Date: Fri, 4 Sep 92 05:00:04 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #164 To: Space Digest Readers Precedence: bulk Space Digest Fri, 4 Sep 92 Volume 15 : Issue 164 Today's Topics: Antarctica (was: SPS) Clinton/Gore Space Position Inflatable Space Stations - Why Not ? Laser distance record? (5 msgs) Shuttle traking programs Sizing of launch vehicles (was Saturn Class) Special Relativity SPS feasibility and other space development Teleoperation TOPEX, demise of SEASAT & nuclear sub wakes What is the speed of light measured from? With telepresence, who needs people in Earth orbit? 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, 03 Sep 92 16:51:56 GMT From: Doug Mohney Subject: Antarctica (was: SPS) Newsgroups: sci.space In article <67523@hydra.gatech.EDU>, ccoprmd@prism.gatech.EDU (Matthew DeLuca) writes: >Besides, there's gravity in Antarctica; I think some of the mystique >of space exploration and colonization is the fact that when you are >floating in the middle of your spacecraft of habitat, you know you aren't >in Kansas anymore. With just freezing weather and snow and ice, you >could be in Toronto for all you can tell the difference. :-) Not true. There's only one Henry and he's in Toronto. Support U.N. military force against Serbia -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 3 Sep 1992 10:57 EST From: Tom Quesinberry Subject: Clinton/Gore Space Position Newsgroups: sci.space I found this on Case Western Reserve University's excellent cleveland.freenet, and I thought It might interest sci.space readers. The Republican Position was not posted on freenet, so I have not included it. If it's posted later I will provide it to sci.space. Quiz ------------------------------------------------------------------------- Tom Quesinberry | E-MAIL: aavso@scivax.lerc.nasa.gov Research Analysis Center/CSD | PBX: (216) 433-5130 Lewis Research Center/NASA | LIFE: I would rather see starlight Cleveland, Ohio 44135 | than streetlights. ------------------------------------------------------------------------- * Some Ignorance Is Indestructible --------------------------------------------------- Article 100 of nptn.campaign92.dems: Newsgroups: nptn.campaign92.dems Path: usenet.ins.cwru.edu!nptn.org!tmg From: tmg@nptn.org (Tom Grundner) Subject: SPACE PROGRAM: Position Paper Message-ID: <1992Aug31.152504.1820@nptn.org> Organization: National Public Telecomputing Network Date: Mon, 31 Aug 1992 15:25:04 GMT Approved: xx001@nptn.org -------------------------------------------------------- CLINTON/GORE ON AMERICA'S SPACE PROGRAM The end of the Cold War offers new opportunities and new challenges for our civilian space program. In recent years the program has lacked vision and leadership. Because the Reagan and Bush administrations have failed to establish priorities and to match program needs with available resources, the National Aeronautics and Space Administration (NASA) has been saddled with more missions than it can successfully accomplish. Bill Clinton and Al Gore support a strong U.S. civilian space program -- for its scientific value, its economic and environmental benefits, its role in building new partnerships with other countries, and its inspiration of our nations youth. A Clinton/Gore Administration space program will seek to meet the needs of the United States and other nations while moving toward our long-term space objectives, including human exploration of the solar system. A Clinton/Gore space program will also promote the development of new technologies, create new jobs for our highly-skilled former defense workers, and increase our understanding of the planet and its delicate environmental balance. Move beyond the Cold War * Restore the historical funding equilibrium between NASA and the Defense Departments space program. The Reagan and Bush Administrations spent more on defense space initiatives than on civilian space projects. * Achieve greater cooperation in space with our traditional allies in Europe and Japan, as well as with Russia. Greater U.S.