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 ; Wed, 13 Dec 89 01:27:37 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 13 Dec 89 01:27:11 -0500 (EST) Subject: SPACE Digest V10 #339 SPACE Digest Volume 10 : Issue 339 Today's Topics: space news from Oct 23 AW&ST clarifications on: Re: V10 No.327 and inflammatory ephithets STOP SPACENET! Relative distances and sizes in the Universe. ---------------------------------------------------------------------- Date: 12 Dec 89 04:30:47 GMT From: mnetor!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: space news from Oct 23 AW&ST News report saying that the main reasons for the Pegasus schedule slip from summer to December were fuel leaks in the NASA B-52 and the need to build a new adapter to connect Pegasus and the B-52's wing pylon. The original welded-steel adapter had to be scrapped due to excessive cracks, and the replacement composite adapter wasn't ready until August. The West's voluntary restrictions on missile-technology exports do not seem to be working. A recent Brazilian launch-services RFP called for export of liquid-fuel rocket engines as well, and the French -- party to the voluntary restrictions -- offered them the Ariane engines. Galileo's two Earth flybys will slow Earth's orbital velocity by 9.6e-18 mph, altering Earth's position 5.3in per billion years. Christic Institute expected to protest. [:-)] "Sen. Jake Garn has risen successfully to the defense of what may be the only group truly unrepresented in this town -- extraterrestrials." (He prevented funding cuts in NASA's SETI program.) California earthquake does minor damage to space-related facilities. USAF communications facilities in Sunnyvale take minor structural damage and a burst water main, but are hastily tested and judged capable of supporting the Galileo launch the next day. Ford Aerospace satellite plant takes structural damage, but satellites currently in works appear unharmed. NASA Ames reports minor water damage. Lockheed facilities in the Bay area are intact and operating, although its Santa Cruz test facilities are without power and some damage is reported. Lawrence Livermore reports "superficial damage". Boeing wins SDI contract to build large ground-based free-electron laser for tests in mid-1990s. [Space relevance is that those thingies are also prime candidates to power a laser launcher.] Galileo up Oct 18, with only minor problems experienced on the flight. One of Atlantis's three APUs unexpectedly switched into high-speed mode just after SRB separation, which may have minor impact on reentry planning. There has also been a minor problem with the shuttle's flash-evaporator cooling system, possibly due to heavy loads placed on it by Galileo's RTG heat. New software and procedures permitted launch on schedule despite a last-minute need to switch abort sites due to weather. Crippen named director of space shuttle program in Washington; he has been deputy director at KSC. Brewster Shaw [another astronaut] will replace him at the Cape. House and Senate make deep cuts in Aerospace Plane, but trim space station only lightly and actually boost funding for Shuttle-C. First commercial Titan launch slips a few weeks due to electrical problems. Ariane V34 slips from Oct 5 to Oct 27 due to relay problems; the payload is the first Intelsat 6. This will be followed by V35 on Dec 13, carrying Japan's Superbird B and BS-2X. That is a change from earlier manifests, which showed Spot 2 (and its piggyback amateur-radio microsatellites) on V35, due to a contractual commitment to get the Japanese payloads up this year. Spot 2 and friends are now scheduled for the next flight, Jan 19. Another story on the Awesomely Lucrative Spacelauncher, er excuse me the Advanced Launch System. It's still being touted as providing, simultaneously, very low cost to orbit, very fast turnaround between launches, and very high reliability. Various details of how Martin Marietta thinks this could be done, some of which makes sense. Vehicles would move to the pad only when ready for launch, and would go up immediately. The pads themselves would be a return to the Saturn V concept: a fairly simple fixed pad without gantries and the like, and a mobile launcher moved on top for the launch. (One reason cited for this is relatively quick repairs to the fixed pad after a launch failure.) Payload integration and mission analysis would be highly automated, to