Date: Sun, 31 Jan 93 05:13:02 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #099 To: Space Digest Readers Precedence: bulk Space Digest Sun, 31 Jan 93 Volume 16 : Issue 099 Today's Topics: Clinton's Promises (space) in Charlotte Observer (3 msgs) Fluidic envelope on a point gravitational source suspended in a uniform field (2 msgs) Help on catching this Lunar Map (2 msgs) People dragging politics into everything (was Re: Today in 1986-Remember the Challenger) Shuttle tiles Solar Sail/Parachute/Brake Surface map of Venus Today in 1986-Remember the Challenger Using off-the-shelf-components 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: Fri, 29 Jan 1993 21:10:12 GMT From: "Edward V. Wright" Subject: Clinton's Promises (space) in Charlotte Observer Newsgroups: sci.space In <1k6beeINNgtf@mojo.eng.umd.edu> sysmgr@king.eng.umd.edu (Doug Mohney) writes: > C) How do you set the damned thing up without using goverment help > in the first place? Guess who owns all the big launch facilities. Aw, yes, the ultimate fallback argument. The government owns all the launch facilities because the government crushes anyone who tries to compete with them. It justifies its strong arm tactics by saying that launch facilities are a "national resource" -- without government, there would be no launch facilities. Perfect circular reasoning. ------------------------------ Date: Fri, 29 Jan 1993 21:14:34 GMT From: "Edward V. Wright" Subject: Clinton's Promises (space) in Charlotte Observer Newsgroups: sci.space In <1993Jan29.084042.10351@rcvie.co.at> se_taylo@rcvie.co.at (Ian Taylor) writes: >Ok say Clinton went off his rocker and did just that, does anyone think >a US corporation would do it for $10bn, tax free? - assuming this station >has a similar specification to Freedom for volume and power and X=4. Well, the Japanese construction industry thinks it could do the job for around one billion. A real space station, a la 2001, not a little tin can like SS Freedom. Unfortunately, Shuttle transportation costs would add another $46 billion to that. But if you encourage the develop of a commercial SSTO first.... ------------------------------ Date: 29 Jan 1993 17:22:31 -0500 From: Matthew DeLuca Subject: Clinton's Promises (space) in Charlotte Observer Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: [Private group putting up a space station] >Well, the Japanese construction industry thinks it could do >the job for around one billion. A real space station, a la >2001, not a little tin can like SS Freedom. Unfortunately, >Shuttle transportation costs would add another $46 billion >to that. But if you encourage the develop of a commercial >SSTO first.... If the Japanese can develop and build a whiz-bang space station from scratch for only $1 billion, why can't they develop their own SSTO for a few million dollars? If they can do one I am sure they can do the other. Claims like this make me wonder: we hear from certain agitators on this group how if we only were to use cheap Soviet hardware, we could do more in space than we do now for only a fraction of the cost. If this is true, why didn't the Soviets do it? At the height of the Soviets' power, it would have been a great propaganda victory for them to have a bustling space activity while the Americans limped along in their Shuttle...instead, we saw the Soviets restricted to the same tin-can technology they've been using since 1961. Something tells me it's just not as cheap and easy as certain people like to make it seem. -- Matthew DeLuca Georgia Institute of Technology, Atlanta Georgia, 30332 uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!matthew Internet: matthew@phantom.gatech.edu ------------------------------ Date: Fri, 29 Jan 1993 19:30:42 GMT From: Bill Hyde Subject: Fluidic envelope on a point gravitational source suspended in a uniform field Newsgroups: talk.origins,sci.space In article , btd@iastate.edu (Benjamin T Dehner) writes: An impressive article, but I have one problem with it. |> Ok, now what about the atmosphere? The force away from the earth |> on a molecule in the atmosphere will be given by |> F(r) = G*m*(Mearth/r**2 - Msat*cos(b)/diss**2) |> where |> Mearth = mass earth |> Msat = mass saturn |> r = distance of object from earth center |> diss = distance of object from saturn |> diss**2 = dise**2 + r**2 - 2*dise*r*cos(b) [law of cosines] |> b = angle bewteen object and Saturn as seen from Earth. |> |> A molecule will be lost to space when it's velocity is high enough |> so that, when it reaches an infinite distance from earth, (where gravity from |> earth is now 0) it is still moving (can't be pulled back). Or, as a limiting |> case, when the velocity at