-Russian cooperation in space will benefit both countries, combining the vast knowledge and resources both countries have gathered since the launch of Sputnik in 1957. Improve the American economy through space * Direct NASA to give high priority to continued improvement of the American civil aircraft industry, which faces increasing international competition. NASA research can play an important role in developing less polluting, more fuel efficient, and quieter aircraft. * Work to improve our space industries competitiveness. Well direct NASA to develop cutting-edge rocket and satellite technologies. We will also develop a new, cost effective, and reliable launch system to maximize scientific and commercial payloads. Link NASA and the environment * Support NASA efforts -- like Mission to Planet Earth -- to improve our understanding of the global environment. * Call on NASA to develop smaller, more focused missions which address pressing environmental concerns. Strengthen NASA and education * Direct NASA to expand educational programs that improve American performance in math and science. Space education can help maintain our technological edge and improve our competitiveness. * Direct NASA to expand the outreach of its educational efforts beyond its five field centers, so that millions more people can learn about space. * Maintain the Space Shuttles integral role in our civilian space program. The Shuttle is extremely complex and will always be expensive and difficult to operate. But we must take full advantage of its unique capabilities. * Support completion of Space Station Freedom, basing its development on the twin principles of greater cooperation and burden sharing with our allies. By organizing effectively on this project, we can pave the way for future joint international ventures, both in space and on Earth. Encourage planetary exploration through the best space science * Stress efforts to learn about other planets. These improve our understanding of our own world and stimulate advances in computers, sensors, image processing and communications. * Fully utilize robotic missions to learn more about the universe. * Although we cannot yet commit major resources to human planetary exploration, this dream should be among the considerations that guide our science and engineering. Because the entire world will share the benefits of human planetary explorations, the costs for any such projects should be borne by other nations as well as the United States. The Record * Senator Al Gore chairs the Senate Subcommittee on Science, Technology, and Space, which has primary responsibility for NASA and plays a key role in efforts to strengthen and revitalize America's space program. * Strongly favors a balanced manned and unmanned space program. Supports completion of Space Station Freedom and enhancements to the fleet of Space Shuttles to ensure safety and reliability. * Has championed Mission to Planet Earth, an initiative designed to gather comprehensive information on the Earth's changing environment. He strongly supports efforts to channel information on the Earth's environment to teachers and school children. * Strongly supports efforts to strengthen our leadership in aviation. * Has tried to use space exploration as a bridge to international cooperation, not competition. Pushed the administration to investigate the possibilities for integrating surviving elements of the Soviet space program into the U.S. program in ways beneficial to America and its aerospace workers. * Following the Challenger disaster, Senator Gore uncovered quality assurance deficiencies at NASA, gaining a greater commitment to quality assurance and accountability at NASA. ------------------------------ Date: Thu, 3 Sep 1992 14:50:36 GMT From: Jim Sims Subject: Inflatable Space Stations - Why Not ? Newsgroups: sci.space >I have read in several sf stories about using the shuttle main tanks as >modules for space habitats...just having the shuttle carry the tank with it >into orbit. Some authors stated that it would not take any extra fuel(??) >to do so. >Any of you experts out there have an answer as to why NASA doesn't use the >tanks as at least a temporary habitation? Maybe this should go into the FAQ so new readers will quit asking it repeatedly? There are many reasons why we dont use the ETs. *I* believe most of them are smokescreens to preserve fred, your mileage may vary... (1) It would "cost" several hundred (up to coupla thousand depending on the orbit) pounds of payload to boost the ETs to the same orbit as the shuttle. No free lunch, kids.... (2) Not all shuttle flights are to the same orbit, not all these orbits are places you'd wanna put an ET "hotel". For example, the HST orbit was as high as the shuttle could reasonably go with that weight of payload and have fuel for two re-dockings with the payload in case of snafus