permit short-notice changes in payloads and missions. New technology for big cryogenic tanks would be useful, notably better alloys and automated production and inspection processes (current welding and X-ray inspection processes are very tedious). Fault-tolerant avionics would be better than the ICBM approach of making guidance systems fault-free at great expense. Possible problems should be simulated in advance, to avoid "having to put a study team together when something fails and have them spend a week figuring out what to do while the crew stands around waiting". [Methinks the US aerospace industry has forgotten that good people with proper authority and experience can do this without massive computerized simulation. There was an incident during Saturn I development when a launch was being scrubbed because some instrument reading went outside launch limits. Kurt Debus -- director of KSC, one of von Braun's old bunch -- looked at the readings for a few seconds and ordered the launch to go ahead anyway! He'd decided that it was instrument error. He was right.] Unified information handling could greatly reduce the mass of paperwork that has to move between different groups. All of this, of course, is going to require considerable adjustment by the customers as well as the contractors. [I would perhaps be a bit less cynical about these pronouncements from MM if I didn't recognize so many of them from an OTA study on reducing launch operations costs. MM talks a good fight, once told what to say :-), but whether they can put it into practice or not is a good question.] Inmarsat shakes up management to get the Inmarsat 2 satellite program back on track. It is currently 18 months behind schedule. The new project head is Roy Gibson (ex-head of ESA, ex-head of the British Space Agency). Hipparcos being prepared for start of its astronomical mission. The big question is how long it will last: less than 18 months would essentially wreck the mission, two years or better would be good (although not as good as the original plans). Controllers are experimenting with things like the attitude-determination system, which were originally intended for the rather different environment of Clarke orbit. So far, Hipparcos is behaving very well. ESA's tracking station in Perth and CNES's station in Kourou are being added to the original single station at Odenwald (West Germany), to reduce the gaps in communications coverage. The big near-term worry is the eclipse period early next year, which will involve eclipses much longer than those experienced in Clarke orbit. CNES [French space agency] begins definition of a radarsat to complement the Spot optical satellites. Construction might start in 1994 for a first launch in 2000-2001. Ground resolution would be from 2-50m, with some ability to steer the beam to cover a wider ground track or linger longer on a single target area. The spacecraft bus would be the same one in the works for Spot 4 and Helios. Soviets plan modest upgrades to Soyuz and Progress spacecraft. Soyuz will add a new window to make manual docking easier. (Nobody is yet sure whether the Soyuz TM-8 episode -- in which the crew aborted the automatic docking with Mir because the pitch angle looked off -- was a real misalignment or just difficulty in seeing the real angle. The current TV/periscope setup is not very convenient.) The new Progress M has a large payload than the old Progress, plus an optional cargo-return capsule (set for first use late next year). NASP developers continue to debate whether orbital flights should make powered or unpowered landings. Everyone agrees on powered landings for early atmospheric tests, but the ability to make a powered landing does impose weight penalties for extra fuel and engine-restart systems. There is also some question about what happens if you're depending on being able to relight the engines and you can't. No final decision has been made, but the NASP office seems to favor unpowered landings. NASP managers are seriously unhappy about the 2.5-year schedule slip that seems to be increasingly a fait accompli. Only about a year of that seems justified by the technology, and there is concern that many of the best people will be lost if the program spends 18 months marking time. Boeing produces a significant boost in efficiency of space-rated solar cells, using a scheme which stacks two cells mechanically to make use of a wider