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NASA Transportation Technology

NASA's NEXT Ion Thruster Runs Five and a Half Years Nonstop To Set New Record 184

Posted by timothy
from the slow-and-steady-and-breathe-and-good dept.
cylonlover writes "Last December, NASA's Evolutionary Xenon Thruster (NEXT) passed 43,000 hours of operation. But the advanced ion propulsion engine wasn't finished. On Monday, NASA announced that it has now operated for 48,000 hours, or five and a half years, setting a record for the longest test duration of any type of space propulsion system that will be hard to beat."
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NASA's NEXT Ion Thruster Runs Five and a Half Years Nonstop To Set New Record

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  • by Gothmolly (148874) on Thursday June 27, 2013 @09:06AM (#44121125)

    Running your engines at full power but standing in one spot for 5 years. That pretty much sums up our space program since Apollo.

    • by h4rr4r (612664) on Thursday June 27, 2013 @09:27AM (#44121251)

      So then those rovers on Mars are figments of my imagination?

      Our space program since Apollo has gotten better. Unless you think their is some scientific value in sending humans to play golf on other worlds.

      • by Penguinisto (415985) on Thursday June 27, 2013 @10:00AM (#44121541) Journal

        Our space program since Apollo has gotten better. Unless you think their is some scientific value in sending humans to play golf on other worlds.

        Laugh and minimize all you want, but the one geologist to land on the Moon [wikipedia.org] managed to learn more (and faster) in his one short trip than all of the Mars rovers combined. Why, you ask? Because he didn't have to waste time looking at a picture and speculating on what a shadow or shape looked like it could be. Instead, he just walked up to an item of interest, looked at it, and was able to discern in seconds something that, well, takes teams of scientists weeks on end to speculate over nowadays.

        ...then there's that niggling fact that someday, space may be the only habitable home we have left after this one gets wrecked - be it by us or by the first asteroid that decides not to simply pass by. It would be nice to already have the tech to live there - preferably long before we're forced to learn it on a tight schedule.

        • by h4rr4r (612664)

          I am not laughing nor minimizing. Scientists are not stuck with pictures, but tools not even available during the Apollo era are on those rovers to sample rocks.

          I agree, but we simply will not bother until we are forced. We can't even get people to update coal power plants, you can forget them wanting to spend a dime on this.

          • by Dyolf Knip (165446) on Thursday June 27, 2013 @10:48AM (#44121975) Homepage

            Not really. The tools are impressive, but mostly in how they try to overcome the crippling need to run remotely from umpteen million miles away.

            Let's have a look: http://en.wikipedia.org/wiki/Curiosity_(rover)#Instruments [wikipedia.org]

            Lists 14 instruments. But 5 of them are just cameras, strategically placed because they can't be moved. My friend the amateur photographer could do much better with her DSLR. The "environmental monitoring station" measures humidity, pressure, temperatures, wind speeds, and ultraviolet radiation; not exactly groundbreaking stuff here. Same with radiation assessment. There's a robotic arm capable of drilling holes a whopping 2" deep and a dust removal tool, commonly known as a 'broom'. The "Dynamic Albedo of Neutrons" sounds sexy as hell, but then you realize a person with a trowel could do the same job.

            The other instruments are all spectrometers and a chromatograph. The means by which they work are novel, due to the aforementioned remote requirements, but the end result is not really different from what could be done in any decent lab 50 years ago. Honestly, a decent scientist with a shovel and a few thousand dollars in high school lab gear could do better than all the rovers ever sent. God help us if we ever needed a probe to do something _really_ difficult.

            So by all means, send what probes are needed to figure out how to get people there, but anything beyond that will just provide minimal information at enormous cost.

            • Re: (Score:2, Insightful)

              by Anonymous Coward

              My friend the amateur photographer could do much better with her DSLR.

              Can your friend do better while fitting in a small box without life support? If we took the budget, both in terms of costs, volume, and amount of equipment needed to send a person there, that could buy a lot of cameras, and ones that could move around just as much as your friend could move them around.

              The "Dynamic Albedo of Neutrons" sounds sexy as hell, but then you realize a person with a trowel could do the same job.

              Not quite the same as a person with a trowel, considering neutron sources get used for analysis by geologists on Earth even where there are plenty of trowels. Even if you had a person on Mars, with a trowel

            • by Shavano (2541114)

              ...The means by which they work are novel, due to the aforementioned remote requirements, but the end result is not really different from what could be done in any decent lab 50 years ago. Honestly, a decent scientist with a shovel and a few thousand dollars in high school lab gear could do better than all the rovers ever sent. God help us if we ever needed a probe to do something _really_ difficult.

