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New Engine Raises Possibility of Cheap Travel To the Moon

Posted by timothy on from the how-many-altarian-dollars-though dept.

shreshtha writes with this intriguing bit from The Daily Mail: "A tiny satellite thruster which can journey to the Moon on just a tenth of a litre of fuel could usher in a new low-cost space age, its creators hope. The mini-motor weights just a few hundred grams and runs on an ionic chemical compound, using electricity to expel ions and generate thrust. The tiny motor isn't built to blast satellites into orbit — instead, it's to help spacecraft manouevre once they're in space, which previously required bulky, expensive engines."

5 of 100 comments (clear)

  1. Someone's reinvented the ion engine by Scareduck · · Score: 3, Interesting

    If this were news for nerds, maybe someone would have researched this before posting?

    Forget it, Jake. It's Slashdot.

    --

    Dog is my co-pilot.

    1. Re:Someone's reinvented the ion engine by wisnoskij · · Score: 4, Interesting

      I do not think that the news is that they reinvented it, and seriously everyone on /. knows of the about ion-engines so there is little point in even mentioning it. But that here is a practical use of that engine that works better then anything else we are currently using.

      --
      Troll is not a replacement for I disagree.
  2. The expensive part by gmuslera · · Score: 4, Interesting

    is launching to space from earth/moon surface. Traveling once there, and landing (at least in earth) could be relatively inexpensive. But once the space elevator, space fountain or other approaches are built and gives us relatively cheap ways to reach space, this kind of approachs could make a difference.

  3. Re:How is this new? by queazocotal · · Score: 3, Interesting

    Well over a decade.

    The fundamental problem with ion thrusters (as a general class) is that you trade power use for fuel use.

    Yes, they may use lots less fuel.
    http://en.wikipedia.org/wiki/Specific_impulse#Examples - for example.

    An advanced ion thruster may use nearly 1/50th of the fuel of a conventional rocket engine.
    But, it needs 50 times the power to do this.

    So, to replace a conventional rocket engine burning a kilo of fuel a second, and producing a thrust of perhaps 500kg, with no electrical requirements, you need about 20 grams of fuel a second, and around 450 megawatts of power.

    Needless to say - for many applications, the power plant ends up heavier than the engine it's replacing.

    It only works in very low thrust applications.

    The low thrust also brings other problems.
    For example, around the earth is a belt of charged particles.
    Ascending through these on conventional rockets is not a problem. You do it so rapidly.

    With ion engines, you need to slowly spiral out (due to being power limited), and your whole craft gets highly irradiated.

  4. Re:Sweet! by tommasorepetti · · Score: 5, Interesting

    https://en.wikipedia.org/wiki/Deep_Space_1 This is not exactly new... at all. NASA's ion engines have been in service for several years now. Also a tenth liter of fuel is also willfully misleading: the engines expell a liter of propellant but that is not fuel. It is just the expelled material whose momentum generates the forward thrust.