during post-deployment (and still come home ;-) (3) Since the foam isn't that well attached (least it wasn't when I was working at Michoud - there were big-time delamination problems on a few), you'd like increase the debris up htere *a lot*. Making sure it stays sub-orbital avoids this problem (and acknowleding and fixing it as well :-( (4) Once you get the ET up there, you need to do a coupla things: (a) remove remaining Hydrogen and Oxygen - sounds like a win, since the shuttle *never* empties the ET on the way up- typically 5% ?? of the fuel goes into the ocean or atmosphere on the way back down... But, how ya gonna get it out? (b) you need a docking port and/or at least a entry hatch - cutting a hole in 1" aluminum has likely never been tried in space. welding (burn a hole) in space is non-trivial as well.... other problems left to the imaginative reader.... --------------------------------------------------------------------------- sims@starbase.mitre.org The MITRE Corporation DECUS AI SIG Symposium Representative 7525 Colshire Drive MS Z421 the opinions are mine, who'd wanna claim 'em? McLean, Va. 22102 ------------------------------ Date: 3 Sep 1992 20:11:59 GMT From: Jeff Bytof Subject: Laser distance record? Newsgroups: sci.space >In article <26059@dog.ee.lbl.gov> sichase@csa1.lbl.gov (SCOTT I CHASE) writes: >>In article , rabjab@golem.ucsd.edu (Jeff Bytof) >writes... >>>To date, what is the farthest that a laser has been seen from? >>> >>>I recall a successful experiment sending a laser beam from the >>>Earth to a Surveyor lander on the Moon in the sixties. That would >>>make the current record approx. 384,400 km? >> >>If you allow masers, then the answer is best measured in parsecs. Oh... you >>want man-made lasers. Never mind. >> >I seem to recall reading something about natural lasers in the atmoshere > of Venus?????? Gee, I thought my question was clearly stated :-(. Manmade transmitter, manmade receiver, confirmation of receipt, of a Laser (optical maser) signal. What is the maximum confirmed link distance of said system? Jeff Bytof rabjab@golem.ucsd.edu ------------------------------ Date: 3 Sep 92 18:45:45 GMT From: Jeff Bytof Subject: Laser distance record? Newsgroups: sci.space To date, what is the farthest that a laser has been seen from? I recall a successful experiment sending a laser beam from the Earth to a Surveyor lander on the Moon in the sixties. That would make the current record approx. 384,400 km? Jeff Bytof rabjab@golem.ucsd.edu ------------------------------ Date: 3 Sep 92 20:23:59 GMT From: SCOTT I CHASE Subject: Laser distance record? Newsgroups: sci.space In article , rabjab@golem.ucsd.edu (Jeff Bytof) writes... >To date, what is the farthest that a laser has been seen from? > >I recall a successful experiment sending a laser beam from the >Earth to a Surveyor lander on the Moon in the sixties. That would >make the current record approx. 384,400 km? If you allow masers, then the answer is best measured in parsecs. Oh... you want man-made lasers. Never mind. -Scott -------------------- Scott I. Chase "The question seems to be of such a character SICHASE@CSA2.LBL.GOV that if I should come to life after my death and some mathematician were to tell me that it had been definitely settled, I think I would immediately drop dead again." - Vandiver ------------------------------ Date: Thu, 3 Sep 1992 19:38:38 GMT From: Ed Faught Subject: Laser distance record? Newsgroups: sci.space In article <26059@dog.ee.lbl.gov> sichase@csa1.lbl.gov (SCOTT I CHASE) writes: >In article , rabjab@golem.ucsd.edu (Jeff Bytof) writes... >>To date, what is the farthest that a laser has been seen from? >> >>I recall a successful experiment sending a laser beam from the >>Earth to a Surveyor lander on the Moon in the sixties. That would >>make the current record approx. 384,400 km? > >If you allow masers, then the answer is best measured in parsecs. Oh... you >want man-made lasers. Never mind. > >-Scott >-------------------- >Scott I. Chase "The question seems to be of such a character >SICHASE@CSA2.LBL.GOV that if I should come to life after my death > and some mathematician were to tell me that it > had been definitely settled, I think I would > immediately drop dead again." - Vandiver I seem to recall reading something about natural lasers in the atmoshere of Venus?????? -- Ed Faught WA9WDM faught@psychosis.ssc.gov Superconducting Super Collider Laboratory ------------------------------ Date: 3 Sep 1992 19:47:59 GMT From: Jeff Bytof Subject: Laser distance record? Newsgroups: sci.space >In article , rabjab@golem.ucsd.edu (Jeff Bytof) writes... >>To date, what is the farthest that a laser has been seen from? >> >>I recall a successful experiment sending a laser beam from the >>Earth to a Surveyor lander on the Moon in the sixties. That would >>make the current record approx. 