              So by all means, send what probes are needed to figure out how to get people there, but anything beyond that will just provide minimal information at enormous cost.

              But the cost of sending a person there dwarfs the mission cost and there would be a much greater chance of total mission failure because of the complexity of the life support systems.

          • Its more the long turn around time between observations, new instruments and different observations.

        • by Rhipf (525263)

          Actually the geologist learned more than the Mars rovers combined since the rovers didn't land on the moon. Its hard to learn more about the moon than a live person when you are millions of miles away.

        • by kamapuaa (555446)

          The guy who went to the moon and didn't find any evidence of water? And now is dedicating himself to disproving the idea of global warming? I'd rather have robots.

          Not totally fair to say he couldn't find water, but Opportunity found it, while the geologist couldn't.

          • by Sperbels (1008585)
            Far easier to find evidence of water on a surface that actually had flowing water on it at one point. Mars did, but the moon didn't. Your argument is idiotic, and hopefully you can see the ridiculous logic (or lack thereof) you just attempted to apply.
            • by kamapuaa (555446)

              If the geologist was far better than a robot, how come the geologist didn't learn the most basic geological facts?

              • by Sperbels (1008585)

                If the geologist was far better than a robot, how come the geologist didn't learn the most basic geological facts?

                He did. He learned there was no evidence for flowing water on that part of the moon...because there was never flowing water on the moon. Seriously? Are you trolling or do really not understand this?

            • by Bengie (1121981)
              He wasn't talking about Mars, but the moon. His argument stands.
              • by Sperbels (1008585) on Thursday June 27, 2013 @02:05PM (#44124281)

                He wasn't talking about Mars, but the moon. His argument stands.

                No, he was walking about Mars. Quote: Not totally fair to say he couldn't find water, but Opportunity found it, while the geologist couldn't. Opportunity is a Mars rover. The geologist in question is Harrison Schmitt who went to the moon. He wasn't even looking for water...not that they put him in a place likely to have it. He was simply there to use his expert geologist eyes to find something geologically interesting, otherwise they would have just had one of their pilot astronauts grab some rocks. These aren't even comparable things. But I'm sure if you placed a geologist in the same spot Opportunity was, he could have found evidence for water in 30 minutes or less and spotted several other interesting things as well. Robots aren't adaptable to other kinds of missions. They do what they're designed for. A human can accomplish a multitude of things, adapt, and apply new knowledge on the spot. Yeah, robots cost a fraction of what it would take to put a human up there, a human can also accomplish far far more. But to argue that humans can't do more than a robot like the GP implied, is totally absurd.

        • by Anonymous Coward on Thursday June 27, 2013 @10:59AM (#44122067)

          ...then there's that niggling fact that someday, space may be the only habitable home we have left after this one gets wrecked

          Don't take offense, because I'm sure you're thinking this because you've been told so many times that this would be the case, but why is there the common belief that mankind would find a complete vacuum, devoid of ANY resources other than photons, be more suitable for our life than the Earth would be in any state of pollutive decay?

          If we can build capsules for space, why not do the same thing here and protect ourselves from the elements? We can use space suits to travel around the exterior here, too, extracting useful resources from the fetid scum we created, and if we can shield ourselves from cosmic radiation, why wouldn't we be able to shield ourselves from any possible post-nuclear-holocaust radiation?

          I'm certainly not suggesting that NASA is a waste of money - I am an aerospace engineer, after all - I'm just saying that if your house became infested with termites, you wouldn't resign yourself to abandoning it and living on a houseboat in the middle of the ocean because there are no termites in the middle of the ocean.

          • devoid of ANY resources other than photons, be more suitable for our life than the Earth would be in any state of pollutive decay?

            Those photons are quite a resource in their own right. But there is also every element you can find on earth floating around in ridiculous abundance, and easier to access too.

            As to why, well there aren't many reasons to choose a station over earth, but there are plenty of reasons to choose a station over anywhere else. We would have perfect control over the gravity in a station for a start, which neatly sidesteps a whole host of problems with either bone decalcification or excessive gravity, not to mention

            • But there is also every element you can find on earth floating around in ridiculous abundance, and easier to access too

              I appreciate a good sci fi yarn as much as the next guy, but do try to keep in mind the "fiction" aspect of it. In fact, the overwhelmingly defining characteristic of space would be the tremendous amount of emptiness that it is comprised of. The vast distances just within our own solar system immediately decry the abundance and easy access to useful resources. That will hold true at least until you solve the problem of cheap and efficient energy. I would argue that when you have solved that problem, yo

              • And if it were cheaper and easier to construct a metal alloy machine using sophisticated internal combustion mechanics after extracting the fuel from suboceanic deposits and refining the stuff before transporting it around the globe in huge container ships, more of these vehicles, and finally pumping it back into the ground from whence it gets pumped up again, we'd do that rather than riding horses everywhere.

