REM@IMSSS (Robert Elton Maas, this host known locally only) (01/26/86)
Voyager 2 has discovered a 3-mile-tall mountain on one of the moons of Uranus. It really sticks out like a sore thumb on the photo I saw on TV. The only thing it could be (my layman's opinion) is a volcanic cone, probably extinct like Mount Shasta in California, but if Jupiter's Io is any example not necessarily. The only major open question is what kind of lava it used. It would have been too cold during the past 4 billion years to be basalt lava, so probably water ice or ammonia (or nitrogen or methane if it is really cold there and the volcano is recent); it couldn't be a very early volcano from the first half billion years when moons were still very hot because it would have been bombarded out of existance by all the meteors that were keepin things so hot then by bombarding everything in sight (layman's opinion again). So, what do the rest of you think, volcano as I claim?, extinct as I guess?, what kind of lava do you guess?, how long since active? When are we gonna get that damn ion rocket developed so we can send Mariner/Viking/Galileo-class spacecraft (orbiter/lander) to all the outer planets without having to wait ten years to get the craft to the very outer ones via gravity-assist from the nearer ones? Those Uranian moons look as interesting as Saturn's (although nothing is as pretty as Dione as far as I've seen to date, but then I haven't seen Uranian moons in color yet).
eugene@ames.UUCP (Eugene Miya) (01/27/86)
> Voyager 2 has discovered a 3-mile-tall mountain on a moon of Uranus. . . . > hot then by bombarding everything in sight (layman's opinion again). So, what > do the rest of you think, volcano as I claim?, extinct as I guess?, what kind > of lava do you guess?, how long since active? Are you certain it's a volcano? I've not seen the imagery (no TV and the print media have not had detailed images). No offense, but most lay people could not recognize a volcano other than pure cinder cones. Was it a profile (how did you get 3 miles?)? or face into the crater or peak (I assume)? did it have obvious flows. I walk over to our auditorium and they are televising clean room shots of some circular hatch: they say they are making history ... :-) [people crawling in and out the shuttle). When are they going to make channels for for something important? ... Guess I have to find a tube. > When are we gonna get that damn ion rocket developed so we can send > Mariner/Viking/Galileo-class spacecraft (orbiter/lander). . . I refer you to James van Allen's article in Sci. Amer. a month or two back. The rocket's been developed years ago the question is when are we going to get the money to send it up? [obvious pilot light]: A mission would cost a fraction of the SDI program, the space station, or a carrier battle group. Viking, BTW, is an order or magnitude more than other missions if you consider the lander technology. Planetary wish list: International Solar polar Comet rendevzous Stellar/solar wind sampler Mercury sample mission Venus mapper, atmospheric sampler Earth --? no intelligent life there :-) Moon -- polar orbiter, sampler missions Mars -- polar orbiter and sampler missions, mars moon missions astroid sampler missions Jovian sampler missions to Europa and I/O Saturn -- Titan orbiter, imager, atmospheric sampler. Uranian -- your suggestions From the Rock of Ages Home for Retired Hackers: --eugene miya NASA Ames Research Center {hplabs,ihnp4,dual,hao,decwrl,allegra}!ames!aurora!eugene eugene@ames-nas.ARPA
doug@escher.UUCP (Douglas J Freyburger) (01/28/86)
> When are we gonna get that damn ion rocket developed so we can send > Mariner/Viking/Galileo-class spacecraft (orbiter/lander) to all the outer > planets without having to wait ten years to get the craft to the very outer > ones via gravity-assist from the nearer ones? My preferred answer would be right-now/yesterday, but... There are some communications satelites that use ion rockets to keep station, and various ion drives have been flown for years. It would seem that the answer really IS yesterday. The major problem with running ion driven spacecraft to the outer planets is their strong magnetic fields. Ion drives have severe problems in strong enough magnetic fields. They work by accelerating charged particles in a straight line to VERY high speeds and out the nozzle. In a magnetic field, the particles follow an arc (f=B-cross-v/c) and foul up the 'combustion chamber'. The other problem is restarting the drives. They tend to foul up when they are shut down, so you only get one sure shot per engine. SO: We just have to send up a probe that 1) has enough regular rocket fuel to maneuver when it gets into the magnetic field, 2) only uses the ions to get there fast and still slow up when it gets close, and 3) can get out of Earth orbit on regular rockets (I'm not sure enough about field strengths to know if this is a problem). This is a tough list to make, and we lose multiple planet missions, but we DO get there the fastest with the mostest. Is it time to push for this for the next wave of planetary exploration? Mariner Mark II doesn't have any ion rockets, and I don't know if the isotopic generators make enough energy. Could be we are restricted to Mars-and-closer until we are willing to fly "real nuclear reactors". -- Doug Freyburger DOUG@JPL-VLSI, JPL Mail Stop 23 escher!doug, escher!teleop!doug Pasadena, CA 91109 etc. <Generic Disclaimer>
space@ucbvax.UUCP (01/31/86)
> > ...The only > thing it could be (my layman's opinion) is a volcanic cone, probably extinct > like Mount Shasta in California, > ...So, what > do the rest of you think, volcano as I claim?, extinct as I guess?... If you mean 'extinct as Mt. Shasta', it's not very extinct at all. Indeed, Shasta *probably* erupted within known (white man) history. It's just about as *extinct* as Mt. St. Helens. There's *a lot* of seismic and hot-steam/ venting activity going on around there. (Don't mean to flame, but I grew up midway between Shasta and Lassen -- yes, in the sticks -- and have a Geologist for a husband.) For your information, none of the Cascade Peaks (save, maybe, Mt. Mazama [Crater Lake] :-) are extinct. Just wanting to set you straight. Barb (Meanwhile, you have some interesting observations -- wish I could see the pict.s -- covet, covet!)
earle@smeagol.UUCP (Greg Earle) (01/31/86)
> When are we gonna get that damn ion rocket developed so we can send > Mariner/Viking/Galileo-class spacecraft (orbiter/lander) to all the outer > planets without having to wait ten years to get the craft to the very outer > ones via gravity-assist from the nearer ones? (a) They're working on it. (b) You (and everyone in net.spaceland) should be grateful for what you got, because it so happens that the relative positioning of Jupiter-Saturn-Uranus, that allowed Voyager to make it to Uranus in 'only' 8.5 years, only happens once in *175* years, and it's happening *now*. Without a major-league improvement in propulsion systems (and they have to operate with low mass fuel supplies, so as to not make the thing a huge fat blimpo when it takes off), you and I are not likely to see *any* outer planet missions within our remaining lifetime. It would normally (given random relative positions) take up to *30* years to get to Uranus, much less get to Neptune at all. Greg Earle JPL sdcrdcf!smeagol!earle (UUCP) ia-sun2!smeagol!earle!csvax.caltech.edu (ARPA)
weemba@brahms.BERKELEY.EDU (Matthew P. Wiener) (02/02/86)
In article <578@smeagol.UUCP> earle@smeagol.UUCP (Greg Earle) writes: [in response to someone's question as to why we don't head out to Uranus again as soon as possible] >because it so happens that the relative positioning of Jupiter-Saturn-Uranus, >that allowed Voyager to make it to Uranus in 'only' 8.5 years, only happens >once in *175* years, and it's happening *now*. I believe that refers to the Jupiter-Saturn-Uranus-Neptune configuration. I do not have figures, but surely a single slingshot Earth to Jupiter to Uranus does not have an unreasonably rare launch window or long journey. I think the only real delay is money and will. ucbvax!brahms!weemba Matthew P Wiener/UCB Math Dept/Berkeley CA 94720