spectrum than a single cell can achieve. People have been trying for years to grow one type of cell in a thin layer on another, with disappointing results. Boeing used some clever mechanical design to get the same effect. NASA and aerospace contractors are very interested. -- 1755 EST, Dec 14, 1972: human | Henry Spencer at U of Toronto Zoology exploration of space terminates| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 12 Dec 89 22:19:01 GMT From: zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!caesar.cs.montana.edu!milton!maven!games@tut.cis.ohio-state.edu (Games Wizard) Subject: clarifications on: Re: V10 No.327 and inflammatory ephithets In article <70@uncmed.med.unc.edu>, unccab@calico.med.unc.edu (Charles Balan) writes: > In article RIDGWAY@MITVMA.BITNET ("Lee S. Ridgway") writes: >>Not all of us "liberals" are not anti-space. > ^^^ ^^^ ^^^^ > Um, could someone from sci.lang please help me out here. What exactly is > being said? All of us "l's" are anti-space? No "l's" are anti-space? > I'm completely befuddled. > Well, this is a triple negation, hence it is a single negation. Simplification at the poibnt of closest bonding yields Not all of us "liberals" are pro-space. (substitute not anti-space for pro-space) However this is not strictly accurate, as not anti-space could also mean neutral ( anti- or pro- are not the only possibilities ) so it might be better to state it as not all of us "liberals" are pro-space or neutral towards space. It might be easier however to simplify the not all into the more appropriate some yielding some liberals are not anti-space or actually with all substitutions some liberals are pro-space, and some liberals are neutral towards space. Does this help any? I thought not. oh well. ------------------------------------------------------------------------------- Trendy footer by: John Stevens-Schlick Internet?: JOHN@tranya.cpac.washington.edu 7720 35'th Ave S.W. Seattle, Wa. 98126 (206) 935 - 4384 ------------------------------------------------------------------------------- My boss dosn't know what I do. ------------------------------ Date: Tue, 12 Dec 89 02:09 MDT From: Subject: STOP SPACENET! Hello, would somebody out there kindly remove me from the SPACENET mailing list????!!!!!!!!!!! I would surely appreciate it!!!!! Jeff Kirkley (JTKIRKLEY @ COLOSPGS) ------------------------------ Date: 12 Dec 89 17:30:11 GMT From: wrksys.dec.com!klaes@decwrl.dec.com (CUP/ASG, MLO5-2/G1 6A, 223-3283 12-Dec-1989 1233) Subject: Relative distances and sizes in the Universe. Several weeks ago I posted a request for slide sets comparing the relative distances in the solar system and the other stars: It would seem that slide sets of this scale system are rather hard to come by. I sent out a request to several other computer networks, along with calling a number of planetariums, museum stores, and searched through various scientific catalogues, all without significant result. I was able to use my resources and gather some information from several friends on various types of relative celestial scales, and have come up with some relevant information. The first selection depicts the solar system on a major league baseball field from E. C. Slipher's "Planet" section of THE WORLD BOOK ENCYCLOPEDIA P, VOLUME 15, Field Enterprises Educational Corporation, Chicago, Illinois, 1964. If the Sun were the size of a United States half-dollar (fifty cents) on home plate, the planet Mercury would be 120 centimeters (four feet) away, Venus would be 225 centimeters (7.5 feet) away, Earth would be 315 centimeters (10.5 feet) distant, Mars would be 480 centimeters (sixteen feet) away, Jupiter would be 1,650 centimeters (55 feet) from the Sun (at the pitcher's mound), Saturn would be 3,030 centimeters (101 feet) away (near second base, and the last planet in the infield), Uranus would be 6,075 centimeters (202.5 feet) away, Neptune would be 9,540 centimeters (318 feet) away, and Pluto would be 12,615 centimeters (420.5 feet) distant from the Sun, deep in the outfield. To compare planetary diameters, if the Sun were the size of an average beachball, then Jupiter would be a golf ball, Saturn a Ping- Pong ball, Uranus and Neptune marbles, Mercury and Pluto pinheads, and Venus, Earth, and Mars would be about half the size of tackheads. The next comparison scale comes from the "Life on Other Worlds" section of Carl Sagan's PLANETS, LIFE Science Library, 