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Space

Delaying Our Visit To The Last Planet 141

Posted by timothy from the make-haste-slowly dept.
O.F. Fascist writes: "Story over at Space.com about how the first NASA mission to Pluto might get cancelled for a variety of reasons." Sounds like the reasons at play here are good, though -- "reliable transport required" applies to multi-year interplanetary journeys, too. (And what are we looking for on Pluto again?)
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Delaying Our Visit To The Last Planet More

Delaying Our Visit To The Last Planet

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  • ooooooooooooooooooooooooo
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  • Aside for information on the origin of the outer planets, and the make up of the outer solar system, there are the Migo. The fungi from yuggoth [geocities.com] who have been visiting our planet for millenia make their home on pluto and have colonies on its moon charon. But what if their pluto base is itself just a colony for a much larger galactic civilization?

    And there are all those stolen brains that could be recovered. Since many of these come from hundreds of years past, at the least they would be of historical interest.

    (-;

    And down the nether pits to that foul lake Where the puffed shoggoths splash in doubtful sleep. But oh! If only they would make some sound, Or wear a face where faces should be found! -- HPL

  • You mean......people read OUR papers? I thought only cosmologists read cosmologists' papers. Hmmm...now I must tone down those sarcastic remarks about those damned observers and their petty telescopes.
  • I agree. They are on their way to building the International Space station. I see many more opportunities for further growth that would launch from funding that project. Eventually you'd hope they'd start being able to collect materials from space itself. Maybe scoop some minerals from the Asteroid belt. Use the moon as a Materials recovery and assembly station. If we could get materials from space, and assemble space flight vehicles out there, they would never have to spend the money to get it accurately launched through the Earth's Atmosphere. I could be wrong here, but that is a major cost isn't it?
  • This apparently cannot be attained from normal operations of a Nuclear Power Plant? If it would I guess it would be in abundant supply. Hmmm. I'm not even studied enough to remember if Plutonium is even USED in Nuclear Reactors. Oh well.
  • Wait Wait.. Isn't PLUTO going to be the ULTIMATE Source of PLUTOnium!!???

    Ok Bad joke.. Be kind!
  • Well.. It might be for the better they just scrap the whole thing and let someone else take over. Since they don't seem to have gotten past the metric conversion problems that ruiend the last Mars mission. Just look at the article:

    "Pluto is also the smallest - just 2,300 miles (1,400 kilometers) in diameter."

    Since when is miles a smaller unit then klicks? Noe if they switched around those numbers they would still be off a bit. But not by much ;)
  • This another example where the love can not be justfied with dollars sad
  • Of course......
    Aliens are invading....
    We believe everything we read on slashdot
    How sad are we.....


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  • ASTRONOMY, NOT ASTROLOGY!

    Opps... Told you I'm not too bright when it comes to Astronomy... and I'm not too bright when it comes to astrology either obviously :-)

    For those that are as dumb as me, these were taken from this [m-w.com] dictionary...

    Astrolgoy - the divination of the supposed influences of the stars and planets on human affairs and terrestrial events by their positions and aspects

    Astronomy - the study of objects and matter outside the earth's atmosphere and of their physical and chemical properties

    Again, sorry for the ignorance :-)

  • If you insist that trace quantities of whatever gasses around Mercury constitute an atmosphere, then our Moon has atmosphere too!
    --
  • Politicians don't want to waste money on the space program that they could be using to build some perfectly good spying machines. *cough* Carnivore *cough*

    --
  • Delaying Our Visit To The Last Planet

    Pluto's orbit is so elliptical that Pluto is currently INSIDE Neptune's orbit; Neptune is really the LAST planet, now.

  • Comment removed based on user account deletion
  • Actually, I thought the point of revoluion was just within earth's circumference.

    that's not different than I said. I believe it's something like 1000mi below the surface, the radius being 4000mi.

    Earth-Terra

    this raises a question I was thinking about when I was reading about the naming of the outer planets: in modern day Greece, do they refer to the planets the way we do (Roman gods) or do they use the names of the Greek gods?

  • Exactly, well put!

    (And what are we looking for on Pluto again?)

    Why, answers to questions we didn't even know enough to ask? I know this was just a glib comment added by timmothy as he posted this, but it makes a good example of the apparent apathy toward scientific exploration that seems to have grown over the years.

    Seems all too common an attitude that there should be some immediate purpose for these types of projects. Granted, it has to be hard to go ask for money for something like this and be asked 'why? what will we get out of spending $900 million to go look at Pluto?' and have to answer 'because we don't know for sure what we'll find and we want to know'.

    Hell of a lot easier to say 'because if we don't do it first, the russians are going to make us look bad and possibly bomb us from space!'

  • Jupiter and Saturn could actually be considered a brown dwarf star. Ganymede and Titan still wouldn't orbit Sol, but they could count as planets in a different system, or planets in a quintuple star system (Sol + the 4 gas giants/brown dwarfs).

    Of course the monolith we dig up on the moon next year will turn Jupiter into a real star and everyone will know I was right... oh, wait, never mind.
  • Cheetos.

    Pluto is speculated to house the world's largest naturally-occuring supply of Cheetos, which due to it's unique chemical and thermal conditions occur in both original and crunchy varieties.