                • Interesting argument. What does it cost to feed and maintain a horse? What is the maximum speed and range of a horse? Can a horse power air travel? The energy cost efficiency of internal combustion is pretty hard to beat with today's technology.

                  That undersea oil was there 100 years ago, but there was more readily available oil that was easier and cheaper to get to so we didn't have a motivation to go after the harder stuff. Technology also improved to enable us to go after the harder to retrieve resour

                  • Interesting argument. What does it cost to feed and maintain a horse? What is the maximum speed and range of a horse? Can a horse power air travel? The energy cost efficiency of internal combustion is pretty hard to beat with today's technology.

                    The advantage of asteroid resource exploitation and indeed deep space manufacturing is that it can be scaled up arbitrarily, not terribly dissimilar to the speeds and economies achievable with internal combustion engines. There are no effective limits to how big we can make things and how much we can do up there, an advantage that terrestrial manufacturing does not share, if for no other reason than we'd have to turn the planet into a slag heap to approach a similar result.

                    That undersea oil was there 100 years ago, but there was more readily available oil that was easier and cheaper to get to so we didn't have a motivation to go after the harder stuff. Technology also improved to enable us to go after the harder to retrieve resources.

                    We've been approaching peak oil for twenty years now. What is the forecast for hitting peak iron or peak nickel?

                    Did we hit peak speed or peak fodd

          • by RoboRay (735839)
            Well, first you have to survive whatever event renders the Earth uninhabitable without life-support systems. And you're not going to have them available to save you from catastrophe if you don't already need them for some other reason.

            The dinosaurs are extinct simply because they didn't have a space program.

            Not to mention, there's an awful lot more resources available in space than just vacuum and photons.
          • If we can build capsules for space, why not do the same thing here ...

            You make good points for cases where the Earth in general becomes less/un-inhabitable - for whatever reason - but not for large asteroid strikes, gamma-ray bursts and eventual Sun death. Yes, those are very rare or far off in the future, but the long-term survival of those types of events requires us living somewhere else.

            Hopefully, we'll evolve into a less stupid, petty, short-sighted, self-destructive species by the time we need to deal with those kind of things.

          • by khallow (566160)

            but why is there the common belief that mankind would find a complete vacuum, devoid of ANY resources other than photons, be more suitable for our life than the Earth would be in any state of pollutive decay?

            Well, one can look at what's actually out there. When you do, you will find that it's not a complete vacuum devoid of any resources other than photons.

        • , space may be the only habitable home we have left after this one gets wrecked

          The least hospitable places on earth are still far more hospitable than pretty much the safest places within traveling distance.

          It's a lot easier to clean up earth than to terraform or colonize a planet. Even if we nuked the living snot out of this planet it would still be lower radiation than the trip to Mars or the Moon. It's easier to filter out viruses than it is to create oxygen. It's easier to dive deep under the ocean to escape a catastrophic tsunami or asteroid impact than to fly to another pl

        • Laugh and minimize all you want, but the one geologist to land on the Moon [wikipedia.org] managed to learn more (and faster) in his one short trip than all of the Mars rovers combined.

          Well, I think you may be comparing apples and oranges (Moon vs. Mars), but your point is valid. We learned more and we learned it faster with the Apollo missions than the Soviet Union did with their plethora of lunar probes, rovers, and sample retrieval missions.

          The question becomes, is it worth the money to learn more faster?

          Imagine you're getting ready to enter college. You can pay, say, $400,000 and spend four years of your life attending college to gain knowledge. Or, with my handy-dandy memory devic

          • by tibit (1762298)

            If we humans go to Mars, it'll be very, very hard not to seed the environment with life. Of course said life might take very long to flourish, but contamination of Martian surface is a real problem for human visitors.

