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Space Transportation Science

Electric Rockets Set To Transform Space Flight 114

Posted by Soulskill
from the flying-to-the-future-at-full-impulse dept.
An anonymous reader sends this quote from an article at Txchnologist: "The spectacle of a booster rocket lifting off a launch pad atop a mass of brilliant flames and billowing smoke is an iconic image of the Space Age. Such powerful chemical rockets are needed to break the bonds of Earth's gravity and send spacecraft into orbit. But once a vehicle has progressed beyond low-earth orbit chemical rockets are not necessarily the best way to get around outer space. That's because chemical propulsion systems require such large quantities of fuel to generate high speeds, there is little room for payload. As a result rocket scientists are increasingly turning to electric rockets, which accelerate propellants out the back end using solar-powered electromagnetic fields rather than chemical reactions. The electric rockets use so much less propellant that the entire spacecraft can be much more compact, which enables them to scale down the original launch boosters."
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Electric Rockets Set To Transform Space Flight

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  • Ahh, the future (Score:5, Interesting)

    by squidflakes (905524) on Tuesday February 21, 2012 @04:55PM (#39115997) Homepage

    The best part about living where I live is that they are building VASMIR engines down the street. It would be a long walk, but I could still walk to a freaking starship drive factory.

  • by wisebabo (638845) on Tuesday February 21, 2012 @05:12PM (#39116261) Journal

    I've actually been following ion powered (and all space flight) for a long time now and have wondered that ever since Deep Space 1 (no, not a TV series) "proved" the technology worked (that was one of its main jobs, it was a technology demonstrator) they didn't use ion engines on the space craft that used RTGs.

    In particular New Horizons has travelled billions of miles coasting to Pluto, 99% of the time in hibernation despite the fact that its plutonium powered RTG is generating electricity whether used or not (it's not a reactor, it is always "on"). Considering the distance it has to travel, an ion drive could've really sped things up (or conversely allowed it to brake, and orbit Pluto!). Cassini might not have been such a good choice because maybe having the drive on doesn't allow good scientific observations (Cassini doesn't have its instruments on a scan tilt platform) and anyway the many delta - V changes might have required more thrust than the very weak ion drives can provide.

    Actually, maybe ANY probe headed further than the moon or mars would find this useful. Juno, the Jupiter orbiter had huge solar panels which, during the cruise phase could have powered a decent ion engine. Messenger, the Mercury orbiter, although not going "far", had a huge delta-V requirement and had access to plenty of solar power.

    Oh well, at least more and more probes like DAWN use this. I would presume when we return to the outer planets with any really ambitious probes (Europa lander/sub, Titan balloon/boat) they'll use this.

    Someday, when we talk about sample return missions and the delta-V requirements at least double (and the fuel requirements go up geoemetrically!), ion drives (or their derivatives like the Vasimir drive) will be essential.

  • by Spy Handler (822350) on Tuesday February 21, 2012 @05:37PM (#39116601) Homepage Journal

    I guess what I'm saying is he isn't a crank.

    Actually, according to Rob Zubrin of Mars Society, he is one. The technology itself isn't a crank, it's real, but his claims (going to Mars in 39 days) and the big bucks he's soliciting are quite cranky.

    To do what he's claiming, you would need to hook up the VASIMIR to a huge nuclear reactor. How do you get that reactor into orbit? You can't, not without a Nova type rocket bigger than a Saturn V. But if you had such a rocket, you could just blast off to Mars the old-fashioned way.

    His other proposal is coupling a fusion reactor (which should be lighter than an equivalent fission one) to the VASIMIR. Well as we all know, fusion is always 20 years in the future.

  • by WindBourne (631190) on Tuesday February 21, 2012 @05:54PM (#39116821) Journal
    Getting the reactor into space is NOT a big deal. The issue with VASIMR is that you need LOADS of electricity. As such, it would weigh so much that VASIMR would not be able to push it around. And that is a reactor without ANY shielding. The issue is that the radiator to dump heat would weigh a great deal.

    It is far more likely that we will send a team on a one-way mission to Mars and keep them there for 10-20 years, while we re-develop NERVA. NERVA makes far more sense for moving around the solar system then does a VASIMR/fission reactors.

    I will say that VASIMR will make great sense once we do fusion that generates electricity directly (IOW, beta- emissions only).
  • by tp1024 (2409684) on Tuesday February 21, 2012 @07:52PM (#39118161)
    Nope, just getting there. Think of it as a beeping monument in the sky.

    A beeping monument with telescopes. The main justification would need to be astrometry, which you could do a hell of a lot better if you had a good telescope several hundred or thousand AU away from earth. Currently, we're doing all our triangulation with a 2AU long base (twice the distance earth-sun). Using the same 29cm telescope as Hipparcos [wikipedia.org], we could easily get 1000 times more accurate ranging data within mere decades.

    It would be a revolution. True trigonometric measurements all the way to the other end of the galaxy, even the nearest neighboring galaxies, instead of the current guesswork based on guessing how bright a certain star is and thus how far it would need to be away in order to appear as bright as it does.

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