384,400 km? >If you allow masers, then the answer is best measured in parsecs. Oh... you >want man-made lasers. Never mind. I mean the "link distance" between a transmitter and an actual reciever. Jeff Bytof rabjab@golem.ucsd.edu ------------------------------ Date: Thu, 3 Sep 1992 19:18:54 GMT From: Matthew Sheppard Subject: Shuttle traking programs Newsgroups: sci.space I had in my possesion a shareware version of a program that showed the shuttles current location on a world map. You had to supply it with certian numbers about the launch such as time and things and it kept track of where it was. Could someone point me to where I could find this program or even it's name so I could find it on ARCHIE? Please mail responses if possible, and post them too. -- | Matthew Sheppard CLARKSON UNIVERSITY sheppamj@sun.soe.clarkson.edu | | I'd rather have a bottle in front of me than a frontal lobotomy.ANoN | | I don't want a pickle. DoD#477 TEP#477 RIDE FREE (8^]..etcetera.. | ------------------------------ Date: Thu, 3 Sep 92 12:23:58 BST From: amon@elegabalus.cs.qub.ac.uk Subject: Sizing of launch vehicles (was Saturn Class) > programs are under different associate administrators). The Space > Station has mandated from the beginning that they will use the Space > Shuttle for delivery, so the question never was asked. > Dani: As you are no doubt aware, it is being asked now. Goldin has a team looking at all the options, including heavy lift and high inclination orbits (which could utilize Energiya & allow joint ops with the russians). Maybe it's just another study and then again, maybe it ain't... ------------------------------ Date: Thu, 03 Sep 92 18:20:28 EDT From: Tom <18084TM@msu.edu> Subject: Special Relativity >>>Neglecting the engineering problems of high speed travel through an >>>imperfect vacuum, you can travel light centuries in subjective >>>hours if you accelerate long enough. If you arrive at the Andromeda >>>galaxy 2 weeks after leaving earth, you could be justified in >>>thinking you travelled faster than c. It's just that the rest of >>>the universe will have aged 2x10^8 years. >> No. You would not feel you are going faaster, but the universe got smaller >> and slower. These are stardard result of Special Relativity. I bet you can't describe the difference between these interpretations of the same event, save that they are made by different observers. One of the standard results of SR is the non-objectiveness of any frame. (The frame of our near-c trip to M31 becomes inertial when the engines are turned off, BTW) Wasn't one of the confirmations of SR that unstable particles moving at near c would decay past their expected places? From our point of view, their time slowed down. From their point of view, our frame got shorter. Aren't both interpretations correct? We can easily extrapolate to the case of an observer at lightspeed, as the original poster (whose name I've stupidly deleted, and forgotten) has done. Isn't all math, from calculus on up, based on an understanding of limits? I think c = infinity, (in the photon's frame) is a pretty good way to get an intuitive idea of what's going on. After all, c is a limit, not a speed (for anything with mass). Has anyone done any actual math in this vein? -Tommy Mac . " + .------------------------ + * + | Tom McWilliams; scrub , . " + | astronomy undergrad, at * +;. . ' There is | Michigan State University ' . " no Gosh! | 18084tm@ibm.cl.msu.edu ' , * | (517) 355-2178 ; + ' * '----------------------- ------------------------------ Date: 3 Sep 92 13:22:38 GMT From: Nick Szabo Subject: SPS feasibility and other space development Newsgroups: sci.space In article amon@elegabalus.cs.qub.ac.uk writes: >There are times when you follow hunches and gut feel on engineering >issues because you simply don't have solid fact to go on. This is quite different than persisting with a narrow set of hunches, turned into religiously held beliefs, even if they have failed over and over, at great cost, while ignoring the many superior alternatives. >I think