    • by fuzzyfuzzyfungus (1223518) on Thursday June 27, 2013 @09:28AM (#44121259) Journal

      Would it be insufferably pedantic to mention Pioneer 10/11, Explorer 49, Mariner 10, Helios A/B(with Germany), Viking 1 and 2, Voyager 1 and 2, Pioneer Venus 1 and 2, ISEE-3(with EU), Magellan, Galileo, Hubble(with EU), Ulysses(with EU), Mars Observer, Clementine, WIND, NEAR Shoemaker, Mars Global Surveyor, Mars Pathfinder, ACE, Cassini-Huygens(with EU), Lunar Prospector, DS1, Stardust, Mars Odyssey, Genesis, Mars Exploration Rovers, MESSENGER, Deep Impact, Mars Reconnaissance Orbiter, New Horizons(in transit), STEREO, Pheonix, Dawn, Lunar Reconnaisance Orbiter, Solar Dynamics Observatory, Juno, GRAIL, Mars Science Laboratory, and Radiation Belt Storm Probes?

      Sure, our man-in-a-can cred isn't what it used to be; but I, for one, welcome our robotic overlords.

    • Re: (Score:2, Flamebait)

      by cdrudge (68377)

      The problem is that the thruster only produces 236 mN of thrust. NASA's bureaucracy coupled with the infinitely massive boat anchor called the US government has created an object so huge that 236 mN over 5.5 years has only moved it an imperceptible distance.

  • by abies (607076) on Thursday June 27, 2013 @09:09AM (#44121149)

    I wonder if they had felt a specific impulse to switch it off?

  • by jellomizer (103300) on Thursday June 27, 2013 @09:21AM (#44121217)

    My Hope if we could build a space craft that can accelerate 9.8m/s^2 (1g) for the duration of going to Mars and Back. You go to at 1g half way to mars, then you decelerate at 1g the other half. Orbit for a period of time. Drop down a landing party for a while. And go back at 1g half way decelerate at 1g the other half. Then you would have a good long range mission with out the 0g effect messing up the body.

    • Not to mention that at 1g it wouldn't take long to get to speed of light :-)

      • by Overzeetop (214511) on Thursday June 27, 2013 @10:17AM (#44121655) Journal

        Without relativistic effects about a year but, as noted by the sibling poster, relativity gets in the way from the outside observers point of view. And what good is next day delivery if the goods are 1 day old and the recipient's great, great, great, great, great granddaughter has to sign for the package?

        Though practically impossible with current or proposed technology, it would, indeed, take only 35 days to reach 0.1c, and we'd be 225 million km from our starting point, ignoring gravitational effects of other bodies. Though in astronomical terms that's not very far (less than the diameter of Earth's orbit) - less than half way to Jupiter on the closest possible approach.

        • by MBGMorden (803437)

          Without relativistic effects about a year but, as noted by the sibling poster, relativity gets in the way from the outside observers point of view. And what good is next day delivery if the goods are 1 day old and the recipient's great, great, great, great, great granddaughter has to sign for the package?

          As a method of delivery its worthless, but as a method of colonization its pretty neat. If by some stretch of the imagination we could identify a planet as definitely habitable from here we send off a crew at some significant fraction of the speed of light. I'm sure the people actually travelling there care a lot more about the passage of time than those of us back on Earth (they'd have to be specially selected with the idea that everyone back on Earth that they knew would be dead by the time they arrived

          • Ideally if we could work out communications via quantum entanglement they could have take a quantum entangled particle with them to make communications faster back to Earth. Perhaps even build some sort of router to hook the computer LAN on that side back to the internet on this side. Probably would be low-bandwidth but latency would be tolerable.

            Wrong. Classical (i.e. useful) communication via quantum entanglement cannot exceed the classical speed limit. See the no-cloning [wikipedia.org] and the no-broadcast [wikipedia.org] theorem (or

          • they'd have to be specially selected with the idea that everyone back on Earth that they knew would be dead by the time they arrived

            Heck, I'd go with understanding that just certain people would be dead back on Earth... :-)

          • by khallow (566160)

            they'd have to be specially selected

            As an aside, "special selection" probably doesn't have to be all that special. The prime criteria in your example probably would be that the person is willing to go and isn't too unhealthy.

        • by sjames (1099)

          So it takes about a year to get up to (oh, lets say 0.75c) and the same to decelerate. That puts a robotic mission to the closest stars on the table.

        • by khallow (566160)

          And what good is next day delivery if the goods are 1 day old and the recipient's great, great, great, great, great granddaughter has to sign for the package?

          If you're the one signing for the package, it's not exciting. If you're the goods, it is. As MBGMorden noted, this would be remarkable transportation for colonization efforts.

    • by Overzeetop (214511) on Thursday June 27, 2013 @10:09AM (#44121607) Journal

      1G of thrust would require, as you mentioned, almost 10m/s2 of acceleration, or your mass x 10 in Newtons.

