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

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."

Comments

Perfect analogy for NASA

[Gothmolly]

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

Re:Perfect analogy for NASA

[h4rr4r]

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.

Re:Perfect analogy for NASA

[fuzzyfuzzyfungus]

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:Perfect analogy for NASA

[Anonymous Coward]

It also sums up the fact that space is an enormous deadly vacuum with no real reason to send people there.

Re:Perfect analogy for NASA

[cdrudge]

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.

Re:Perfect analogy for NASA

[Penguinisto]

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 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.

Re:Perfect analogy for NASA

[Penguinisto]

It also sums up the fact that space is an enormous deadly vacuum with no real reason to send people there.

Hate to say it, but we already live in space - this big ball of mud and air that we call home happens to float in it. It'd be nice to get out in the neighborhood a little, no?

Re:Perfect analogy for NASA

[h4rr4r]

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.

Re:Perfect analogy for NASA

[Rhipf]

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.

Re:Perfect analogy for NASA

[Anonymous Coward]

You forgot New Horizons. It's almost to Pluto, we're busy rehearsing the flyby right now.

Re:Perfect analogy for NASA

[Dyolf Knip]

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

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:Perfect analogy for NASA

[kamapuaa]

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.

Re:Perfect analogy for NASA

[Anonymous Coward]

...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.

Re:Perfect analogy for NASA

[Sperbels]

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.

Re:Perfect analogy for NASA

[Anonymous Coward]

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.

I don't see why space exploration have any value at all unless we intent to eventually move off world.
Yes, it is cheaper to send robots, but it is even cheaper to observe from Earth, or not at all.

Re:Perfect analogy for NASA

[kamapuaa]

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

Re:Perfect analogy for NASA

[ColdWetDog]

If you've got the money, honey - I've got the time.

Re:Perfect analogy for NASA

[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 or not, it would be quicker for them to drag a sled behind them with a similar instrument than to dig up the ground everywhere.

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.

50 years ago, such equipment was quite bulky and not very rugged. While you could do such work with a 50 year old lab, you wouldn't want to send a such a whole lab to Mars. Especially in the last decade or two, such equipment has become much more portable allowing for their use in the field, on Earth or not. There is plenty of equipment that went from, "I'll have to take these samples back to look at them," to "we could set up a large tent or shed to do local work," to, "I have one in the back of my truck."

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.

Because sending a person will provide slightly more than minimal information at an even more enormous cost? If you had the budget you would spend on such a mission spent on probes, you would quickly make up for a large part of the lack in versatility, and for most work surpass what the person can do in terms of speed by having many probes work in parallel.

Re:Perfect analogy for NASA

[Sperbels]

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?

Re:Perfect analogy for NASA

[h4rr4r]

Knowledge has no value to you?
That must be one hell of a miserable existence you live.

Re:Perfect analogy for NASA

[Anonymous Coward]

Space is most definitely a hostile environment. On the other hand, it's infinitely more survivable than, say, Venus.

Space is largely *passively* hostile. Outside of debris moving at cosmic speeds, space presents some fairly basic engineering issues, after which survival is sorted out until someone makes too big of a mistake.
Venus, on the other hand, is *actively* hostile. It doesn't just want to kill you if you make a mistake, it wants to eat your shelter, and destroy you even when you're doing everything right.

Venus is very similar to Earth in many ways. Absent the runaway greenhouse effect, she is a potentially habitable planet. If we manage to do that to Earth, Space looks utterly hospitable in comparison.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

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 being able to fine tune the environment any way we like. The idea might seem a little claustrophobic at first glance but really, it would be like living in a large city with vacations elsewhere from time to time.

I predict we'll colonise space itself long before we start colonising other worlds.

Re:Perfect analogy for NASA

[Anonymous Coward]

No, but the other issue is that for us to land hmans on Mars, we need crafts that can land there, and robots to help. With Apollo, it was just a day trip. With Mars, it will not be 2 years, but far more likely a decade stay. And before you claim that these things are easy to develop, you will note that we are the only nation with truly successful landings on Mars. USSR sent a number of them, but only 1 actually landed, and it lasted for less than 20 seconds. ESA has lost one as well. Heck, Russia and China simply tried to go to Mars and failed. There is NOTHING easy about all of this.

However, we have private space up and coming now. With Red Dragon, we will gain not just the ability to double the amount of science that has actually landed on Mars, but it will provide the craft for landing humans on mars as well. And yes, red Dragon has gained a great deal from NASA's experience with robotics and engines.
 
I would have to say that if O can kill the SLS, push private space, and can stop the neo-cons from the opposite actions, then we will be on the moon by 2020, and Mars by 2025. If the neo-cons are successful, then we will be one of the last on the moon and mars.

Re:Perfect analogy for NASA

[Bengie]

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

Re:Perfect analogy for NASA

[im_thatoneguy]

, 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 planet.

Until the sun dies there is no real challenge humanity faces that would be easier to face on another planet. If we legitimately were worried about contingencies we shouldn't spend our resources on space exploration we should just burrow deep into the earth and build a deep underground base that can sustain itself for hundreds of years.

Re:Perfect analogy for NASA

[RoboRay]

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.

Re:Perfect analogy for NASA

[R3d M3rcury]

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 device, you can spend four days in a chair and learn the same information. But it'll cost you $40,000,000. Yup, you'll be paying those college loans off for the rest of your days and then some. And you've learned the same information. But you're four years ahead of your compatriots who took the slow method.

Is it worth it?

If we sent human beings to Mars, we could find life (assuming it exists) in two months rather than puttering around with rovers which may take a generation to find life on Mars. But Mars isn't going anywhere and the life will be there in 50 years. If a Mars-killer asteroid were going to impact in 50 years, I might say it's worth the trip to determine whether there is life on Mars as quickly as possible. But without such a scenario, is it worth the money to send people to Mars?