infinity is zero. Or, when the work done on the |> particle (\int F dx) does not equal it's kinetic energy. So if we start at |> velocity V at the earth surface, the escape velocity will be |> |> /infinity |> | |> Vesc**2 = 2G| [-Msat*cos(b)/(r**2+dise**2 - 2*cos(b)*r*dise) + Mear/r**2] dr |> | |> /Rearth |> |> which evalutates too (not a hard integral; split into two components, and |> use algebraic substitution)(and change notation d = dise) |> |> Vesc**2 = Vold**2 - 2*G*Msat*cos(b)(pi/2 - arctan(Rear**2+d**2*(1-cos(b)**2)) |> |> Where Vold is the nominal value of the escape velocity of 1.12e6 cm/s. |> Expanding the arctan in a series, this gives us |> |> Vesc**2 = Vold**2 - 2*G*Msat*cos(b)/(Rear**2+d**2*(1-cos(b)**2)) |> |> Taking as a representive value of cos(b) = 1/2, for a numeric example we have |> Vesc = 1.119e6 cm/s. You should actually take cos(b) to be one, since the loss of atmosphere will be dominated by escape at the sub-saturnian point. Escape velocity is a function of the square root of the gravitational acceleration, so if we are postulating an effective gravitational force of 4m/sec**2 the escape velocity should be less than two thirds of the current value. The probability distribution for molecular velocity is maxwellian F(v)dv = const*exp(-const*v**2)v**2 (where the constants are temperature dependent). This distribution has a long "tail" leading out to infinite velocity. Any substantial decrease in escape velocity greatly enhances the fraction of molecules which are moving fast enough to escape. Even if the planet were somehow as cool as earth is today, the bulk of the atmosphere would leak out in a fairly short time. If the saturnlit side were somehow temperate, then at the center of the dark side temperatures would be well below the freezing point of carbon dioxide. (Since in Ted's postulated word all of the continents are grouped around the north pole, there would be a completely zonal (i.e. east-west as oppposed to north-south) circulation in the southern oceans, and no substantial energy transport from the equator (a chilly place anyway, in this scenario) to the antarctic. Similarly, with no mountain ranges or land/sea contrast to kick off long waves, the southern jet stream would also be quite zonal, so there would be few of the baroclinic eddies which currently transport most of the atmospheric heat north in midlatitudes.) C02 levels would rapidly drop to the point where photosynthesis would be impossible, and pretty much everything would die. Quite a golden age. |> flux at the top of the earth's atmosphere? Let's assume an albedo of 0.8 |> (Venus is 0.76) which, among other things, implies thick cloud layers such |> that no one would ever SEE the bloody sun. If we let energy freely radiate |> at the opposite side of the earth (to 0 K space) the equlibrium temperature |> will be such that Flux(in) = Flux(out), or |> |> 2*pi*Rear**2*.2*1.e9 = 4*pi*Rear**2*sigma*T**4 |> |> T**4 = .2*1.e9/(2*sigma) |> |> T = 1152 K |> |> While this is an incredibly crude approximation, the point is made |> (I think) that the earth will be fried. Even more so in that these one level models tend to underestimate planetary temperatures as it ignores the atmospheric greenhouse effect. For example, such a model predicts the earth's temperature to be 255 absolute. Bill Hyde Department of Oceanography Dalhousie University, Halifax, Nova Scotia hyde@Ice.ATM.Dal.Ca or hyde@dalac ------------------------------ Date: Fri, 29 Jan 1993 22:17:37 GMT From: Benjamin T Dehner Subject: Fluidic envelope on a point gravitational source suspended in a uniform field Newsgroups: talk.origins,sci.space >What would the characteristics be of the fluidic envelope (atmosphere and >hydrosphere) of a gravitational point source (say, the earth) if it were to >be suspended (through some magical method which would NOT affect the oceans) >in a uniform (or near-uniform) intense (approximately 6 meters per second >per second) gravitational field (say, from something that would become Saturn)? >Off hand, I wonder about the long-term status of the atmosphere. Would the >escape velocity on the "near" side be reduced such that the molecular velocity >at "room temperature" be sufficient to "bleed off" the air? What WOULD the >imposition of a uniform field over the inverse square field do the e.v.? >Someone care to perform the integral? Excuse me for being stupid, by I made a fundamental f***up last time I tried to answer this (in addition to misunderstanding the question.) Typically when calculating the escape velocity, one simply calculates the work needed to take a particle an infinite distance away. This, however, is no longer the case. One simply