    Of course, Cheetos are just the easiest Plutonian resource for us to extract. Researchers have speculated that there may be literally millions of Brittany Spears CDs, Teletubbies dolls, and other objects of highly marketable value to our advanced society.

    Of course, there is some concern that we'll have to scrape away layers of frozen methane, abstract scientific research, technological challenge, impact crater detrius, and new knowledge of our universe, before we can get to even the most shallowly buried N'Sync singles; but isn't it worth it to try?

  • Pluto's not getting any closer (Score:4)

    by EngrBohn ( 5364 ) on Sunday July 30, 2000 @04:45AM (#894111)
    The problems with delaying the flight are:
    • It's frustrating. No elaboration needed.
    • Pluto's racing away from perihelion.
      • The longer we wait for launch, the longer the flight must be.
      • If we don't get Pluto Express there soon, then we'll miss the opportunity to study Pluto's atmosphere before it freezes-out.

    Christopher A. Bohn
  • What about the exploration of Venus? then the moons of Saturn. And so on and so on.

    Well, Venus has been explored quite a bit. There were Mariners 2&5 and some landers that melted. I don't think we have any materials (economical ones anyway) that could hold up to the heat on the surface. Most of the surface is mapped I think anyway.

    They already launched Cassini [nasa.gov] (that nuclear thing that got people mad) which is going to drop a probe onto the surface of Titan, and do other stuff in orbit.

    I agree with the last part. If you don't know anything about somewhere, you don't know what you'll get out of it. If you have to explain everything about somewhere before you explore it, you aren't going anywhere.
  • (And what are we looking for on Pluto again?)

    a damn cold place to stick racks and racks of overclocked Abit BP-6 dual celeron systems. pluto would be ideal. dare i say it...a beowulf cluster of these?
  • I just had an idea! I'm going to write a song about outer space! Looking into the moon.... Anyone wanna help me name the planets so I can use them too. I know this pluto planet is cold and like not really like cool to be like living on, but what about the others. If NASA doesn't want to go to the moon, I'll have my record producer take me, since he's always saying, "baby with all the money I, um, you make, I could buy a rocket ship!"
  • Pluto [lowell.edu] was given "planet" status only as a reward to the discoverer [klx.com] - hell, it's smaller than own moon [nasa.gov]

  • (yes, tenth... one planet was destroyed and now orbits the Sun as dibris asteroids)

    The asteroid belt was never a planet. They used to think that in the 50's or something, but it isn't. It's leftover debris (not dibris [i know, i'm being a grammar nazi but i can't help it {where did "grammar nazi" come from anyway? }]) from the formation of the solar system that was collected by Jupiter's gravity. There isn't enough space between Mars and Jupiter for a planet to have formed. All the debris needed would have been pulled apart by Jupiter's gravity before it could form. If Jupiter wasn't there a planet might have formed, though.
  • Disney reference.

    Pluto was a complete waste of time.

  • Space travel is so incredibly expensive.

    Rather than spending the big $$$ on going into space now, they should be spent on finding more efficient means of space travel.

    They should be researching propulsion systems, building waystations in orbit, building lunar refueling and repair facilities, gas^H^H^Hwater stations for fusion reactors etc.

    In 100 years, when we have a reasonable handle on these things, we can begin sending probes into deep space, taking holiday trips to Mars and much much more, and we will learn infinitely more than we would learn from a Pluto mission today. To attempt these things before we have developed decent space travel logistics, is just a waste of resources.

    OK, so you and I will not live to see the the results of such a long term plan. But then space exploration is inherently long term.

    /A

  • It has nothing to do with size. Pluto used to be a moon of Uranus. It was kicked off when Uranus was hit by a comet. Again, this is all theory, but it makes for an explanation of Pluto's odd orbit and Uranus' other moon that is on a deteriorating retrograde orbit. Nor does its location fit in with Bode's law. The tenth planet should be further away.

  • I think the space-travel mentality is being rushed a bit here. In the early seventies, they (the US) promised that there would be a man on mars by the year 2000. It's going to take a bit longer than that.

    What about the exploration of Venus? then the moons of Saturn. And so on and so on.

    I don't think they (NASA) need to be giving excuses why they need to put off traveling to Pluto. That would be like Columbus, before every hitting America, saying "ahh, I'm gonna hold off building that 7-11 for a while first".

    --
  • Oh, I should qualify that 10th planet statement... There was another planet. It was destroyed and orbits the sun as a buch of asteroids.

  • Isn't it obvious? A data haven. (Score:3)

    by John Jorsett ( 171560 ) on Sunday July 30, 2000 @05:39AM (#894122)
    And what are we looking for on Pluto again?

    Put a server farm out there, use heavy encryption, et violá! instant data haven. Let the FBI try to seize that! Of course, a half-day transaction latency could be a problem, but faster than lightspeed communication [slashdot.org] is just around the corner, right?
  • It was intended to be a joke about the metric to english conversion problem [fas.org] NASA had with the Climate Orbiter spacecraft around Mars.
  • c'mon people! let's take risks....we need to start sending manned missions to places like Mars and Pluto.

    i got an idea on how we can fix the problem of overcrowded prisons ;-)

    mitnick in space: coming to theatres this fall.