Re:Perfect analogy for NASA

[fahrbot-bot]

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.

Re:Perfect analogy for NASA

[a-zarkon!]

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, you will still be able to fix the earth's issues at the same or lower cost than going out in to space. (Props to the termite infested house analogy posted earlier.)

Looking at this another way, if it was cheaper and easier to get iron, gold, or boron by mining asteroids I'm pretty sure someone would be doing it right now. The reason they aren't doing it is because it's cheaper not to. Something about skipping the roughly 180M mile round trip to the asteroid belt probably explains that.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

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.

Re:Perfect analogy for NASA

[Sperbels]

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.

Re:Perfect analogy for NASA

[Anonymous Coward]

Uh, did you really mean to list Mars Observer?

Re:Perfect analogy for NASA

[Cold hard reality]

You're perfectly correct. And in fact cars and oil are cheaper (and do more) than horses. On the other hand terrestrial mining is cheaper than asteroid mining, which is why that is what we're doing.

Re:Perfect analogy for NASA

[Cold hard reality]

And the mammals did?

The dinosaurs are extinct because they didn't adapt to a changing environment. With technology and science, we're a lot more adaptable than any other animal. In fact you can find us everywhere on earth, as well as in space.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

The point of course is that without massive investment in infrastructure, pipelines, manufacturing capability, and technological advancement which continues to this day, cars would make much less sense than horses, particularly economically. Cars and oil didn't become cheaper by accident/act of god, they are the product of decades, even centuries, of effort.

Obviously it isn't difficult to extrapolate this as regards asteroid mining.

Re:Perfect analogy for NASA

[a-zarkon!]

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 resources.

We've been approaching peak oil for twenty years now. What is the forecast for hitting peak iron or peak nickel? Maybe that will be motivation to drive us after the asteroid resources or maybe it will be motivation to more aggressively recycle our local resources. If you look at the pyramids in Egypt and the coliseum in Rome - a lot of the stone work was recycled into building materials for nearby construction. Yes, they had stone quarries they could have gone to get material for the new construction, but it was cheaper and easier to re-use the easily scavenged stones from the previous generation's efforts. Similarly as we hit the back side of peak oil maybe it will push us back to horses - or maybe (hopefully) drive investment into wind, solar, hydro, and nuclear.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

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 fodder to force a change from horses to cars? No of course not, and with enough effort cars became much more viable than horses.
The only difference between the rise of the car and the rise of solar system resource exploitation is a longer period to profitability. But this has always been the case for game changing technologies - once upon a time only the richest of nations could afford a trireme, and we look back upon them as future generations will look back upon us with our miniscule space exploration efforts.

Re:Perfect analogy for NASA

[tibit]

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.

Re:Perfect analogy for NASA

[symbolset]

It has moved 34 AU.

Re:Perfect analogy for NASA

[Anonymous Coward]

That's absolutely true, but neglects the important fact that, for cars and related industry, infrastructure et al, every step of the way was valuable and profitable for somebody. The earliest cars were able to use roads already created for horses and wagons, made largely with the same skills and materials (aside from the engine, and even that had analogs with stationary engines for mining, mills etc). Any moderately wealthy man could buy one and very soon any small business saw the value in using them instead of the horses and goods wagons too. Motor vehicles had the advantage of using industry and infrastructure that itself had been built literally over thousands of years and very quickly became more economical and more useful than horsepower at doing all the things (and more) that horses had done.

Space travel doesn't have those advantages, there is NO prior infrastructure to exploit up there. Right now it takes a very wealthy many indeed to buy a personal trip up there and doing so is pure recreation/tourism and ego stroking. Similarly, there's little or no *direct* value for the vast number of SMB's. It takes a large international enterprise, sometimes many of them working together to do anything useful up there. Long before space travel gets cheap enough for schmoes like me, it has to become not just economical but downright profitable for things like AAA-Acme Satelitte Towing and in-orbit Re-fuel services. When the big transport outfits like UPS, FedEx, Schnieder and Day & Ross have dozens of inter and intra orbital spaces trucks doing a profitable business, *that's* when you will see space travel boom. That first step up into orbit is always the hardest after all.

Re:Perfect analogy for NASA

[Anonymous Coward]

The advantage of asteroid resource exploitation and indeed deep space manufacturing is that it can be scaled up arbitrarily,

"How do you make money doing this?" The answer is simple: Volume. That's what we do.

Even if you had monotonically decreasing marginal costs due to economies of scale, that doesn't mean it will approach a cost below the production of things on Earth. At the moment there is very little demand for such products in space, and it can't compete with things on Earth. This might change, but it will have to wait until either prices skyrocket by orders of magnitude on Earth, or there is a demand for doing things in space beyond the occasional exploration and those who think building stuff so they could build more stuff for the sake of building stuff in space counts as demand.

Re:Perfect analogy for NASA

[khallow]

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.

Re:Perfect analogy for NASA

[khallow]

The dinosaurs are extinct because they didn't adapt to a changing environment.

And one way to adapt to a changing environment is to not be there when it's changing.

Re:Perfect analogy for NASA

[Cold hard reality]

It happens to be an infeasible one. Colonizing the bottom of the bottom of the ocean is easier by far.

Re:Perfect analogy for NASA

[Cold hard reality]

Exactly.

For every step of aviation history there was an economic or military justification. Sometimes advances were carried out for national ego justification (e.g. the Concorde), but without economic justification, it could not be sustained and technology reverted a step back.

Space is in the same position. There is economic justification for commercial satellites, but no economic justification for the manned space program (or for the unmanned science and exploration program, but don't tell anyone). That is why we haven't been to the moon again and that is why the ISS will eventually be deorbited.