needs to go out to an Rmax, where Rmax is given by the distance at which the external force balances out the earths force. Rmax would be given by the equation g = GM/Rmax**2, where g is the external field, G is gravitational constant, M = earth's mass. Plugging in numbers, this gives us Rmax = 8.153e8 cm. Now the total energy required would be an integral from Rear to Rmax of m(GM/r**2 - g)dr, and set this equal to an initial kinetic energy 1/2*m*Vesc**2 to find Vesc. Doing this gives us an answer of Vesc = 1.72e5 cm/s, compared to the current value of 1.12e6 cm/s, which is quite a change. (As an aside, the earth could not hold bound any body beyond Rmax, either atmosphere or satellite. While this is far enough out atmosphere shouldn't be a problem, what about satellite?) Now, what fraction of the molecules in our atmopshere will have a velocity above this? If we assume the atmosphere has a Maxwellian distribution (good for most of atmosphere), then the velocity distribution function looks like f(v)dv = (m/2/pi/k/T)**1.5*exp(-m*v**2/2/k/T)*4*pi*v**2*dv where m = molecule mass = 5.31e-23 g (O2, for example) T = temperature = 250K (Why not?) k = Boltzmann constant = 1.381e-16 erg/K So we want to integrate this beasty from Vesc to infinity. It turn out that only about 8.e-8 of the molecules are statistically above the escape velocity. (No, I didn't do this myself. I used maple.) I am uncertain of what this says about the long-term lifetime of the atmosphere. Accorind to Zelik and Smith (1987), the rms velocity must be > 10*escape velocity to retain an atmosphere for billions of years. In this case, Vrms = (3*k*T/m)**(1/2) = 4.414e4 for O2, < 10 * Vesc. Anybody got a better idea on the diffusion rate out of the atmosphere? Also, I took low temper- atures in the above example. A higher representive temperature would make things a bit worse. Also, N2, being ligher, would leak out even faster. It has a Vrms = 4.72e4 cm/s, and a fraction above the escape velocity of 1.1e-6. I do not think the earth could hold on to N2 for very long at all (timescale of ~ a few hundred years??). >What would the physical distribution of the object be? On the planetary >surface, the vector sum of the two fields would make "downhill" towards >the primary (except in a line straight through the center of mass of the >secondary (earth). On the "near" point, 'g' would be reduced and on the >"far" point 'g' would be increased. The equipotential surface would >be furthest from the center of mass of the secondary on the "far" side >and nearest to the center of mass on the "near" side. How would this >affect things? Would the lithosphere retain sphericality, or is the >material strength insufficient to prevent drastic redistribution to conform >with the equipotential shape (read: terminal earthquakes). What would >the atmospheric pressure be, since the mass of the atmosphere would be >on the "far" side and the 'g' is reduced on the 'near' side? Would the >partial pressure of O2 be sufficient for respiration? Would there be >ANY oceans & lakes on the "near" side? I'm not sure how to answer these. A 'uniform' field would cause no gravitational gradients, and so I would need a more exact definition of exactly what was holding the earth in place. Plus, it's time I got back to work anyway :) Ben Rerences: Zelik and Smith (1987) "Introductory Astronomy and Astrophysics", CBS: Philidelphia -- James W. Meritt: m23364@mwunix.mitre.org - or - jmeritt@mitre.org The opinions above are mine. If anyone else wants to share them, fine. They may say so if they wish. The facts "belong" to noone and simply are. ----------------------------------------------------------------------------- Benjamin T. Dehner Dept. of Physics and Astronomy btd@iastate.edu Iowa State University Ames, IA 50011 ------------------------------ Date: Fri, 29 Jan 1993 21:31:11 GMT From: Rajesh Batra Subject: Help on catching this Newsgroups: sci.space,sci.physics Hi, Here's a problem that I'm just plain stuck on, see if you can help. Scenerio: You're on the moon, a 1700 m/s container (containing ice) which weighs approximately 120 kg is hurled at you. How do you catch it such that you can salvage the ice? You have free reign over the container- hence the size/material. I'm currently investigating silica aerogels-- or a big crater coated with steel or some tough material to ram the projectile into. Hopefully, I can close the opening of the container before the vaporized ice escapes. Thanks for your time, Rajesh Batra University of Cincinnati Aerospace Engineering rbatra@uceng.uc.edu ------------------------------ Date: Fri, 29 Jan 1993 19:40:30 GMT From: Lord Vader Subject: Lunar Map Newsgroups: sci.space,sci.space.shuttle I need a digital map of the moon for ground tracks. What I am looking for is a projection onto a rectangular area like you commonly see when earth ground-tracks of orbiters are shown (I can't think of the name of that type of projection). I have been told that no such thing exists, although one would think that someone took the Apollo and lunar orbiter data and did this at some point. I also saw recently someone say that the Smithsonian has some lunar stuff on laser disk, which would imply that the data were digitized at some point. Anyway, If anyone knows of the existence of such a map, I would appreciate hearing from you. Mike Loucks loucks@orbit.colorado.edu and no, I don't have any noble statement to put after my name ------------------------------ Date: Fri, 29 Jan 1993 21:07:41 GMT From: Edmund Hack Subject: Lunar Map Newsgroups: sci.space,sci.space.shuttle In article <1993Jan29.194030.3638@colorado.edu> loucks@csn.org (Lord Vader) writes: >I need a digital map of the moon for ground tracks. What >I am looking for is a projection onto a rectangular area >like you commonly see when earth ground-tracks of orbiters >are shown (I can't think of the name of that type of >projection). I have been told that no such thing exists, >although one would think that someone took the Apollo and >lunar orbiter data and did this at some point. There is no "official" NASA digitized moon map available as best as I can tell from talking to a bunch of NASA lunar science and cartography types. Remember that at the time the data were generated, digital cartography was just starting. If someone could scrape together the data, lots of lunar science types would like to have one. >I also >saw recently someone say that the Smithsonian has some >lunar stuff on laser disk, which would imply that the >data were digitized at some point. This is mainly surface and astronaut photography. I have handled some of the cartographic camera images from the later Apollo missions. They are 12 inch wide by many feet long B&W prints (35-40 feet or so long!). Note that _Mars_ has better maps (and digital ones!) than the Moon. Except for some equatorial regions, the uncertainty in object locations and elevations is really crummy on Lunar maps. >Anyway, If anyone knows >of the existence of such a map, I would appreciate hearing >from you. > One could take one of the commonly available maps of the moon (i.e. National Gepgraphic Society, USGS), digitize it, dewarp it and reproject it with some work. -- Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah.. "I'm not an actor, but I play one on TV." "Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode" ------------------------------ Date: Fri, 29 Jan 1993 16:04:49 GMT From: fred j mccall 575-3539 Subject: People dragging politics into everything (was Re: Today in 1986-Remember the Challenger) Newsgroups: sci.space In <1949@tnc.UUCP> m0102@tnc.UUCP (FRANK NEY) writes: >> I can't believe they wouldn't let you discuss on of the most tragic >> events in recent history. >I can. Public schools are notorious for the collection of politically >correct liberals infesting them. They probably thought that the money >would have been better spent on welfare and that NASA and the >Challenger Seven deserved what they got. It could as easily have been a bunch of crypto-fascist right-wingers who thought that any discussion of something that failed would be 'unAmerican'. But I think it most likley that they simply wanted to try to conduct the classes that they were supposed to be conducting, figuring that people could talk about this on their own time. >God, I hate PC Libs! Especially when they are in positions to >indoctrinate our future. God, I hate partisan ideologue fanatics! Especially when they are in positions to pollute an otherwise reasonable discussion. -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Ames Dryden ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. ------------------------------ Date: Sat, 30 Jan 93 11:41:08 EST From: John Roberts Subject: Shuttle tiles -From: shanleyl@ducvax.auburn.edu -Subject: Re: Shuttle tiles -Date: 25 Jan 93 07:09:06 GMT -Organization: Auburn University, AL -In article , roberts@cmr.ncsl.nist.gov (John Roberts) writes: -> -> -From: gary@ke4zv.uucp (Gary Coffman) -> -Subject: Re: Let's be more specific (was: Stupid Shut Cost arguements) -> -Date: 11 Jan 93 15:48:12 GMT -> -> -Shuttle designers... chose to use refractory silicates in the form of -> -tiles. These are very poor conductors of heat, you can place your bare -> -hand against one side of the tile while playing an oxy-acetylene torch -> -on the other and not notice a temperature rise. -> -> I