Date: Wed, 2 Jun 93 05:07:04 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #656 To: Space Digest Readers Precedence: bulk Space Digest Wed, 2 Jun 93 Volume 16 : Issue 656 Today's Topics: Can we use HST to look at possible Jupiter/comet collision? Comet Shoemaker-Levy, Possible Collision With Jupiter in 1994 (2 msgs) Detecting planets in other system (2 msgs) DSN Usage Hey Ken! You awake? You exist? (LEO Cost; Return cost) (3 msgs) Hey Sherz! (For real!) Cost of LEO (3 msgs) lunar metallurgy Magellan Update - 05/30/93 More on Comet-Jupiter Collision Possibility non-solar planets Seeding Mars with "Mars box" life Space Marketing would be wonderfull. The crew is toast Tom Wolfe's THE RIGHT STUFF - Truth or Fiction? Why is everyone picking on Carl Sagan? Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 1 Jun 1993 19:21:18 GMT From: "Bruce d. Scott" Subject: Can we use HST to look at possible Jupiter/comet collision? Newsgroups: sci.space In article <1993Jun1.164416.24191@cs.ucf.edu>, clarke@acme.ucf.edu (Thomas Clarke) writes: [I wrote] |> >How is it that _one_ picture of a collision event would be useful? |> >I should think that to have any bearing on modelling of the collision |> >process one would need a series. Working on turbulence computation, I |> >have seen a lot of this type of problem... |> I think one picture of the spectrum of the colliding comet |> might be useful in that it could be used as the basis of a |> chemical analysis of the comet. But you could get that from just looking at the comet whenever you want. The collision process itself is another matter. -- Gruss, Dr Bruce Scott The deadliest bullshit is Max-Planck-Institut fuer Plasmaphysik odorless and transparent bds at spl6n1.aug.ipp-garching.mpg.de -- W Gibson ------------------------------ Date: Thu, 27 May 1993 22:20:00 GMT From: "Phil G. Fraering" Subject: Comet Shoemaker-Levy, Possible Collision With Jupiter in 1994 Newsgroups: sci.space richmond@spiff.Princeton.EDU (Stupendous Man) writes: > Gosh, Phil, I don't MEAN to rain on your parade, but the High-Speed >Photometer will be removed from HST and replaced by COSTAR (the >device with special mirrors to fix the spherical aberration for the >other instuments) in the repair mission in late 1993 or early 1994. >Sorry. I realized that shortly after posting the article w/ the photometer bit; and posted about that yesterday morning. I wish people would read all the existing articles on a thread before following up... Finally: is this yet another example of the Space Shuttle hurting space science? (If you need a smiley on that statement, put it there yourself). >-- >----- Michael Richmond >"This is the heart that broke my finger." richmond@astro.princeton.edu -- +-----------------------+---------------------------------------+ |Phil Fraering | "...drag them, kicking and screaming, | |pgf@srl03.cacs.usl.edu | into the Century of the Fruitbat." | +-----------------------+-Terry Pratchett, _Reaper Man_---------+ ------------------------------ Date: Thu, 27 May 1993 22:24:40 GMT From: "Phil G. Fraering" Subject: Comet Shoemaker-Levy, Possible Collision With Jupiter in 1994 Newsgroups: sci.space jfc@athena.mit.edu (John F Carr) writes: >Something has been left out of all this speculation: why do we want to >observe this event? Why do we want to observe this event? What newsgroup are you reading this on? I'm reading it on sci.space. Perhaps when I started the thread I should have cross-posted to sci.astro as well. We want to observe this because we don't get very many chances to see what happens when a kilometer-wide piece of ice hits the atmosphere of a planet. It's an experiment we can't repeat at our leisure (at least not until Nick gets a good head of steam built up on an ice tanker...) What might we learn? What might we learn that the >atmosphere probe would not learn the next year? >Could we observe the spectrum of the comet as it vaporizes? That would >be interesting, since we would not be limited to volatile substances. >But would it be hot enough while still above the cloud layer? We could use photometry (prob. ground based; Hubble won't have any advantage) to observe the explosion; perhaps the light curve from said explosion could shed some light on the internal structure of the former object. -- +-----------------------+---------------------------------------+ |Phil Fraering | "...drag them, kicking and screaming, | |pgf@srl03.cacs.usl.edu | into the Century of the Fruitbat." | +-----------------------+-Terry Pratchett, _Reaper Man_---------+ ------------------------------ Date: Thu, 27 May 1993 13:22:55 GMT From: "Bruce T. Harvey" Subject: Detecting planets in other system Newsgroups: sci.space,sci.astro in article <1993May27.102938.14323@vax.oxford.ac.uk>, clements@vax.oxford.ac.uk says: > In article , sasbck@spain.unx.sas.com (Brenda Kalt) writes: >> In article <1993May26.184001.16542@cs.ucf.edu>, clarke@acme.ucf.edu (Thomas Clarke) writes: >> |> In a recent issue of Science there