The problems of space travel are real. It takes huge amount of energy and labour to get something into orbit, and even more to get a human there and keep him alive. And what do you get in return? NOTHING.

Re:Perfect analogy for NASA

[__aaltlg1547]

...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.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

It takes huge amount of energy and labour to get something into orbit

This is in fact the only major stumbling block in the way of economical and profitable space exploration and development. The solution to this problem can be found here: http://maglaunch.com/

Re:Perfect analogy for NASA

[MichaelSmith]

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

Re:Perfect analogy for NASA

[Anonymous Coward]

Even at $40/kg to launch, there would be very few to zero things more profitable to obtain in space than on the ground for the time being.

Re:Perfect analogy for NASA

[cthulhu11]

Galileo though was seriously crippled by stupidity.

Re:Perfect analogy for NASA

[Cold hard reality]

Its by far the biggest, but by no means the only major one.

For example, links with malware can bring down any launch vehicle, including the one you linked to, according to google.

Re:Perfect analogy for NASA

[Intrepid imaginaut]

Perhaps we're using different googles.

Re:Perfect analogy for NASA

[Cold hard reality]

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Content from www.sfdt.com, a known malware distributor, has been inserted into this web page. Visiting this page now is very likely to infect your computer with malware.
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Re:Perfect analogy for NASA

[Intrepid imaginaut]

Oh for pity's sake. Here, you muppet: http://www.youtube.com/watch?feature=player_embedded&v=BLRJ_A9KKrk

Re:Perfect analogy for NASA

[Anonymous Coward]

You see, we have this little problem. No human has been in zero gravity for more than 6 months and those that were came back in seriously declined health. Now a one-way trip to Mars at the best window is going to be 9 months of zero-gravity. All other issues aside, the astronauts will not be able to walk on the planet once they get there.

NASA needs to create a test craft that stays in orbit (docked with ISS??) so that they can test out new propulsion systems and possibly some kind of artificial gravity, at the very least.

Re:Perfect analogy for NASA

[peawormsworth]

the one geologist to land on the Moon managed to learn more (and faster) in his one short trip than all of the Mars rovers combined.

Manned space missions are a terrible waste of money. I think people who support them dream of one day being able to fly out into space like in Star Trek. We can explore far more and at much less cost using rovers, satellites and probes. Expecting to fly men to Mars is a horrible waste of resources and will stall progress and funding spent on missions impossible for men. We would know far less about the planets and commets if we felt a need to put a person on every spaceship.

My 1000 year dream of space exploration is to one day have a probe fly to another star. It may be an outrageous idea, but certainly isnt something we should hope to achieve with a crew on board. My immediate dream is to never put another man in outer space and instead spend resources more wisely.

Re: Perfect analogy for NASA

[Anonymous Coward]

Do you also dream about tying your shoelaces some time within the next century?

Specific impulse

[abies]

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

Re:Specific impulse

[Anonymous Coward]

badump-tsh!

Re:Specific impulse

[Impy the Impiuos Imp]

Nah. The lead scientist felt it was ok to let it run as long as they kept a close ion it.

Re:Specific impulse

[Anonymous Coward]

Well, they might have been trying to stop the Earth's rotation... now I know why the days seems shorter(!)

Too bad it's at NASA

[rhadamanthus]

Which all but guarantees that this engine will never do anything more.

Re:Too bad it's at NASA

[fuzzyfuzzyfungus]

Which all but guarantees that this engine will never do anything more.

Sort of like the ion thruster on the Dawn probe, which left Vesta about a year ago with an ETA on Ceres sometime in 2015?

Re:Too bad it's at NASA

[Anonymous Coward]

So who's going out to attach this engine to the Dawn probe? Sounds like a one way trip.

Re:Too bad it's at NASA

[burisch_research]

http://en.wikipedia.org/wiki/Dawn_(spacecraft)

It was launched in 2007 with an ion thruster.

Re:Too bad it's at NASA

[nojayuk]

The ion thrusters on the Japanese Hayabusa asteroid sample-return mission kept on breaking down but after a lot of TLC the main spacecraft did get back to Earth and its sample capsule was recovered.

A European Space agency probe, the 370kg SMART 1 was powered by an ion motor and flew from Earth orbit to Lunar orbit under ion propulsion in 2004. It burned 80kg of fuel over about 13 months producing 68 mN of thrust.

Re:Too bad it's at NASA

[WindBourne]

wow. The fact that NASA has more interplanetary probes out there than all of the other nations combined, means nothing to you, eh?

NASA's been stymied by the neo-cons, BUT, that is about to change over the next 2 years. The neo-cons continue to pour money into the SLS, but it will not fly humans until 2022. OTOH, SpaceX will have their Falcon Heavy available at end of this year, or early next year. At that time, Musk is supposed to announce how much longer to develop the Dragon Rider (human rated launch capsule), and is saying that he will introduce information about MCT. MCT is what others of us know as BFR (big fucking rocket), but the new name is Mars Colonial Transport. if the inside info is to be believed, it will be ready by 2020, and will launch 150-200 tonnes, while the neo-con's SLS will take only 70 tonnes and will cost 3-5x the costs to launch.
So, I fully expect that NASA WILL get back on track, assuming that we can keep neo-con's dirty stinking paws off NASA for about 1 year or so.

Re:Too bad it's at NASA

[tlambert]

wow. The fact that NASA has more interplanetary probes out there than all of the other nations combined, means nothing to you, eh?