think perhaps you mean a propane torch, or butane torch like Mary described. -> Pulling some numbers from the Rogers report and elsewhere, the leading -> edges of the Shuttle wings have to withstand heating up to 2750 F, and are -> made of layers of graphite cloth in a carbon matrix, with the outer layers -> chemically converted to silicon carbide. The upper fuselage, the coolest -> portion during reentry, is only heated to about 600 F. The Shuttle has -> high-temperature and low-temperature ceramic tiles, which are described in -> this report as being "nearly pure glass" (I had thought they were silica), -Not sure what the difference is, silica/sand/glass,. Same different thing isn't -it?. Silica is silicon dioxide (quartz being one well-known form). Sand is "little bitty rocks", which is frequently (but not always) composed largely of silica. (As a counterexample, the sand at White Sands, New Mexico is mostly gypsum.) Glass is an amorphous supercooled liquid composed of any of a variety of substances. The definitions overlap somewhat - for instance, I believe fused quartz would count as both silica and glass. Rapidly-cooled rocks and metals (the latter cooled at rates of up to hundreds of thousands or millions of degrees/s) can sometimes form glasses. In everyday usage, glass generally refers to silica dissolved in a molten alkaline material, such that the mix is liquid below the melting point of silica. (I've done that with an ordinary propane torch and a homemade crucible - melt some baking soda or washing soda, then pour in some clean, fine-grain quartz sand - the grains of sand will sort of swirl around like "Cream of Wheat" then dissolve into the mix, making an astonishingly poor-quality glass. In case anybody gets ideas, be careful working with high-temperature materials, and wear safety equipment.) Common glasses: # Soda-lime glass: 72% silica, 15% sodium oxide, 9% calcium oxide. # Soda-lead glass: (made by substituting lead oxide for the CaO and some SiO2) # Borosilicate glass: 80% silica, 4% alkali, 2% Al2O3, 13% boric oxide (Pyrex) # 96% silica glass: can be heated red-hot, then plunged into ice water without cracking. (Vycor) I got the tile description from the Rogers report, which doesn't really explain what it means by "glass". I'm inclined to believe they meant one of the kinds with melting point lower than that of pure silica. One reason: fused quartz is so difficult to work with (high melting point and high viscosity) that if you do manage to do something with fused quartz, you *brag* about it - you don't use the generic term "glass". Also, the lower-temperature glass tiles are rated to 1200 F, and pure silica ought to be good up to 2950 F (continuous exposure rating). -> with nearly 90% of the volume being "air". The low-temperature ceramic tiles -> are are rated to 1200 F, and the high-temperature tiles to a higher value, -> but something below wing leading-edge temperatures. -> -> While such temperature resistance is admirable, a properly-designed -> acetylene torch can heat a thermally isolated object to 6000 F (~ 3300 C). -That's great, not all acetylene torches rate much lesss run up to 6000F. I've -used one myself with the tile in my hand just for kicks. Was that a properly-adjusted oxygen-acetylene welding torch with the tip of the inner flame touching the tile? I know some plumbers use an air-acetylene torch that presumably doesn't get as hot as an oxyacetylene model. It's also possible to run an oxyacetylene torch with the oxygen turned off - you get low temperatures, and a billowing, sooty flame. (Try that in cold weather sometime - the acetylene flame makes little fragile streamers of soot, which float gracefully through the air and land on your clothes, at which point they sink in and *never* wash out. :-) Torch outfits sometimes come with a "heating" head, which might provide a lower temperature. But that's somewhat of a cop-out - if you're going to advertise thermal tiles as "able to withstand the heat of an oxyacetylene torch", you'd better mean that they can withstand some reasonable application of such a torch - not the mildest possible application. Tell you what - you send me two intermediate-temperature (glass) Shuttle tiles, and I'll try to melt one with an acetylene torch. If I succeed, I'll send the melted one back to you. (Naturally, I'd have to keep the other tile as an experimental control. :-) Of course, melting point isn't the whole story - the rate of energy input and energy output have to be considered. Shuttle tiles can radiate energy at an impressive rate - but an oxyacetylene torch with a reasonable-size welding tip can produce heat at an impressive rate too. I suspect that