is a discussion of a project >> |> to look for MACHOs (Massive Compact Halo Objects - things like >> ^^^^^ >> [......] >> Sexism in research strikes again. Obviously, a modern, non-sexist name >> for this phenomenon would be McHalos... >> Brenda Kalt >> sasbck@unx.sas.com > It should be noted that MACHOs were so named to contrast them with the > previously suggested WIMPS (weakly interacting amssive particles). > Your post does suggest an interesting thought though... > > Perhaps we could get corporations to sponsor the adopted names of classes of > objects. Thus we'd have McHalos sponsored by McDonalds, the Burger King Quark > instead of bottom, etc etc... > ================================================================================ > Dave Clements, Oxford University Astrophysics Department > ================================================================================ > clements @ uk.ac.ox.vax | Umberto Eco is the *real* Comte de > dlc @ uk.ac.ox.astro | Saint Germain... > ================================================================================ How about ... Baltimore Quark (CHARM City Quark) Calcutta Object (Black Hole) PBS-Award-Winning-Documentary-Program (NOVA); and, Super-PBS-Award-Winning-Documentary-Program Classic Ford Congregation (Galaxy) I could go on into different areas ... Explosive Ford Legume (Pinto beans) ... but why bother :-) -- :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Bruce T. Harvey (B-{>:: UUCP: ... {uunet|mimsy}!wb3ffv!idsssd!bruce Manager Appli. Devlopmt.:: INTERNET: wb3ffv!idsssd!bruce%uunet.uu.net@... INsight Distribution Sys::CompuServe: 71033,1070 (410)329-1100 x315, x352:: SnailMail: 222 Schilling Cir.,Hunt Valley, MD 21031 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ------------------------------ Date: Tue, 1 Jun 1993 17:30:57 GMT From: Frank Crary Subject: Detecting planets in other system Newsgroups: sci.space In article lou@Cadence.COM (Louis K. Scheffer) writes: >>Actually, an interferometer(sp?) array in the thermal IR has a reasonable >>chance, if you can get a couple of orbital telescopes and a baseline >>of ~500,000 km. In the thermal IR the signal to noise (i.e. star's >>flux to that of the planet) is greatest, since you are in the peak of >>the planet's Plank curve but well away from the star's peak. >This is off by a factor of 100,000! >Assume a planet 8 light minutes from a star (earth orbit). The star is >8 light years away. That's one part in 500,000. So to first order, you >need your mirrors 500,000 wavelengths (NOT kilometers) apart, or 5 meters >for 10 micron IR. If you had a perfect telescope, I'd agree. But in fact, no real telescope can resolve a star into a nice circular spot. What you actually get is a bessel function (or, if you are clever, a gaussian). For the one part in 500,000 figure above, you could resolve two stars of equal brightness: The image of the star would be about 65% dimmer allowing you to observe anything of comparable brightness 8 light minutes away from the star. But a planet is _much_ dimmer than a star. You need the light of the star to drop off by as much as 40 or 50 orders of magnitude. That requires a diffraction limit a few hundredths of the star-planet seperation. Frank Crary CU Boulder ------------------------------ Date: 1 Jun 1993 20:45:28 GMT From: Steve Derry Subject: DSN Usage Newsgroups: alt.sci.planetary,sci.space The Deep Space Network is a crucial resource supporting all U.S. (and probably international also) deep space missions. Scheduling DSN time must be an interesting problem of juggling competing demands. How busy is the DSN? What are the most heavily loaded DSN resources? Which missions are using DSN, either on a regular or irregular basis? How much time does each get? How far in advance is DSN time scheduled? How are "spacecraft emergencies" handled? What additional requirements and upgrades are planned over the next several years? Are things going to get better or worse? Thanks! -- Steve Derry ------------------------------ Date: Tue, 1 Jun 1993 19:17:30 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Hey Ken! You awake? You exist? (LEO Cost; Return cost) Newsgroups: sci.space Writing to the other Ken, Phil Fraering (pgf@srl01.cacs.usl.edu) wrote: : "Ken," it isn't important if it takes more money to return something : than it does to build another one and launch it. Sorry. Phil, you're assuming here that immediate profitability is the sole criterion for "importance." That has never been true in Government, and since most of the space program is (unfortunately) reliant on Governments, this seems to be an invalid assumption. If we were talking about a space program which private industry uses as a means of making profit, then profitability is very important. But there are many other considerations, even there, like investment in plant/infrastructure, market share, experience and corporate knowledge -- things which may affect future profitability, but which do not require that