NASA's been stymied by the neo-cons, BUT, that is about to change over the next 2 years. The neo-cons continue to pour money into the SLS, but it will not fly humans until 2022. OTOH, SpaceX will have their Falcon Heavy available at end of this year, or early next year. At that time, Musk is supposed to announce how much longer to develop the Dragon Rider (human rated launch capsule), and is saying that he will introduce information about MCT. MCT is what others of us know as BFR (big fucking rocket), but the new name is Mars Colonial Transport. if the inside info is to be believed, it will be ready by 2020, and will launch 150-200 tonnes, while the neo-con's SLS will take only 70 tonnes and will cost 3-5x the costs to launch.

So, I fully expect that NASA WILL get back on track, assuming that we can keep neo-con's dirty stinking paws off NASA for about 1 year or so.

Most of the space exploration done by the U.S. has been done on the watch of a Republican president, including all of the Apollo missions.

https://en.wikipedia.org/wiki/Timeline_of_Solar_System_exploration
http://en.wikipedia.org/wiki/List_of_Presidents_of_the_United_States

Also, Elon Musk is a registered independent, neither a Republican nor a Democrat:

http://en.wikipedia.org/wiki/Elon_Musk

You should also be aware that the backdrop for the majority of the space program was military, and based in the cold ware; when the U.S. lost their "best enemy" with the end of the cold war, that's when funding dried up, and that's when military contractor consolidation took a particularly big bite out of our technical capability with the demise of the DC-X program and the X-33 program.

It's unlikely that we are going to have cheap access to space any time soon, in any case, since as soon as someone can pull a John Travolta and buy a used SSTO spacecraft instead of a Boeing 707–138 is the day some idiot lofts a load of ceramic coated rebar and effectively ends up with the functional equivalent of a bunch of tactical nuclear weapons they can deorbit onto ground targets at will. Believe me, an Andy Griffith equivalent is not going to be launching a cement mixer body on top of a texaco gasoline tanker any time soon. Private launches will be heavily regulated for the foreseeable future.

Re:Too bad it's at NASA

[Anonymous Coward]

Most of the space exploration done by the U.S. has been done on the watch of a Republican president, including all of the Apollo missions.

You mean like Apollo 1, 4-8, and all of the other tests and development that happened before Nixon came in in 1969? If you just wanted to use the launch dates, Carter seems to have done well with Voyager and Pioneer...

Or maybe it is just that there has been a steady stream of missions of various sizes, most of which were projects longer than a president's term, and Republicans have been in the White House more often than not between Apollo 11 and the Mars Rovers.

Re:Too bad it's at NASA

[tlambert]

Most of the space exploration done by the U.S. has been done on the watch of a Republican president, including all of the Apollo missions.

You mean like Apollo 1, 4-8, and all of the other tests and development that happened before Nixon came in in 1969? If you just wanted to use the launch dates, Carter seems to have done well with Voyager and Pioneer...

Or maybe it is just that there has been a steady stream of missions of various sizes, most of which were projects longer than a president's term, and Republicans have been in the White House more often than not between Apollo 11 and the Mars Rovers.

Kennedy was as much a hawk as anyone else when it came to the communists, including political assassinations in Vietnam, an attempted assassination of Castro, the Cuban missile crisis vs. the former Soviet Union, and the Bay of Pigs.

Make no mistake: Kennedy and Johnson don't qualify as what we think of today when we talk about Democrats.

Re:Too bad it's at NASA

[Anonymous Coward]

And I guess development of Galileo and Magellan under Carter (well, latter scaled back under Reagan) don't count because he's not a "true Democrat" either. And the Mars rovers under Clinton don't count either, because he's not a true Democrat. ..

The largest change to NASA's budget after the spindown of the Apollo program during Johnson and Nixon's years, was the drop at the end Nixon's and Bush Sr.'s term, and the increase at the end of Carter's term, and under Clinton. Trying to correlate it with presidents makes a bunch of them look schizophrenic as several have both large increases and decreases. This should make it clear it is more about who is in Congress than the president. And in the last 20 years, it has been increasing under Democrats and decreasing under Republicans (although most of the time is flat either way...). If you go further back, you might as well credit all of the space race to a Democrat controlled Congress since they held onto it for such a long time, especially if you are going to credit Republicans (and pseudo-Democrats) for when they were in power for a long stretch.

Re:Too bad it's at NASA

[WindBourne]

Hmmm.
You really should check your history.
NASA was started under Eisenhower, and then massively funded under Kennedy/Johnson.
Nixon did massive cuts to it, and gave us the too expensive shuttle.
Carter was focused on energy crisis, economy, and rebuilding the military (quietly).
reagan spread NASA's mission all over, while not doing jack with funding.
Poppa Bush, a true republican, DID increase NASA's budget, but cut it in 4th year. In addition, he tried to get NASA focused.
Clinton did focus NASA, but in 1995, republican CONgress insisted that massive cuts come to NASA and that they be gutted. Clinton had us locked in with treaties on the ISS, that prevented republicans from gutting NASA more.
Under W, NASA was gutted again, and then had their money devoted to re-starting the shuttle, getting Constellation going, and providing a MINIMUM private space via COTS.

Under O, he has tried to up the money to NASA, and fully fund private space. However, the republican controlled house has actually cut NASA and has fought to kill private space, and have all NASA money devoted to SLS.

Look at those missions on the link and then click on them. You will find missions like voyager were started nearly a decade earlier. Lots of technology had to be developed. The Hubble was a good one. It was started by Carter, but cuts came under reagan and then challenger, delayed it until 1990. BTW, one major exception was clementine. IIRC, it was done in 4 years.
At this moment, the house republicans have continued to gut NASA, and push their money towards SLS. We have actually cut missions that we agreed to pay for. However, W's admin did not use treaties with Europe, so the missions were killed.
And having the launches watched, is not a big deal.

awesome

[endosynth1]

that is just cool...

Could we achieve 1G of thust.

[jellomizer]

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.

Re:Could we achieve 1G of thust.