    FluX
    After 16 years, MTV has finally completed its deevolution into the shiny things network
  • Pluto used to be a moon of Uranus. It was kicked off when Uranus was hit by a comet. Again, this is all theory, but it makes for an explanation of Pluto's odd orbit and Uranus' other moon that is on a deteriorating retrograde orbit. Nor does its location fit in with Bode's law. The tenth planet should be further away. (yes, tenth... one planet was destroyed and now orbits the Sun as dibris asteroids)


  • If a Europa Orbiter were to fly, some thought is now being given to using a more expensive Titan 4 launcher and using leftover Cassini-era RTGs. If the plutonium were used for Europa Orbiter, that means little, if any, would remain for the Pluto-Kuiper Express, effectively spelling its doom.

    So their supply of plutonium is limited, right? Why?
  • This story [space.com] says that Pluto might have once been bigger than it is now. They say that perhaps the old Pluto had a collision with something else, causing Charon, (much like the theories of our own moon's formation, probably most big moons are made this way) the Kuiper belt, and the odd orbit Pluto has now. Maybe Pluto did cause the eccentricity of Neptune's orbit, it just did it when it was bigger.
  • No, it's not.

    RTG Plutonium is Pu-238, with a much shorter 89 year halflife (Pu-239's is 24,000 years). Pu-238 is generally considered not fissile. Other isotopes used have included Ce-144, Cm-242, Sr-90, Po-210; Pu-238 has the longest lifetime of those and that led to its being the standard for all RTGs flown by the US since 1964, though some other experimental units with other isotopes were tested in the 60s and 70s.

    Heat output is roughly inversely porportional to halflife (how much of it decays in a given time period?).
  • Pu-238 is produced by irradiating Np-237 and chemically extracting the Pu-238. I don't know what the process is for creating the Np-237. The problem with spent commercial reactor fuel is separating the desired material from all of the other elements and isotopes. Special "low burn-up" reactors are used to produce Pu-239 from uranium. A commercial reactor produces plutonium with a high percentage of short-lived plutonium isotopes, which is undesirable for use in nuclear weapons. Chemical separation extracts all of the plutonium, not just the desired isotope. For RTGs, you only want the Pu-238.
  • no, that's douglas adams.

    Close, though.

  • What do you mean by "more efficient" ways of space travel? Let's investigate your ideas one by one :

    Whoops. My title "Build the space infrastructure first" was slightly off-key. It should have said "Invent the space infrastructure first". It wasn't that I have a lot of brilliant ideas as to how space travel should really be done, and every single one of the specific ideas that I hintet at may well be useless. But if these ideas don't pan out then we need to get some other great idea, because today we really don't have a clue on how to do space travel in a reasonably efficient manner.

    The fundamental problem of how to get materials, mainly fuel, free of earth's gravitational pull, will not be solved by going to Pluto. Such a project would just use the same old big multi-stage rocket, which is proven technology. It is simpler to buy a huge fuel tank and fill it up than it is to develop some future technology that we haven't even begun to imagine yet. But we need the latter if it's ever going to be more than the odd one-off giga-dollar expidition.

    Repair Facilities : In space, you don't "repair" something : you replace them. It's WAAY cheaper to be redundant in components than to build elaborate facilities to repair things..

    Quite right. But again, it doesn't scale. So we'll just have to figure out how to build simple, generic repair facilities instead of elaborate, bulky, a-tool-for-every-job facilities.

    A better challenge than going to Pluto would be this: Build a self-sustaining space station. In orbit, on the Moon, on Mars, I don't care. Any which way it is a formidable challenge, but in return we would learn a lot, not just about space, but also about ourselves, ecosystems, life.

    /A

  • >holiday trips to Mars

    If you're lucky to have a holiday that lasts several years, that is.

    Hit the throttle, accelerate at 10 m/s2 the first day, decelerate at the same rate the second day, and you're there, and you even had gravity all the way. Why would you want to spend years on Mars? :-)

    Sure, with today's staged rockets and slingshot technology the voyage alone would take years. Which is exactly why I wouldn't go today.

    /A

  • Its pure speculation but it might be the X-33. Its well known that they have had problems with the fuel tank- and its also well known that they don't want to announce anything on it until after the elections...

  • Damn straight.

    I am disgusted that there is sooo much ucking around when it comes to space exploration.

    Even if it is hard and difficult...

    The us military uses old $7.5 million jet fighters as target practice...!

    When you are looking at waste on this scale perhaps resources would be better directed to space stations or terraforming.
  • No. As of 1998, Pluto is on the outside.
  • Brain: The same thing we always do in space, Pinky - try to find the unexpected.

    Pinky: I'd be a lot happier if we knew what the unexpected was before I paid for it. Narf!

    Brain: Give me strength.

  • AFAIK some nuclear reactors are designed to generate weapon grade Plutonium as part of their waste (Or at least products that can be used to get that Plutonium). Couldn't those reactors be changed somewhat to rather produce this usable variant of Plutonium? (There are too many nuclear weapons already anyway.) Then they would have enough of that for the mentioned missions and probably enough for others as well.
  • Excuse me, yes you do own child222 but my account is parent and no the password isn't slashdot....
  • And what are we looking for on Pluto again?

    Exactly what we've been looking for on all the other planets. Some sort of Amazon society. Standard operating procedure is that we send a team of astronauts (they must have names like "Duke" or "Buzz") onto the planet. They are captured by the warlike Amazons. While imprisoned, the Amazon leader's daughter falls in love with Duke (or Buzz), helps them escape, and they take off in their rocket back to earth.

