From ota Sat Jun 18 03:06:28 1988 Received: by angband.s1.gov id AA00680; Sat, 18 Jun 88 03:06:14 PDT id AA00680; Sat, 18 Jun 88 03:06:14 PDT Date: Sat, 18 Jun 88 03:06:14 PDT From: Ted Anderson Message-Id: <8806181006.AA00680@angband.s1.gov> To: Space@angband.s1.gov Reply-To: Space@angband.s1.gov Subject: SPACE Digest V8 #256 SPACE Digest Volume 8 : Issue 256 Today's Topics: Re: women in space Re: Naming the space station. The launch loop author replies: NTSL := John Stennis Tony England resigns from NASA Re: Space Agencies Re: Space Station Names ---------------------------------------------------------------------- Date: 26 May 88 14:11:24 GMT From: mmm!allen@UMN-CS.ARPA (Kurt Allen) Subject: Re: women in space In article <8805260102.AA08795@angband.s1.gov>, clopez@ORION.CF.UCI.EDU ("Carlos A. lopez") writes: > I remember hearing on one of those half hour "Gee, isn't science neat" > shows that women have lower metabolisms (overall) than men. Some comments > were also made that the first interplanetary crews might be mostly women > to reduce the demands on the life support system. Just a note. Women scuba divers typically use approx. 2/3'rds of the air that male scuba divers, of the same abilities, use. My women diver friends will last almost as long on a 40 cu foot air tank as myself on a 72. -- ----------------------------------------------------------------------------- rutgers!umn-cs!mmm!allen | Kurt W. Allen ihnp4!mmm!allen | 3M/Digital Imaging Acquisition Center ----------------------------------------------------------------------------- ------------------------------ Date: 26 May 88 15:26:53 GMT From: eachus@mitre-bedford.arpa (Robert Eachus) Subject: Re: Naming the space station. I like the idea of naming something after Robert Heinlein, but it shouldn't be a space station in low earth orbit. A lunar colony would be much more appropriate. Willy Ley is already on the moon, but his name would be very appropriate for a station on or around Mars. I hope George Low's name can get on to the list considered for the Space Station, to me it seems the most appropriate, and it would be used! "I'm going to Low Station next week...", does not sound pretentious and delivers the message, where "I'm going to Minerva next week..." just doesn't hack it. Robert I. Eachus with STANDARD_DISCLAIMER; use STANDARD_DISCLAIMER; function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is... ------------------------------ Date: 26 May 88 03:13:28 GMT From: tektronix!tekcae!vice!keithl@ucbvax.berkeley.edu (Keith Lofstrom) Subject: The launch loop author replies: As John Gregor (a former student of mine and an unabashed partisan for the launch loop) observes, it is hard to make a valid criticism of the launch loop without reading the technical paper. The December 1983 "Analog" article wasn't the proper forum for technical details; it also was written 5 years ago and many problems have been solved since then. However, John has done an able job of answering most of the questions (BRAVO, John), saving me some effort. I will touch again on a few points and add a few of my own: Important ideas since the Analog article: 1) The loop should be built over mid-ocean, far away from land. This actually eases construction (the biggest ocean wave is flatter than most hills, for example, and things are surprisingly quiet 20 meters down) but the most important aspects are safety and security. If the loop fails and throws pieces, they are unlikely to come down on people. 2) Loop technology is useful for other things, and this provides a growth path for the technology. Underground power storage and transmission may be possible (this depends on real world small-bore rock tunneling costs, an unknown). "Simple" towers built around 2Km/sec ribbons can poke above the atmosphere, and are useful for scientific observations and the modification of intercontinental ballistic "gift packages". Why that instead of passive structures? Well, without active control of guy wires and such, the passive towers must be quite massive to survive atmospheric perturbations (The atmosphere scales the launch loop cross section, too; a lunar launch loop can be millimeters across and launch kilogram payloads). So, with your active guy wires you might as well buy the whole package, and get the better strength-to-weight of the loop, and get energy storage for your "gift" modification apparatus. 3) "But what if it fails? Isn't there a lot of electronics to keep running?" --- the control sections are about 1 meter long in the middle of the loop. If they are designed properly, they will fail or not fail independently of each other. It takes about a 20 percent global failure rate, or 50 control sections in a row, to cause the loop to go unstable. (Why so many small segments? Resolution. What percentage good pixels are required for a readable terminal screen, assuming a slow hollywood scroll?) The controllers and magnets, and even ribbon sections, may be repaired and replaced during operation. The launch loop has lots of small, identical pieces; don't think of it as intricate, think of it as highly redundant. What is most likely to bring the machine down is incorrect programming. With proper instrumentation, and post-mortem analysis, such problems will eventually go away. In the interim, you just pick up the pieces, make some new ones, and start the system up again. This is part of the designed-in system cost. Down time with a "hot spare" would be about 2 weeks. Down time from on-shore warehouses a few months. No two year waits while your engineers try to fix boosters designed like fragmentation grenades (to please pork-barrel senators from Utah). You should eventually have a whole bunch of launch loops, anyway; there's room near the equator for thousands of them. Unlike Paul Birch's orbital rings, many loops can coexist without tangling if one fails. 