Date: Wed, 20 Jan 93 05:10:09 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #065 To: Space Digest Readers Precedence: bulk Space Digest Wed, 20 Jan 93 Volume 16 : Issue 065 Today's Topics: ** BUSSARD RAMSCOOP ** Antarctic meteorites (was Re: Cheap Mars Rocks) Earth's rotation rate may be due to early collisions [Release 93-12] (Forwarded) Handling Antimatter (2 msgs) Oxygen in Biosphere 2 Parting Words Planetary Ephemeris Routines? Sabatier reactor? (was Re: Oxygen in Biosphere 2) Soyuz as an ACRV Territorial conquest? Toutatis Captured by Radar Images Two-Line Orbital Element Set: Space Shuttle Znamya: Orbiting mirror. 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: 20 Jan 93 03:56:00 GMT From: Josh Hopkins Subject: ** BUSSARD RAMSCOOP ** Newsgroups: sci.space 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? Depends on the sail. Heliogyros are fairly trivial to deploy and retract (although of course "trivial" is comparative in this case). Other types are more difficult. The next question though is _why_ you want to combine a solar sail with a ramjet. Solar sails are fairly slow and ramjets have to be moving very quickly to work. Solar sails have to be near the sun for efficiency whereas I suspect bussard ramjets benefit from being outside the solar system (someone want to back me up or shoot me down on this one?). Get a first stage with more thrust. Or better yet, build a big laser in the solar system and just use the sail for propulsion. It may well be easier than trying to build an interstellar ramjet. > Okay, anyways, >(no more parentheses anymore) does anybody know of a way to retract this >solar sail (which must be rigid (but possibly foldable), as it will >contain solar panels VERY useful for the initial approach I'd be very impressed if you could combine the function of pv cells with solar sail material. The sail material must be very thin and strong (as well as a few other requirements) and should be reflective to a very high degree. Solar cells must absorb light, and tend to be to thick and heavy to be very useful. Besides, even if you could make a solar sail the generated power you'd have a hard time figuring out what to do with it all. A sail big enough to boost an interstellar probe up to the speeds you require would be intercepting enough light to power a good sized planet. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu Q: How do you tell a novice from an expert. A: A novice hesitates before doing something stupid. ------------------------------ Date: Tue, 19 Jan 1993 16:47:08 GMT From: zrepachol@cc.curtin.edu.au Subject: Antarctic meteorites (was Re: Cheap Mars Rocks) Newsgroups: sci.space,sci.astro,alt.sci.planetary In article <1jg0b7INNigf@gap.caltech.edu>, kwp@wag.caltech.edu (Kevin W. Plaxco) writes: > In article S.J.Morden@newcastle.ac.uk (S.J. Morden) writes: >>Similar situations occur in the Nullabor Plain in Western Australia, and in >>"blow-outs" in the Southern U.S., where the ground is eroded away, leaving >>concentrated meteorites. >> >>Any questions? > Yup. What is the concentration mechanism on the Nullabor Plain? For the last n thousand years, wind and thermal cycleing. " Null Abor " literaly "no trees" is a *VERY* apt name. A typical day/night cycle would be 35-40C day to -15-0C overnight. Geologicaly it is the oldest part of the earths crust overlaid with soft lime-stone, full of HUGE cave systems. The rainfall is sporadic thunderstorms, which may deliver several years rain in 1/2 an hour! My mother was a teacher at Rawlinna in the 30s, so if you would like details, let me know. ~Paul ------------------------------ Date: Tue, 19 Jan 1993 18:08:43 GMT From: "Robert F. Drury" Subject: Earth's rotation rate may be due to early collisions [Release 93-12] (Forwarded) Newsgroups: sci.space In article <1993Jan18.210842.12714@hpcvca.cv.hp.com>, rayd@hpcvcas.cv.hp.com (Ray Davis) wrote: > > > "A popular theory holds that the collision of a Mars-sized planetary body > > with the Earth threw considerable debris into orbit, which then came together > > to form the moon," Dones said. "Thus, the same impact which gave Earth its > > spin, could also have formed the moon." > > How does this popular theory account for the moon having zero spin? > > Ray Davis (rayd@cv.hp.com) > hplabs!hp-pcd.cv.hp.com!rayd The moon doesn't have "zero spin"; the period of rotation just matches the period of revolution. With zero spin, we'd get to see the "darkside" every month. My understanding is that this situation arose due to the frictional effects of tidal forces, and had nothing to do with the spin states of Earth and Moon upon formation. (in other words, the moon's rotation slowed down to its current equilibrium state). Standard disclaimer--my opinions are my own. ------------------------------ Date: 19 Jan 93 19:18:13 GMT From: Gary Coffman Subject: Handling Antimatter Newsgroups: sci.space In article <1993Jan18.212511.12464@emr1.emr.ca> budd@ccrs.emr.ca (Mark Budd) writes: > >This whole approach has the problem of equipotential within a spherical >shell. It has been long known that