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Bush's space vision loses focus

  1. Jul 25, 2004 #1

    Ivan Seeking

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    http://www.nature.com/news/2004/040719/full/040719-19.html
     
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  3. Jul 25, 2004 #2

    marcus

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    Personally I think it would be great if some astronauts got to
    tour the Jovian moons and eventually were able to set up a
    base under the ice on Callisto.

    Luna and Mars are dry barren places unsuitable for our kind of life,
    and anything we want to know about them can be found out by
    robot probe. Sending men to either place is not a bright idea, IMO.

    Too bad NASA is getting jerked around like this---Bush idiocy may
    severely damage the agency and the supporting science/engineering
    cadres. Best would be if the "Back-to-Moon" project had never been
    mentioned or set in motion. Next best would be if it were quietly dropped
    as soon as possible. Worst-case scenario is actually going through with it.
     
  4. Jul 25, 2004 #3

    turbo

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    Too true. The cost-benefit ratio of any real scientific mission to the Moon or Mars is VERY unfavorable when you have to transport delicate human beings around with all the materials and systems needed to keep them alive. Every pound of water, oxygen, foodstuffs, personal hygiene supplies, etc, etc, that have to be carried reduces the payload availability for scientific apparatus. (Not to mention the weight of the shielding and insulation needed to keep the crew's living space safe.)

    NASA has always been a political football. Unfortunately, they may have a tougher time riding this one out due to a seemingly total lack of leadership. The shuttle program is on the ropes, and NASA's administrators want to abandon HST because of concerns over crew safety, yet "the cowboy" puffs up his chest and proclaims that he wants to send men to the Moon and Mars. I don't think he talked to any scientists before he revealed his visionary "plan", just to some aerospace industry contractors. Bush is scientifically unsophisticated (to be polite) so don't expect to find a compelling logical reason in his plan, just follow the money.

    You're right - actually following through would be the worst-case scenario, but second-worst would be making the US taxpayers fork out billions of dollars to the aerospace industry to do all the studies, planning, preliminary engineering, etc, before the project gets dumped. I'm afraid that second-worst scenario is VERY likely to happen unless some rational people intercede.
     
    Last edited: Jul 25, 2004
  5. Jul 25, 2004 #4
    That is BS. They can't just ruin NASA's plans like that! What a waste of money... :mad:
     
  6. Jul 25, 2004 #5

    Hurkyl

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    I don't think we're going to travel to any class M planet/moon anytime soon. A moon base would be far easier to establish than anything else.

    First off, there is little to no environment to fight on the moon. I don't see any reason to think that there is a less hostile environment than the moon; sure it's dry and barren, but there's no duststorms, no icequakes, no volcanoes, and you're not surrounded by toxic liquids/gasses.

    Secondly, there are fewer surprises on the moon. We are quite familiar with the universe near earth; but do we really know enough about the surface of Io? The alledged sea on Callisto? Will Jupiters radiation belts / magnetosphere throw us any curveballs?

    Thirdly, consider resources. It's a lot easier to resupply and maintain a moon base than it would be a Callisto base.


    I just can't imagine how it could be beneficial to skip these early learning opportunities.
     
  7. Jul 25, 2004 #6

    turbo

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    It is beneficial in the sense that our tax money would be better-spent elsewhere. There is NO plan for us to colonize space or travel to other planetary systems (a la Star Trek) because our current technology could not take anyone to another star. We already have our hands full giving modest-sized probes simple one-way tickets to other planets. Even then, the trips take months or years, and we often have to use the gravitational wells of other planets to maneuver the probes because we just can't economically loft enough fuel to make large corrections and braking maneuvers.

    Once we come to grips with reality, how could missions to the Moon and Mars be "early learning opportunities" for anything? Without some very radical breakthroughs in propulsion, our species is going to spend its entire existence either on Earth, or very near it. Until some alien shows up with a load of "dilithium crystals" and shows us how to build and fuel an engine with them, there is no point in throwing chemically-fueled rockets (and many billions of dollars) at the moon. Of course, there's the little problem of "warp" drives, since accellerating a massive object to the speed of light is impossible and travelling at multiples of the speed of light is strictly forbidden outside Hollywood. The president got a great sound-bite out of his "mission" to the Moon and Mars, but anybody who follows the work of our space agency knows that what he proposed is misguided and wasteful at best, given our present technology. Someone is going to have to develop a really efficient dependable propulsion system before we start junketing to other planets. Simply throwing mass out the tailpipe (our current technology) will not suffice.
     
    Last edited: Jul 25, 2004
  8. Jul 27, 2004 #7

    turbo

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    A good link, and a rant from a codger.

