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, 14 Dec 1990 01:39:21 -0500 (EST) Message-ID: <8bO7BnS00VcJI0ak4V@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 14 Dec 1990 01:38:45 -0500 (EST) Subject: SPACE Digest V12 #651 SPACE Digest Volume 12 : Issue 651 Today's Topics: ASTRO mission status at 5/10:30 Question on tidal locking. Re: Press briefing on Augustine Committee final report (Forwarded) Re: Planetary Society Re: Shuttle Status for 12/06/90 (Forwarded) Re: ASTRO status at 4/16:00 MET Re: Another Russian first UIT Status for 12/07/90 [1600 CST] (Forwarded) Re: * SpaceNews 03-Dec-90 * Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 7 Dec 90 17:17:27 GMT From: uvaarpa!murdoch!news@mcnc.org (Greg Hennessy) Subject: ASTRO mission status at 5/10:30 The UV instruments on the ASTRO observatory are again taking data. Shift 10 had essentially no science done with the three UV instruments, while the BBXT continue to take data. While the first two orbits of Shift 11 did not have any sucessful acquisitions, UIT obtained three deep exposures of NGC 1399, and WUPPE and HUT also got data on this galaxy. Later HUT was able to obtain lots of data on the quasar Q1821, and two orbits later WUPPE wa sback in business by itself as it obtained the star Gamma Gem on its own. The astronauts are tracking the stars by using a joystick, and they have about 5 arcsecons of jitter, which is acceptable to HUT and WUPPE (they have large slits) and the Image Motion Compensator is working to keep UIT stable to about a tenth of an arcsecond. The philosophy of the misssion has changed a bit, to get longer observations of fewer targets, since the overhead per observation is greater than expected. This makes UIT very happy, since they get nice deep exposures to work with. Here is a breakdown of the shift number, observing time scheduled, and acutally obtained, times in minutes. Shift Scheduled Obtained Percentage Notes 6 345 54 17 7 418 163 38 Startracker patched 8 429 189 44 9 428 247 57 10 36 8 4 2nd DDU died 11 343 187 55 The prelaunch expectations were that about 80 percent of the time scheduled would be observed, so while we are not there yet, we are gettin gcloser. There may be a 11'th day of the mission, which would allow us to recover some of the lost time due to the problems with spacelab. -- -Greg Hennessy, University of Virginia USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA Internet: gsh7w@virginia.edu UUCP: ...!uunet!virginia!gsh7w ------------------------------ Date: 7 Dec 90 17:54:51 GMT From: jcr@MBUNIX.MITRE.ORG (Rogers) Subject: Question on tidal locking. Hope somebody out there can settle a question about tidal locking. When the tidal locking process has run its course, will the rotational axis of the satellite be perpendicular to the plane of its orbit about its primary? This question was generated by Isaac Asimov's _Nemesis_, in which he describes a stellar system composed of a red dwarf star called Nemesis, a single gas giant planet called Megas, and a single moon of the gas giant, called Erythro. Here's an excerpt from the posting which started all this: ---------------------------------------------- On pg. 78 of the paperback edition, a character says of Erythro, "'... [due to tidal lock] only one side faces Megas, which is much cooler than Nemesis. Furthermore, the satellite's orbit is tilted substantially to Megas' equator. This means that in the satellite's sky, Megas is seen from only one hemisphere and it moves north and south with a cycle of about one day, while Nemesis moves across the sky, rising and setting, again with a cycle of one day. One hemisphere has twelve hours of darkness and twelve hours of light. The other hemisphere has the same but during its daytime, Nemesis is frequently in eclipse for up to half an hour at a time, with the cooling made up for by Megas' mild warmth. During the dark hours, in that hemisphere, the darkness is ameliorated by Megas' reflected light.'" Now, forgive me if there's something simple that I'm not getting here, but I can't see how Megas can move north and south in Erythro's sky if one side of Erythro permanently faces Megas. Especially if this has come about via tidal lock. Furthermore, Asimov implies that Megas moves north and south in Erythro's sky BECAUSE of the fact that Erythro's orbit is inclined relative to Megas' equator. But in fact there is no such causal connection. The only thing that would cause Megas to move north and south in Erythro's sky is if Erythro's axis were not perpendicular to the plane of Erythro's orbit about Megas. And the angle between a satellite's axis and its orbit is independent of the angle between the satellite's orbit and its primary's equator. However, doesn't the mechanism of tidal lock basically guarantee that a satellite's axis WILL be perpendicular to the plane of its orbit? I.e., the same mechanism that acts to slow the satellite's revolution with respect to its primary will also act to slow the rotational