4) The cost can be controlled if you use the following rules: (a) Don't make any pieces you can't buy (b) Make the pieces small (c) Make the pieces identical (d) Don't stop making the pieces. The launch loop has a few big pieces (the stations, the end magnet platforms, and the motor platform), but those can be build by any big steel construction company. The rest of the stuff is small and distributed, or off-the-shelf (like barges with gas-turbine power plants on them, cable ships, or the factory where you make new pieces). I still expect the loop to be damned expensive; perhaps as much as a replacement Shuttle, meaning it will be a while before it's worthwhile to do. 5) Stabilization: A big problem has been the stabilization of the infamous equation 33: .EQ (33) { { a sub rs ~ + ~ a sub 0 } over { a sub s ~ + ~ mu omega sup 2 } } ~ = ~ { ( omega - omega sub k ) sup 2 } over { mu omega sup 2 ~ + ~ ( omega - omega sub k ) sup 2 } .EN The $$ a sub 0 $$ term is the natural instability of a magnetic levitation system, while the $$ a sub rs $$ term is the controller output as a result of measuring the ribbon-track spacing. The $$ a sub s $$ term is based on the absolute position of the track, and must be determined (much more expensively) with laser interferometers and other such arcana. The trick is to come up with control equations that yield a finite number of damped poles over a wide range of $$ omega sub k $$ (which is the wavenumber times the velocity for a perturbation, == $$ 2 pi V sub r over lambda $$). I spent over a year stupidly banging away on $$ a sub rs $$ only, until I realized it was impossible to stabilize without ground measurements of some sort. After that, another year banging away on user-fiendish symbolic math packages trying various likely permutations of both control equations. Finally it dawned on me that you should add a term to the left side proportional to the right, and to the right side proportional to the left, throw in a few appropriately scaled damping factors, and everything stays hunky-dory and fourth order. This is where things are at right now; I am still figuring out what the physical implications of all this are. I've got a new version of the paper with the equations in it; I'll be bringing copies to the Denver conference. 6) "Okay, smarty pants, if it's so simple, why aren't you building one?" Well, first, I'm lazy. I wrote the "Analog" article to drum up interest. I mailed out around 200 copies of the paper, and wrote hundreds of personal letters. I was hoping someone would steal the ball and run with it. Nuh-uh. 7) "Where's my copy of the paper?" Well, see the part about lazy. Keep bugging me, third try should do. If you live in Tierra Del Fuego, find out what the U.S. postage for 5 ounces is to you, so I won't have to call the always-busy line at the post office (would someone send me a list of current international mail rates? Thank You!). Postage is cheap, time is precious. 8) "Why do this?" Well, I want to live and work in space. I don't want to make somebody else pay for it, so it must be affordable. Since nobody else is working on $10/lb low-gee launch systems, I guess it's my job. Sure the thing is too damn big. So are the alternatives, and they yield a much smaller payback for the same investment. If somebody out there has a system that will accomplish the same ends with a smaller investment, PLEASE LET ME KNOW! I'll send them money. I'll build their electronics. I'll clean their toilets if they need it! I may not get into space by working on the launch loop, or even helping on some yet-to-be-defined better system. But I sure as hell WON'T get there by telling somebody else how hard it is. If there were easy solutions, we'd already be there! Forty years from now, when you're in the back of the ambulance racing to the hospital, while the EMT is trying to restart your heart, you may have other regrets, but mine will probably be "I didn't make it into space". Most of the current crop of space "activists" will be dead before it's affordable to go there. Whose fault is that? -- Keith Lofstrom ...!tektronix!vice!keithl keithl@vice.TEK.COM MS 59-316, Tektronix, PO 500, Beaverton OR 97077 (503)-627-4052 ------------------------------ Date: 26 May 88 07:38:09 GMT From: sonia!khayo@cs.ucla.edu (Eric Behr) Subject: NTSL := John Stennis =========================================================================== PRESIDENT RENAMES NASA CENTER FOR SEN. JOHN C. STENNIS May 20, 1988 RELEASE 88-36 NASA's National Space Technology Laboratories (NSTL) was officially renamed the John C. Stennis Space