    I had lost this nice link about space propulsion, and managed to find it again just tonight. It puts the whole chemical/fission/fusion-fueled spacecraft thing in a bit of perspective.

    http://www.grc.nasa.gov/WWW/PAO/html/warp/scales.htm

    We need a revolutionary advancement in propulsion systems (VERY efficient and non-fuel) before we can start bopping around the Solar system, or even consider visiting our nearest stellar neighbor. It takes over four years for its light to get here, so even if we could somehow manage an average velocity of c/100 on the trip, we would need the brave journeyers to spend about 399 years in yet-to-be-developed stasis, or prepare to pack lunches (just kidding!) for 16 generations of travelers on the way out, and an equivalent amount for the way back, plus a little extra, in case they want to hang out at Proxima Cent. and picnic a bit. That's a lot of baloney sandwiches and potato salad, folks! REAL Science Fiction writers (I was born in the early 50's and cut my teeth on even earlier fiction during the '60s) tackled these practical issues head-on, so multi-generational ships, "recyclers", closed systems, etc are second nature to us geezers. Most modern SF is more "Speculative" than "Science" and the authors lean on props like *advanced technology* (indistinguishable from magic) for plot devices, so practicality and possibility are tossed for the sake of entertainment. Star Wars is one of my all-time favorite movies, but it's pure horse-opera-in-space type entertainment. There was a time when many SF writers allowed themselves to be constrained by real physics and still wrote entertaining stories, and I wish the younger folks here could be immersed in that for a while. There are more modern "hard-science" writers, too, like Larry Niven (Ringworld) but they tend to assume advanced space travel in order to develop their (still entertaining) worlds.
     
  9. Jul 27, 2004 #8

    Hurkyl

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    When you're ready to... ahem... come down to Earth, maybe we could discuss the topic at hand, hrm? :biggrin:
     
  10. Jul 27, 2004 #9

    turbo

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    No problem. The original topic (complaint) was that there is somehow no real U.S. budget for sending men to the Moon or Mars. There *should* be no such budget, since we can most efficiently do the bulk of our astronomical research robotically. Before any plan is advanced to send people beyond the Earth's environs, there should first be a discussion of the purpose of the project. If the purpose is to establish remote, expensive human outposts within in our solar system, then the scientific community should first agree on whether to set that goal and whether we can fund it before the president announces the plan on national TV. If the ultimate goal is space travel outside our solar system, there can be no discussion of same unless there is first a revolutionary advance in propulsion technology that does not require us to endow each space-vehicle with HUGE (impossible to acheive) disposable mass to use as thrust.

    My point in the last post was that Science Fiction writers in the 40's and 50's were at least cognizant of the very real limitations imposed by our technologies and our morphologies as humans. They were the kind of people who would have populated this forum if it had existed 'way back then, and their insights would be invaluable here. As for coming my "down to Earth", I think I am pretty well centered. If you can think of some really compelling reasons to establish a permanent base on the Lunar surface, you're free to express them here. I'll be happy to hear why a manned Lunar base is so critical. :smile:
     
  11. Jul 27, 2004 #10
    a moon base would be excellent at providing a launch pad for other space missions. granted the engineering and financial dificulties are steep, but not unmanageable.
     
  12. Jul 27, 2004 #11

    marcus

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    Hello Hurkyl, didnt see til now you'd replied on this thread
    Your arguments can be turned around to suggest sending robot probes to land on Callisto

    Personally I think the surface of Callisto (4th Galilean moon out, less magnetic bother) is dry and barren

    I believe the Callisto crust is estimated to be very thick (not like europa which is speculated to have an ocean under moderate ice crust)

    I personally do not expect any atmosphere, no toxic gas, no dust storm, no volcano, probably no ice-quake either.

    But you are right that it is good to KNOW for sure. So let us send some probes to Callisto surface.

    Personally i dont expect there is a lot of environment to "fight", as you say, but let's find out.

    I suspect that Callisto looks and feels rather like Luna except that the surface rock is chemically easier to use. The surface rock is made of rocket fuel, that is it is largely H2O. That (besides being scientifically more interesting and in a more interesting location) is a big advantage Callisto has over Luna.

    -----
    You make a big point about cost. You also make a point about learning and practice and experience. It is an appealing thought that Luna missions could be seen as practice for Callisto.

    You are doubtless mostly right about cost----however cooling the power reactor might not be so costly, replacing oxygen losses might not be so costly, replacing water losses might not be as difficult as on the moon.

    the main reply to the cost point, though, is what do you get for your money? IMHO a boondoggle base on the moon with make-work "science" experiments for astronauts risking their lives for no real benefit---unless it counts as practice.

    Versus IMHO a really exciting new experience, engaging the intense interest of first-rate people, and a fascinating thing for the rest of us to share in as the adventure unfolds.

    :smile:
    You see, hurkyl, the screen saver on this old monitor is the Jovian moons/
    I just have to stop typing and they come on/
    it zooms down towards the surface of Callisto/
    so I cant forget
     
  13. Jul 27, 2004 #12

    Hurkyl

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    Oh, did I mentally mix up Eurpoa and Callisto? *sigh* It's been far too long since I studied that stuff.
     
