Slashdot Mirror
Revolutionary Ion Thruster To Be Tested On International Space Station (abc.net.au)
Three Australian researchers have developed "an ion thruster that could replace the current chemical-based rocket propulsion technology, which requires huge volumes of fuel to be loaded onto a spacecraft." Slashdot reader theweatherelectric shares this article from the ABC News:
An Australian-designed rocket propulsion system is heading to the International Space Station for a year-long experiment that ultimately could revolutionize space travel. The technology could be used to power a return trip to Mars without refuelling, and use recycled space junk for the fuel... It will be placed in a module outside the ISS, powered, as Dr Neumann describes, by an extension cord from the station. "What we'll be doing with our system is running it for as long as we can, hopefully for the entire year on the space station to measure how much force it's producing for how long."
In the early 2000s "it was basically a machine the size of a fist that spat ions from a very hot plasma ball through a magnetic nozzle at a very high velocity," and the researchers are now hoping to achieve the same effect by recycling the magnesium in space junk.
In the early 2000s "it was basically a machine the size of a fist that spat ions from a very hot plasma ball through a magnetic nozzle at a very high velocity," and the researchers are now hoping to achieve the same effect by recycling the magnesium in space junk.
Didn't they watch Space 1999? The entire station could suddenly be thrust into an unknown part of the galaxy.
If I had a DeLorean... I would probably only drive it from time to time.
uh huh. thought so
This is the missing piece we need for our colonization of Mars and the planets and beyond. With this and Musk we are well on our way to Mars. We truly live in exciting times!
For those interested, there is a lengthy and interesting interview with Dr Neumann about this on The Space Show. http://thespaceshow.com/show/0...
Being totally brainwashed and deliberately misinformed I know for certain that it is absolutely impossible for the French or anyone other than an American to discover or develop anything. That is why it is so critical that we admit no immigrants so that our glorious superiority can not be contaminated by foreign thoughts. Donnie Trump explained that to me.
Hi,
I'm Ian Whitchurch, the CEO of Neumann Space.
First of all, if you want more technical information about the Neumann Drive, there's an article in Applied Physics Letters. It may be available here
http://scitation.aip.org/conte...
If that isnt working, then you might know someone with an APL subscription, or it might be somewhere on the internets under "A centre-triggered magnesium fuelled cathodic arc thruster uses sublimation to deliver a record high specific impulse Patrick R. C. Neumann, Marcela Bilek and David R. McKenzie".
Secondly, it's not just the Neumann Drive that's going up to the Bartolomeo platform on the ISS. We're planning on taking a bunch of other peoples small projects, which deserve to go into space, but cant by themselves get a ride into orbit, or an easy method to get power, heating, cooling and communications once they are there. If you're interested, you might want a look at this fine Airbus DS press release.
https://airbusdefenceandspace....
There is also information available about the Facility for Australian Space Tests on our website, at http://neumannspace.com/fast/
Thirdly, Im happy to answer further questions people might have.
Finally, our poor, poor website. Also, the original post lacks a poll, which itself lacks a Cmdr Taco option. What the heck am I supposed to vote for ?
How does the energy input and thrust produced compare to NASA's current operational ion engine, which has been in use on the Dawn mission for the last ten years?
Be great if Milner and Zuckerberg would put up the cash or shut up and design a photonic laser thruster for the ISS to test the interstellar "nanocraft" concept before the most expensive object in history / Russian-U.S. peace keeping effigy gets burned up instead of funding studies. Be even better if they also funded a propulsion system like the Magnetic Sail that could slow down on the other end an interstellar journal and not require a laser that threatens the existence of the space capabilities of a nation state and provide justification for starting another arms race.
The problem with space junk is less about getting to it and more about getting to it safely. Everything in orbit is travelling a minimum of 17,000 mph. Have you seen what happens when car into a wall at only a 100 mph difference? Think two flimsy satellites colliding with a 400 mph difference. There will be hypersonic shards of metal everywhere.
Anons need not reply. Questions end with a question mark.