1966. This one depicts the solar system on a map of Europe and Africa, with the average distance between the Sun and Earth, 150 million kilometers (93 million miles) - also known as one Astronomical Unit (A.U.) - now equaling 240 kilometers (150 miles). If the Sun were situated in Norway, Saturn would orbit just south of Italy, and Pluto would be 10,400 kilometers (6,500 miles) away along the Cape of Good Hope in South Africa. The next source on various celestial scales comes from THE STARFLIGHT HANDBOOK: A PIONEER'S GUIDE TO INTERSTELLAR TRAVEL, by Eugene F. Mallove and Gregory L. Matloff (John Wiley & Sons, Inc., New York, 1989, ISBN 0-471-61912-4, hardcover), which gives the following description on page 5: If the Sun were the size of a one-centimeter (0.4-inch) marble, then Earth would be 0.1 millimeters (0.004 inches) in diameter and one meter (39.37 inches) from the Sun. The planet Pluto would orbit 42 meters (139 feet) from the Sun, and Proxima Centauri - the Sun's nearest stellar neighbor - would be 292 kilometers (175 miles) away. The next two books listed are both authored by Neil McAleer. The first is THE COSMIC MIND-BOGGLING BOOK (Warner Books, Inc., New York, 1982, ISBN 0-446-37932-8, paperback). On the front cover of the book, the following comparison is made (one of my favorites, from an aesthetic point of view): If the solar system out to the orbit of Pluto could fit in a coffee cup, the Milky Way Galaxy would be the size of the North American continent. On page xiii - If you had a specially-designed automobile which could handle the rigors of spaceflight, it would take you 201 billion years to "drive" from the Sun to the center of the Milky Way Galaxy at 161 kilometers per hour (100 miles per hour). Also, if the solar system were 2.54 centimeters (one inch) across, the Milky Way Galaxy would be 161,000 kilometers (100,000 miles) wide. On pages 3-4 - If the Sun were the size of a sixty-centimeter (two-foot) beachball, Earth would be the size of a pea and 6,450 centimeters (215 feet) away. The planet Jupiter would be a large orange 31,680 centimeters (1,056 feet) distant from the Sun. On pages 12-13 - If the Sun were a 14-centimeter (5-inch) orange, Earth would be a sesame seed fifteen meters (49 feet) away. Pluto would be the size of a grain of millet six hundred meters (3,400 feet) away, and the star Alpha Centauri would be four thousand kilometers (2,500 miles) from the Sun. On page 83 - If you could fly a specially modified Boeing 747 jetliner through space at 965 kilometers per hour (six hundred miles per hour), it would take you 1,903 years to fly from the orbit of the planet Uranus out to the orbit of Neptune. On page 128 - If the Sun were a basketball in New York City, then Alpha Centauri would be another basketball eight thousand kilometers (five thousand miles) away in Honolulu, Hawaii. On page 129 - If you traveled at the speed which the APOLLO spacecraft used in an average six-day round-trip journey to Earth's Moon (approximately 40,000 kilometers per hour/25,000 miles per hour), it would take you 850,000 years to reach Alpha Centauri. By contrast, the faster PIONEER 10 and 11 and VOYAGER 1 and 2 Jovian probes will reach that distance (4.3 light years) in only eighty thousand years. On page 161 - If you used a starship traveling at one-tenth the speed of light (300,000 kilometers per second/186,000 miles per second) to reach the farthest star in the Milky Way Galaxy, the ship would take 800,000 years to reach it from the Sun. If one Astronomical Unit (A.U.) - the distance between the Sun and Earth, which is roughly 150 million kilometers/93 million miles - were reduced to 2.54 centimeters (one inch), then that farthest star would be 127,000 kilometers (79,000 miles) away. The next selection is from the other Neil McAleer book, THE MIND-BOGGLING UNIVERSE (Doubleday & Co. Inc., Garden City, New York, 1987, ISBN 0-385-23039-7, paperback): On pages 10-11 - If the solar system out to Pluto were 2.54 centimeters (one inch) in diameter, then the center of the Milky Way Galaxy would be 609 kilometers (379 miles) away. Also, to walk one A.U. at five kilometers per hour (three miles per hour) would take 3,500 years. To drive one light year at 88 kilometers per hour (55 miles per hour) would take 12.2 million years. On page 15 - The Milky Way Galaxy's longest spiral arm of gas, dust, and stars is 125,000 light years long. It would take an