there is no gravitational gradient >within a uniform spherical shell of mass. The intuitive reason for this >is the counteracting of the 1/r^2 distance factor and the r^2 mass factor >within a cones on either side of any point within the shell. (Did this >make any sense without an ascii drawing?) The same would be true for >a charged sphere. Of course this assumes that the sphere is uniformly >charged, but for an electron confined to the atoms of the shell (but not >to any individual atom) this would essentially be the case. I'm not sure this would be true. Certainly we are dealing with quantum events on this scale. The electron "wavicle" is going to be smeared out with probability lumps at the bond angles. I don't think a uniform spherical cloud shape can be assumed. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: 20 Jan 93 00:15:22 GMT From: Sam Warden Subject: Handling Antimatter Newsgroups: sci.space -- samw@bucket.rain.com (Sam Warden) -- and not a mere Device. ------------------------------ Date: 19 Jan 93 21:16:33 GMT From: Pat Subject: Oxygen in Biosphere 2 Newsgroups: sci.space Bill Higgins asked me to post a little bit on the Sabatier reaction and on how it could be made in a small facility. Now I am not a chemical engineer or a chemist. Actuually my total knowledge of this is mostly bounded by a talk i went to given by Robert Zubrin PhD. and some dinner conversation with him. Basically if CO2 + H (Over Iron Catalyst) --> H2O + Carbon. You crack Electrolytically H2O --> O2 + H. Free Hydrogen is then Brought back to the carbon to get CH4. I cant remember the exact details, but basically for a small amount of starting hydrogen, you can take CO2 and make methane. or you can run the different reaction and just keep scraping carbon off the catalyst bed. Now as to size, Zubrin implied that the process plant only needs to be no larger then 1-2 CF in scale, because you run the gear more or less continously. B2 has lost appx 9000 liters of o2 over 1 year???? if so we are talking about an imbalance of only 1-2 liters per hour. If you think about it, you can blow that amount of gas through a capillary tube in an hour, hence even if the reaction chambers are not large, they only need to process 10cc/min appx. Now maybe i lost an order of magnitude in there, but i'd appreciate anyone with better chemical engineering pointing it out. thanks pat ------------------------------ Date: 19 Jan 1993 13:59 EDT From: Greg Macrae Subject: Parting Words Newsgroups: sci.space In article , flb@flb.optiplan.fi ("F.Baube x554") writes... >> "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology >> -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry > >Are these perhaps the *last* words spoken on the moon ? >If not, what *were* the last ? > >-- One of my favorite lines from the space program were the last words spoken on the moon. A flowery speach was prepared for and read by the Apollo 17 astronauts. It was intended as the last words spoken from the Apollo lunar missions. After reading the speach, the commander turned to the pilot and said, over an open mike (ie. it was broadcast), "Let's get this mother out of here." Those were the last words spoken on the moon. -------------------------------------------------------------------- MacRae | Darting dragonfly... | Pull off its shiny wings and look... spgreg@mars.lerc.nasa.gov | Bright red pepper pod! | -Kikaku -------------------------------------------------------------------- ------------------------------ Date: 19 Jan 1993 20:45:37 GMT From: Jonathan Young <93jay@williams.edu> Subject: Planetary Ephemeris Routines? Newsgroups: sci.space,sci.astro,comp.lang.c I am trying to write a small program to add external computer control to our existing telescope system. The current computer cannot calculate planetary postitions but can accept coordinates from a serial line. It would be pretty simple to write a program that would present the user with a menu of planets and send the coordinates of that planet to the telescope computer. What I need are some routines which can calculate planet positions with accuracy more important than speed. Since I'll have to put these eventually onto a Macintosh, C code is preferred over Fortran although I can try to translate others. Thanks in advance Jonathan Young Williams College Astronomy Department ------------------------------ Date: 19 Jan 93 18:14:53 GMT From: Willie Smith Subject: Sabatier reactor? (was Re: Oxygen in Biosphere 2) Newsgroups: sci.space I'm not convinced that such a reactor would do any good in this case, unless you had a _lot_ of them. 9,000 kilograms of LOX comes out to something like (scribble, scribble) 50,300 cubic feet of oxygen gas. At one cubic foot per hour, that's 5.7 years to make up the deficit... On the other tentacle, it sounds like interesting technology, pleae tell us more! Startup costs, maintainance and operating costs, reliability? Willie Smith wpns@pictel.com -- Willie Smith wpns@pictel.com N1JBJ@amsat.org "I'll make Beelyuns and Beelyuns from the book contract and the TV show with government funding