each mission be profitable. The first few missions which the Hudson Bay Company funded to the New World probably weren't profitable. But overall, their program certainly was. Isn't that important? -- Ken Jenks, NASA/JSC/DE44, Mission Operations, Space Station Systems kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "It is mankind's manifest destiny to bring our humanity into space, to colonize this galaxy. And as a nation, we have the power to determine whether America will lead or will follow. I say that America must lead." -- Ronald Reagan ------------------------------ Date: Tue, 1 Jun 1993 19:42:41 GMT From: "Allen W. Sherzer" Subject: Hey Ken! You awake? You exist? (LEO Cost; Return cost) Newsgroups: sci.space In article <1993Jun1.191730.17246@sol.ctr.columbia.edu> kjenks@gothamcity.jsc.nasa.gov writes: >Phil, you're assuming here that immediate profitability is the sole >criterion for "importance." Granted it isn't. However, we should see progress toward eventual profitability; we aren't. >The first few missions which the Hudson Bay Company funded to the New >World probably weren't profitable. But overall, their program >certainly was. Isn't that important? That was a very different sort of program than what we have today. An Apollo era engineer was speaking at ISDC last week. He told a friend of mine when asked about the biggest difference between now and the Apollo days: "Now you hear engineers in the hallway having arguements about what font to use on their viewgraphs, back then we didn't even know what fonts where". Every major space effort we start is getting more expensive and producing less. From 84 to 90 we spent $6 BILLION on a station which couldn't have been built even if funded. Our 'program' is spiraling in and is headed for a crash, a far cry from the Husdon Bay Company. Allen -- +---------------------------------------------------------------------------+ | Lady Astor: "Sir, if you were my husband I would poison your coffee!" | | W. Churchill: "Madam, if you were my wife, I would drink it." | +----------------------15 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: Tue, 1 Jun 1993 20:45:43 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: Hey Ken! You awake? You exist? (LEO Cost; Return cost) Newsgroups: sci.space Allen W. Sherzer (aws@iti.org) wrote: : Every major space effort we start is getting more expensive and : producing less. From 84 to 90 we spent $6 BILLION on a station which : couldn't have been built even if funded. Our 'program' is spiraling : in and is headed for a crash, a far cry from the Husdon Bay Company. 'Way back when the Hudson Bay Company was launching its first missions to the New World, there were probably many similar efforts which failed. Our history books, unfortunately, don't teach us about the failed attempts, only the successful ones. This is historically inaccurate, and we'd probably learn more from studying the unsuccessful missions and the causes of their failures, but that's the way history books are written. To some degree, history is written by the victors, and by historians who are thrilled with writing about winners. Although I can't verify it, I think we'd learn more by studying the losers. By analogy, in a hundred years, our failures in the space program may be just a footnote to history, while our successes will be remembered by all. This doesn't mean we shouldn't make mistakes. The only way we can avoid making mistakes is to stop trying. -- Ken Jenks, NASA/JSC/DE44, Mission Operations, Space Station Systems kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "The man who makes no mistakes does not usually make anything." -- Edward John Phelps, American Diplomat/Lawyer (1825-1895) ------------------------------ Date: Tue, 1 Jun 1993 19:40:41 GMT From: Josh Hopkins Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space prb@access.digex.net (Pat) writes: > Actually, here is a real condemnation of SHuttle. If shuttle >is so great, why did the soviets Abandon BURAN? It's not a completely closed question. There is still some pressure to refly it, though I personally doubt it will happen. It was built soley for political reasons as far as I can tell. >Buran is 99% like >shuttle in capacity, except BIG PLUS, it has Liquid Boosters, >and a jet engine assist on landing. Buran does not have jet engines. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "This Universe never did make sense; I suspect it was built on government contract." -RAH ------------------------------ Date: 1 Jun 1993 17:32:50 -0400 From: Pat Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes: >prb@access.digex.net (Pat) writes: >>and a jet engine assist on landing. >Buran does not have jet engines. Really? pat ------------------------------ Date: 1 Jun 1993 17:37:58 -0400 From: Pat Subject: Hey Sherz! (For real!) Cost of LEO Newsgroups: sci.space In article <1JUN199309502042@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: |In article <1993May26.193103.28480@mksol.dseg.ti.com>, mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes... |>In <1ttm8j$90i@access.digex.net> prb@access.digex.net (Pat) writes: |> | |>>Ken, |> |>>pat. |> |>>Don't include contingency satellitte return missions. It would have |>>been cheaper to build new ones and pop them off. |>-- |>Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. | |It is real funny for me to read the "experts" talking about the cost of |satellite construction from those who have never laid their hands on one, or |been responsible for the construction and operation of one. | |If you want to make statements like this back them up with numbers both the |cost of reconstruction and the cost in lost revenues during the construction |period. That's kind of an impossible question, Dennis. If you are talking about a commercial comsat, the missed revenue is the anticipate dcash flow during construction. For something like voyager, there is no price. you miss the launch window, you are hosed. Please specify, the cases. Also, NASA in the 70's had a policy of building 3 birds for each mission. A ground engineering test vehicle, the Flight bird and a flight spare. I saw something where they said they saved 10% off the DDTE by skipping the flight spare. They were tired of putting the flight spares into the NA&SM. Personally, if that's teh kind of savings, they might as well always build a flight spare. if it gets tossed in the drink, fine you are ready for an immediate re-boost, otherwise you have a very good source of spares, for some other mission. pat ------------------------------ Date: Tue, 1 Jun 1993 14:29:09 MST From: "Richard Schroeppel" Subject: lunar metallurgy Nick Janow (Nick_Janow@mindlink.bc.ca) writes > There's also the potential for alloys that can be prepared in lunar gravity but not in Earth gravity, and still more that can be made in zero-g. There are also alloys that aren't used or even studied much on Earth due to problems with atmospheric interaction (both in forming and use). Who knows, calcium alloyed with bismuth and lithium (for example) could turn out to be an important material. There's a minor glitch here - any lunar environment with people nearby will have minor outgassing of water vapor, air, & CO2. Although this isn't comparable to an Earth rain-storm in corrosive power, it will be a nuisance for things made of potassium, for example. Another side of this coin is that you will be reluctant to make things that can't be brought inside the airlock to be worked on, machined, assembled, etc. Rich Schroeppel rcs@cs.arizona.edu ------------------------------ Date: 1 Jun 1993 17:27:16 -0400 From: Pat Subject: Magellan Update - 05/30/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary Isn't this majestic? ------------------------------ Date: 1 Jun 1993 20:52 UT From: Ron Baalke Subject: More on Comet-Jupiter Collision Possibility Newsgroups: sci.space,sci.astro,alt.sci.planetary COMET SHOEMAKER-LEVY (1993e) According to IAU Circular 5807, A. Carusi has confirmed that the center of the comet train for Comet Shoemaker-Levy (1993e) will collide with Jupiter in 1994 during the period of July 23-27. This confirmation is based on the orbital elements published in IAU Circular 5800. He also suggests that the the entire comet train may be involved with the collision since the window for the collision is 30 times the length of the comet train. Donald Yeomans and Paul Chodas from JPL have computed that the probability of the center of the comet train colliding with Jupiter in July 1994 is as high as 64 percent. IAU Circular 5807 also reports that J. Scotti from the Lunar and Planetary Lab has recovered Comet Shajn-Schaldach, designated as 1993k. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand, |_____|/ |_|/ |_____|/ | has three eyes. ------------------------------ Date: 1 Jun 93 13:50:48 From: Steinn Sigurdsson Subject: non-solar planets Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: I wrote: >The only extra-solar planets whose existence is beyond dispute are one >or two around pulsars... They're also, last >I heard, somewhat puzzling -- the supernova that produces the pulsar >should blow them away. Update: I'm told, in private mail, that the theorists are sweating a bit but have produced one or two plausible ways for pulsars to have planets. Well, I suppose this depends on your definition of "plausible" but the two summary papers in "Planets Around Pulsars" PASP v39, 1992 list 20 general formation scenarios... that's of the same order as the number of theorists who have considered the problem of course ;-) I'd personally rank two or three as "likely" and another half-dozen as "possible", with the likely ones applicable to the particular circumstance of PSR1257+12, while some of the "possibles" are not applicable to that class of pulsar. (PSR1257+12 is a "recycled" millisecond pulsar). Interested parties should keep an eye out for a pair of papers by Thorsett et al (ApJL) and Backer et al (Nature, I