    I hereby volunteer for the mission.

    And I'm changing my name to Duke (or Buzz).

    --
  • Don't you remember where they found Fwiffo the Spathi in Star Control II? The prophets Fred Ford and Paul Reiche III were correct! Oh, here come those friendly men with the white jackets again...
  • I cannot believe in all reality, that you consider your pension to be of more importance than the future of the human race and and all the other species on our planet, it seem like to me you have never spawned, therefore do not understand the future or the past.
  • ...we wouldn't need to go, would we? That's why they call it space exploration. Otherwise, it'd they'd call it shopping trip. "While you're out, could you pick up a dozen igneous rocks and a six pack of space-borne microbes."

    Personally, I'm hoping Pluto turns out to be the construction shack for the solar system. Who wrote "Construction Shack" anyway? Clifford Simak, wasn't it?
  • In short, the Congress is loaded with porkbarrel pussies and cowards (and criminals) and these clowns hold the purse strings of NASA. NASA has to walk on eggshells because if they don't, Congress will use the slightest excuse to transfer NASA funds to pork to buy votes.

    This is probably the best answer I've ever seen to why the private sector should take the lead in space exploration. I don't remember the Wright Brothers, Charles Lindbergh, or Amelia Earhartdt waiting on Congress to OK funds before starting their explorations.

    As for giving scientists their head, that's a Bad Thing(tm) for Congress to do. Not everyone paying taxes agrees with you (and me) that space exploration is beneficial, why should their tax dollars support something they don't believe in? Do you want your tax dollars supporting abortions/free guns for everyone? (Figured I'd catch both sides of the isle with that one.)

  • Well jesus christ, since when do we need a reason to go looking for information?

    Ever since stuff stopped being free.

    Nobody is saying that stuff shouldn't be explored. It's just that there's a finite amount of resources. Wouldn't it suck if we went ahead and sent something to Pluto, at the expense of not having enough money for, say, a Europa mission? There's a lot of interesting things to look at, Pluto is only one of them.

    Unless you have a solution to the age-old economic problem of scarce resources, there's always going to be someone who looks at the nebulous expected returns of a mission and wonders why he should give up _____ for it.


    ---
  • Yep, there was a supply of plutonium that could have solved the RTG problem. When the Russians dismantled missiles to comply with START, they saved the plutonium as a national resource.

    And we just paid the Russians to dispose of it.

    Oh, well. Who needs space exploration when there are proven-ineffecive programs like Head Start and DARE on which we can piss away money...

    (Head Start has been shown to have no effect on the student's future high-school grades, graduation rates, college admissions, standardized test scores, dropout rates, or any other measure of academic achievement. DARE has been shown to have no effect on drug use.)

    Steven E. Ehrbar
  • The planet pluto, known as glacier. Land of ice and snow, home of the spice melange. The spice controls the universe...whoever controls glacier controls the spice.

  • It would be more accurate to say that the Moon is not considered a planet because of one little detail. Doesn't orbit the Sun, but rather the Earth. Something orbiting the Sun is either a planet, comet, or asteroid. Something orbiting a planet is a moon.

    I agree, though, the Pluto/Charon pair [arizona.edu] (Charon, pluto's moon, is probably 12.5% of the size of Pluto (that number has an accuracy of +/-35%, one of the things this mission wants to clarify) - relatively, the largest moon in the Solar system) should probably be considered a pair of minor planets/captured asteroids or Oort objects. However, that is unlikely to happen [iau.org].

  • Re:Is their supply of plutonium limited? (Score:4)

    by Detritus ( 11846 ) on Sunday July 30, 2000 @06:08AM (#894150) Homepage
    This isn't Pu-239, the isotope that is used in nuclear weapons. We have huge amounts of Pu-239. Radioisotope Thermoelectric Generators (RTG) use Pu-238, a plutonium isotope with a much shorter half-life (87.7 years). The problem is producing the material. Pu-238 was produced by the Department of Energy as a byproduct of the nuclear weapons materials production infrastructure, which has largely been shut down. There has been discussion of restarting a capability to produce Pu-238, but I'm not sure if any progress has been made. There are plenty of anti-nuclear know-nothings who are opposed to the idea.
  • ah... i just realized what you're doing here.... cute... very cute. :-)
  • If it was kicked off Uranus, wouldn't it be in some sorta orbit around Uranus (either round or eliptical)?

    It seems strange that the sun would provide more of a gravitational pull from millions of miles away than a nearby planet the satelite was just "kicked off of" (think of the Earth and its moon).

  • Many people here seem to think this kind of missions are quite useless and especially to the Pluto; the small, frozen planetary body far far away.

    In my opinion it is one of the most interesting planets in the solar system. We know almost nothing about it. Anyway, the facts we know about of it's size, mass and possible compounds it consists of, are really interesting. Like already said here, the planet is believed to have an atmosphere which is now in a gaseous state because the planet is close enough to the sun (it has a weird, a bit like asteroid or comet style orbit but it's much bigger than any of them). When the planet moves on, it also get's more far away from the sun and the atmosphere is going get frozen. Or to put it the other way, it's gonna lose it's atmosphere for some 200 years.

