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  1. Subscriber scoop122
    scoop122
    27 Oct '09 22:59
    apparently the technology has taken a big leap recently and they are now proposing we could send a flight to mars in 39 days using an ion propulsion engine.
    This seems to be a practical realistic application as opposed to what seem some purely theoretical concepts e.g. worm hole travel
    i am interested in the cobncept of interstellar travel... anything to get away from liverpool !... but wondered if anyone know of any other current research or had any thoguhts on it
    i have read a bit on solar sails and Bussard Ramjets and find it a fascinating subject.
    is it possible ? and when ?
  2. Standard member joneschr
    Some guy
    27 Oct '09 23:36
    Can you provide a reference on this 39 day transit to mars with improvements in ion engines? I'm curious.

    I just read about plans to use the VASIMR ion engine to get from low earth to lunar orbit with a month long transit time.

    So, if it takes a month to get to the moon, I's hard to see how we get to mars in the same amount of time. I'm curious what developments you're citing.

    And even still, that's inter-planetary, not inter-stellar. Getting to another star is something else entirely.
  3. Subscriber AThousandYoung
    Do ya think?
    29 Oct '09 00:43
    We could do it now if we really wanted. Put people in hibernation -or- create a ship where generations can live and die without ever leaving. It would take forever and a day though.
  4. Standard member joneschr
    Some guy
    29 Oct '09 01:13
    We can put people in hibernation? I mean, I know there was that crazy case of the lady in (norway?) that fell in frozen water and managed to be revived a few hours later. But that's a little different than putting people to sleep for decades and then waking them up by machines.
  5. Subscriber coquette
    Already mated
    29 Oct '09 05:10
    Originally posted by joneschr
    We can put people in hibernation? I mean, I know there was that crazy case of the lady in (norway?) that fell in frozen water and managed to be revived a few hours later. But that's a little different than putting people to sleep for decades and then waking them up by machines.
    No, it's the same.
  6. Standard member joneschr
    Some guy
    29 Oct '09 05:18
    Are you volunteering?
  7. 29 Oct '09 08:31
    Originally posted by coquette
    No, it's the same.
    It's not the same.
    She was lucky, that's all. If she was found an hour later, it would be *it* for her.
    Here we're talking about decades.
  8. Subscriber AThousandYoung
    Do ya think?
    29 Oct '09 09:36
    Originally posted by joneschr
    We can put people in hibernation? I mean, I know there was that crazy case of the lady in (norway?) that fell in frozen water and managed to be revived a few hours later. But that's a little different than putting people to sleep for decades and then waking them up by machines.
    Not quite. But we could do a generation ship, and we're very close to a hibernation ship. They've ressurected dead dogs using hibernation technology and hibernated pigs too.
  9. Standard member joneschr
    Some guy
    29 Oct '09 16:31 / 2 edits
    Originally posted by AThousandYoung
    Not quite. But we could do a generation ship, and we're very close to a hibernation ship. They've ressurected dead dogs using hibernation technology and hibernated pigs too.
    At a 90% success rate with brain damage in the surviving test subjects.

    Agreed though, it seems like there's potential in the technology -- it just needs some time and effort to perfect it.

    And of course, there's the question of what we do when we get there. It's not like there's going to be an exact copy of earth lying in every solar system.

    My point in arguing it wasn't to say it's not feasible, but more that we're not there yet.
  10. Subscriber scoop122
    scoop122
    29 Oct '09 18:03
    Originally posted by joneschr
    Can you provide a reference on this 39 day transit to mars with improvements in ion engines? I'm curious.

    I just read about plans to use the VASIMR ion engine to get from low earth to lunar orbit with a month long transit time.

    So, if it takes a month to get to the moon, I's hard to see how we get to mars in the same amount of time. I'm curious wha ...[text shortened]... 's inter-planetary, not inter-stellar. Getting to another star is something else entirely.
    it was a recent newspaper headline about a Canadian Astronaut quoting that they were developing an ion propulsion engine. if you read the article the 39 days claim is a bit vague but they seemed to be saying it was a new approach and could ' theoretically' get to Mars in 39 daysHOME
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    Round Trip to Mars: 39 Days or Less [NASA Ion Propulsion Rocket Engine Sends You to Mars and Back in Over a Month; Special Fees May Apply]
    Posted by Chris Smith on October 20th 2009 | Respond?


    Are you still dreaming about going to Mars one day? Well I can’t promise that you’re actually going to make it as an astronaut but I still have some good news for you. It looks like travelling to Mars is a lot easier nowadays thanks to a new Ion propulsion rocket engine.

    Regular trips to Mars take up to two years with current technology with the crew having to wait a full year before the planets realign for a safe return. Well in all honesty, no man or woman has ever gone to Mars although we did send probes and various missions in the past.

    Now we find out that in the near future we will be able to go to Mars and back in just 39 days. That would be an impressive achievement for mankind but we shouldn’t expect to see man on Mars in the very near future.

    The new Ion propulsion engine has been designed mainly by Canada although it was an international effort as more countries were involved in the project. The engine uses electrical power which could be obtained directly from the Sun and then transformed into thrust. The engine would work non-stop half-way to Mars and it will decelerate the other half. And that’s how you go to Mars in a 39-day period.