both Dennis and I and Allan would all agree that the fastest >way to drive a technology (rather than science) into the the future >capabilities we want is to build lots of quick and dirty prototypes >that we can crash, blow up and otherwise mangle as a means of >collecting EMPIRICAL data. This is not at all what Dennis and Allen have been promoting. They have been advocating huge, expensive projects like HLVs, space stations, astronauts to Mars, and SPS that, when they fail, bring big chunks of the space program down with them. They say we lack "vision" or "guts" unless unless we are willing to bet the house on such singular spectaculars. I say we have lost too many houses on such bets, and look where we are. Let's indeed learn from our failures, and invest in projects that, when they fail, indeed let us learn quickly and move on. Let's invest in small, automated spacecraft that can hold a wide variety of payloads, from biological adaptation to planetary prospecting. Let's explore the entire solar system, which we can do with just a fraction of NASA's budget with many small spacecraft, instead of prejudicially planning our space future as if we know all we need to know, and any barriers or failures are of just due to "lack of will" (what a god-awful cliche, used by everybody from HUD-boosters to astronaut fans to promote their favorite piece of pork). Let's make NASA support the commercial space industry, by buying their launchers and leasing their communcations networks, instead of NASA dictating their narrow, obsolete plans for the shape, size, and orbit of space infrastructure to all the other space users. Let's stop pushing $10's of billions of scarce funds down the ratholes of bureacracy that surround the HLVs, the shuttles and space stations, long after they have failed. These techno-sacraments have little to do with discovery, of either the scientific or engineering sort, and everything to do with a disturbingly narrow, obsolete vision of how to move civilization into space. In short, you have expressed a great strategy for the space program, a visions of diverse and quick experiments, nearly 180 degrees opposed to the way things have been promoted in the space advocacy community and done at NASA. Let's turn the keel and get on course. -- szabo@techbook.COM Public Access User --- Not affiliated with TECHbooks Public Access UNIX and Internet at (503) 644-8135 (1200/2400, N81) ------------------------------ Date: 3 Sep 92 12:54:40 GMT From: John Roberts Subject: Teleoperation Newsgroups: sci.space -From: arnold@clipper.ingr.com (Roger Arnold) -Subject: Re: With telepresence, who needs people in Earth orbit? -Date: 1 Sep 92 19:39:08 GMT -Organization: Intergraph Advanced Processor Division - Palo Alto, CA -Many space activists appear to view telepresence as a threat to a -cherished and beleagured manned space program. Most of the discussion -here has been cast in a "manned vs." context. So a lot of diversionary -non-issues get tossed about: "it can't do everything", "it's limited by -time lag", "it's limited by bandwidth". Plus the biggest confusion -factor of all: failure to distinguish between teleoperation and robotics. -It's easy to make telepresence look bad or difficult if you can get away -with discussing it in terms of the capabilities of autonomous robots. Fortunately, NASA is still working on telepresence and teleoperation. I don't know the exact level of spending, and no doubt it would be nice if it were higher than it is, but it's considerably better than ignoring the subject entirely. I believe one of the cost-cutting measures for SSF was to have the external robots operated largely from the ground rather than exclusively by the astronauts on the station. I would say that the subject line chosen isn't very useful if you want to discuss constructive cooperation between humans and robots in space. -If it ever did, western culture no longer has the will or vitality to -move into space in pursuit of a vision. Sure, if we applied the same -fraction of GNP that went into building cathedrals in the Middle Ages, -or the pyramids in ancient Egypt, we could easily support lunar and -Martian colonies. That's a pretty harsh accusation, and I think you're exaggerating. I don't know about ESA, but the US is still working at it. Remember that many of the cathedrals took on the order of a century to complete - the US has only been really working on the space program for 30 years or so. Many