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NASA's Ion Thruster Sets Continuous Operation Record
cylonlover writes "NASA's Evolutionary Xenon Thruster (NEXT) ion engine has set a new world record by clocking 43,000 hours of continuous operation at NASA's Glenn Research Center's Electric Propulsion Laboratory. The seven-kilowatt thruster is intended to propel future NASA deep space probes on missions where chemical rockets aren't a practical option. The NEXT is one of NASA's latest generation of engines. With a power output of seven kilowatts, it's over twice as powerful as the ones used aboard the unmanned Dawn space probe, yet it is simpler in design, lighter and more efficient, and is also designed for very high endurance. Its current record of 43,000 hours is the equivalent of nearly five years of continuous operation while consuming only 770 kg (1697.5 lbs) of xenon propellant. The NEXT engine (PDF) would provide 30 million newton-seconds of total impulse to a spacecraft. What this means in simple terms is that the NEXT engine can make a spacecraft go (eventually) very far and very fast."
This ion thruster placed on Voyager 1 would have taken it up to 37 km/s over 5 years compared to the 17km/s it is going now. Not part of my calculations is that Voyager 1 would have been slightly lighter due to the reduced fuel load. i don't have exact enough numbers to do the calc, but it would have likely been in the low 40's km/s.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
The simple concept that we now have "Ion Thrusters" is extremely cool to me.
OK, brace yourself for techno-orgasm.
The first recorded successful firing of ion thrusters in space was onboard the Soviet Zond 2 probe. 8th December 1965.
Yes, fifty years ago.
That particular installation was experimental, but ion engines were widely used in subsequent Soviet probes. Mainly developed at the Kurchatov Institute.
My calculations would say it probably went at a speed of around 0km/second, placing it now around 0km from Earth after 5 years.
EMail: 0110001101100010010000000110001101110010 0110000101111010011011100110000101110010 0010111001100011011011110110
lots and lots and lots. just expensive to separate as it is widely distributed.
Xenon is a trace gas in Earth's atmosphere, occurring at 87±1 parts per billion (nL/L)
(wikipedia is fun)
being heavy it doesn't escape the atmosphere.
It is very dense as a liquid, stores compactly, and can used as a heatsink for the engine.
for fun:
770kg of xenon is 130641 L at STP
it is 252 L at xenon boiling point (as liquid)
it is also ~2% of total xenon production (in 1998)
Check your maths. My calculations place it about .001 km from Earth...
How come Slashdot never gets Slashdotted?
More importantly, some Xenon isotopes are common byproducts of our current fission reactors.
while(1) attack(People.Sandy);
I keep hoping, but interstellar is extremely difficult. It won't happen in our lifetimes. To get to Alpha Centauri in just 70 years requires acceleration to near 0.1c. That takes way more energy than we can currently give our probes. Thinking that a gravity assist can help significantly with that is like thinking you can make your car go significantly faster by having a person stand beside the road and blow air at your back as you pass.
Maybe we could eventually swing something on the order of 700 years. But just 70 years is really pushing the longevity of our current designs. Plutonium doesn't last long enough. In any case, how to make a probe last 700 years is only half the problem. Keeping a project alive, relevant data fresh on current media, and people trained for such a length of time would be the other half. 700 years is an awful long time for circumstance to scuttle the project. Can NASA or any other agency last that long? Can the US?
Barring catastrophe, we will eventually do it.
Intellectual Property is a monopolistic, selfish, and defective concept. It is "tyranny over the mind of man"
"220 watt-hours of energy."
Less power than running a dungeon in world of warcraft using a decent gaming rig. doubly so, if you run dual cards.
total power usage of gaming rig under load - ~400 watts
Time to run a dungeon - between 45 min - 1 1/12 hours.
300 - 600 watt hours
Likely they shut it down periodically to look for any problems, signs of breakdown or other signs that this cannot be scaled up for any reason.
.
Not. It was 43,000 hours of continuous operation.
That's still a lot of time to spend in Kansas.
And first put on a small one man fighter called the Twin Ion Engine fighter in 1977.
Paying taxes to buy civilization is like paying a hooker to buy love.
To get to Alpha Centauri in just 70 years requires acceleration to near 0.1c.
And then to actually stop there to land on a planet requires deceleration by nearly 0.1c.
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Maybe they mean "continuous" operation the way ISP's mean "unlimited" bandwidth?
The villainous Tie fighter pilot straps in, ready to squash the rebellion once and for all. He charges his heavy blasters, straps into the seat, and twists the knob for full throttle, feeling the exhilarating rush of a barely perceptible acceleration and the knowledge that in two or three years time he will be moving at a pretty good clip, just so long as he never has to change directions.
I read the internet for the articles.
In a chemical sense, yes Xenon is inert and doesn't like to ionize. However, in the case of an ion thruster, the ionization is accomplished using high voltages - very easy to do.
Xenon is preferred because it's non-toxic, comparatively easy to handle, and has a 'heavy' nucleus -- meaning that you can more easily give each atom more of a push, resulting in higher thrust. You could use ions of any atom you like, though. Hydrogen's got the lightest nucleus there is, so it's not much use, not to mention being a royal pain to handle.
The Russians started out with, iirc, cesium and mercury thrusters. But of course these are really nasty substances and you really don't want to be around them if you can help it.
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Xenon is easy to ionise - it's a large, diffuse atom with the outer electrons far from the nucleus. It's also inert and heavy, giving you a non-toxic, non-corrosive fuel with a high mass/charge ratio; ideal for an ion thruster.
If only it were cheaper to buy!
It's also not true that "nothing reacts with it". The lower end of group 18 does react with strong oxidisers and you can form (and isolate) crystals of XeO4 and so on. The closest to being truly "noble" gasses are helium and neon.
And first put on a small one man fighter called the Twin Ion Engine fighter in 1977.
But it was short range only, and couldn't operate far from base.
I am not a crackpot.