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 ; Wed, 14 Nov 1990 01:57:32 -0500 (EST) Message-ID: <8bECew200VcJI9aE4P@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 14 Nov 1990 01:57:00 -0500 (EST) Subject: SPACE Digest V12 #546 SPACE Digest Volume 12 : Issue 546 Today's Topics: NASA Headline News for 11/09/90 (Forwarded) Re: LLNL Astronaut Delivery Fundamental FITS Information Re: Synchronous rotation Re: Galileo Update - 11/02/90 Synchronous rotation The Ariane V36 failure (was Re: Ariane launches ON TIME! (again)) 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 ---------------------------------------------------------------------- Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 9 Nov 90 19:38:50 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Organization: NASA Ames Research Center, Moffett Field, CA Subject: NASA Headline News for 11/09/90 (Forwarded) Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu Headline News Internal Communications Branch (P-2) NASA Headquarters Friday, November 9, 1990 Audio Service: 202 / 755-1788 This is NASA Headline News for Friday, November 9, 1990 At the Kennedy Space Center, preparations for STS-38 continue to go according to schedule. Atlantis close out activities are going well, with aft compartment closeout scheduled to be completed Sunday evening. Purging operations on Atlantis' three fuel cells were finished yesterday. Ordnance activities are set for early tomorrow morning, during which time Launch Pad 39-A will be closed to all non-essential personnel. The countdown process picks up at 10:30 pm EST, Sunday, Nov. 11. At Launch Pad 39-B, technicians are servicing the Astro-1 Broad Band X-ray Telescope with argon again. The film in the Ultraviolet Imaging Telescope has been removed and will be replaced with fresh film just prior to launch of Columbia. Work to close out orbiter activities progresses with activities such as updating the mission data contained in the onboard mass memory unit. SLS astronauts were at the Operations & Checkout building yesterday for a series of integration activities. A Space Life Sciences-1 team photo was also taken. * * * * * * * * * * * * * * * * * * * * * * * * * * The Galileo spacecraft is now less than 15.4 million miles from Earth, approaching us at a velocity of more than 23,000 miles per hour. The first of the twin Earth Gravity Assists is now just one month away on Dec. 8. Galileo is in excellent condition, and the general level of spacecraft activity remains fairly low. Galileo will undergo a course correction maneuver next week to allow for additional fine tuning of its Earth flyby trajectory. * * * * * * * * * * * * * * * * * * * * * * * * * * Magellan remains in good condition. Earth and Venus are still in superior conjunction with the Earth-Sun-Venus angle, still less than 2.5 degrees. The downlink from the spacecraft, on both X and S bands, is reasonably good, with few data transmission errors resulting from solar interference. However, the uplink from the Deep Space Network to Magellan is not nearly as good, and is accompanied by numerous data errors. Since the resumption of mapping activities requires a new mapping sequence to be transmitted to Magellan, Jet Propulsion Laboratory flight controllers have deferred the mapping activities until tomorrow. JPL has predicted that the uplink data integrity will be regained by later today, and will attempt to uplink the new mapping sequence at that time. Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are Eastern. **indicates a live program. NASA Select TV programming will resume Tuesday, 11 / 13 / 90 All events and times may change without notice. This report is filed daily, Monday through Friday, at 12:00 pm, EST. It is a service of Internal Communications Branch at NASA Headquarters. Contact: CREDMOND on NASAmail or at 202/453-8425. NASA Select TV: Satcom F2R, Transponder 13, C-Band, 72 degrees West Longitude, Audio 6.8, Frequency 3960 MHz. ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 9 Nov 90 04:35:35 GMT From: sumax!thebes!polari!crad@beaver.cs.washington.edu (Charles Radley) Organization: Seattle Online Public Unix (206) 328-4944 Subject: Re: LLNL Astronaut Delivery References: <2669@polari.UUCP>, <9011072124.AA13810@iti.org>, <1990Nov7.232525.5633@engin.umich.edu> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu OOps, I guess government centers are not subject to the restrictions of commercial companies. The premise there I suppose is that government security centers have "better" security arrangements that commercial companies. By thesame token, it should be that much easier for LLNL to launch their staion using Soviet boosters, and to purchase Soyuz vehicles, cheaper than developing their own. ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 8 Nov 90 19:39:02 GMT From: dftsrv!nssdca.gsfc.nasa.gov!bschlesinger@ames.arc.nasa.gov (Barry Schlesinger) Organization: NASA - Goddard Space Flight Center Subject: Fundamental FITS Information Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu This information is posted in response to requests for where general FITS information can be found. The best references are the following three papers: Wells, Greisen, and Harten, 1981, "FITS: a flexible image transport system", Astronomy and Astrophysics Supplements, v. 44, p. 363. Grosbo\"l et al., 1988, "Generalized extensions and blocking factors for FITS", Astron. Astrophys. Suppl., 88,359. Harten et al., 1988, "The FITS tables extension", Astron. Astrophys. Suppl., 88,365. The titles of these papers show that FITS is not exclusively for the transport of digital images but can transport a wider variety of structures. An additional paper, immediately following the 1981 paper cited above discussed "groups" format. In practice, this format is used only to transfer and store radio interferometry results. It is not widely used or understood elsewhere. Originally, as discussed in the first FITS paper, the data matrix could contain only integers. By international agreement, it now may contain IEEE-754 single and double precision floating point numbers. If a data matrix is composed of floating point numbers, then the BITPIX keyword in the preceding header has a negatrive value (-32 for single and -64 for double precision). The FITS Handbook is not yet available; the first sections, covering the Introduction, FITS history, and FITS fundamentals are expected to be available later this year. We have not yet collected contributed software. Probably, this office will have information on software that the originators are willing to make publicly available before the office itself has software to distribute. Barry Schlesinger NSDSSO FITS Support Office ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 10 Nov 90 00:45:55 GMT From: ubc-cs!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld@beaver.cs.washington.edu (Christopher Neufeld) Organization: University of Toronto Physics/Astronomy/CITA Subject: Re: Synchronous rotation References: <7712.273a7b89@uwovax.uwo.ca>, <1990Nov9.190858.11889@ns.network.com> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <1990Nov9.190858.11889@ns.network.com> logajan@ns.network.com (John Logajan) writes: >17001_1511@uwovax.uwo.ca Phil Stooke writes: >>This produces stresses and movements in the crust >>which involve some energy dissipation. Therefore energy is slowly being >>lost from the system, and that manifests itself as a gradual slowing of the >>rotation period, until syncronous rotation is reached. > >Okay -- so where does the angular momentum go? It has to be conserved. > It goes into orbital angular momentum, boosting the orbit of the moon (assuming that the moon was originally rotating around an axis parallel, not anti-parallel to the orbital axis). Our moon is moving away from us still, as it tries to lock the Earth to face it. Velocity in orbit decreases as the square root of the distance from the centre of rotation, so higher orbits have higher angular momenta, with an angular momentum proportional to the square root of the distance. >- John Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 >- logajan@ns.network.com, 612-424-4888, Fax 612-424-2853 -- Christopher Neufeld....Just a graduate student | neufeld@helios.physics.utoronto.ca Ad astra! | S = k log W cneufeld@{pnet91,pro-micol}.cts.com | Boltzmann's epitaph "Don't edit reality for the sake of simplicity" | ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 7 Nov 90 08:28:02 GMT From: eru!hagbard!sunic!mcsun!unido!mpirbn!p515dfi@bloom-beacon.mit.edu (Daniel Fischer) Organization: Max-Planck-Institut fuer Radioastronomie, Bonn Subject: Re: Galileo Update - 11/02/90 References: <1990Nov2.225442.8608@jato.jpl.nasa.gov> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <1990Nov3.050407.1642@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <4680@cvl.umd.edu> herve@cvl.UUCP (Jean-Yves Herve') writes: >>There is just one little thing that bugs me: how come the Galileo are given >>with funny units only, while the Ulysses report have both metric and funny >>units? >Probably because Ulysses is a European project and hence the European >audience is being considered. [...] But then again, Galileo is an American-German bilateral project, and I can assure you that we here are metric. The strange obsession of American aerospace activists (officials and journalists alike, esp. Av'Leak's!) with ancient unit systems definitely does *not* clarify issues, even for the U.S. audience. Just think of a) the conversion precision problem: how many figures of a 'mile' number are significant? The 1.609...