    The mission doesn't have so much time.. The probe should be sent now or really soon to get to the planet in time when there is still an atmosphere.

    As a conclusion, I think the planet is WEIRD and that makes it a perfect and an interesting case of study from which we could learn something (at least scientifically).

    In addition, the probe would not be there to only study Pluto, but also general conditions in that part of the Solar System - the Kuiper disk. It would also study some astoroid bodies there etc... We don't know almost anything about the Kuiper disk either.

  • Pluto doesn't have enough mass to explain the distortions in the orbits of other planets (esp. Neptune). This is why many believe there must be a 'Planet X'.

    Actually, there *are* no distortions in Neptune's orbit. Once, it seemed that there were, which led to the search and discovery of Pluto, which then turned out to be too small to have affected the orbits anyway. It turned out that our estimate for the mass of Neptune (and Uranus) was wrong. Once you use the correct masses, the orbital oddities go away.

  • Moving Your Terminal by Marius Aamodt Eriksen [marius@linux.com] - Skill: I - Jul 26, 2000 You can move your terminal window via escape sequences. To do this, simply echo -e "\33[3;x;yt" where x and y are coordinates from the upper left of the screen. [ Add Reply ] U s e r . C o m m e n t s: Shouldn't that be? Comment by Stephen Martin [smartin@canada.com] - Jul 26, 2000 echo -e "\033[3;x;yt" (1 comments) [ more ] Not all terminals Comment by gus3 [gus3@eskimo.com] - Jul 26, 2000 Works with xterm, but not gnome-terminal.

  • The reactors you mention are called "Breeder" reactors were specifically designed to produce Plutonium in the corse of their operation for two reasons, 1. for atomic weapons production and 2. For civillian pllutonium reactors that are never going to be built because of the many fold risks of either plutonium theft, not to mention what would happen if the stuff were released into the atmosphere.
  • "It was intended to be a joke about..."

    If you have to explain, then it ain't a joke.
  • i got an idea on how we can fix the problem of overcrowded prisons ;-)

    Aggressive marketing of birth control?

  • Some info (Score:5)

    by Bryce ( 1842 ) on Sunday July 30, 2000 @06:44AM (#894160) Homepage
    I worked on a team that did one of the concept definition for this mission (I designed the propulsion system), for TRW's proposal to build this spacecraft. (Guess we didn't get it, eh?)

    Pluto/Kuiper Express (PKE) was to be one of three JPL solar system exploration missions. The other two include Europa Orbiter (intended to determine the existance of a subsurface ocean), and Solar Probe (intended to determine the origin of the solar wind). PKE's purpose was to image Pluto and Charon (Pluto's moon) and a Kuiper Belt object. EO's biggest challenge is it's complex orbit insertion. SP, of course, has to deal with an intense thermal environment.

    PKE's principle challenge was to reliably conduct an autonomous encounter navigation after spending 8 years travelling out there. The craft would be zipping past Pluto at a good clip, and clicking a few pictures (for later transfer back to earth) would be tricky - gotta have the camera pointed in just the right directions at just the right time.

    The reason autonomy is necessary, is that at Pluto, the round-trip time for a beam of light to travel between Pluto and ground control is 8 hours, but the entire Pluto encounter only lasts a few hours.

    Another problem, mentioned in the article, is that finding a launch vehicle with sufficient performance to get enough mass (a few hundred kg's) going on an accurate trajectory, is pretty tricky.

    I think it'd be a pretty cool mission, although I can understand why NASA may prefer to direct their funds towards other projects that would return larger amounts of results for less risk. I hope this doesn't mean Europa Orbiter or Solar Probe are also in danger of cancellation.

  • There are three ways to dissipate heat, radiation, conduction and convection. In a vacuum, your choice is limited to radiation. You radiate the excess heat into space. There is some tricky engineering involved in keeping the different parts of a spacecraft within a reasonable temperature range.
  • but it makes for an explanation of Pluto's odd orbit and Uranus' other moon that is on a deteriorating retrograde orbit.

    You mean Neptune, not Uranus.

    Nor does its location fit in with Bode's law.

    Bode's Law is probably a coincidence, and there most likely is no tenth planet.

  • That's what those radiators are for.u Just like the one stuck on top of the CPU for your computer. Besides with most probes heading away from the Sun, solar heating becomes a nonissue after a point.

  • Re:Not EVEN a planet... (Score:4)

    by tesserae ( 156984 ) on Sunday July 30, 2000 @06:47AM (#894164)
    Pluto was given "planet" status only as a reward to the discoverer

    Uhhhh... interesting statement, but I have to disagree. When Clyde Tombaugh discovered Pluto on February 18, 1930, he was searching for a ninth planet predicted to exist because of discrepancies between the predicted and actual orbits of Uranus (and Neptune) -- the precise reason that the planet Neptune had been discovered, in fact (here's a detailed story of the whole affair [itsnet.com]). At the time, no one had any notion that Pluto would be so small: it was predicted to be between two and seven times the mass of Earth, and everyone expected it to be dim -- why else would it be so hard to find?

    As it turned out, the most likely cause for Uranus and Neptune's orbital discrepancies is probably observational error [itsnet.com], and Pluto just happened to be in the approximate neighborhood being searched. If it were discovered today, we might not call it a "planet" -- it's only the largest (so far) of a number of objects in the Kuiper belt [arizona.edu] -- but this has been the subject of a lot of controversy, and it's been officially decided to keep calling it a planet. [nasa.gov]

    At the time it was discovered, no one had any notion that things would turn out this way, so it was just considered a planet and named as such. No special considerations or rewards -- just ignorance of the future, as always...

