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 ; Fri, 20 Apr 90 02:55:29 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 20 Apr 90 02:54:59 -0400 (EDT) Subject: SPACE Digest V11 #292 SPACE Digest Volume 11 : Issue 292 Today's Topics: NASA Headline News for 04/18/90 (Forwarded) Re: Apollo 13, STS-1, Vostok 1 anniversaries Re: Earth Observing System Intercepting "alien" probe signals Re: SETI Re: Fermi Paradox Re: Apollo 13, STS-1, Vostok 1 anniversaries Re: Drake Equation (was Re: Interstellar travel) ---------------------------------------------------------------------- Date: 18 Apr 90 17:31:52 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 04/18/90 (Forwarded) ----------------------------------------------------------------- Wednesday, April 18, 1990 Audio Service: 202/755-1788 ----------------------------------------------------------------- This is NASA Headline News for Wednesday, April 18.... Testing of Auxiliary Power Unit # 1 aboard the orbiter Discovery was completed early today at Kennedy Space Center. Visual checks were underway mid-morning to make sure the test did not reveal any problems. An announcement is expected this afternoon on the probability of advancing the launch date from April 25 to April 24. Charging of the Hubble Space Telescope batteries is also ahead of schedule. * * Controllers at Jet Propulsion Laboratory report all subsystems are operating satisfactorily aboard the Venus-bound Magellan spacecraft. It's traveling at a velocity of over 35-thousand miles per hour relative to the planet and now is just 34 million miles away. An attitude reference test was successfully completed last week, star calibrations have gone well and two Deep Space Network checks have been successful. * * Meanwhile, the Galileo spacecraft is operating extremely well. The first four-day portion of a complicated trajectory maneuver was completed last week. The second part of the maneuver is scheduled for mid-May. Several more corrections will be made before the spacecraft's gravity assist flyby of Earth in early December. * * Scientists are puzzled with some data from the Cosmic Background Explorer Satellite launched last November, but also pleased with a visual byproduct. Wire service reports say scientists meeting in Washington, D.C., are confounded by data which indicate an unexpectedly smooth and uniform expansion of the universe and no indication of other cataclysmic events that had been theorized. Michael Hauser, of NASA's Goddard Space Flight Center says, "The quandry is deepening". A color image of the galactic center of the Milky Way was released yesterday free of cosmic dust that has obscured our galaxy's center previously. * * President Bush was criticized yesterday by some western European delegates to a White House conference on global warming for not taking a stronger stand on the issue. The President has called for more data before taking drastic control efforts which could have serious effects on the world economy. _________________________________________________________________ Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are EDT. Thursday, April 19..... 11:30 a.m. NASA Update will be transmitted. Friday, April 20.... 10:30 a.m. STS-35 astronaut news conference from Johnson Space Center. Sunday, April 22..... 1:00 p.m. STS-31 crew arrival at KSC Tuesday, April 24..(Subject to change) 9:00 a.m. STS-31 Countdown Status Report 10:00 a.m. APU/telescope Status Report 11:00 a.m. Prelaunch News Conference Wednesday, April 25..(Subject to change) 4:00 a.m. STS-31 mission launch coverage begins. NOTE: During the STS-31 mission television highlights will be transmitted on Satcom F1R, transponder #13 at 12 midnight, EDT, for the benefits of TV stations and educational institutions in Alaska and Hawaii. All events and times are subject to change without notice. ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, EDT. ----------------------------------------------------------------- A service of the Internal Communications Branch, NASA Hq. ------------------------------ Date: 19 Apr 90 13:43:11 GMT From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!cbs@uunet.uu.net (Chris Syed) Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries In article <1227@urbana.mcd.mot.com> rnoe@urbana.mcd.mot.com (Roger Noe) writes: > >Trivia time: The nickname of the Apollo 13 command module was Odyssey, >after the ship in the movie "2001". The lunar module, which served as >the astronauts' "lifeboat", was nicknamed Aquarius. More trivia - the motto of that mission, as emblazoned on its crest, was, if I'm not mistaken, "Ex luna, scientia." (Knowledge from the moon). The way the problem was solved has been considered "exemplary" and good stuff for "problem solving & decision making" courses. There's a bit about it in the Kepner Tregoe management training book, "The New Rational Manager." So even if the knowledge they hoped to gain didn't happen.... There is also a book called "13 - The Mission that Failed", but it is long out of print. --- cbs@gpu.utcs.utoronto.ca (Chris Syed) -- --- cbs@gpu.utcs.utoronto.ca (Chris Syed) ------------------------------ Date: 19 Apr 90 13:51:21 GMT From: dftsrv!iris613.gsfc.nasa.gov!flanigan@ames.arc.nasa.gov (Dennis Flanigan Jr.) Subject: Re: Earth Observing System >From: stein@dhw68k.cts.com (Rick 'Transputer' Stein) >1) Given that EOS will generate 1 Tbyte/day, how will this data be >managed? Granted a Tbyte/day is a phenomenal amount of