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NASA Ground Tests Ion Engine
herda05 writes "New Scientist reports from a press release by NASA on a successful ground test of the HiPEP (High Power Electric Propulsion) ion engine, which is the first 'major milestone' for Project Prometheus. Also some pictures and more info on the HiPEP engine."
"This new class of NEP thrusters will offer substantial performance advantages over the ion engine flown on Deep Space 1 in 1999. Overall improvements include up to a factor of 10 or more in power; a factor of two to three in fuel efficiency; a factor of four to five in grid voltage; a factor of five to eight in thruster lifetime; and a 30 percent improvement in overall thruster efficiency. GRC engineers will continue testing and development of this particular thruster model, culminating in performance tests at full power levels of 25 kilowatts.
All I have to say is damn!, I'm impressed.
--"The perfect example of the man of action is the suicide." - William Carlos Williams
Is there really a lot of xenon gas in outer space? Wouldn't ionizing hydrogent work a lot better? And, is it really a vacuum chamber if it's filled with xenon gas?
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is a portable 25-kilowatt reactor. Pluto here I come!
I hold it, that a little rebellion, now and then, is a good thing. -- Thomas Jefferson
I still want my TIE Fighter.
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As the other respondant said, Xenon is the fuel they take with them. Several obvious reasons spring to mind - it's a bit easier to ionize a gas than, for example, solid propellant... also, it's a lot less volatile than hydrogen. I'm not sure why Xenon was chosen over other inert gases, but it could be because it's the heaviest one (thus more thrust per atom) that is affordable?
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Okay, this isn't exactly my area of expertise, so please forgive me if I'm asking an ignorant question. If they're propelling xenon gas out the back of the engine, then how much do they have to bring aboard? Is that where the x000 seconds of impulse figure comes in? Would the gas come out hot/cold/inbetween? Why'd they choose xenon?
"Derp de derp."
Ground being an adjective modifying "tests". As in "NASA tested it on the ground".
"NASA Ground-tested an Ion Engine" would have been a less headline-ish way of saying it.
"Murphy was an optimist" - O'Toole's commentary on Murphy's Law
"NASA Ground-tests Ion Engine." If I remember my APA style guide correctly, when forming a compound verb the parts should be joined with a hyphen unless the compound word is in the dictionary (i.e., the on-the-fly construction of the compound word is frequent). There are some exceptions to this rule as well, such as the hyphens aren't dropped if doing so would create confusion of the word with another word. It goes on and on...
Before anyone has visions of nimble fighters, we must remember that ion engines have extremely low thrust. A quick calc based on the numbers in the article, which I hope I did correctly, suggests that the thrust is only about 0.3 Newtons (1 ounce for you Imperialists). What makes these engines exciting is that they can sustain that thrust of years. Estimated fuel consumption is only about 14 grams per hour.
Slow and steady wins the race.
Two wrongs don't make a right, but three lefts do.
One of the earlier "nuclear" test engines was this puppy, the nuclear thermal rocket. If you have seen a video of it when it was being tested, you would know that that thing is one mighty beast. The soviets also attempted to design one (both the Soviet and the American versions had the purpose of getting people to mars) which looks a lot cooler. I would love to have a model of that sitting on my desk. :)
Anyway, this nuclear propulsion is somewhat related to the newer Xenon method albeit with lower specific impulse but much higher acceleration.
I had but a simple dream, to destroy all humans.
Yep. And considering current "MMRG" units and SRGs(check out their homepage- they're basically two of I-dunno-how-many nuclear-powered generators NASA has at the moment) top out at 100W per module, well...
I think the problem is that NASA, rightly so, is extremely nervous about putting nuclear stuff into orbit, because of the frequency with which these things blow up. So it tends to be very simple, not very efficient(the MMRG only captures 100 out of 250w produced), and not very powerful. For example, the MMRG modules produce heat just by natural decay, and they're designed to survive a crash as a whole intact(nasa notes that previously they were designed to burn up, but are now designed to stay intact- probably because things don't always get high enough to burn up).
Problem is, even with solar power- which starts getting pretty sparse(why they came up with the nuclear power sources)- a large(sheet of plywood sized) solar panel isn't much, at least on earth(you get more power outside the earth's atmosphere). It'd take a LOT of that sized solar panels to power such an engine. Probably somewhere above 50 for starters...
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Those were the days.
Hah, when I first scanned it quickly I thought it said Ion Cannon.
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.... can someone actually tell me what potential application this has... i.e. how far it'll get a rocket.... will it just be a quicker trip to mars for probes or are we looking at something which could send probes out the solar system and beyond...? If so... how long will/would it take to get to amrs, and simiarly, are we anywhere near reaching the nearest star after the sun? :)
Does anyone know the feasability of using a gas engine to get the vehicle started at a faster pace that what the ion engine would begin with? Then, unload the standard engine once it is empty and kick on the ion for the remainder of the trip. Would that initial boost get it to it's distant destination quicker?
If I remember my 25th century history lessons correctly, Dralasites and Vrusk are essentially the same species. The Vrusk were erroneously renamed by pioneers from Lotar who didn't know of the Dralasites and gave the Vrusk that name from the moon they inhabited. I could be wrong.
