Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Tue, 23 Apr 91 02:02:53 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 23 Apr 91 02:02:48 -0400 (EDT) Subject: SPACE Digest V13 #444 SPACE Digest Volume 13 : Issue 444 Today's Topics: POTENTIAL GEOMAGNETIC STORM WARNING UPDATE - 23 APRIL Re: Cape York launch facility Energiya (was Re: Saturn V blueprints) Re: Laser launchers Re: Uploading to alpha Centauri Re: Why the space station? researching Baltimore Application Project Re: Transportation Tethers Re: Atlas Centaur bites the big one, 4/18 Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: Mon, 22 Apr 91 19:58:46 MDT From: oler <@BITNET.CC.CMU.EDU:oler@HG.ULeth.CA> (CARY OLER) Subject: POTENTIAL GEOMAGNETIC STORM WARNING UPDATE - 23 APRIL X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ SOLAR TERRESTRIAL BULLETIN 23 April, 1991 00:00 UT /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Please note: The Potential Geomagnetic Induced Current (GIC) Warning has been replaced with a 'condition code' status, described as follows. This method will be employed in all future alerts and warnings. It applies to areas in the middle and high latitude regions, particularly within or near the auroral zone. Condition: GREEN - No GICs expected or possible. AMBER - No GICs observed, but a risk exists. Precautionary or preparatory actions warranted. RED - GICs possible or observed. POTENTIAL GEOMAGNETIC STORM WARNING UPDATE Potential GIC Status: AMBER. The following Warning remains IN EFFECT until 24:00 UT on 23 April: - POTENTIAL MINOR GEOMAGNETIC STORM WARNING. The following Warnings have been CANCELLED: - POTENTIAL LOW LATITUDE AURORAL ACTIVITY WARNING (cancelled). - POTENTIAL MAJOR SOLAR FLARE WARNING (cancelled). An interplanetary shock has so far, failed to arrive from the major X-class flare of 20 April. We are still within the window and may yet see some effects from this flare. However, as time passes, the probability for observing geomagnetic storming is decreasing. The Potential Geomagnetic Storm Warning will remain in effect until 24:00 UT on 23 April. There is still a good possibility for increased geomagnetic activity from the 20 April major flare. Geomagnetic activity is not expected to be as strong as was first predicted, because of the amount of time which is taking for the effects to reach the Earth. As a result, we have downscaled the potential geomagnetic activity prediction to generally Minor Storm conditions, if a flare shock arrives. Geomagnetic activity likely will not reach major storm levels, and may in fact only reach low-intensity minor storming. The predicted planetary A-index for 23 April is 30. High latitudes could surpass A-indices of 40 if a shock arrives. Low latitude auroral activity will likely not be observable. Lunar phase will begin hampering attempts to view auroral activity now, as well. However, northerly middle and high latitudes could still witness moderate to high levels of auroral activity if any flare effects arrive. HF propagation conditions could still see some moderate levels of degradation, but conditions are no longer expected to be as poor as was first predicted. A risk still exists for VHF auroral backscatter communications, particularly over the northerly middle and high latitudes, provided geomagnetic activity increases over the next 24 hours. If a shock fails to arrive within the next 18 to 24 hours, geomagnetic and auroral activity will likely remain generally dormant. ** End of Bulletin ** ------------------------------ Date: 22 Apr 91 12:23:32 GMT From: agate!bionet!uwm.edu!spool.mu.edu!munnari.oz.au!metro!cluster!andrewt@ucbvax.Berkeley.EDU (Andrew Taylor) Subject: Re: Cape York launch facility In article , c8921212@jupiter.newcastle.edu.au (Luke Plaizier) writes: > Actually, from what I last heard the Cape York Space Agency have > hit apon a problem that seems to hit every large scale project. ... > that was sponsoring them have decided to sell out. ... The government is still looking for proposals and these are likely to be at other sites on Cape York. Expected completion date has been pushed back a year to 1996. > [environmentalists] have come up with some new variations of wildlife that > live nowhere else, and capeyork will be so comprehensive a destruction of > wildlife that they can't risk letting it go ahead. > > yeah, tell that to the [alligators] at Cape Canaveral. Tell it to the extinct Dusky Seaside Sparrow - "Welcome to Cape Canaveral we sent a man to the moon and a sparrow even further". For a little more detail see postings by Bill Venables and I in sci.environemnt answering the same question about the Cape York launch site. Andrew Taylor ------------------------------ Date: 22 Apr 91 15:54:43 GMT From: bu.edu!transfer!lectroid!sw.stratus.com!tarl@bloom-beacon.mit.edu (Tarl