data, but there are ways to handle such huge amounts of data. Optical disk is the current technology and optical tape ( sometimes called digital paper) soon to come. I suspect that while 1 Tbyte seems a lot to us now, 5 years from now it won't seem that unmanageable. >2) How do you analyze 1 Tbyte of data, let alone 1800 Tbytes? With a Cray and lots of workstations. Again, like the storage problem, just the technology that we know about should be able to handle the processing. The concern in this case does not center around the hardware technology, but the software technology. UNIX, networks and distributive processing are a big help, but software "building" will still require a tremendous effort. >3) If a scientist were to apply some visualization technique to >this volume of data, on what type of machine would he do it? Can you >stuff 1 Tbyte into a graphics workstation and learn anything? Yes. One of the advantages of EOS will be the ability to look at an one area with several types of instruments at the same time. By combining data from spectrometer images, RADAR images and LIDAR profiles a scientist will be able to analysis a subject in greater detail and with better accuracy. Detecting cloud heights is one good example. By measuring the length of shadows produced by the cloud, the height of cloud tops at their edges can be measured. The height at the center of the cloud can be measured with LIDAR and then by matching that data with the thermal image data, the height of the entire cloud can detected. >4) Is anyone at NASA asking these kinds of questions, given the >prior revelations about poor archive procedures and data loss? Lots of people are asking these questions and lots of people are are trying to address them. >Richard M. Stein (aka, Rick 'Transputer' Stein) Dennis Flanigan, Jr. Applied Research Corporation flanigan@iris613.gsfc.nasa.gav ------------------------------ Date: 19 Apr 90 15:14:24 GMT From: hadron!inco!fontana@decuac.dec.com (Tod Fontana) Subject: Intercepting "alien" probe signals Without starting a tangent debate, let's suppose that there is intelligent life outside of our solar system. If they have (had) technology equal or greater than our current level and have sent a probe that is currently travelling "aimlessly", like our voyager crafts, what would be the chances of our interception of their telemetry (or whatever) signals? Would we have to lie in a very narrow straight line between the probe and its home planet, or would a wide transmission "cone" be adequate? If we could somehow pick up such signals, who would be given responsibility for deciphering and evaluating the data? Just a bit of speculation.... ------------------------------ Date: 19 Apr 90 21:41:12 GMT From: mephisto!prism!fsu!gw.scri.fsu.edu!pepke@handies.ucar.edu (Eric Pepke) Subject: Re: SETI It's not entirely that grim. We can determine some things for sure about anybody who receives those signals. We know that they have figure out radio. If they hadn't, they wouldn't be listening. There are a whole lot of things that you have to figure out before you can figure out radio. Mathematics, for instance. There will no doubt be differences in the way we percieve major areas of mathematics, but there should be many similarities. The most commonly suggested message that would take advantage of this common knowledge is a sequence of prime integers, encoded as simply as possible--uniformly spaced pulses counting the integer followed by a pause. This is easily comprehensible, and such sequences are not generated by any known natural process. Now, there are a number of possible extreme theoretical objections to this, if you really want to reach. Perhaps the BEMs do not understand the concept of integers. However, even if they naturally think in continua and live in the liquid phase as part of a group mind, they would have to figure out that things are countable in the study of physics and chemistry and, failing that, if only to be able to wind the wire the right number of times around the ferrite core. Perhaps the BEMs have no interest in prime numbers and wouldn't recognize one if it kissed them (or whatever it is that BEMs do). This is also very unlikely. Prime numbers are so staggeringly useful, and have such tight connections with fundamental problems in mathematics and algorithm design that it is almost beyond belief that they would never stumble onto them. Finally, perhaps C.M. Kornbluth was right, and at some point the machines they built would acquire self-sustaining capability and the beings would evolve into happy little technologically advanced morons, forgetting even the basic principles that once they needed to survive. This one is a little bit harder to laugh off. Eric Pepke INTERNET: pepke@gw.scri.fsu.edu Supercomputer Computations Research Institute MFENET: pepke@fsu Florida State University SPAN: scri::pepke Tallahassee, FL 32306-4052 BITNET: pepke@fsu Disclaimer: My employers seldom even LISTEN to my opinions. Meta-disclaimer: Any society that needs disclaimers has too many lawyers. ------------------------------ Date: 19 Apr 90 16:16:49 GMT From: uc!shamash!timbuk!lfa@tut.cis.ohio-state.edu (Lou Adornato) Subject: Re: Fermi Paradox kauel@mentor.com writes: >Humans are very Chauvinist when it comes to carbon and water I'm posting this in case there is someone out there who's never heard this... First, it's pretty safe to assume that anything we're likely to consider to be alive is going to have