oscillations that would give rise to the described north & south movement of the primary as seen from the satellite. ---------------------------------------------- Thanks in advance for any help. --- Jeff R. ------------------------------ Date: Fri, 7 Dec 90 16:45:01 -0500 From: "Allen W. Sherzer" Subject: Re: Press briefing on Augustine Committee final report (Forwarded) Newsgroups: sci.space Cc: In article <1990Dec7.164556.9062@news.arc.nasa.gov>: >PRESS BRIEFING ON AUGUSTINE COMMITTEE FINAL REPORT There is also an article on this in today (Friday')s Wall Street Journal on the back of section 1. Among the recommendations are: 1. Less reliance on the Shuttle 2. Build a new launcher. This looks like ALS but they didn't call it that. This new launcher can be configured to launch various payloads and will cost $10B to develop. 3. Reorganize the centers so that each has a well defined area of expertise. This will prevent duplication of effort so more work can be done for less money. 4. Drop plans to build a new Shuttle and use the money for this new launcher. And now, my editorial comments: 1. Don't build the launcher they are talking about. For the cost of the new orbiter we can build two different HLV's using existing designs AND have a good chunk left to build capsules. 2. The reorganizaiton is good as far as it goes but more is needed. Operational responsibility however, must be taken away from NASA and turned over to the private sector. It would have been interesting to see the documents which went into the final version. The recommendations released where the consensus view of the panel and there where many who held stronger (and weaker) views. However, it is likely that the House will begin its own hearings into NASA. They are looking to make much more radical changes than proposed here. It should be an interesting year. Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation | | aws@iti.org | programs, spare parts for 25 years. Who cares if it | | | works or not? - Dick Jones, VP OCP Security Concepts | ------------------------------ Date: Fri, 7 Dec 90 18:39:10 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Planetary Society >From: zephyr.ens.tek.com!tektronix!sequent!crg5!szabo@uunet.uu.net (Nick Szabo) >Subject: Re: space news from Oct 6 AW&ST >In article <1990Dec4.025945.15482@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >> >>Planetary Soviety invitation-only meeting to "critique" the current space >>station... >>...(On the other hand, >>some of the attendees commented that the deck was stacked: the choice >>of participants seemed to be deliberately aimed at such a conclusion.) >Isn't "invitation only" also true of NASA commitees, the Space Council, >NSS commitees, etc.? Your biases are showing, Henry. :-) The stated purpose of the meetings should be taken into account. If NASA is seeking external input to its own project, it may reserve the right to concentrate on the advice of those whose knowledge and judgement it has come to respect. (It should not, however, refuse to accept input from others. NASA conducted a program a few months ago soliciting ideas from the general public.) If the Planetary Society wants to produce a consensus statement of people who hold a particular point of view, then fine. If they want to produce a statement and claim that it is the general consensus of everyone in the field, then they shouldn't make a deliberate effort to stack the meeting with people known to hold a particular point of view. My own opinion is that the space station was in need of redesign, particularly in light of the predicted need for maintenance during assembly. I would also consider at least the option for use as an assembly point for lunar and interplanetary craft to be very important. >It is about time the man-in-space people started listening to the >Planetary Society folks. While NASA has wasted most of its money on >earth-orbiting manned projects, the Planetary Society (many of them >ex-Voyager and Viking project people) have quietly pushed the >continuation of our U.S. program that has explored most of the planets >and moons in the solar system, with only a tiny fraction of NASA's >budget. This, and the development of the first and largest commercial space >industry (unmanned communication satellites) have put the U.S. far >ahead of any other country in space, yet we squander this with attention >and money lavished on dead-end manned projects. Last I heard, the Planetary Society was still pushing for a hideously costly, crash-priority one-shot manned trip to Mars, mainly to serve as an inspiration to mankind and generate political goodwill, and at the expense of most or all other manned space activity for the forseeable future. I do not consider this a good utilization of human resources in space, and since I have read claims that the Planetary Society in its lobbying tends to imply that *all* its members support the "official" view, I have avoided joining the Planetary Society in spite of its many excellent features. Perhaps this "outsider's" view is overly biased, and a member could give a more accurate perspective. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Fri, 7 Dec 90 11:07:26 -0500 From: "Allen W. Sherzer" Subject: Re: Shuttle Status for 12/06/90 (Forwarded) Newsgroups: sci.space Cc: In article <1990Dec7.073019.7551@ux1.cso.uiuc.edu>: >So here's the $6e6 question for the day: What's going to happen to Astro >when it gets back to Florida? I wonder if anybody has considered putting it on Freedom? That way people could do observations during spare time or as part of the regular schedule. Of course, this assumes that there will be a space station which may not be a good bet the way the redesign is going. :-( Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation | | aws@iti.org | programs, spare parts for 25 years. Who cares if it | | | works or not? - Dick Jones, VP OCP Security Concepts | ------------------------------ Date: 7 Dec 90 16:14:20 GMT From: uvaarpa!murdoch!astsun.astro.Virginia.EDU!gsh7w@mcnc.org (Greg Hennessy) Subject: Re: ASTRO status at 4/16:00 MET Harry P Bloomberg writes: # Now get back to work and fix those *&(*&^% star trackers! :-) :-) :-) They won't. The astronauts do a good enough job, and the better stability that the star trackers give us is not worth the lost time that they cause. The astronauts are doing better than expected, and the machines worse. When I get some sleep (right now I won't catch up on sleep till about the 15th) I'll probably consider the implications of that statement. -- -Greg Hennessy, University of Virginia USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA Internet: gsh7w@virginia.edu UUCP: ...!uunet!virginia!gsh7w ------------------------------ Date: 7 Dec 90 01:01:57 GMT From: uokmax!munnari.oz.au!bruce!monu1!monu6!minyos!rxtgep@apple.com (Glen Pill) Subject: Re: Another Russian first From article <546@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): > In article <1990Dec3.231611.6288@isc.rit.edu> swd0170@ritvax.isc.rit.edu writes: > > Interesting to note that the Soviets have had a string of workable space > stations, while Skylab 2 is sitting inside of the National Air & Space Museum. > I always thought skylab was splattered over Western Australia. :-) -- Glen Pill ACSNet: rxtgep@minyos.xx.rmit.oz.au RMIT Computer Centre Snail : 124 LaTrobe St, Melb. Oz. 3000. Phone : +61 3 660 2538 ------------------------------ Date: 8 Dec 90 05:21:27 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: UIT Status for 12/07/90 [1600 CST] (Forwarded) UIT Status Report #05 4 p.m. CST Dec. 7, 1990 Spacelab Mission Operations Control Marshall Space Flight Center Huntsville, AL Principal Investigator Ted Stecher and other members of the Ultraviolet Imaging Telescope Team worked even harder than usual, with ground command of their instrument added to their normal duties. But, "I'd even say that commanding from the ground is fun," said UIT member Barbara Pfarr. Targets observed today by UIT included the cluster of galaxies Abell 2597, Supernova 1987A, and the Andromeda galaxy (M31). UIT was developed at Goddard Space Flight Center in Greenbelt, MD. ------------------------------ Date: 9 Dec 90 19:47:43 GMT From: usc!cs.utexas.edu!ut-emx!aoab314@apple.com (Srinivas Bettadpur) Subject: Re: * SpaceNews 03-Dec-90 * In article <1990Dec6.121859.836@qualcomm.com> antonio@drzeus.qualcomm.com (Franklin Antonio) writes: >> newman@batcomputer.tn.cornell.edu (Bill Newman) writes: >>> henry@zoo.toronto.edu (Henry Spencer) writes: >>>> antonio@drzeus.qualcomm.com (Franklin Antonio) writes: >>>>So, the basic work was done 371 years ago! This is one of the humbling >>>Kepler is not the really humbling example in celestial mechanics. That >>>honor goes to Isaac Newton, ... >>>mathematicians of the next two centuries basically just added footnotes >>>to his work. > >I agree with Henry. Newton humbles us all. As for the following 370 years of >many-body perturbation and stability theory: bah! "plausible" and "could be" >are waffle-words. While I will agree that Newton established all the fundamentals for the CM, that he did grind the 2-body problem to dust, and that the science of CM is indeed four centuries old, I cannot agree to calling the later work "footnotes" or dismissing the following works as being un-verifiable. This argument is similar to one that may be made in "showing" that all of science and engineering boils down to Physics, or that the only truly original discoveries appear in some esoteric branches of Physics, and everything else follows. The point is not that the basic problem of CM has remained unchanged for the past four centuries. It is that all the variations on that problem have prompted some remarkable contributions from a large number of mathematicians, and more importantly, these contributions have had implications far beyond just CM. Srinivas Bettadpur ------------------------------ End of SPACE Digest V12 #651 *******************