Neustaedter) Subject: Energiya (was Re: Saturn V blueprints) In article <1991Apr22.142624.26294@en.ecn.purdue.edu>, irvine@en.ecn.purdue.edu (/dev/null) writes: > the equivalent in technology and cost to the Saturn V. Notice how only one > Energiya Buran launch was made? I heard it was COST that is causing such > a delay in further launches. The actual booster is the Energiya, and it has flown twice (once launching a dummy payload which didn't make it to orbit, once launching the Buran). The Buran is the shuttleski. It's unclear whether Buran (means snowstorm) is the name of the specific shuttle which was launched, or the name of the system (they had another two under construction at last word). I'd disagree that the Energiya is equivalent in technology to the Saturn V. The basic program was a rip-off of the shuttle program, so I would assume they copied as much as they could of the propulsion systems. The strap-on boosters are an improvement over our SRBs, in that they are oxygen-kerosene and thus safer (can be shut down) and more environmentally friendly. There doesn't appear to be a lot known in the west about the energiya main engines, but they seem to be comparable in efficiency to our SSMEs. As to actual performance of the Energiya (according to information the soviets provide via the Space Commerce Corporation), it can boost 100,000Kg of payload into low-earth orbit (they actually list a series of weights, from 100,000Kg through 250,000Kg, probably by varying number of strap-ons. I'll use the lower figure), and 30,000Kg to the moon. I don't have comparable figures for the Saturn V, so I'll rely on someone else posting those. ----------------------------------------------------------- Tarl Neustaedter tarl@vos.stratus.com Marlboro, Mass. Stratus Computer Disclaimer: My employer is not responsible for my opinions. ------------------------------ Date: 22 Apr 91 20:33:03 GMT From: agate!bionet!uwm.edu!caen!ox.com!fmsrl7!wreck@ucbvax.Berkeley.EDU (Ron Carter) Subject: Re: Laser launchers In article <2753@ke4zv.UUCP> gary@ke4zv.UUCP (Gary Coffman) writes: >Well consider that for an electrically powered laser, conversion of >primary fuel to electricity is, at best, 40% efficient. Combined-cycle plants have hit 52%. >Transmission, >control, and application of the electrical energy is, at best, 80% >efficient. A large laser-launching facility would probably have its own generators on-site, and sell power when nothing was launching. Also, you ignore CO2 gas-dynamic lasers. >Then add in the fact that >atmospheric blooming will reduce the delivered energy of the beam >by a factor of 1000 to 1000000 at high altitudes Support this assertion. What conditions are you assuming? What sort of optical system, etc? The sun puts ~1KW/m^2 onto the California desert, and nobody notices thermal blooming. An optical system designed to avoid blooming will have many mirrors, and mirrors much larger than the target. This will keep the power density much lower than a simplistic system, with one aperture equal to the size of the target. >with terrible efficiency. While for a rocket, the longer it runs, the >faster it goes since it's mass ratio is continually improving right >up until burnout. This statement ran my bogosity meter off the scale. It reflects such amazing ignorance or carelessness, one wonders where to begin to pick it apart, and whether one should bother. So I won't. >This is *the* advantage of the laser scheme. If the power stored in >those ground mounted tanks could really be delivered to a spacecraft >at high altitude with good efficiency, then laser launching would >be practical. Energy costs are a tiny part of the current cost of space launches. Trading energy for efficient use of capital (being able to run the launcher for 12 hrs/day, for example) would make laser-launchers practical even if they used 10x the energy/kg of rockets. >but fundamental physical laws would have to be broken >for it to pay off. My bogosity meter pinned again. >At the power levels required to loft real payloads >into orbit, atmospheric blooming is an intractable physical problem. Consider the power level of the solar energy striking the ground, and tell me why sunlight isn't an intractable physical problem. Now consider the power levels of a laser launch. What is the greatest power density which avoids blooming? Now, how much aperture is required? Did you ever ask yourself this question? If not, shame on you. >Talk to the guys who have actually >fired high power lasers, the laser fusion folks, and see what they >say about the absolute necessity of having a hard vacuum to fire the >beam through. I'd prefer that you do sanity checks on your statements before posting them. Imploding fusion pellets is a very different problem than vaporizing a layer of a meter-wide target. It takes vastly greater