automobile driving at 88 kilometers per hour (55 miles per hour) 1.5 trillion years to cover that distance. On page 35 - An automobile driving at 88 kph (55 mph) would take 52 million years to reach Proxima Centauri from the Sun. The next selection comes from THE UNIVERSE...AND BEYOND by Terence Dickinson (Camden House Publishing, Ltd., Camden East, Ontario, Canada, 1986, ISBN 0-920656-48-X, paperback): On pages 16-19 - If the actual distance between the Milky Way Galaxy and the Andromeda Galaxy (two million light years) were shrunk to a typical book-reading distance, then the most remote galaxies known would be 1.6 kilometers (one mile) away. If the Sun were shrunk to the size of a 2.54-centimeter (one inch) Ping-Pong ball, Earth would become a dust speck 240 centimeters (eight feet) away, with the Moon being an even smaller speck just 6.25 millimeters (0.25-inch) from Earth. Jupiter would be a pea 1,200 centimeters (forty feet) from the Sun, and Pluto is a dust speck nine thousand centimeters (three hundred feet) away. The Oort Cloud of comets surrounding our solar system would be the size of atomic particles and reside several kilometers distant, with the comets themselves averaging several meters apart from each other. The Alpha Centauri trinary star system would consist of two walnuts (Alpha and Beta) and a pea (Proxima) 640 kilometers (four hundred miles) from our solar system. If Earth's solar orbit were reduced to the size of a United States dime, the average distance between stars is now a little over one kilometer (1.6 miles). The Milky Way Galaxy would be the actual size of Earth. The distance to the Andromeda Galaxy would be over half the actual distance between Earth and the Moon. If you could hold the Milky Way Galaxy in your hand, the stars in it would be sub-atomic in size, and the Andromeda Galaxy would be 210 centimeters (seven feet) away. My final textbook selection comes from CYCLES OF FIRE, by William K. Hartmann and Ron Miller (Workman Publishing, New York, 1987, ISBN 0-89480-502-9, paperback): On pages 14-15 - If Earth were the diameter of a microparticle of soot, then the Sun would be one hundred times larger, the size of a mote of dust, or one hundredth of a millimeter across. The solar system would be the size of a saucer, and the Oort Cloud of comets would exist several house lots away. Alpha Centauri would be another dust mote one to two city blocks from the Sun, and the Milky Way Galaxy would be the size of North America. Some of the other nearby galaxies would be the varying sizes and distances of Earth's continents. The known limits of the Universe would stretch halfway across the solar system. My friend and co-worker Drew LePage came up with some various calculations on the celestial distance scale: If the orbit of Pluto were the size of a U.S. dime, this would be the size of various distances in the Universe: Earth's orbit would have a diameter of about 0.5 millimeter (about half the thickness of a dime). One light year would be about 15.2 meters (49.9 feet). One parsec (3.26 light years) would be about 49.7 meters (163 feet). The closest star would be 65.4 meters (214 feet) away. The closest one hundred known stars would be inside a sphere about 640 meters (2,100 feet) across. The Sun would be 456 kilometers (283 miles) from the center of the Milky Way Galaxy. The Milky Way Galaxy would be 1,520 kilometers (945 miles) across. To put intergalatic distances into perspective, if the Milky Way Galaxy were the size of a dime: The orbit of Pluto would be about the size of a hydrogen atom. The Andromeda Galaxy would be 41.8 centimeters (16.5 inches) away. One megaparsec would equal 61.9 centimeters (2.03 feet). The recently discovered "Wall" of Galaxies would be about 40 meters (125 feet) to 60 meters (190 feet) away, about 3 meters (10 feet) thick, and extend for at least 100 meters (300 feet). The most distant quasar known would be about 2.6 kilometers (1.7 miles) away. The size of the observable Universe would be about 5.7 kilometers (3.5 miles) across. If nothing else, these figures should give some idea as to just how incredibly vast the known Universe is. Larry Klaes klaes@wrksys.dec.com or - ...!decwrl!wrksys.dec.com!klaes or - klaes%wrksys.dec@decwrl.dec.com or - klaes@wrksys.enet.dec.com or - klaes%wrksys.enet.dec.com@uunet.uu.net N = R*fgfpneflfifaL ------------------------------ End of SPACE Digest V10 #339 *******************