The first use of an ion thruster as the main engine was in 1998 in Deep Space 1. Russians use it quite a bit to correct orbits of some of their satellites. IOW this is not a new technology.
I'd like to see an EM Drive put into testing up there too (yes, yes, yes - I know it's defying the [known] laws of science. No reason not to test it in space since it seems to pass all tests on earth)
Hey maybe we could strap the ION Drive face-to-face with an EM Drive, throw them out the hatch and see who pushes who around!
Don't give this to SpaceX if you want it to actually make it to orbit!
... There will be hypersonic shards of metal everywhere.
Um, I know this may be a dumb question, but I'm trying to get a handle on how fast those shards would be going.
So, what's the speed of sound in space?
Thanks,
P. Edant.
yeah yeah
... There will be hypersonic shards of metal everywhere.
Um, I know this may be a dumb question, but I'm trying to get a handle on how fast those shards would be going.
So, what's the speed of sound in space?
Thanks,
P. Edant.
The speed of sound is dependent on temperature, but doesn't vary all that much - 1200 km/h to 1000 km/h at about -60 C.
Once you get to vacuum, "the mean free path" of the particles becomes so long that the atmosphere begins to act less like a gas and more like individual particles. Changes in pressure are not propagated efficiently in this situation, so the idea of "sound" starts to lose its meaning.
I think the OP was just making a visceral point. If we use the sea-level 1200 km/h speed and note that orbital velocity is about 28000 km/h then depending on the angle the shards could hit anywhere from 0 to twice the orbital speed.
A 1 gram bolt hitting the front of your spaceship at 28000 x 2 = 56000 km/h would deliver an energy of 121,000 joules on impact (if I did the calculations right), equivalent to about 25 grams of TNT.
Roughly 1000 times impact of a sledge hammer. (10 kg hammer going 5 m/s => 125 joules).
The last link says something about recycling space junk but it is just a link the wiki page on ion thrusters.
Is there an actual article about this and is there research in this area?
I'm a good cook. I'm a fantastic eater. - Steven Brust
Star Wars, here we come!
How on earth (or halfway to Mars) did the 'Tigger' typo in the diagram slip past checks? Or did no-one at the company look over the 'How it works' page? And that unsecured capacitor in the video makes me shudder.
However, ion thrust technology has some real problems when it comes to moving people around the solar system: transit time. If you look at this description, it turns out that the fastest travel time from Earth to Mars they quote is seven months. That's not from LEO but from a station at L5 to a Mars orbit where there is another orbiting station. Getting out of the gravity well is assigned to chemical rockets. This architecture requires a lot of infrastructure investment. Without these stations it's likely the transit time are much longer, closer to the 9/18 month burn and coast transfer orbits.
Long term exposure to weightlessness is not good for humans. For example, space station cosmonauts (tweaked you on that one) have long term vision problems. Even worse is the radiation exposure outside the Van Allen belts. The manned mission to Mars community, including NASA, seem to be underestimating the seriousness of this problem. It's not just about cancer. There are other long term problems like heart disease and general decline in health and longevity. For example, the long term effects of exposure to radiation from Chernobyl have been terrible in affected areas in Belarus and the Ukraine. (There is a huge coverup over this situation, so you don't hear anything about it. Even the World Health Organization seems to want to sweep it under the rug.)
It's surprising that no one here has made any comparison to the recently released road-map from SpaceX. They propose a 30 day transit time without needing any orbital infrastructure either at Earth or at Mars. They are further along then Neumann, having their first generation hardware already proving itself in space flight, while Neumann is only now doing a flight test. Even so, it's unclear if ion or chemical engines are the best way to send humans to Mars, assuming that is a good idea in the first place,
Looking at the specs, if the Neumann system works as advertised it would be well suited for exploring the outer solar system. If paired with an RTG It would allow significant size missions to the outer planets that could go into orbit and not be limited to flybys. They confidently describe continuous acceleration for years at a time with a single fuel slug weighing in at a few kilograms. Even though manned missions to Mars are more glamorous, exploring the solar system is equally important in the long run.
Why is Snark Required?