    ---

  • Ganymede is larger than Mercury, yet it is still considered a moon.

  • What would you say is the purpose of government?


    ---
  • Aside from pluto being the last unvisited planet in the solar system, its surface layers should contain a record of conditions in the early solar system as the gas giants were coalescing. I work with a group of planetologists who study solar system origins, and some of it's rubbing off on me (I normally study the other end of the solar system -- the big hot thing in the center) as I begin to understand the points of interest.

    The issues surrounding PKE have mostly to do with large budget squeezes within NASA, with the long flight time, and with the radiothermal generator stuff. No need to spout about the reasons why the budget is tight -- though astute people will recall that there's some sort of orbital treehouse that's a leetle bit over budget. It's also hard to justify now spending a bunch of money that can't conceivably pay off until after the next president's term is over -- the flight time to Pluto is >8.5 years. (That sounds like a long time, until you realize it's taken over 12 years just to get the project from NASA HQ outside the Capitol Beltway.) Other folks have pointed out that, due to the unexpected outbreak of world peace, there's comparatively little nuclear weapons development going on -- and hence not much Pu-238 to be had. Further, all the reactionaries who tried to prevent the Cassini launch (did any of them actually bother to calculate the worst-case release scenarios?) are still around, and now they're mad as Hell. The protests and legal action tripled the cost of the RTGs in Cassini, and PKE will have similar problems.

    Solar Probe will have trouble with Pu as well, but at least that mission has an alternative. Solar panels, oddly enough, won't work -- they'd get too hot to work around Mercury's orbit, and melt a few days after that. The current plan has a couple of different solar flybys happening -- that requires RTGs, which will last long enough to do the job. But NASA could back off to a single-flyby mission. Then a jettisonable set of solar panels would be used during cruise phase. During the flyby, power would be supplied by a bank of chemical batteries. But then the probe would be dead, dead, dead shortly after the last data from the flyby were downlinked to Earth.

    Both of these spacecraft concepts would require incredible miniaturization. Our proposal (I helped write one submitted by Southwest Research Institute) has instruments that are about the size and mass of full beer cans.

  • Thats not true, at least the part of Jupiter's gravity. Compared to the Sun Jupiter isn't shit. The AB is the point where the dense heavy materials in the early Solar System's accretian disk started to thin out to such an extent they could not form a planet. There is plenty of space between Jupiter and Mars to fit a planet the problem is the lack of dense material in the inner Solar System.
  • The ISS is such a piece of shit I cannot understand who's billiant idea it was. Not only is the ISS not high enough off the ground to get effective radiation measurements but it also costs way more than a space station ought to. The real purpoe of a space station is to do microgravity experiments and to study how humans can adapt to the environment. An orbital waystation is utter crap, it takes fuel to get the fuel to the space station, and even then once you're in orbit the hardest part of the journey is already over and done with. A good point you made was assembling vehicles in space, it would save a great deal on the individual mission cost if they could be lauched from a high orbit or from the moon rather than from Florida.
  • I understand from a friend that worked on the Cassini project that the problem was that there no more power plants available of that type left.

    Apparently they were built to power nuclear subs but only a limited number were made. No more are ever planned to be made due to the namby pamby, wishy washy, liberal eco-loons. Which completely stuffs the deep space exploration programme.

    This may of course be complete rubbish, so if someone more qualified wants to comment, please do so.
  • Pluto is asking to be explored merely as a scientific and technological challenge. There is still plenty to learn from our Solar System. I'd like to see close up pictures of Pluto in my kids' text books someday. There are all of the aguments about pure science exploration because it "wastes" money and doesn't return much of empirical value. If I seem to remember correctly, before the Apollo program computers inhabited a very large room and sucked a great deal of power. Amazingly NASA ended up being able to fit a self contained computer into the Apollo spacecraft to aid the Astronauts in their navigation. Finding faster and cheaper ways of launching scientific flights also solves the problem commercial flights have, the transit from the surface of the Earth into orbit. You don't seem to mind using the technology researched by NASA when you watch satillite TV or make an international telephone call. I've also seen people comment about wasting money going to Mars (and Pluto) when children in various places are starving. Why not dismantle militaries to feed people rather than worry about peaceful programs, or better yet sell your SUV and feed them yourself.
  • Headline: Pluto mission cancelled - Plutonium shortage.
  • How do these space probes keep from overheating? A car's radiator disperses heat with the airflow from its motion, but there's no air in space!
  • A NASA press release the other day had wrong temperature conversions: "-100 F (or -40 C)".

    They meant -70 C. Idiot engineering schools are to blame. My engineering friends learn conventional units in their applied classes, while physics classes are all in mks units. And I go to UT, which supplies a lot of NASA's engineers.

    BTW, I'm an astronomer -- I use cgs units. :)
  • It would be more accurate to say that the Moon is not considered a planet because of one little detail. Doesn't orbit the Sun, but rather the Earth.