think) whihc should come out soon. * Steinn Sigurdsson Lick Observatory * * steinly@lick.ucsc.edu "standard disclaimer" * * The laws of gravity are very,very strict * * And you're just bending them for your own benefit - B.B. 1988* ------------------------------ Date: Thu, 27 May 1993 15:43:39 GMT From: Brian Tao Subject: Seeding Mars with "Mars box" life Newsgroups: sci.space In article <4488@uswnvg.uswnvg.com>, Dan Williams writes... > > But any experiments on Mars will always have the possibility to > contaminate the Mars biosphere. Since Viking at least, there is the > chance we have already seeded the planet despite our efforts not to. There's also an outside chance that good old Mother Earth will be contaminated by Martian life forms (if any exist)... -- Brian Tao:: taob@r-node.hub.org (r-Node BBS, 416-249-5366, FREE!) ::::::::::: 90taobri@wave.scar.utoronto.ca (University of Toronto) ------------------------------ Date: 1 Jun 93 12:53:50 From: Craig Powderkeg DeForest Subject: Space Marketing would be wonderfull. Newsgroups: misc.consumers,talk.environment,talk.politics.space,sci.space,alt.flame In article billn@hpcvaac.cv.hp.com (bill nelson) writes: Yeah - I miss the Burma Shave signs, also. They were small and discrete, not large monsterous pictures. Hey, don't you mean `They were small and discrete, not large *continuous* pictures'? Or was that `They were small and *discreet*, not large monstrous pictures'? -- DON'T DRINK SOAP! DILUTE DILUTE! OK! ------------------------------ Date: Thu, 27 May 1993 21:04:03 GMT From: Henry Spencer Subject: The crew is toast Newsgroups: sci.space References: <1u0pnn$8gp@access.digex.net> <1993May27.185510.26287@mksol.dseg.ti.com> Organization: U of Toronto Zoology Lines: 24 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1993May27.185510.26287@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >>What they really needed were ejection seats. According to henry, >>Martin baker had a design for seats for all STS occupants. > >It would also require adding lots of extra mass, extra safety >procedures for having explosives armed in the Shuttle, large changes >to the structure to allow them to eject, and would not appreciably >improve the odds in the 'typical' accident requiring ejection... The structural revisions wouldn't have been major. M-B's proposed scheme had the upper-deck crew ejecting first, through the roof, and then the mid-deck crew following them up, with guide rails to take the seats up through the upper deck and out. This is really about the only practical way to eject the mid-deck people, there's too much stuff in the way in all the other directions. Fred's right about the rest, though. :-) Ejection seats are heavy, somewhat dangerous to have around, and quite limited in the safe range of ejection conditions. Ejecting from the shuttle is a particularly awkward problem, because getting out of the orbiter won't help you much if you then get fried by the SRB exhaust plumes. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 28 May 1993 18:54:59 GMT From: Fred Drinkwater Subject: Tom Wolfe's THE RIGHT STUFF - Truth or Fiction? Newsgroups: sci.space,sci.space.shuttle,rec.arts.books In article court@newton.physics.mun.ca (J. Lewis) writes: >Wolfe captures the feel of a mid-1950's airbase where high-performance >aircraft were being flown, and I don't know of any other book that does - >the excitement, the grimness (many of the personnel were WWII veterans, >and a nuclear conflict with the USSR was considered more likely than not), >the youthfulness, and the commonness of sudden death. Ah, yes. I recall being puzzled by my childhood friends puzzlement at the frequency with which my father attended funerals. Didn't everybody's dad go to lots of funerals? For what it's worth, the pilots at NASA Ames all gobbled up _The Right Stuff_ when it first came out. Don't know what most of them thought about it, though. My dad said it was pretty realistic about the mood of Pax River and Edwards / Dryden. Fred Drinkwater ------------------------------ Date: 28 May 1993 18:06:29 GMT From: "Bruce d. Scott" Subject: Why is everyone picking on Carl Sagan? Newsgroups: sci.space Bob Hill (do I know you from IUE Goddard in 1982?) writes: "[...] (What breaches of taste? Nearly all of Cosmos, for example. He did everything but put on a cape and pointy hat and wave a magic wand. Ludwig von Drake was a more dignified picture of the scientist than Sagan.)" One should recognise how much of that was forced on Sagan by the producers of Cosmos. All the "meaningful glances" from the spaceship were the ideas of the latter, not the former. Ah, the price of dancing in the light. Either he did the show on their terms, or not at all. -- Gruss, Dr Bruce Scott The deadliest bullshit is Max-Planck-Institut fuer Plasmaphysik odorless and transparent bds at spl6n1.aug.ipp-garching.mpg.de -- W Gibson ------------------------------ End of Space Digest Volume 16 : Issue 656 ------------------------------