      NEXT produces 236 mN of thrust at 7kW of power

      A typical terrestrial nuclear power plant will produce about 1 GW of power, or enough to power 143,000 of these engines. That would result in 33,700 Newtons of thrust, able to accelerate a spacecraft at 1G weighing 3433kg.

      To put that into perspective, those (143,000) engines would burn 2860kg/hr in fuel alone.

      • by iggymanz (596061)

        to put in perspective for some here, that's not quite 0.05 pounds of thrust. Not quite quite in the range of pushing a viable starship (let's estimate with mass of say a "boomer" submarine) to anywhere in the solar system, let alone the stars

    • Even a level of trust that can help a satellite/ship leave an asteroid would be useful.

      After that, a level of trust that can make a ship escape the gravity of the moon would be very useful.

    • by MrChips (29877)
      At 1g accel/decel you could get to Mars in about 24 hours. At 1/3g it would be about 48 hours. And for those who want to approach the speed of light, that would take a year at 1g.
    • If that were true it would only take one day to reach a speed of 1.9 million miles/hour. Pretty sure that's not happening.
    • You could get a 1g acceleration on the astronauts just by spinning the craft at the appropriate speed. That also gives you a nice gradient between 1g living spaces and 0g work spaces.
    • Then you would have a good long range mission with out the 0g effect messing up the body.

      Or you can just spin the spacecraft and save all that fuel.

  • Fools! (Score:5, Funny)

    by Anonymous Coward on Thursday June 27, 2013 @09:21AM (#44121225)

    Running that engine for 5 years attached to the planet already caused a diversion of 0.01 on the orbit we have around the sun! That's why the sudden global warming! Tin foil ionic hat

    • Nope. They pointed it straight up, meaning all that happened was the desk now has a dent 1x10^-9m deep where the bracket was, and someone on the floor above got a slightly warm bum.
    • by wvmarle (1070040)

      I'm sure they every now and then turn the engine around to compensate for this effect.

  • by Rob Riggs (6418) on Thursday June 27, 2013 @09:34AM (#44121313) Homepage Journal
    If you had one of these on a spacecraft like Voyager with 1000kg of fuel running for 50,000 hours, what does that acceleration translate to in terms of velocity, assuming an initial velocity after launch of something like 40,000km/h?
    • Well, NEXT produces 236 milliNewtons of thrust, according to this article: http://www.newscientist.com/article/dn12709-nextgeneration-ion-engine-sets-new-thrust-record.html#.UcxBsfmcf4o [newscientist.com]

      NEXT + nuclear reactor ~ 5000kg* (wag)
      Fuel 1000kg
      Voyager = 722kg

      If we take our mass as an average to simplify the math, and ignore relativity (which I'm betting we can),
      6222kg avg mass at 0.236N is 4.22x10-5 m/s2 acceleration. And for 50,000hx3600s/h = 7600 m/s delta V
      So in 6 years, we will have accelerated from 11,100 m/s to

    • by JTsyo (1338447) on Thursday June 27, 2013 @10:18AM (#44121667) Journal
      F=ma
      .236 N = 1000 kg * a
      a = .000236 m/s^2

      V=V0+a*t
      V=(40,000 km/h)/(3600 sec/hr) + (.000236 m/s^2)*(50000 hours *3600 sec/hr)
      V=53,591 m/s => 192928 km/hr =>0.00018 c
  • So, if they had launched it into space, how fast would it be going after all this time? And would it still be receiving enough energy from the sun to maintain that level of thrust?
  • All we need is two of those engines, a spherical cockpit, and two large solar panels attached to each side.

  • it's time for NASA to admit they locked the keys inside the thing, swallow their pride, and call AAA
  • Seriously, we should put this on a small unit with solar cells and then attach this to the ISS. Better to put this to use, than having it sit there.
    • by symbolset (646467) *
      That is what they are doing, but only with the 200kW model. WIKI VASIMIR.
      • The VASIMIR will not be ready for a couple of years. Worse, because it is so inefficient compared to this. This is a small 7KW system. A couple of solar panels would cover the amount of energy. Note that the efficiency of this unit is over 70%, while the efficiency of the VASIMR is about 60%.
        • by symbolset (646467) *

          We can do the energy input with free-electron laser to 500kW or so, and multiple lasers and targets can of course multiply that. That's not a problem. VASIMIR uses Argon rather than Xenon. Argon is more common and Xenon is quite rare. The difference in efficiency is appropriate for the difference in availability of reaction mass. Ideally Hydrogen would be best as that's the commonest material in space, and VASIMIR works on hydrogen but less efficiently.

          VASIMIR is scheduled for test on the ISS in 2015.

  • Yeah, Thomas Gold was right.

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