    Interestingly enough, the orbit of the Moon is smoothly convex relative to the Sun -- it's orbital period around Earth is long enough that there aren't any cusps in its orbit, as there are in so many other moons. So in a sense it could be considered to orbit the Sun in gravitational association with Earth, and there have been numerous suggestions that the Earth/Moon pair should be considered a double planet rather than a planet/moon.

    But there's that history thing again, so I think the nomenclature won't change...

    ---

  • We were lost.
    None of us knew where we were.
    And then Harry began feelin' around on all the trees. And then he says, I got it: we on Pluto.
    And we said, Harry how can you tell?
    He said, From the bark you dummies. From the bark.

    (love that part)
    Water my ass. Bring this guy some PemptoBismal.

  • Don't you think that the discoveries made in the meantime will help generate the interest to keep expending the bucks to develop the infrastructure? Otherwise, why bother?

    ---

  • Look, NASA has been dead in the water since 1986 apart from little sucess on Mars. Mir was great but that's the last the Russians could muster without help. The Russians got to be the first in space, the First Dog, Man and Woman, and the first Orbit IIRC, as well as the first to land on the Moon unmanned. The Yanks walked on the moon for 2 1/2 years up until 6 months after I was born and so I don't remember it and could care less and really get annoyed with people telling me how great an accomplishment it was when it's so distantly removed from my own life experience -- kind of like the Kennedy and McKinly assassinations. Anyway, so the Americans explored the Sun and Murcury, the Russians landed on Venus and the Yanks got lots of orbitals, Viking and Mars belonged to the Americans, as well as the 4 gas giants and the Voyager series (so when are we going to build Voyager 6 anyway?!?); we have even vised a comet with the Europeans.

    But what have there Chinese got in their space exploration history besides very accurate charts and the famous gunpowder-powered flying emperor -- did he go *boom*! Now they want to go to the moon, and that's all well and good for Chinese pride and at least something for my generation to enjoy, but here is the opportunity to finally be the FIRST, the COUNTRY that claims the TITLE! China-Pluto 2004. After all, no country has a greater concentration of Physicists and what better way to make your mark. PLEASE STOP writting NASA and send your letters to the Chinese Space Angency. You can't get water from a stone and until NASA starts using Metric they're not getting anywhere. We NEED to urge the Chinese government to put its resources into this project and get to this last King of the Kuipers! It's the only way, otherwise given the declining style of life around the world, I could be dead before the Americans get there! :(

    Be Seeing You,

    Jeffrey
    <Activate Flame-Retardant Long-johns/>
  • What do you mean by "more efficient" ways of space travel? Let's investigate your ideas one by one : (a) Research New Propulsion systems : And to go where? Propulsion systems technology is driven by need, and if you don't plan to go anywhere, there is no need. So no new systems. (b) Building Waystations in Orbit : This is one of those "myth" ideas that perpertuated by too much science fiction. Waystations in orbit are stupid : you waste fuel getting into an orbit instead of just flying straight to your target. Now, you say (ala Armageddon), we can "refuel" there. But then how the hell does the fuel gets there in the first place? Answer : you fly them there, and that takes MORE fuel. It's easy to show (mathematically) that costs more (basically, rockets scale up favourably : the bigger they are, the cheaper they get per kg payload). So go do some maths. (c) Building Lunar Refueling station : That's another science fiction myth. Do you know it's CHEAPER (i.e. smaller rocket) to land something on Mars than to land something on the Moon? Crazy? No : mars has an atmosphere to aerobreak a probe. Moon does not. I know : I spent a month doing calculations in a feasability study on a "Cheap Lunar Lander" mission. Going to the Moon to refuel is like going to New York to refuel on a trip from Chicago to Los Angeles. (d) Repair Facilities : In space, you don't "repair" something : you replace them. It's WAAY cheaper to be redundant in components than to build elaborate facilities to repair things....without knowing what things/spare parts/equipment to stock because you don't know what's going to fail. (e)Water stations for Fusion Reactors : Water has H and O inside, and H2O2 (Hydrogen Peroxide) is standard rocket fuel. But you need FISSION reactors to get H and O out, NOT Fusion Reactors. And you don't need Water Stations : you need water extractors : and they already exist. My professor once told me that people who think that they can "plan everything ahead", and do all the groundwork before pushing the "magic button" and elaborate things will happen is going never going to be successful. Because research is a trial and error procedure. So There!

  • What are we looking for?? (Score:5)

    by gammatron ( 120978 ) on Sunday July 30, 2000 @04:49AM (#894184)
    (And what are we looking for on Pluto again?)

    That type of statement is the reason NASA's budget has been cut so drasticly over the years, which directly led to the high-profile failures of some of the recent Mars missions. We're not looking for anything in particular; the whole point of a mission such as this one would be pure exploration - we don't really know what to look for, so you have to begin somewhere. It's true that there will never be (in our lifetime, at least) any commercial value from the exploration of Pluto, but does that mean we shouldn't go there? If that kind of test were applied to all matters of exploration and research, we'd still be in the dark ages.
    --
  • You're kidding, right?

    How about solving the question of whether it formed here or was captured? And, if the latter, learning about how planets form around other suns.

    If you don't understand what we're looking for on Pluto, you shouldn't be editing Science stories on /., Timothy.