for looking for the nothing in the void where The Bang caused the hole in the middle of it all" Frank Hayes - Cosmos. ------------------------------ Date: Tue, 19 Jan 1993 20:11:33 GMT From: Edmund Hack Subject: Soyuz as an ACRV Newsgroups: sci.space In article <561810c62@ofa123.fidonet.org> David.Anderman@ofa123.fidonet.org writes: >AW>Oh, that's a given. The booster may be the Shuttle but we will see Soy >AW>being launched for (at the very least) ACRV on US launchers. > >Under the terms of the Launch Services Purchase Act, NASA is prohibited >from orbiting non-shuttle-specific payloads. Therefore, >using the shuttle to orbit Soyuz spacecraft contravenes the LSPA. Why do you assert that it is not STS specific, since the final design is not yet established? For example, the design might require a full load of fuel/oxidizer to do safe deorbit and landing, so it would need to be docked without using the propulsion system by placing it with the RMS on the Shuttle. > >However, several U.S. commercial vendors can supply launchers that >can easily orbit a Soyuz for a more reasonable price than the shuttle. As >a nice side benefit, this would create a second means of access to space >in the US, in case the shuttle fleet is grounded. The cost to orbit might be cheaper by commercial carrier, depending on how you do the accounting. As we have seen here, the entire government uses different procedures for figuring the "cost" of something. If the STS fleet is grounded, the only impact aside from STS-specific ops woud be on Freedom. This might or might not be critical. -- Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah.. "You know, I think we're all Bozos on this bus." "Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode" ------------------------------ Date: Tue, 19 Jan 1993 17:55:17 GMT From: Ed Faught Subject: Territorial conquest? Newsgroups: sci.space In article 18084TM@msu.edu (Tom) writes: > >>>>The urge to colonize the universe seems to come from an urge for >>>>territorial conquest that has been with us for a long time. It is >>>>interesting how old themes are constantly repeated in the present. > IMHO, territorial conquest was the politcal reason used to obtain funding. -- Ed Faught WA9WDM faught@berserk.ssc.gov Superconducting Super Collider Laboratory ------------------------------ Date: 20 Jan 93 01:46:48 GMT From: Ron Baalke Subject: Toutatis Captured by Radar Images Newsgroups: sci.space,sci.astro,alt.sci.planetary From the "JPL Universe" January 15, 1993 Earth-approaching asteroid captured by radar images By Mary Hardin Using a large radar antenna at the Goldstone Dep Space Communications Complex in the Mojave desert, JPL astronomers have obtained the sharpest images yet of an Earth-approaching asteroid, 4179 Toutatis, as it passed extremely close to Earth last month. "This is our first clear look at one of the many thousands of asteroids whose orbits can intersect Earth's orbit," said Dr. Steven Ostro of the Geology and Planetary Section 326 and leader of the radar team. The radar images reveal Toutatis to be a "contact binary" asteroid, consisting of two irregularly shaped, cratered objects about 4 and 2.5 kilometers (2.5 and 1.6 miles) in average diameter and rotating with a period between 10 and 11 days. Toutatis passed 4 million kilometers (2.5 million miles) from Earth on Dec. 8 -- less than 10 times farther away than the Moon. Discovered by French astronomers on Jan. 4, 1989, almost nothing was known about Toutatis before the radar images were taken. The asteroid has now been shown to have a jagged, cratered surface which indicates a complex history of collisions. "The binary nature of Toutatis is the most important single result of this radar experiment," Ostro said. Previous radar images taken by Ostro and his colleagues of another Earth-approaching asteroid, 4769 Castalia (1989 PB), were too crude to reveal surface details but did show the object to be bifurcated into two 1-kilometer (0.6 mile) lobes. Radar echoes bounced off of other asteroids have also contained hints of contact-binary configurations. "Three years ago we were startled by the initial evidence for contact-binary asteroids," Ostro said. "Now it seems that double bodies might be very common in the Earth-approaching asteroid population. If so, then their abundance has important implications for theories of the origin and evolution of asteroids and meteorite source bodies. "For example, sub-catastrophic collisions might play an important role in delivering asteroidal bodies into the inner solar system from the main asteroid belt between Mars and Jupiter," he said. The two components of Toutatis probably joined in a relatively gentle collision, but their origins and the times and circumstances of events leading up to the asteroid's current configuration are unknown, Ostro continued. "Toutatis may be two pieces of a much larger asteroid that once orbited in the main belt between Mars and Jupiter, but was disrupted in a catastrophic collision with another large object," Ostro speculated. Another possible scenario is that Toutatis was