[Prof.Phreak]

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

Re: Could we achieve 1G of thust.

[iamhassi]

But wouldn't this engine continue to build speed forever since there is no resistance in space? So 1g should be easily achievable.

Re:Could we achieve 1G of thust.

[tilante]

No matter what your acceleration is, it will take you infinite time to get to the speed of light. Relativity, man.

Re: Could we achieve 1G of thust.

[Anonymous Coward]

Are you ... serious? Are you a troll? Have you finished high school physics yet?

Re: Could we achieve 1G of thust.

[jellomizer]

Still you need to fight momentum. If you have a ship big enough to hold heavy people with heavier supplies that is a lot of momentum to fight all the time. Sure we can burst speed of multiple G's but once the fuel runs out and the ship goes at a constant speed we are down to 0g.

Re: Could we achieve 1G of thust.

[Anonymous Coward]

Acceleration is what determines gravity. 1G gravity would be achievable as long as you keep accelerating and its thrust is equivalent to 1G

Re: Could we achieve 1G of thust.

[Binestar]

Really? Or are you trolling? 1G is acceleration, not speed. So build at much speed as you want, it's still building it at whatever your acceleration is. You're not suddenly "traveling at 1G"

Re:Could we achieve 1G of thust.

[Anonymous Coward]

I suspected that with a constant acceleration of 1G you'd reach lightspeed before you'd get to Mars. Turns out I was wrong, or I'm bad a physics.
By my calculations you'd be at Mars within 2 days. Your speed would peak at 275km/s, that's (just) 0.00251c.

Re: Could we achieve 1G of thust.

[Anonymous Coward]

Heh, my non-physics brain went to the same thought initially, but we're thinking velocity (m/s) and not acceleration (m/s2 or g). 1g = 9.8m/s2

Re:Could we achieve 1G of thust.

[Anonymous Coward]

Sure, but the distance you need to travel will become shorter.

Re:Could we achieve 1G of thust.

[denis-The-menace]

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.

Re:Could we achieve 1G of thust.

[Overzeetop]

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.

Re: Could we achieve 1G of thust.

[Squidlips]

Nope! As you approached the speed of light, undesirable things start happening such as increasing mass etc. Basic relativity...

Re:Could we achieve 1G of thust.

[MrChips]

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.

Re:Could we achieve 1G of thust.

[Last_Available_Usern]

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.

Re: Could we achieve 1G of thust.

[Evtim]

There is no resistance but the mass of the ship and the cargo will increase with the speed. Thus, if you had to spend, say, Z amount of joules to achieve 1g acceleration at low (compared to c) speeds, you woudl need many more joules to sustain the 1g acceleration the closer you are to c.

Re:Could we achieve 1G of thust.

[MBGMorden]

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 - for settling one could take their family with them or just select people without any existing family).

Once they get there they could setup a base of operations/colony and begin communicating back with Earth (I assume that the project itself would still be up and running).

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.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

That just, like, your opinion, man.

Re:Could we achieve 1G of thust.

[elfprince13]

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 and the no-broadcast theorem (or just read the first paragraph on quantum teleportation).

Re:Could we achieve 1G of thust.

[sjames]

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.

Re:Could we achieve 1G of thust.

[pr0fessor]

The idea has been used so much in science fiction Ansible. I think the idea of using quantum entanglement sounds like it came straight out of Ender's Game or possibly an episode of Eureka.

This isn't my field of study so no helpful tips on how to make it actually work, just thought I would point out why people think it might.

Re: Could we achieve 1G of thust.

[Anonymous Coward]

You would need more and more power to maintain 1 g acceleration to an external observer, and would reach a point where that is simply impossible to do. But that is pointless, as you would want to maintain a 1 g acceleration in a local frame, and that would require a constant amount of power (or less, as you shed mass from using up fuel).

Re: Could we achieve 1G of thust.

[GodfatherofSoul]

It won't be like driving a car. You accelerate 1/2 of the way there, turn around, and decelerate the rest of the way. That way you're at 1 G the whole time.

Re:Could we achieve 1G of thust.

[ebh]

"Level of trust"? Is that anything like John Glenn's quip about sitting on top of two million parts, all built by the lowest bidder?

Re:Could we achieve 1G of thust.

[Anonymous Coward]

The delta-V needed to fly a 1g brachistochrone to Mars is freakin' ridiculous. A nuclear saltwater rocket might be up to the challenge, maybe. Heck, even doing that flight at 0.1g would be a heck of an accomplishment.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

Just a minor speedbump. All we need to do is to change our idea of information, and voila - we can communicate via quantum entanglement. Easy-peasy. We had a few leaps like that in the past, why not now? We just need to wait for another brilliant mind to enlighten us...

Re:Could we achieve 1G of thust.

[elfprince13]

Oh, I'm not at all in the dark as to why people think it could work or where they get the ideas (and I'm a huge Ender's Game fan myself), but it's still a disturbingly common misconception that needs to be corrected.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

Accelerating at 1G for 24 hours you will have a velocity of 846720 m/s, or 311,040,000 m/h, or 311,040 k/h.

Re:Could we achieve 1G of thust.

[ravenscar]

This made me laugh out loud. A toast to you my good AC.

Re:Could we achieve 1G of thust.

[Just Some Guy]

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.

Re: Could we achieve 1G of thust.

[Anonymous Coward]

It takes an exceptional amount of energy to maintain 1 g of thrust for the full time, for diminishing returns in terms of reduced travel time.