-factor connecting it with metric units causes many writers to provide their mile-values with a ridiculous pseudo- precision (a topic discussed in sci.space many times...). And b) the fact that km, mile and nautical mile are all of the same order of magnitude, esp. ml. & nm. which also sound so similar, frequently causes confusion: when a space expert tells you a satellite is at '400 miles' altitude, you can never be sure whether he is talking about ordinary miles or nautical miles (and skipping the 'nautical' because it's sooo obvious). [I am aware that the topic must have been discussed on the net and in journals countless times before - recall the 'no metric units on Fred'-saga? - but obviously it *has* to be repeated :-< ] ------------------------------ Date: 9 Nov 90 14:48:56 GMT From: ubc-cs!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax!17001_1511@beaver.cs.washington.edu Subject: Synchronous rotation Regarding synchronous rotation of natural satellites: It is indeed common for satellites to be in synchronous rotation. Of the nearly 60 satellites in the solar system that are known at present, rotation states are reasonably well known for perhaps 40, and all but 3 or 4 are in synchronous rotation. Exceptions: Saturn's Hyperion and Phoebe, Jupiter's Himalia (one of the very distant small satellites). There might be one or two other small outer satellites of Jupiter whose periods are now known from photometry and are not rotating synchron- ously but I'm not quite up to date. The reason is that orbiting bodies raise tides in each other. For instance, the Moon raises a tide in Earth's oceans of a couple of metres and a tide in the solid crust of a few centimetres. If the Moon once rotated faster, the Earth must have raised a fairly large tide in the lunar crust - certainly several tens of centimetres, I would guess (somebody else can do the math!) This produces stresses and movements in the crust which involve some energy dissipation. Therefore energy is slowly being lost from the system, and that manifests itself as a gradual slowing of the rotation period, until syncronous rotation is reached. At that point the tidal deformation is still present but it is locked into one place with respect to the crust and no more energy is lost. For this to work the tidal effect must be large enough. We do indeed see that all satellites close to even small planets like Mars and Pluto are tidally locked. Also large satellites far from a planet, like Iapetus, are locked because the tidal effect is greater across a large body (what counts is the difference in strength of a planet's gravity from the near side to the far side of the satellite, naturally greater across a larger diameter). The exceptions are very small and very distant moons (Phoebe, Himalia) and the special case of Hyperion which is in chaotic rotation because of its bizarre shape and complex interactions with Titan as well as Saturn. Phil Stooke Department of Geography, University of Western Ontario, London, Ontario, Canada N6A 5C2 ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 10 Nov 90 15:11:30 GMT From: eagle!news@ucbvax.Berkeley.EDU (Ronald E. Graham) Organization: NASA Lewis Research Center Subject: The Ariane V36 failure (was Re: Ariane launches ON TIME! (again)) References: <1990Nov6.192118.6012@cc.ic.ac.uk>, <1990Nov9.145517.1891@cc.ic.ac.uk> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu I included sci.engr in this follow-up, hoping for some extra technical insight. The original posting was sent to sci.space and sci.astro. In article <1990Nov9.145517.1891@cc.ic.ac.uk>, zmapj36@cc.ic.ac.uk (M. S. Bennett) writes... [From an article entitled "Ariane Returns to Business" by Neville Kidger...] > Arianespace, the company which markets and flies the Ariane launcher, >has resumed operations following the loss of the V36 launcher in February >1990. > The loss of the rocket - with two Japanese commercial satellites >aboard - was found to have been due to the presence of a piece of cloth >in the water supply line to one of the four Viking first stage engines. I've never been part of a failure investigation (thankfully ;-)) since I joined NASA, so I don't know much about the procedure. I hope someone can offer insight on the following questions: (1) the failure was due to a piece of cloth. How could this have been isolated after the failure? (2) what is the mechanism by which a piece of cloth was able to cause the failure? By that I mean - was the cloth of sufficient size/porosity to totally restrict water flow? or did it have to be? - how is a piece of cloth able to be in the water line anyway? - what is the sequence of events leading to the failure, given the presence of the cloth? (3) how can Arianespace ensure no repeat of this mechanism/sequence of events? Please don't give any over-simplified answers like "they screwed up," or "they need to look harder." Unless (3) absolutely requires a very simple answer. I won't assume you know what you're talking about. And, if there are some answers out there, I will gladly summarize. RG - lvron@earth (or mars, or saturn - your choice) .lerc.nasa.gov ------------------------------ End of SPACE Digest V12 #546 *******************