in order to radiate at a rate equal to the heat production of such a torch, the tile would have to be hotter than the melting point of the constituent glass. -> I wouldn't expect any trouble melting most ceramics - I've accidentally -> melted fire bricks that I was using as a backstop for acetylene welding. -> ->>From the 1961 CRC handbook, here are some temperature ratings for ceramics -> and other materials: -> -> SAFE CONTINUOUS OPERATING TEMPERATURE / MELTING POINT - [list of materials, some of which would be viable candidates for heat - shields.] -lets not be more specific, let's allow some linguistic (not always the same as -scientific) lattitude. You're missing the point - while some people value sci.space only as a "debating society", others are actually interested in space-related technology and applications. The topic being discussed was spacecraft thermal shielding, and the actual magnitudes are extremely relevant to this discussion. I posted the temperature limits on other materials as part of the general topic of thermal shields. Linguistics had nothing to do with it, except insofar as everything we deal with in sci.space is words. A significant problem with electronic networks is that once an incorrect item gets posted, it can propagate for months or years. However, as long as you bring up the point, being able to express yourself so that you can be understood is vitally important. Many of the technical problems that have arisen in the aerospace effort are due to people having difficulty making themselves clearly understood. (I'm not referring to people who use English as a second language - in fact, many of them use better English than most native English speakers, because they work harder at it.) For you unfortunate people who just can't seem to learn to write intelligibly, there are automatic spelling checkers and style checkers. (Yes, I'm aware that my own English is far from perfect - you folks are a bad influence on me. :-) For an example of good communication through clear expression, study Henry's posts - consistently at least 99% perfect. -Paul S. Shanley John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Fri, 29 Jan 1993 22:17:30 GMT From: Rob Douglas Subject: Solar Sail/Parachute/Brake Newsgroups: sci.space In article <1106.2B68D2BB@gisatl.FIDONET.ORG>, jonathan.deitch@p7.f411.n133.z1.FIDONET.ORG (Jonathan Deitch) writes: |> |> >From: nsmca@acad3.alaska.edu |> >Date: Mon, 25 Jan 1993 15:50:33 GMT |> >Newsgroups: sci.space |> |> >A Solar Sail if I understand right when it arrives at its Steller destination |> >it becomes a Solar Parachute/Brake. Am I right? |> |> Yep ... you simply turn it around and use it to capture the *outward* solar |> wind of your destination star to slow you down. |> Works ok if your destination is another star, but for destinations within the solar system you will need another way to stop. You could use rockets or something, but the point was to avoid them altogether, so I would say, you would have to sail past your objective and then turn around, maintaining your momentum, and head back in towards the sun. Turning around the solar sail won't matter at all anyway, as both sides will be able to reflect (and therefore absorb momentum from) photons. Its the old "Which side of the aluminum foil is it better to have facing out" argument. Doesn't matter. If a photon passes through one way, it passes through the other. -- ========================================================================== | Rob Douglas | Space Telescope Science Institute | | AI Software Engineer | 3700 San Martin Drive | | Advanced Planning Systems Branch | Baltimore, MD 21218, USA | | Internet: rdouglas@stsci.edu | (410) 338-4497 [338-1592 (fax)] | ========================================================================== Disclaimer-type-thingie>>>>> These opinions are mine! Unless of course they fall under the standard intellectual property guidelines. But with my intellect, I doubt it. Besides, if it was useful intellectual property, do you think I would post it here? -- ========================================================================== | Rob Douglas | Space Telescope Science Institute | | AI Software Engineer | 3700 San Martin Drive | | Advanced Planning Systems Branch | Baltimore, MD 21218, USA | ------------------------------ Date: 29 Jan 93 17:53:18 GMT From: Willie Smith Subject: Surface map of Venus Newsgroups: sci.space In article <1494@pacsoft.com> chris@pacsoft.com (Chris Ott) writes: > I'm looking for a surface map of Venus, i.e. the one returned >from Magellan, in computer readable form. Call the NSSDC at (301) 286-6695 and ask for their catalog. You want the MIDR data set, which