Suppose we used a ion thruster with exceptional specific impulse, and accelerated at 1 g for 0.5 AU, then decelerate by 1 g for another 0.5 AU. This would take about 2.9 days. If we only accelerated by 1 g for 0.25 AU, coasted for 0.5 AU, then decelerated for another 0.25 AU, this would instead take about 3.6 days. In the former case though, we would need a mass of fuel about 400 times that of our payload, so the craft would need to be >99% fuel by mass. In the latter case, this drops to about 20 times as much mass in fuel as compared to payload, so the craft would need to only be about 95% fuel. That is a factor 20 less fuel for the same payload, while only adding 25% to the travel time.

Re:Could we achieve 1G of thust.

[fahrbot-bot]

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... :-)

Re: Could we achieve 1G of thust.

[fahrbot-bot]

If you have a ship big enough to hold heavy people with heavier supplies that is a lot of momentum to fight all the time.

Only send skinny people - duh.

Re: Could we achieve 1G of thust.

[fahrbot-bot]

There is no resistance but the mass of the ship and the cargo will increase with the speed.

Or does the mass of the Universe decrease?

Re: Could we achieve 1G of thust.

[jellomizer]

You mean accelerating at 9.8m/s^2
The same as the pull of gravity of earth.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

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?

That's not how relativity works. If it takes a year, it takes a year. To the observer in the accelerating frame, time is slowed down and it takes less than a year.

Re:Could we achieve 1G of thust.

[pr0fessor]

Is that the miss conception that scifi is real, quantum entanglement can be used for instantaneous communication, or both.

I actually had to explain to someone that electrolysis is not cold fusion and all they were going to do was cause a small explosion if they didn't use the right kind of valves.

I'm not a chemist or physicist but come on hydrogen force into a carburetor without any kind valve is an accident waiting to happen. {yeah they got that idea off of youtube}

Re:Could we achieve 1G of thust.

[MrChips]

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.

35 days at 1g to get to 0.1c is about right, but the distance you'd travel in the process is around 45 billion km. You'd pass the Voyager probes.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

Let's do the math...
The distance between Earth and Mars ranges from 54.6 million kilometers to 401 million km, averaging about 225 million km.
To solve for distance traveled based on time and acceleration, you use: d = .5 at^2

Accelerating at 1G for a half a day, gets you a good chunk of distance, ...
d = .5 * 9.8 * (43,200^2) = .5 * 9.8 * 1,866,240,000 = 95,216,326.5m = 95,216km ... but not enough.

Accelerating at 1G for a full day, gets you much, much farther.
d = .5 * 9.8 * (86,400^2) = .5 * 9.8 * 7,464,960,000 = 36,578,304,000m = 36,578,304km
That's more than half the minimum distance. So Mars is about a 2 day trip at best.

Now, how about the average, or maximum distances? Let's add another day of acceleration and see where we end up...
d = .5 * 9.8 * (172,800^2) = 146,313,216,000m = 146,313,216km
That's enough to cover the average distance in 4 days.

At 1G acceleration, it would take about 6 days and 14 hours to reach Mars.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

You could reach 80% of "c" in about 6 months, at 1 G acceleration. No need to get any higher in speed.

Re:Could we achieve 1G of thust.

[bill_mcgonigle]

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.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

This is why I am working on changing the definition of unicorns. Don't be surprised if the population of unicorns skyrockets in the next year or two.

Re:Could we achieve 1G of thust.

[khallow]

In other words, you agree that's how relativity works in this situation.

Re:Could we achieve 1G of thust.

[khallow]

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.

Re:Could we achieve 1G of thust.

[khallow]

Or had already skyrocketed. They're very resistant to temporal notions of causality.

Re: Could we achieve 1G of thust.

[Binestar]

Hello Troll.

I mean what I said. Acceleration is a different measurement than speed.

Re:Could we achieve 1G of thust.

[elfprince13]

I was thinking the second moreso than the first, but there are definitely people for whom the first is a problem as well.

Re:Could we achieve 1G of thust.

[Anonymous Coward]

My definition of a unicorn is a category of creatures with one horn before 2014, and with two horns in 2014 or later. Now we just need to update the definition of antelope and other such animals to be "not a unicorn before 2014, but a kind of unicorn after 2014"...

Re:Could we achieve 1G of thust.

[__aaltlg1547]

That depends on where you're going. At 80%c, time dilation is only 64%. I wouldn't get across the galaxy in my lifetime.

Re:Could we achieve 1G of thust.

[khallow]

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.

Fools!

[Anonymous Coward]

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

Re:Fools!

[Anonymous Coward]

So far as I can tell from the pictures, the engine was mounted horizontally, so it would only have an effect on the rotation of the Earth, not its orbit. (I doubt it had any effect on global warming.)

Re:Fools!

[Anonymous Coward]

Well that explains why my clock is off, and I've noticed the sun rise is earlier lately.

Re:Fools!

[Anonymous Coward]

More rotation = more magnetic shielding from solar winds... we should have a global cooling.

Re:Fools!

[Anonymous Coward]

And at any rate you're missing a dozen zeroes after the decimal point.

Re:Fools!

[burisch_research]

Bzzt you are both wrong. The net acceleration due to this test is zero, because the ions ejected out of the engine are halted by the test chamber. Net result is zero force.

Re:Fools!

[jalopezp]

This is how we solve global warming!

Re:Fools!

[NatasRevol]

Wait till next week.

Re:Fools!

[L4t3r4lu5]

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.

Re:Fools!

[wvmarle]

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

Re:Fools!

[Anonymous Coward]

every day

Re:Fools!

[tibit]

This is one of the most insightful short AC comments, like, ever. Good job, AC! :)

Re:Fools!

[Brett Buck]

By the way, also undermining the value of this test was the fact that a test chamber is a grounded metal tube. Running in free space is utterly difference, as hs been discovered the hard way

Re:Fools!

[Anonymous Coward]

Considering for much of the solar system the Debye length is on the order of 10 meters, such a thruster being used in space would be not too different from operating inside a large grounded vacuum vessel. Plus there is the cathode to neutralize the out going stream of particles so beyond a certain scale, the thruster looks like a neutral device and not something with a net charge.