a pretty complex chemistry, based on large, complex, chain-like molecules (like the protien molecule). Second, there must be some kind of solvent in which these molecules can undergo sustained chemical processes. There are only 2 elements that are capable of being the basis of creating long, complex molecules, and those are carbon and silicon. Of the two, carbon is the only one that forms molecules that are soluble in water. There are (I think) fluid compounds in which silicon is soluble, but they are much more complex than water and therefore are much less likely to occur in large amounts naturally. This doesn't rule out the possibility of silicon based life, but, absent any other data, we _do_ know for sure that carbon based life is possible. It's therefore more logical to limit ourselves to looking for conditions where carbon based life could evolve (i.e. anyplace with a big supply of liquid water), if only because we have no idea what conditions could lead to the rise of silicon based life. >Also, we may be blinded >by our assumptions about what intelligent life looks like and how it >behaves. Agreed. However, you have to make _some_ basic assumptions or you'll never be able to do anything. The basis of the scientific method is to make assumptions, test them, and throw away the ones that don't work. You have to start somewhere. BTW, just to define "life" objectively, never mind "intelligent", is a non-trivial exercise. Lou Adornato | Statements herein do not represent the opinions or Cray Research | attitudes of Cray Research, Inc. or its subsidiaries. lfa@cray.com | (...yet) ------------------------------ Date: 19 Apr 90 23:26:57 GMT From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries In article <1227@urbana.mcd.mot.com> rnoe@urbana.mcd.mot.com (Roger Noe) writes: >...The crew of AS-204, the mission posthumously >(and unofficially) designated Apollo 1, were Gus Grissom, Ed White, and >Roger Chaffee... Actually, "Apollo 1" was unofficial *before* the fire; the astronauts used it, and the shoulder patch they designed carried it, but NASA HQ had not officially approved a name for the mission. After the fire, it *was* made official, at the request of the astronauts' widows. AS-204 was the designation of the booster, also used to designate the mission as a whole. The booster, and the AS-204 designation, were used for a later mission. (To head off a question that's come up before... The first post-fire unmanned test, the fourth such, was officially Apollo 4. Nobody figured out that there was a problem here until too late. :-) The final decision was that the pre-fire unmanned tests had no "official names", retroactive or otherwise, and there never was an Apollo 2 or Apollo 3.) -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 18 Apr 90 18:22:06 GMT From: att!cbnewsl!moss!feg@ucbvax.Berkeley.EDU (Forrest Gehrke,2C-119,7239,ATTBL) Subject: Re: Drake Equation (was Re: Interstellar travel) In article <2277@wrgate.WR.TEK.COM>, dant@mrloog.WR.TEK.COM (Dan Tilque) writes: > feg@moss.ATT.COM writes: > >dant@mrloog.WR.TEK.COM (Dan Tilque) writes: > >> > >Who is this "we" that has been listening? And with what? These > >signals are not going to be picked up on a boombox with the > >announcement the signal is from outer space. > > There's this obscure branch of science which you are probably unaware > of. It's called Radio Astronomy. One of the things they're good at is > aiming large radio antennae at the sky. > You can save the sarcasm. I was directing the argument to listening for limited power source signals, not that of the Big Bang or the radiation resulting from energy released by a supernova. To pick up the signals of Voyagers at the outer limits of the solar system we need 70 meter parabolic antennas, carefully aimed, tuned, and internally noise-reduced within the limits of our technology. Ok, our Voyagers don't start out with very much transmitting power and their antennas are not very large. But extend that out 50 ly and then tell me how much effective radiated power will be required to achieve the Voyager signal. We could do that, but we are not doing it; nobody would agree to the expense. Voyager level signals are what I would expect to be listening for and those means required to make the search. I don't know of any such search going on. If some intelligent life happened to be out beyond a Voyager on a straight line, on the same frequency, we might hear them. Else forget it. I don't expect any intelligence in this galaxy to initiate a supernova and then sentiently modulate it to get our radio astronomers' attention. > > We didn't really start to send signals in very high strength until TV > and radar were in widespead use in the 40's. None of our TV broadcast signals, despite often using effective radiated power of a few megawatts, are aimed at outer space. Those canny transmitter owners spend a lot of money making sure that energy is directed pretty close to the earth's surface where the paying customers are. So their signals are not going to be very strong out at 50 ly. That intelligence at the other end will have to aim their 70 meter dishes very carefully, tuned to channel 6, and listen hard. Let's see, that will be about the year 2010. Maybe if our grandchildren are listening about 2060, they will hear that long-awaited "CQ Earth--what happened to Mr. Ed?". (;-)) Forrest Gehrke feg@dodger.ATT.COM ------------------------------ End of SPACE Digest V11 #292 *******************