > Should we > concentrate on ground based work and de-emphasize space based > observation until some smart cookie makes it a lot cheaper and easier Some things must be done from space. Some things are cheaper to do from space than from the ground. ------ Greg Lindahl | gl8f@virginia.{edu,bitnet} | Veraj Programistoj ne uzas PASCAL-on ------------------------------ Date: 30 Apr 89 05:38:09 GMT From: att!pegasus!psrc@ucbvax.Berkeley.EDU (Paul S. R. Chisholm) Subject: Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!) In article <20041@genrad.UUCP>, dls@genrad.uucp (Diana L. Syriac) writes: > UFOs are definitely pertinent to Space....last I heard, most of > them are from OUTER SPACE. UFO's are, by definition, unidentified. Some are natural phenomena, seen in unexpected ways. I've seen a couple of those myself, such as an airliner at sunset, reflecting light to look like windows in a flying saucer. None are clearly, indisputably from outer space. As for "close encounters of the third kind" . . . I remember reading a serious book on UFO's, by someone who thought some of them really were spacecraft from Out There. His section on personal encounters ended by saying that such stories "travelled at the speed of lie." The rest of us are even more skeptical. Certainly, no one to my knowledge has increased our understanding about space (or our ability to go there) by studying UFO's. Most of us aren't interested in hearing about flying saucers, and most "flying sorcerers" aren't interested in what we talk about here. > Diana L. Syriac, {decvax,linus,mit-eddie,masscomp}!dls@genrad.com That should be either dls@generad.com or {decvax,linus,...}!genrad!dls (mixing at's and bang's can be hazardous to your e-mail's health). Paul S. R. Chisholm, AT&T Bell Laboratories att!pegasus!psrc, psrc@pegasus.att.com, AT&T Mail !psrchisholm I'm not speaking for the company, I'm just speaking my mind. ------------------------------ Date: 30 Apr 89 14:03:15 GMT From: usc!nunki.usc.edu!manderso@bloom-beacon.mit.edu (Mark Anderson) Subject: Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!) >In article <20041@genrad.UUCP>, dls@genrad.uucp (Diana L. Syriac) writes: >> UFOs are definitely pertinent to Space....last I heard, most of >> them are from OUTER SPACE. > >Most of us aren't interested in hearing about flying saucers, and most >"flying sorcerers" aren't interested in what we talk about here. > >Paul S. R. Chisholm, AT&T Bell Laboratories UFO's can't be any more far out than some of the more "scientific" arguments posted here, such as blowing up the Sun or mining asteroids. Loosen up a little. Mark ------------------------------ Date: 30 Apr 89 03:41:40 GMT From: att!pegasus!psrc@ucbvax.Berkeley.EDU (Paul S. R. Chisholm) Subject: Re: wireless electricity <"Would you like me to summon Data so he could offer a few dozen synonyms?"> In article <269@poppy.warwick.ac.uk>, phupp@warwick.ac.uk (S Millington) writes: > There have been recent sugestions that a satellite in a > geostationary orbit could use a high power microwave transmitter to > transmit power to earth, this would mean that the solar cells picked > up more light than they would on earth. Recent? These proposals were first made in the seventies. The original proposal was made by Peter Glaser (of Arthur Little, I think). Princeton's Gerard K. O'Neill suggested that, rather than lifting all that mass from the Earth, it would be cheaper to build a lunar colony, get all the mass from the Moon, and build the solar power satellites from space habitats. I did my term paper for Engineering Economics on O'Neill's proposal back in 1977 or 1978. What effect would that kind of microwave flux have on birds, crops, people, and the environment in general? No one knows. Terrestrial fusion might well be cheaper, and looks from here to be much simpler. Please follow-up to sci.space. > Stuart Millington. Paul S. R. Chisholm, AT&T Bell Laboratories att!pegasus!psrc, psrc@pegasus.att.com, AT&T Mail !psrchisholm I'm not speaking for the company, I'm just speaking my mind. ------------------------------ Date: 1 May 89 15:21:07 GMT From: hp-pcd!hpcvlx!gvg@hplabs.hp.com (Greg Goebel) Subject: Re: Asteroid Encounter I have a set of old photocopies and clippings at home that I have slowly been "digitizing" (the hard way -- eyes on text, fingers on keyboard) as a means of keeping them organized. I have two on meteor strikes. They're a little old, but as long as I'm writing them up I might as well post them, since they're still interesting. This one's on Dr. Shoemaker of the USGS. I have a SKY & TELESCOPE article on the Tunguska strike which I'll post later this week. | Greg Goebel | INTERNET: cwo_online@hp-pcd ------------------------------ Date: 1 May 89 15:21:48 GMT From: hp-pcd!hpcvlx!gvg@hplabs.hp.com (Greg Goebel) Subject: Re: Re: Asteroid Encounter Dealing With Threats From Space Michael Lemonick TIME / 9 JUN 86 / P 65 It is a sunny afternoon in Karachi, and streets of Pakistan's largest city are crowded with shoppers, apparently unconcerned about the rising tension between Pakistan and India. Suddenly a second sun bursts into view overhead, so bright it