How Fast?

[Rob Riggs]

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?

Re:How Fast?

[Anonymous Coward]

Maximum speed 90,000 mph.

By Newton's law: f = m a, solve for a: a = f / m.
Plug in the numbers:
a = 0.092 N / 1,100 Kg
gives us an acceleration of:
a = 8.8 x 10^-8 meters per second per second

  ???

Re:How Fast?

[Overzeetop]

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

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 18,700 ms, or from 0.000037c to 0.000062c

People may say physics is a bitch, but based on these numbers, it looks more we are physic's bitch. (insert Soviet Russia joke here).

*a goal in the above article is to create a small, portable reactor of 5Mg to produce 40kW, which would actually power almost 6 of these thrusters. For the sake of argument I scaled it down to 4Mg to allow for 1Mg of thruster and fuel tank hardware, but that's still a pretty wild guess.

Re:How Fast?

[Anonymous Coward]

I revoke your geek card... http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

Re:How Fast?

[Anonymous Coward]

DeltaV = V_exhaust * ln (m_0 / m_1)

V_exhaust for a NeXT is about 145,000 km/h.

Say two tonnes of spacecraft and one tonne of fuel.

145000 * ln(3/2) = 58792 km/h of delta V from the NEXT thruster. That is a huge delta V by any standard, and incredible for a craft that's only 33% fuel.

Re:How Fast?

[Anonymous Coward]

18700 meters / second = 41830.7087 miles / hour

Re:How Fast?

[JTsyo]

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

Re:How Fast?

[Anonymous Coward]

The mass is constantly changing, so you actually have to integrate to account for the loss of reaction mass due to the engine firing Xenon out the back and into space.

Re:How Fast?

[tibit]

You need to use the rocket equation for that. At the end of the burn, you'll be lighter.

Assuming Voyager with a NEXT thruster (unrealistic since the NEXT would need a much heavier RTG!),

delta_v= v_exhaust * ln(m_initial / m_final)

At 720kg initial weight, assuming 80kg initial propellant weight (I couldn't find it anywhere!), at I_sp=4000 we have exhaust velocity v_ex = I_sp*g = 40,000m/s.

Thus delta_v = 40,000 m/s * ln(720/640) = 4.7 km/s (10,500 mph).

How fast would it be going?

[complete loony]

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?

Re:How fast would it be going?

[Anonymous Coward]

Missions with that kind of planned range and duration generally don't have solar panels, because the sun is so faint where they're headed (even at the orbit of Mars, solar flux is less than half of that on Earth). Instead, they use radioisotope thermoelectric generators -- a lump of radioactive metal creates heat as it decays, which the spacecraft converts to power via thermocouples.

Re:How fast would it be going?

[stiggle]

Actually they started looking at using full fission reactors (space capable submarine reactors) rather than RTGs for outer planet ion drive craft.
http://en.wikipedia.org/wiki/Project_Prometheus
http://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter

di3k

[Anonymous Coward]

OpenBSD, as the least of Which is = 1400 NetBSD become an unwanted bunch of retarded to decline for in ratio of 5 to

Distance estimate

[Anonymous Coward]

I think I've calculated this correctly - assume this was bolted to the back of a spaceship in 0g, and the whole unit weighed 2000kg and not accounting for weight decreasing over time as propellant burns, how far would you get? Assuming constant acceleration for the first half of the trip, constant slowing for the second.

7500kW = 2000N / a
a = 3.5m/s^2
t = 48000hrs / 2 = 86400000s
c = 299792458 m/s
d = (c^2/a) * (sqrt(1+(a*t/c)^2) - 1)
      = 10794747340804852 = 1.14ly

So 1.14ly before you turn the thruster around to slow, and you've traveled 2.28ly after 5.5yrs.

Am I right? Does a career in space engineering beckon?

PS. What, STILL no Unicode in comments? Hi, Slashdot, it's been around for at least 20 years - move with the times, grandad.

Re:Distance estimate

[Anonymous Coward]

Please excuse my extraneous SI prefix - output is 7.5kW or 7500W, not 7500kW.

Re:Distance estimate

[abies]

Don't know where you got these numbers from, but:
- There is no way this ion engine can produce 0.3g acceleration on 2000kg probe; something is way off.
- in addition to propellant, ion engine requires power - a lot of power ; you need to add weight of nuclear reactor on top of that (which is probably only thing able to produce enough power for long term with small amount of consumable fuel); for 2000N you would need something like 50MW of constant power supply

But yes, if you can create imaginary engine giving you even 0.1g of constant acceleration for spaceship over period of few decades, entire galaxy is yours.

Re:Distance estimate

[Anonymous Coward]

Does a career in space engineering beckon?

Hopefully not, but sadly it wouldn't be the first time someone f'ed the calculations at NASA.

Re:Distance estimate

[burisch_research]

Something is seriously wrong with your maths here. Don't quit your day job.

Thruster = 0.000236 N
Mass = 2000
f=ma ; a=f/m=0.000236/2000=1.18e-7 (this is a VERY low acceleration)
s=ut+(1/2)at^2 (u=0 so we ignore that part)
assume t=24000 hrs=2e9 seconds (to turnaround point)
s=0.5 * 1.18e-7 * 2e9 * 2e9=2.360e9 metres
By turn-around you would have travelled 2.36 million kilometres.
1 light year is 9.461e15 metres, so the space craft would have travelled about 2.5 millionths of a light year.

Re:Distance estimate

[Anonymous Coward]

Well.. everything within 1-200 light years. Beyond that it gets to the point of diminishing returns or you're just sending people off, never to see or hear from them again. The milky way is 100,000 light years. Even with this happy imaginary spaceship travelling at c, it would take almost the age of humanity to go from one side to the other and back.