power levels and faster rise times. The pitfalls experienced by the LF workers will not be applicable. >Tethers need to exceed the theoretical strength of materials limits by >orders of magnitude to work. Again, a fundamental scientific breakthrough, >not engineering R&D, needs to occur before tethers can become reality, if >ever. How many tether studies have you read? Did you ever read anything about non-synchronous tethers, or work any figures yourself? If not, you are talking through your hat. ------------------------------ Date: 22 Apr 91 22:07:29 GMT From: agate!bionet!uwm.edu!cs.utexas.edu!rosen@ucbvax.Berkeley.EDU (Eric Carl Rosen) Subject: Re: Uploading to alpha Centauri In article <249@hsvaic.boeing.com> eder@hsvaic.boeing.com (Dani Eder) writes: >Freeze the crew solid, and scan their entire bodies atom by atom. Then >send a radio message reading "carbon,oxygen,hydrogen,hydrogen..." to a >receiving station at the destination. There a set of drexler-style >nano-machines build a copy of the crew atom by atom. Finally, you unfreeze >the crew. In his book "The Emperor's New Mind", Robert Penrose (a famous math/physics type at Oxford) gives various arguments (which I don't pretend to understand completely) based on quantum theory that suggest that although this might be possible, you would necessarily destroy the crew in the process of "scanning" them. Also, if I read Penrose correctly, he's not convinced that what you reassemble would control the same "consciousness" as what you scanned. Anyway, it's a fascinating book. --Eric ------------------------------ Date: 22 Apr 91 14:32:57 GMT From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!watdragon!watyew!jdnicoll@ucsd.edu (James Davis Nicoll) Subject: Re: Why the space station? It occurs to me that one useful purpose of Fred is employing people who are, one supposes, gaining experience in designing, and perhaps even building space stations. I don't know what these people would do if and when the Fred project dies (If for no other reason than because Fred may someday have been built and reached its operational lifespan's limit. On the other hand, if the UK can continue to employ someone to watch for Napoleon's fleets up until 1945's audit, perhaps the bureaucracy intended for a specific project can outlive the project) but I doubt it would have much to do with building Fred-style space stations. Anyone know how much expertise left the industry back when Apollo got axed? James Nicoll ------------------------------ Date: 22 Apr 91 15:21:48 GMT From: haven!cs.wvu.wvnet.edu!jdm@purdue.edu (James D Mooney) Subject: researching Baltimore Application Project I found a report on the Baltimore Application Project rather serendipitously while researching for a report on technology utilization. Unfortunately, I failed to write down any of the pertinent information. It's a project that's been going on since about 1975, and as far as I know all the progress reports are entitled "Baltimore Application Project: Annual Progress Report." If anyone can get me either an overview of this project or the latest progress report, I'd appreciate it. Thanks, Tara Mooney -- Jim Mooney Dept. of Stat. & Computer Science (304) 293-3607 West Virginia University Morgantown, WV 26506 INTERNET: jdm@a.cs.wvu.wvnet.edu ------------------------------ Date: 22 Apr 91 14:44:56 GMT From: mnemosyne.cs.du.edu!isis!gaserre@uunet.uu.net (Glenn A. Serre) Subject: Re: Transportation Tethers Another use for tethers: If you are orbiting in a planet's magnetic field, you can transform your orbital velocity into electric power. Using this technique, you can get >100% chemical efficiency from the propellents you bring up for station-keeping (some of the kinetic energy of the propellent gets converted to electricty). Also, you can reverse the effect and use electric power for propulsion. -- --Glenn Serre gaserre@nyx.cs.du.edu -- --Glenn Serre gaserre@nyx.cs.du.edu ------------------------------ Date: 22 Apr 91 09:46:14 GMT From: dev8a.mdcbbs.com!rivero@uunet.uu.net Subject: Re: Atlas Centaur bites the big one, 4/18 In article <1991Apr19.161351.6679@ux1.cso.uiuc.edu>, mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes: > > In article <1991Apr19.055759.4781@nas.nasa.gov> ranma@noc.arc.nasa.gov (Robert Gutierrez) writes: >>I wrote: >>> Aside from the usual news reports, does anybody have any better details >>> on the Atlas Centuar KSC self-destructed??? >> >>I'll bet those Arainespace launchings are looking better and better >>every day to everybody else ... > > The folks who lost one to the Atlas had just finished losing one to > Arianespace. > Okay! What is everybody doing WRONG? How can we (meaning all of Earth) develop a reliable, economic orbital delivery system? Mike ------------------------------ End of SPACE Digest V13 #444 *******************