split into two parts by a collision not quite energetic enough to completely pulverize it. The best way to study the history of Toutatis would be through the analysis of samples returned from both Toutatis components. While there are no plans yet to rendezvous with Toutatis, Ostro said it and dozens of other near-Earth asteroids are leading candidates for robotic flyby, rendezvous and sample- return missions because of the asteroids' small gravitational fields and because of the ease of maneuvering spacecraft between the orbits of Earth and the asteroids. For most of the radar observations, a 400,000-watt coded radio transmission was beamed at Toutatis from Goldstone's main 70-meter (230-foot) antenna. The echoes, which took as little as 24 seconds to travel to Toutatis and back, were received by the new 34-meter (112-foot) antenna and relayed back to the 70-meter station where they were decoded and processed into images. Full processing of the Toutatis radar data over the next few months is expected to reveal details of surface features less than 100 meters (330 feet) across. Eventually a detailed three- dimensional computer model of the object will be constructed from the data, Ostro said. In addition to Ostro, members of the JPL radar team include Dr. Raymond Jurgens, Keith Rosema, Ron Winkler, Denise Howard, Randy Rose, Dr. Martin Slade and Dr. Donald Yeomans. ### ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while, /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck. |_____|/ |_|/ |_____|/ | ------------------------------ Date: 19 Jan 93 23:20:51 GMT From: TS Kelso Subject: Two-Line Orbital Element Set: Space Shuttle Newsgroups: sci.space The most current orbital elements from the NORAD two-line element sets are carried on the Celestial BBS, (513) 427-0674, and are updated daily (when possible). Documentation and tracking software are also available on this system. As a service to the satellite user community, the most current elements for the current shuttle mission are provided below. The Celestial BBS may be accessed 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using 8 data bits, 1 stop bit, no parity. Element sets (also updated daily), shuttle elements, and some documentation and software are also available via anonymous ftp from archive.afit.af.mil (129.92.1.66) in the directory pub/space. STS 54 1 22313U 93 3 A 93 19.25033564 .00058283 00000-0 18298-3 0 219 2 22313 28.4724 112.5776 0013729 296.3232 214.4186 15.89736109 902 -- Dr TS Kelso Assistant Professor of Space Operations tkelso@afit.af.mil Air Force Institute of Technology ------------------------------ Date: 19 Jan 93 09:49:52 GMT From: Dennis Newkirk Subject: Znamya: Orbiting mirror. Newsgroups: sci.space In article <1993Jan17.173706.1@vax1.tcd.ie> apryan@vax1.tcd.ie writes: >In article <30262@castle.ed.ac.uk>, ntc@castle.ed.ac.uk (N T Clifford) writes: >> >> Apparently a recent Progress cargo ship (1992-71A?) currently docked >>(or station keeping) with Mir is due (maybe next month) to unfurl a 65 foot >>'space mirror' constructed from aluminium coated plastic film, in an >>experiment known as `Znamya' (Banner). >> >> Apparently this is an attempt to extend the daylight hours of the Siberian regions by reflecting sunlight to the required areas. >> >The information carried on our UK newsline (0891-88-1950) says that >the last Progress in Oct'92 carried p an experimental solar sail perhaps >this is where the confusion arises? Anyway, Mir will now be crossing UK and >Ireland in daylight until it is visible in morning skies in early Feb. (and >evening skies from early March) although such a large item could probably be Progress M-15 launched on Oct 5 1992 is the ship in question. It will remain docked to Mir through the Soyuz TM-16 docking and Soyuz TM-15 undocking. In February it will undock to begin several days of mirror tests using its Znamya solar sail. The tests were originally scheduled for October but were delayed due to control and thermal reasons. This was reported in an Energiya-USA press release. There are also reports of budget problems contributing to the delay. Source: James Oberg, a Houston space engineer and consulting speciallist in Russian aerospace. Dennis Newkirk (dennisn@ecs.comm.mot.com) Motorola, Land Mobile Products Sector Schaumburg, IL ------------------------------ From: Ed Faught Newsgroups: sci.space Subject: Re: Antimatter Message-Id: <1993Jan19.174752.12232@sunova.ssc.gov> Date: 19 Jan 93 17:47:52 GMT References: <1993Jan18.230756.849@ualr.edu> Sender: News Admin Reply-To: faught@berserk.ssc.gov Organization: Superconducting Super Collider Laboratory Lines: 8 Nntp-Posting-Host: berserk.ssc.gov Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1993Jan18.230756.849@ualr.edu> writes: >Does anyone have any proposals for how the actual matter/antimatter "reaction" >would be regulated. Dilithium crystals, of course! -- Ed Faught WA9WDM faught@berserk.ssc.gov Superconducting Super Collider Laboratory ------------------------------ End of Space Digest Volume 16 : Issue 065 ------------------------------