Center by Executive Order of the President today. President Reagan signed the executive order to rename the NASA center for the distinguished Mississippi senator who is retiring after 41 years of service to the nation and the state. The president's executive order said, "Sen. John C. Stennis has served his country as a United States senator for over 40 years and has steadfastly supported the nation's space program since its inception. He has demonstrated visionary leadership and has consistently worked to assure United States world leadership and preeminence in space. NASA Administrator James C. Fletcher said "John C. Stennis has served as the father of NSTL since he led the efforts for its creation. His leadership of the nation's space program stands as a monument to his career of significant accomplishments." At NSTL, director Jerry Hlass said, "Senator Stennis made major contributions to our country and our state throughout his long and distinguished career. His support to the national space program has been consistently strong since NASA's inception. His close association with our center has contributed significantly to the growth and progress we have experienced over the past 27 years. He has been a leader and strong advocate for a preeminent role in space for the United States. The senator's interest in the advancement of science and technology continues today with his support of the Space Station, our nation's next logical step into space." The space center is one of eight NASA field centers in the country. NASA selected its Hancock County location in 1961 to test the Saturn V first and second stages for the Apollo program. The site was designated the Mississippi Test Facility when Saturn rocket testing began. In 1974 the installation was named the National Space Technology Laboratories because of its achievements and unique capabilities in space applications and Earth resources technologies. During the period between the Apollo and Space Shuttle programs, Stennis was instrumental in helping NASA achieve full utilization of the installation's facilities. Today, the NASA center employs more than 5,400 people and is the home of 18 federal and state agencies engaged in environmental, oceanographic and defense-related activities. Stennis, a frequent visitor to the space center that now bears his name, continues to support the space agency's current and future efforts. In his December 1987 "Report to Mississippians" newspaper column, the senator wrote, "While it is essential that we prioritize our spending and bring our federal deficit under control, we must look ahead to the future of our country." "The next logical step in space exploration is the establishment of a permanent Space Station that will assure world leadership in space for our country in the 1990s and beyond. We must be committed to this important program that will enhance our capabilities for scientific learning while stimulating our nation's economic development and defense programs." =========================================================================== Eric ------------------------------ Date: 26 May 88 08:17:59 GMT From: thumper!karn@faline.bellcore.com (Phil R. Karn) Subject: Tony England resigns from NASA Another astronaut has resigned from NASA because of delays in the Shuttle and Space Station programs: Dr. Tony England. He flew once, on a 1985 Challenger Spacelab mission during which he ran an amateur radio operation in his spare time. Tony's recent project in NASA had been the Space Station. See the AMSAT bulletin on rec.ham-radio for further details. Phil ------------------------------ Date: 26 May 88 18:14:07 GMT From: trwrb!ucla-an!ondine!steve@ucbvax.berkeley.edu (Steve Jenkins) Subject: Re: Space Agencies In article <3121@charon.unm.edu> seds@ariel.unm.edu.UUCP (SPACE EXPLORATION) writes: > > > Hello everyone. We need the addresses for ESA and the Soviet > space program. European Space Agency 8-10, rue Mario-Nikis 75738 Paris Cedex 15 FRANCE (33.1) 42.73.76.54 -- Steve Jenkins ucla-an!steve@EE.UCLA.EDU Research Engineer {decvax,ihnp4}!hermix!ucla-an!steve UCLA Crump Inst for Med Engr (213)-825-4364 Steve Jenkins ucla-an!steve@EE.UCLA.EDU Research Engineer {decvax,ihnp4}!hermix!ucla-an!steve UCLA Crump Inst for Med Engr (213)-825-4364 ------------------------------ Date: 26 May 88 20:30:35 GMT From: uflorida!novavax!proxftl!rafael@umd5.umd.edu (Rafael Mayer) Subject: Re: Space Station Names In article <1833@brahma.cs.hw.ac.uk>, adrian@cs.hw.ac.uk (Adrian Hurt) writes: > I thought Minerva was the Roman name for the Greek goddess Athene, the goddess > of wisdom. > > Maybe the Romans, being more militaristic, put her in charge of both, but I > thought that war was the speciality of Mars (Ares in Greek). Your right. She was also a warrior though. Her shield, the Aegis, is famous in the Greek Mythos. According to Homer, in the Iliad, she was one of the gods egging on the Greeks and Trojans against each other. (Oh, embarrasment, I forget on what side whe was on.) How about calling it Aegis? I like the concept of the shield, and the wise warrior and all that. JMHO. Rafael allegra!novavax!proxftl!rafael ------------------------------ End of SPACE Digest V8 #256 *******************