    All this sounds great in theory but conclusive testing will have to prove that the engine can run for 39 days straight without any problems. The engine will probably be thoroughly tested around the moon so NASA scientists can look at in action in the vacuum of space. The Ion engine could also be used on the space station in order to counteract the current drag which forces astronauts to burn fuel regularly in order to boost their orbit.

    In other words, man’s first trip to Mars will not be possible immediately, let alone public tours of the planet. But by the time we get to tell our grandkids Neil Armstrong stories, Mars missions will probably become a lot more popular and much easier to accomplish.


    Read more: http://nexus404.com/Blog/2009/10/20/round-trip-to-mars-39-days-or-less-nasa-ion-propulsion-rocket-engine-sends-you-to-mars-and-back-in-over-a-month-special-fees-may-apply/#ixzz0UgnTNWmz
    as opposed to about 12 months at present.
  11. Standard member sonhouse
    Fast and Curious
    29 Oct '09 22:19 / 1 edit
    Originally posted by joneschr
    Can you provide a reference on this 39 day transit to mars with improvements in ion engines? I'm curious.

    I just read about plans to use the VASIMR ion engine to get from low earth to lunar orbit with a month long transit time.

    So, if it takes a month to get to the moon, I's hard to see how we get to mars in the same amount of time. I'm curious wha 's inter-planetary, not inter-stellar. Getting to another star is something else entirely.
    Here is one story in New Scientist about the Vasimir Ion rocket:

    http://www.newscientist.com/article/dn17476-ion-engine-could-one-day-power-39day-trips-to-mars.html

    It is technically possible but would entail having either a 200 megawatt nuclear power supply or the same amount of power from solar energy. Andrew Hamilton and I did the calculations on what sort of acceleration it would provide and it turns out to be very low, maybe not even able to be felt by the crew: something like .003 G's. I was surprised an acceleration that low could get you to mars in less than two months!

    The Vasimir is a vast improvement on other ion rocket technologies because it is basically a microwave oven with a rocket nozzle at the output, meaning there is no grids to get in the way of the exhaust like earlier electric propulsion rockets, which had several grids with holes in them and they were charged up with a high voltage which produced some thrust but the accelerated ions eventually wears out the grid and the rocket loses thrust, but the Vasimir has nothing solid in the way of the ions, all controlled by magnetic fields and such and powered by microwave energy to accelerate the ions. It is also a variable thrust engine where you can get more thrust at the expense of specific impulse or less thrust for a much longer time with higher specific impulse.
  12. Standard member sonhouse
    Fast and Curious
    29 Oct '09 22:22 / 1 edit
    Originally posted by AThousandYoung
    We could do it now if we really wanted. Put people in hibernation -or- create a ship where generations can live and die without ever leaving. It would take forever and a day though.
    See 'The book of the Long Sun', by Gene Wolfe, a sci fi story of just such a journey, it's a series with 5 volumes. I thought it was pretty good.
  13. Standard member joneschr
    Some guy
    29 Oct '09 22:48
    Cool

    Who's good with math and can reverse engineer the specifications on that drive?

    Mars and the earth, at their closest, are 54.6 million kilometers away from each other.

    Assuming:
    * you travel round trip in 29 days
    * accelerate constantly
    * Spend half your time on each leg accelerating and half decelerating
    * the planets stay 54.6 million km from each other during those 29 days.

    What rate must you accelerate at?

    Assuming a 100kg spacecraft (more or less Apollo sized), how many N of thrust must be applied?

    Perhaps I should but this on the posers forum
  14. Standard member joneschr
    Some guy
    29 Oct '09 22:52
    Sorry, 39 days, not 29
  15. Standard member sonhouse
    Fast and Curious
    30 Oct '09 03:11 / 2 edits
    Originally posted by joneschr
    Cool

    Who's good with math and can reverse engineer the specifications on that drive?

    Mars and the earth, at their closest, are 54.6 million kilometers away from each other.

    Assuming:
    * you travel round trip in 29 days
    * accelerate constantly
    * Spend half your time on each leg accelerating and half decelerating
    * the planets stay 54.6 ...[text shortened]... zed), how many N of thrust must be applied?

    Perhaps I should but this on the posers forum
    Perhaps you missed my former post about this subject, we calculated that already, it accels at about 0.006 G so assuming a 100Kg craft, the thrust would be about 600 grams. Of course the craft would be a lot larger than that because the thrust needed would have to account for the weight of the entire craft, power supplies and all.

    The formulae are not that complex: from the original, S=(AT^2)/2, solve for A,
    A=2S/T^2, where the units are all the same, miles and feet, miles converted to feet, one G=32ft/sec., or 9.8 meters/second. So you have to account for the fact when you accel at a constant rate, you must accel halfway to your intended endpoint and turn the rocket around and decel the rest of the way. So you have a maximum velocity at the halfway point and minimums at the beginning and end.
    So plugging in 0.006G (using feet and miles) 32 ft/sec^2*0.006=0.192 ft/sec^2 of accel which applied for 19.5 days (half of the 39 day trip) puts you about 51 million miles away from Earth. We are assuming Mars would be about 100 million miles away when we start the journey, so at the halfway point the rocket turns around and decel's at the same rate of 0.192 ft/sec^2 to arrive at Mars with zero relative velocity. Of course it is not exactly that simple but you get the idea.