And oh yes, the many hours of jimble-jack. I really miss those tournaments on Senwan 4! That place reeked of sourweed!
Good times. Good times.
...which may mean you could produce more Xenon in space if they can come up with a way to get the xenon out of the fuel rods. This assumes, of course, that any real ion engines will be nuclear powered - which of course they will.
What they really should be doing is coupling ion engines to nuclear reactors. Then you'd have a power plant capable of producing a large quantity of energy for a long time, and keep going for many, many years.
I remember reading somewhere that nuclear-powered ships could keep going and going for 20+ years or more. The only reason why such nuclear aircraft carriers eventually must return to port is other supplies like food and water for the crew, not fuel. Same thing goes for ballistic missile submarines, which can stay submerged for years on end, using the power from the nuclear reactor to produce drinkable water and breathable air for the crew. A typical deterrence patrol for an Ohio class SSBN only lasts for two months only because that's probably how long a crew can stay cooped up in a very small space without going crazy. :)
Only thing is there are all these groups that seem to be afraid to put anything nuclear in space for some reason. If anyone's still really serious about doing manned space exploration, we'll have to do this eventually, I think. Solar just won't be able to produce the kind of power required to provide extended life support and reasonably fast travel at the same time. It's no good to be cooped up in a space capsule for eight months to get to Mars, and back again... These ion engines could probably produce a lot more thrust with the kind of juice a nuclear reactor onboard could put out, possibly even enough to accelerate the ions to relativistic velocities, and then we could have some real serious speed, to make interstellar travel, at least by machines, a realistic possibility.
As for radiation shielding, that's something you'll have to deal with anyway, nuclear reactor or not. Even a small coronal mass ejection could produce far, far more radiation than the power plant would.
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
One of my big disappointments with the name "Trek" was my initial belief that it would be a trek, that the ship would require long times to reach interesting destinations after the fashion of old West wagon trains, but with the warp drive zooming around to encounter aliens at every corner was kind of a cheat.
Oh, and the episode with the Romulan cloaked ship that was destroying Federation outposts was a direct ripoff of a WW-II film about a German U-boat and an American destroyer in a deadly cat-and-mouse game, and it had pretty much the same dialog about the U-boat captain admiring his destroyer captain enemy about his intuition as to where to lay down depth charges.
Now the work cluster f*ck is not hyphenated because it is a compound noun: while f*ck is normally a verb, it is used here as a noun.
From: Robert Clark (rgclark@my-deja.com) Subject: Microwave powered ion drive. Newsgroups: sci.astro, sci.physics, sci.space.policy Date: 2000/07/30 Found this site while looking up info on microwaves: Physics inside a Microwave Oven http://home.earthlink.net/~marutgers/fun/microwave /microwave.html
One of the demonstrations on this page appears to show plasmas being
generated by heating grapes with a microwave oven. Nice Quicktime
movies here. It's also described on the page:
HOW THINGS WORK: Microwave Ovens
http://rabi.phys.virginia.edu/HTW//microwave_ovens .html
Would this provide a low energy means of creating the plasma required
for ion engines? One means of creating the required plasma is by
irradiating the propellent gas with intense laser or x-ray beams to
strip off the electrons of the atoms of the gas, producing an ionized
plasma. However, these are both high-frequency forms of EM radiation
and therefore require high energy to produce. Microwaves being longer
wavelengths require less energy to produce.
Another means that is actually used for the Deep Space 1 probe is to
use electrons emitted by a cathode to irradiate the gas, ionizing it.
How does the energy requirement for the heating element of a cathode
compare to the energy requirement for producing the microwaves?
If this can be exploited as a low energy means of producing plasmas
then this might be used not only for low thrust engines as on DS 1 but
also for lauching ships into space by beaming the microwaves into a
reaction chamber of a rocket lined with, er, grapes.
--
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"In order for a scientific revolution to occur,
most scientists have to be wrong"
-- Bob Clark
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Another recent story discusses the applications of using cold plasmas:
Force Fields and 'Plasma' Shields Get Closer to Reality,
http://www.space.com/businesstechnology/technology /cold_plasma_000724.html
An advantage of the cold plasmas is the low power required to generate
them. However the article mentions that hot plasmas can be generated
with higher densities. Perhaps the microwave plasma generation method
can match the efficiency of the cold generation system while allowing
the high densities of the hot plasmas.
From: Robert Clark (rgregoryclark@yahoo.com)
Subject: Plasma propulsion for access to space?
Newsgroups: sci.astro, sci.physics, sci.space.policy, rec.arts.sf.science
Date: 2002-11-05 21:21:09 PST
http://groups.google.com/groups?th=87680963df54e46 c
Bob Clark
Lucky for all humanity, APA = American Psychology Association. For one, most people aren't American. Second of all, NASA folks' are Scientists, not Psychologists (thank heavens), and thirdly: The APA Style really sucks.
Psychology is a science, of course.. but it doesn't matter. The APA rules are evil.