  14. Jul 27, 2004 #13

    BobG

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    I felt Bush's "Vision for Space Exploration" was really just a way to start phasing NASA out. The dollars he proposed putting into NASA were way to small and Bush would be long gone by time NASA failed (not Bush).

    If you only look at the dollars and cents, this was an easy call to make - provided you sugar coated it and pushed the goal way beyond your own time in office. At one time, NASA and the military space program were the seeds of space industry. The civilian space industry is becoming mature enough that it doesn't need nearly as much government help - in fact, it's become mature enough that the military is beginning to buy off-the-shelf satellite buses and then fitting them with their own sensors.

    Of course, if you only look at the dollars and cents part of it, you miss the bigger picture. NASA's exploratory probes have given us some great views of our solar system and beyond (which is why abandoning Hubble is such a sad move). I'm not sure continuing to send manned missions to Earth orbit is worth the money, but the race to the Moon provided a lot of tangible (technology) and intangible benefits. It would be nice if NASA lasts long enough for a change in administration that might look a little more favorably on the US space program.

    Regardless, it's going to take a drastic change to generate the enthusiasm necessary to start sending humans to other planets. In the 60's, we had the cold war. I'm not sure what would stir us to make a real effort now. Who knows. Maybe the Chinese will do it - they have a thing or two to prove to the rest of the world.
     
  15. Jul 29, 2004 #14

    turbo

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    For an idea where our government's current administration is headed with space exploration, manned space travel, and interstellar probes, please go to this site:

    http://www.grc.nasa.gov/WWW/bpp/

    It is the Breakthrough Propulsion Physics project. A breakthough in propulsion is absolutely essential if we are to send people to outer planets or send probes to nearby stars. NASA funded this project until 1992 and then withdrew the funding. Our president paid lip service to manned space travel while failing to support the only NASA program that could conceivably make it practical. Of course, the BPP are studying how to provide propulsion for space vehicles without fuels, which wouldn't benefit Halliburton, Texaco, etc. If they were studying how to fuel space probes with petrochemicals, they might still have funding.

    There are so many great links on the BPP site that it's hard to decide which one to visit next.

    For those unaware of the enormous energy requirements for space travel, PLEASE visit this site that I linked above:

    http://www.grc.nasa.gov/WWW/PAO/html/warp/scales.htm

    Then visit this linked demonstration of the relative fuel masses needed to fuel space vehicles powered by chemical rocket engines and three proposed (imagined, actually) more efficient engine types. The numbers will stagger you. Did you know that using chemical engines (our current technology) there is not enough mass in the entire universe to fuel the rocket engines to send a small probe to Proxima Centauri (ONE WAY ONLY) and arrive there in 900 years?

    http://www.grc.nasa.gov/WWW/PAO/images/warp/warp06.gif

    Maybe if we hadn't invaded Iraq and we instead collectively agreed to go in debt to the amount required by that war, we could consider putting a small, largely symbolic manned station on the Moon. Instead of the Moon silliness, I'd rather adequately fund the people studying propulsion physics and then spend the remainder toward other goals, such as universal health care coverage or affordable higher education for our citizens.
     
    Last edited: Jul 30, 2004
  16. Jul 31, 2004 #15

    turbo

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    Fuel a problem even for small Mecury probe

    I lifted this from the LA Times. It is from a story about the Mercury probe that is scheduled to launch tomorrow. As you can see, this probe (using chemical rocket engines) was unfeasible until someone devised a complicated route that uses SIX planetary fly-bys for braking and even so, over half the weight of the probe consists of fuel for the final braking into Mercury orbit.

    "The biggest challenge is achieving a stable orbit around Mercury. In the 1970s, Mariner engineers thought it was impossible.

    The spacecraft, they thought, would fall in toward the sun much too quickly to be caught in Mercury's small gravity. At the time, there was no way for a spacecraft to carry enough fuel to brake sufficiently.

    A Mercury orbiter became feasible in the 1980s when Chen-Wan Yen of the Jet Propulsion Laboratory in Pasadena discovered a complex flight path that uses gravity from three planets to slow the spacecraft down, passing by Earth once, Venus twice and Mercury three times.

    Even so, more than half of Messenger's weight is fuel — almost all for the final entry into orbit, when the craft must slow down by more than 5,000 mph. It will settle into an elongated oval orbit, passing as close as 124 miles over the surface, and as far away as 9,400 miles."
     
  17. Aug 11, 2004 #16

    pervect

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    I think that the money for the "Mars initiative" would be slashed from useful Nasa projects, divirted to political friends, with no real expectation that the noble-seeming but far out goals would actually be accomplished. Basically, the money would quietly dissappear.
     
  18. Aug 11, 2004 #17

    Chronos

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    Blind ambition is... er, very nearsighted.
     
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