temporarily blinds thousands and so hot it blisters the skin. Thirty seconds later, the shock wave hits, crumbling buildings and throwing people to the ground. To the Pakistanis, only one explanation is possible for the tremendous blast: India has launched a nuclear attack. They immediately order their bombers, armed with atomic bombs, to strike back at India, which responds in kind. Only later do the surviving officials learn of their mistake. The object that exploded over Karachi was not a nuclear weapon but a large meteor hurtling in from outer space. Though this sounds like the plot for a TV movie, Eugene Shoemaker, a respected US Geological Survey scientist, is concerned that just such an event -- and an unwarranted reaction -- could occur. Shoemaker expressed his fears at a Baltimore meeting of the American Geophysical Union (AGU): "The effect of a meteor blast appears the same as a high-altitude nuclear explosion," he said. "If this happens in the wrong place, people will think they've been nuked." Meteors, which are asteroids or cometary debris that has entered the atmosphere, continually shower the Earth. Most of them are small and either break up or are burned to ash by friction. But, explains Shoemaker, the incineration of larger asteroids is far more violent. As asteroid 80 feet across, striking the atmosphere at 50,000 MPH, compresses the air in its path so much that in effect the asteroid is stopped dead in its path, converting kinetic energy almost instantaneously into heat, light, and a powerful shock wave. That causes a tremendous explosion, in this case equivalent to a one-megaton bomb. If a meteor were to burst in the atmosphere tomorrow, Shoemaker says, "the Soviets and the US would know what it was" and not react militarily. Their detectors could distinguish between a nuclear explosion -- which generates million-degree temperatures, X-rays, and gamma rays -- and an exploding meteor -- which would produce considerably lower temperatures and no deadly radiation. But smaller nations, unaware of the nature of the blast, might react violently. Says Shoemaker: "Suppose it happens over Syria or Pakistan?" He proposes that the US immediately try to determine whether the explosion was of cosmic origin and notify the affected nation. Since 1973, Shoemaker has been photographing the sky in search of asteroids that periodically cross the Earth's orbit and thus pose a danger of collision. To date, he says, 57 such asteroids at least 1 km in diameter have been catalogued. In addition, about three Earth-crossing comets are detected each year. From the rate at which new Earth-crossers are detected, Shoemaker estimates that there are some 2,000 asteroids in this category and that 100 comets intersect the Earth's orbit every year. His calculations suggest that asteroids packing the explosive energy of one megaton should enter the atmosphere on an average of once every 30 years, larger asteroids with a 20-megaton punch every 400 years, and a 1 km, 10,000 megaton comet or asteroid once in 100,000 years. This century has already seen a major meteorite blast. In 1908, either an asteroid or comet exploded about five miles above the remote Stony Tunguska River region of Siberia, igniting and flattening trees over hundreds of square miles. From descriptions of the blast and photographs of the damage, scientists have estimated that the object was at least 200 feet across and caused a 12-megaton explosion. Depending on their velocity, size, and composition, some meteors survive the fiery trip through the atmosphere at hit the ground, at which point they are called meteorites. Most are in the form of pebbles or small rocks, but occasionally they are much larger. Scientists think it was a 130-foot chunk of meteoric iron that hit Arizona with a force of 15 megatons between 20,000 and 50,000 years ago, digging a crater three-quarters of a mile across and 600 feet deep. But even greater menace lurks in the darkness of space. Scientists have speculated that objects as large as several miles across have crashed into the Earth, spewing millions of tons of debris into the atmosphere, blotting out the Sun for months or years, and causing mass extinctions of life -- including, many believe, the dinosaurs. Of the known larger Earth-crossers, none seem to pose a threat in the near future. But, says Shoemaker, "until we have tracked all of them, something could sneak up on us." What if a large asteroid or comet is discovered heading for the Earth? At the AGU meeting, Shoemaker and colleage Alan Harris, of the Jet Propulsion Laboratory in Pasadena, California, suggested that the intruder could be diverted by landing a thrusting device on it. As a last-ditch effort, a small nuclear warhead could be detonated on or near it. Says Shoemaker: "We have the technology to do that right now." But if the explosion simply broke the meteorite into large chunks, the danger would only be multiplied. "The more prudent solution," says Harris, "is to burrow a substantial charge into the object and blow it to smithereens." [<>] ------------------------------ End of SPACE Digest V9 #405 *******************