Re:Distance estimate

[abies]

Not for the people on spaceship - and you care about them, not Earth. You can colonize the galaxy, you just cannot exploit settlers afterwards.
http://einstein.stanford.edu/content/relativity/q917.html

0.9c 2.29
0.99c 7.08
[...]
0.999999c 707.1
0.9999999c 2236.0

Of course, at high speed you will get problems with acceleration... fortunately, your fuel will get heavier as well. It all depends on that imaginary, perfect 0.1g engine which can sustain it even at close-to-lightspeed pace.

Re:Distance estimate

[Anonymous Coward]

if you can create imaginary engine giving you even 0.1g of constant acceleration for spaceship over period of few decades, entire galaxy is yours.

No. There is not enough reaction mass in the entire universe to accelerate a payload to relativistic speeds with an ion engine. With an exhaust velocity of 40 km/s, you would need one trillion kg of propellant to accelerate a tiny 100 kg payload to just 0.3% of the speed of light. The only method that comes even close would be a pure anti-matter drive.

Tsiolkovsky rocket equation calculator

Re:Distance estimate

[Anonymous Coward]

But yes, if you can create imaginary engine giving you even 0.1g of constant acceleration ...

If you have 0.1g constant acceleration, and the Earths gravity is 1g, then your ship will only accelerate until it hits the ground... ;-)

Re:Distance estimate

[amaurea]

Your spaceship won't feel the speed at all. That is the whole point of relativity. As far as the spacecraft is concerned, it is sitting still with its normal mass, and only the rest of the universe is moving. So the question isn't if the engine will have problems working due to the speed, but whether it will have enough fuel to keep up that acceleration for so long.

1G of thust - you're gonna need a bigger boat

[Overzeetop]

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.

Re:1G of thust - you're gonna need a bigger boat

[Anonymous Coward]

Increase v of the ions.

Re:1G of thust - you're gonna need a bigger boat

[Anonymous Coward]

The ion engine already makes the ions move very fast. That is why ion engines like this one are so efficient. I'm sure NASA would love to make the ions go faster, but it's easier said than done.

Re:1G of thust - you're gonna need a bigger boat

[Impy the Impiuos Imp]

Yes, the article mentions 90,000 kph of the ions. Compare vs. what, maybe a few kph for chemical rocket exhause? The obvious difference in reaction mass speed shows tremendous relative efficiency.

The real gem will be in a future accelerator that can do a noticeable fraction of the speed of light.

Re:1G of thust - you're gonna need a bigger boat

[iggymanz]

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

Re:1G of thust - you're gonna need a bigger boat

[marcosdumay]

That reduces the efficiency, requiring more nuclear reactors to power it (but less fuel).

Re:1G of thust - you're gonna need a bigger boat

[__aaltlg1547]

That's not a problem. Many physics labs have accelerators can do more than a significant fraction of c. An efficient ion drive must also be low-mass.

Re:1G of thust - you're gonna need a bigger boat

[khallow]

Incidentally, the limit is the speed of light. If you wanted optimal ISP (which to be honest, you probably never will want), then use photon propulsion, say fluorescent light tubes. But you'll get remarkably bad thrust/weight ratios and you won't be going anywhere at 1G.

In practice, having your exhaust velocity near your final delta-v tends to be a pretty good combination of speed and propellant to vehicle mass ratio.

We all know what comes next.

[gallondr00nk]

All we need is two of those engines, a spherical cockpit, and two large solar panels attached to each side.

Re:We all know what comes next.

[Anonymous Coward]

All we need is two of those engines, a spherical cockpit, and two large solar panels attached to each side.

Darth Vader's space car?

Re:We all know what comes next.

[Anonymous Coward]

|-o-| or the more fancy (-oO-)

Re:We all know what comes next.

[Anonymous Coward]

and a bathroom and lots of cat photos.

NASA should come clean

[bitt3n]

it's time for NASA to admit they locked the keys inside the thing, swallow their pride, and call AAA

Re:NASA should come clean

[Anonymous Coward]

*Facepalm* NOW I remember why we weren't supposed to lay off that tech !

NASA's NASA (NASA's Acronym Standard Acronym)

[Anonymous Coward]

Tautologically speaking, I say this is redundant.

What is strange is that it is on the ground.

[WindBourne]

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.

Re:What is strange is that it is on the ground.

[symbolset]

That is what they are doing, but only with the 200kW model. WIKI VASIMIR.

Re:What is strange is that it is on the ground.

[WindBourne]

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%.

Re:What is strange is that it is on the ground.

[symbolset]

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. Obviously that means it's tested on Earth and works. The issues they're concerned about is that the test will wrench the ISS from orbit or give it uncontrollable spin.

The other issue is that it's a 200kW system. They can only operate it a few minutes at a time on batteries that have to be recharged from surplus solar cell energy. So it's going to burn at 200kW in short bursts. Maybe they should have got up the FEL receivers at the same time.

Laws of Physics

[EmagGeek]

If the Laws of Physics are getting in the way of scientific advances like this, then that's something we need to get Congress to take a hard look at in the coming years. /tic

Re:Laws of Physics

[MichaelSmith]

Oh no it might just be a question of scale. How about a vehicle roughly the size of Discovery in 2001. Fission reactors for power and iion drives for propulsion. Plan on a ten year cruise to Saturn.

Imagine the thrill of having to monitor that thing

[YoungManKlaus]

from the protocols:
[quote]
...
Day 1500 09:00: still running within required parameters
Day 1500 10:00: still running within required parameters
...
[/quote]

Speaking of, how's that space sail working out?

[fygment]

Yeah, Thomas Gold was right.