comes in volumes of 33, 18, or 5 CD-ROMs depending on the resolution you want. The disks aren't very expensive, there's a _lot_ of data there, and the 'pictures' are quite impressive. I've got volume 1 of the 33-volume set, and once I work on my print-to-HPLJ program a bit, I'm gonna start making wallpaper! Willie Smith wpns@pictel.com -- Willie Smith wpns@pictel.com N1JBJ@amsat.org "I'll make Beelyuns and Beelyuns from the book contract and the TV show with government funding for looking for the nothing in the void where The Bang caused the hole in the middle of it all" Frank Hayes - Cosmos. ------------------------------ Date: 29 Jan 1993 20:27:59 GMT From: Doug Mohney Subject: Today in 1986-Remember the Challenger Newsgroups: sci.space,sci.space.shuttle In article , shafer@rigel.dfrf.nasa.gov (Mary Shafer) writes: >I work on a base named after a guy who was killed in flight test and >all the streets I drive on are named after dead aircrew. It's sad, >it's regrettable, but it happens. I still accept any ride I can in >any airplane (high-performance types preferred since ejection seems >superior to bailing out). >There have been a number of studies that show that people overestimate >the risk of rare events (airliner crashes, for example) and >underestimate the risk of everyday events (driving, for example). >Obviously there's more in the perception of risk than just the >numbers. Perceptionally/culturally/M-TV-wise: There's a difference between dying in prime time with the world watching a unique event verses a twenty second one-time on the local news coverage verses a two column inch notation on page B3 of the local paper. "Dan, let's play the video again one more time for our viewers--" Consider the 120-plus people who died during Desert Shield/Storm operations. More people probably died in auto accidents in the U.S. during the same time period, but only one set will (eventually) get their own memorial. Be discreet. Die in the middle of the wilderness in your sleep. I have talked to Ehud, and lived. -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 29 Jan 93 18:01:43 GMT From: Willie Smith Subject: Using off-the-shelf-components Newsgroups: sci.space In article ewright@convex.com (Edward V. Wright) writes: >Space-qualifed today means [...] I forget where I saw it (maybe BIX?), but here's a couple of alternates: Space Qualified: The mass of the paperwork exceeds the mass of the vehicle Man Rated: The height of the stack of paperwork exceeds the designed flight altitude. "I say, that's a joke, son!" Foghorn Leghorn Willie Smith wpns@pictel.com -- Willie Smith wpns@pictel.com N1JBJ@amsat.org "I'll make Beelyuns and Beelyuns from the book contract and the TV show with government funding for looking for the nothing in the void where The Bang caused the hole in the middle of it all" Frank Hayes - Cosmos. ------------------------------ To: bb-sci-space@CRABAPPLE.SRV.CS.CMU.EDU Xref: crabapple.srv.cs.cmu.edu sci.space:55458 sci.astro:31077 alt.sci.planetary:628 Path: crabapple.srv.cs.cmu.edu!cantaloupe.srv.cs.cmu.edu!rochester!udel!bogus.sura.net!howland.reston.ans.net!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke From: Ron Baalke Newsgroups: sci.space,sci.astro,alt.sci.planetary Subject: Magellan Update - 01/29/93 Date: 29 Jan 1993 19:52 UT Organization: Jet Propulsion Laboratory Lines: 27 Distribution: world Message-Id: <29JAN199319523695@kelvin.jpl.nasa.gov> Nntp-Posting-Host: kelvin.jpl.nasa.gov Keywords: Magellan, JPL News-Software: VAX/VMS VNEWS 1.41 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU Forwarded from Doug Griffith, Magellan Project Manager MAGELLAN STATUS REPORT January 29, 1993 1. It was another quiet week for the Magellan spacecraft as it continues to operate normally transmitting a carrier signal plus 1200 bps X-band telemetry. All temperatures are in the expected range. 2. The spacecraft has completed 6655 orbits of Venus and is now 55% complete on its gravity data collection in Cycle-4. 3. Dr. Steve Saunders gave a presentation on the results of the Magellan Venus Mapping Mission at NASA Headquarters on Wednesday, January 27. It will be aired on NASA Select at a later date. 4. The Project continues its systematic archiving of science data. A complete validated catalog of data from the first 243-day mapping cycle has been delivered to the Planetary Data System Central Node at JPL and to the PDS Geosciences Node at Washington University. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while, /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck. |_____|/ |_|/ |_____|/ | ------------------------------ End of Space Digest Volume 16 : Issue 099 ------------------------------