space enthusiasts are more impatient than that - they think that space colonies could be built with something like the level of effort required to build a local K-Mart, or else that we should speed things up by throwing hundreds of billions of dollars a year at the problem. As has been shown by previous missions, doing things in space is actually quite difficult compared to doing them on the ground - anything that's actually been done has been much harder than the wilder visionaries had thought. Current public support for the civilian space effort seems to be around $15-20 bilion a year. As Allen has pointed out, that's enough to eventually get quite a lot accomplished if you spend it wisely, or even if you only spend part of it wisely. As you point out, a large commercial interest could speed things considerably. Part of what NASA's mission is to develop or encourage the development of space technologies and markets that will attract private enterprise. -I see telepresence not as competition to manned space activity, but -as a bridge to the level of space activity that will be necessary to -bring costs down and make it worth building real space stations. Sounds reasonable. -Most of the objections to teleoperation that people raise, or the -problems that they posit as standing in the way, are easily avoided. -It's absurd to tie teloperation in low earth orbit to a communication -path involving two round trips to Clark orbit. Build a necklace of -co-orbiting microsats to relay signals from the facility to whichever -satellite is currently in position to downlink. NASA wanted to build such a network several decades ago, and was overruled. It would be pretty expensive now to set up such a network just as a precursor to teleoperation. Much better to develop and demonstrate it with the current communications system, then make a decision on whether to change the communications. (Would Iridium work for this type of application?) I've had a chance to play with the lunar delay simulator that Bill Higgins has written about. It's surprisingly easy to learn - with about two minutes of training, you can drive the robot around, use it to pick up and move objects, etc. No doubt a trained operator could do better. Except for applications that require the application of momentum (i.e. swinging a hammer or driving a bulldozer through a pile of dirt), and applications that require rapid response (i.e. cat juggling), the main effect is that operation is greatly slowed down. But even with a slowdown of 10-20 times teleoperation could be more economical than doing the same work with humans in space, provided that it can be done at all with teleoperation. Other challenges to near-term use of teleoperation: - A video display uses up a lot of bandwidth, and provides a lot less visual information than seeing the object in person. One thing that can help tremendously with this is true 3D or stereo imaging, using two cameras side by side. The currently popular way to display it is with alternating frames on a conventional video monitor, with liquid crystal shutter goggles to separate out the views to the two eyes. Doing this in the NTSC format (a pair of views every 1/30 of a second), flicker isn't really a problem if the light levels aren't too high. Faster refresh rates of course are possible if you have the bandwidth. The JPL people working on the small Mars rovers use this kind of 3D imaging. - Aside from feedback delay, most currently available remote-control general-purpose robots don't have particularly great dexterity and strength. Improving the strength shouldn't be too hard, but dexterity is very tricky - we're a long way from what humans can do, even in EVA suits. But there is progress - I saw some interesting robot hands at Bell Labs in Holmdel. - Sophisticated robots are among the most complicated mechanical devices around, and not particularly reliable even on Earth. In space, mechanical devices seem to break down even more easily. Building a teleoperated robot that can manipulate its environment isn't too difficult, but building one that can be used effectively to repair another robot of the same kind is a much more difficult task. When the robots start to break down, it can be very useful to have humans nearby to repair them. (This would apply to a space station, for instance, where humans are already present.) John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 3 Sep 92 18:51:14 GMT From: Lee Mellinger Subject: TOPEX, demise of SEASAT & nuclear sub wakes Newsgroups: sci.space In article <1992Aug29.133659.9062@samba.oit.unc.edu> cecil@physics.unc.edu (Gerald Cecil) writes: :I think that the accepted explanation of its failure after only a few weeks wa :a chip burnout, remarkable that there was no redundancy.) Have sub props been :modified? Does anyone have further details on the demise of SEASAT? :-- :Gerald Cecil cecil@wrath.physics.unc.edu 919-962-7169 The official cause of the failure was metal particles shorting across the solar panel power slip rings causing a massive and nearly instantaneous power failure. Lee "Mit Pulver und Blei, die Gedanken sind frei." |Lee F. Mellinger Caltech/Jet Propulsion Laboratory - NASA |4800 Oak Grove Drive, Pasadena, CA 91109 818/354-1163 FTS 792-1163 |leem@jpl-devvax.JPL.NASA.GOV ------------------------------ Date: 3 Sep 92 12:44:00 GMT From: pete Subject: What is the speed of light measured from? Newsgroups: sci.space In article <1992Sep2.153142.7358@unocal.com>, stgprao@st.unocal.COM (Richard Ottolini) writes... >In article <2SEP199204264283@reg.triumf.ca> >vincent@reg.triumf.ca (pete) writes: >>Neglecting the engineering problems of high speed travel through an >>imperfect vacuum, you can travel light centuries in subjective >>hours if you accelerate long enough. If you arrive at the Andromeda >>galaxy 2 weeks after leaving earth, you could be justified in >>thinking you travelled faster than c. It's just that the rest of >>the universe will have aged 2x10^8 years. > >No. You would not feel you are going faaster, but the universe got smaller >and slower. These are stardard result of Special Relativity. *sigh* ...I should just learn to keep my mouth shut. OK consider: you've accelerated to .99999 c relative to your original frame. Tangential to your world line at that instant is an inertial frame, in which your speed is instantaneously 0. Now consider this new frame to be the rest frame, and your velocity relative to it is small, but steadily increasing as you continue your constant acceleration. Clearly, a newtonian approximation of your situation considered from this frame will conclude that you continue to experience the full force of your acceleration, just as you did when you first started from your initial rest frame. That is, just because you are travelling at nearly c relative to your initial frame doesn't mean that in your frame you sense your acceleration decreasing. And you have absolutely no reason to model the universe outside as getting smaller. That's just silly. As far as you're concerned, the simplest model is just that you're going steadily faster. Now if you were able to detect the passing of time in the universe at large, which is assumed to be at rest relative to your initial frame, it would seem to you that their time was going by faster and faster, til millenia were going by with every breath. =========================================================================== Jeez, I really _liked_ the image of Pete Vincent time and space pivoting about the speed of light. Had a nice Minkowski sort of feel to it. ------------------------------ Date: Thu, 3 Sep 1992 15:21:29 GMT From: Thomas Clarke Subject: With telepresence, who needs people in Earth orbit? Newsgroups: sci.space In article <1992Sep1.193908.25701@clipper.ingr.com> arnold@clipper.ingr.com (Roger Arnold) writes: > In article <1992Aug28.123432.16321@iti.org>, aws@iti.org (Allen W. Sherzer) writes: > Most of the objections to teleoperation that people raise, or the > problems that they posit as standing in the way, are easily avoided. > It's absurd to tie teloperation in low earth orbit to a communication > path involving two round trips to Clark orbit. Build a necklace of > co-orbiting microsats to relay signals from the facility to whichever > satellite is currently in position to downlink. It's easiest if the > orbit is equatorial, and so what if that means using Pegasus or Ariane > for launches? Easier still, use the Motorola Iridium constellation of 77 satellites for teleoperation. Iridium should work just as well for LEO as for "cellular phones" on the ground. -- Thomas Clarke Institute for Simulation and Training, University of Central FL 12424 Research Parkway, Suite 300, Orlando, FL 32826 (407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu ------------------------------ End of Space Digest Volume 15 : Issue 164 ------------------------------