    --
  • What's with all this crap about being soooo cautious about space exploration. Let's just keep sending stuff out there until we succeed in getting to the other planets. I don't care if people die trying - shove the next door neighbours dog in the damn things and see if they get there. Aim my microwave at Mars and launch the sucker. I'm sick of waiting for this so called "space program"... the best way to succeed is to learn from failure.

    If the "space program" ran the aviation industry in the first half of this century we wouldn't have aeroplanes, we would be sitting on the tarmack too frightened of flying for fear of killing someone, or losing a buck.

    By the time the space program ever gets anywhere, intelligent life will have evolved on another planet and they will have found US.
  • The same picture says that Ganymede and Titan are larger than Mercury. Does it mean that Mercury is not a planet, or that Ganymede and Titan are planets?
    --
  • What we need are some good old fashioned megalomaniacs (sp?) to go to the world's rich, lie to them really effectively that there are rivers of gold on pluto, and get them to finance the journey.

    Christopher Columbus was the man. :)

  • Looks like Pluto IS the LAST planet, again, as of February 11, 1999. According to this link Buie: Pluto Research [lowell.edu]:

    Pluto reached perihelion (closest point to the Sun) on 1989 September 5 at 12:00 UT. At that time it was at 29.66 AU, or 4.4 billion kilometers, or 2.7 billion miles from the Sun. Pluto became the "eighth" planet on 1979 February 7 at 10:44 UT when it came to a distance from the Sun less than Neptune. It will continue in this status until 1999 February 11 at 11:22 UT when it will once again be further from the Sun than any other planet. Its status as the ninth planet will remain undisputed for the next 220 years when it will once again be approaching perihelion.

    Crunch, crunch; chew, chew; crow. Pttui! <g>

  • We are looking for that which we do not know.

    --

  • Okay, that's it (Score:3)

    by doom ( 14564 ) <doom@kzsu.stanford.edu> on Sunday July 30, 2000 @07:57AM (#894213) Homepage Journal
    (And what are we looking for on Pluto again?)

    Okay, that's it. You guys aren't real nerds. Time to change your slogan.

    And the Department of Energy now reports that work on a power source replacement for the traditional plutonium-238 radioisotope thermoelectric generators (RTGs) called the Advanced Radiological Power Source (ARPS) has not been productive, yielding lower than predicted output.
    Somehow I suspect that this Plutonium "shortage" has more to do with fear of another political flap, like the one surrounding the launch of the Cassini probe (oh my god, they're launching *Plutonium*... on a rocket!).

  • And this is why pure science goes... (Score:5)

    by gbowland ( 97425 ) on Sunday July 30, 2000 @05:03AM (#894216)
    It's impossible for there not to be something interesting on Pluto. We'd find out about the history of the solar system, whether Pluto was formed in the original solar system or captured, a million questions could be answered and a million new questions could be asked.

    Science shouldn't always have a direct application or use. It's their because once in a while it creates something amazing, that changes everything and affects everyone. You can't always directly apply science to solve a need. Sometimes you don't know a need was there until it has been satisfied.

  • What are we looking for? (Score:3)

    by sopwath ( 95515 ) <justins at visi dot com> on Sunday July 30, 2000 @05:07AM (#894217) Journal
    Well jesus christ, since when do we need a reason to go looking for information?

    I mean we still don't know what (if any) atmosphere exists around pluto. Knowing the material composition would tell us more about where Pluto actually came from, like was it formed at the same time as the rest of the solar system or was it just a BIG comet...

    Why do we study any of the planets, why do we look for bones in the ground that are a few million years old? We know Dinosaurs exitst, I guess for some people that's enough infomation.

  • Re:Some info (Score:3)

    by Claudius ( 32768 ) on Sunday July 30, 2000 @08:37AM (#894221)
    I think it'd be a pretty cool mission, although I can understand why NASA may prefer to direct their funds towards other projects that would return larger amounts of results for less risk. I hope this doesn't mean Europa Orbiter or Solar Probe are also in danger of cancellation.

    I agree that this would have been an interesting, if somewhat risky, mission and it's a bit disheartening that we aren't giving it a shot. I do think that both the Europa Oribter and the Solar Probe enjoy considerable advantages over PKE, however. EO has the public's imagination behind it with the possibility of liquid water and extraterrestrial life existing there. The Solar Probe may answer longstanding issues of the heating and dynamics of the solar corona, which will imporove our understanding of solar flares, CMEs and the origin of the solar wind. Since much of today's economy relies upon the spacecraft buzzing over our heads, this mission has much practical value in its ability to help us understand and predict solar storms.

    Of course these reasons hardly exempt either mission from being cancelled--they just queue them in front of missions whose sole objective is scientifc. With election-year politics and the ensuing silliness, I wouldn't bet on their fates.
  • Bye the way here is the link [space.com] to the actual Space.com story. What really intersts me is not really Pluto per se, but exploring around in the Kuiper Belt, where most of the comets are thought to be from, and just getting useful information from just beyond our solar system.

  • Plutonian message (Score:4)

    by Money__ ( 87045 ) on Sunday July 30, 2000 @05:16AM (#894233)
    Last night, while running my SETI@Home program, my screen wnet blank and a message from the people of the "United People Of Pluto" and it said:

    "People of Earth. Welcome.
    Please come to our planet.
    We are only 5,913,520,000 mil^H^H kilometers from the sun.
    er ummm .. or was it miles?.
    Nevermind."

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