Neumann thrusters work very differently from existing ion thrusters, though. At a high enough level, the concept is the same - ionize some stuff, accelerate it using an electric field - but the details matter a ton. Or, indeed, several tons. The existing ion thrusters mostly use gases - xenon is popular - as reaction mass. That means your reaction mass is already conveniently in tiny individual particles (single atoms, since it's a noble gas) suitable for extreme acceleration, but it also means you need to have a bunch of tankage, valves, and so on... and once the xenon runs out, you're done. Xenon thrusters - especially the most efficient ones, which use grids that the particles fly through - have a limited lifetime, too; they wear out pretty fast if you use them with a lot of power.
Neumann thrusters use solid fuels, usually metals (though they also tested with pure carbon, and it worked reasonably well). There's no tankage, no moving parts such as valves (although the fuel rods may occasionally need replacement), and no risk of your fuel leaking off into space. What's more, in theory you can simply use metal that is *already in orbit* (such as discarded rocket upper stages, end-of-life satellites, or even outright junk if you can catch it safely) and that means you can easily "refuel" while in orbit. The performance you get varies depending on the reaction mass, with some metals producing absurdly high specific impulses (11000 seconds?!? That's far better than existing ion thrusters) and some producing more moderate efficiency but permitting quite high thrust (well, relative to other ion thrusters; it's still measured in m/s of delta-V per month) if you have the power (without eroding any part of the thruster except the fuel rod, unlike a conventional ion thruster running at such power levels).
Some of it, like the in-space "fueling", is more than a little difficult, but the basic idea seems sound. It's also a pretty new technology, and they've already come up with some improvements (such as a magnetized "nozzle" that gives better thrust, presumably meaning it improves electrical-power-to-thrust efficiency) so I'm sure the technology will mature still further as research on it continues.
There's no place I could be, since I've found Serenity...
http://neumannspace.com/ - the web site of the company / research lab building these things. Kind of hype-y, of course, but has some good info.
http://neumannspace.com/scienc... - the section of the site that gives an overview of how the Neumann thruster actually works, how efficient it can get, and so on. Includes links to blog posts about a number of the fuels they've tested, such as http://neumannspace.com/blog/f... (which has an utterly ludicrous specific impulse).
There's no place I could be, since I've found Serenity...
I wondered when someone was going to ditch lightweight gasses and try to use denser materials (water, iron, etc). They're a lot easier to store, have a much higher thrust to weight ratio and are usually much easier to find in space. I suppose the only problem is power, they're talking about arc welding levels of power, which either requires pretty large solar arrays or nuclear. Its seeming more and more apparent that we need larger power systems for spacecraft, it is the only thing limiting various ion/plasma thruster designs from achieving significant size to replace chemical propulsion.
The problem with space junk is less about getting to it
Actually, that is the problem. Maneuvering to intercept a piece of space junk requires a huge amount of energy when you're already traveling 17,000 mph, that's a lot of momentum to change.
NASA was funding this technology in the early 1970's. The article taped on the wall at my school was of a hand holding the actual engine to show its size. It had enough power to move a ping pong ball, in space. It does look like the engineers have "improved" the design.
This is quite obviously *not* any sort of general replacement for chemical fuel due to the low thrust. A Nuclear Salt Water Rocket or Fission Fragment rocket otoh might do it. I wonder if this tech would be useful for micro-ships.
Quite an experience to live in fear, isn't it? That's what it is to be a slave.
But the junk you're trying to reach is also moving exactly at orbital velocity for whatever orbit it's in, it's just at a slightly different angle. And almost all of it is moving in nearly the same orbit. So the difference in velocity would be relatively small. Of course, "relatively small" is still pretty large, but the GP's estimate of 400 mph is probably a reasonable guess. But the masses are low, so a reasonable catcher is probably possible. But you'd need to wait until a shard approached you (preferably on an skew course), and then shoot out a net to catch it. Not easy. Much easier to scavenge from the second stage that launched you.
I think we've pushed this "anyone can grow up to be president" thing too far.
"Crockpot" is probably relative. Einstein's ideas were greeted with skepticism, bordering on ridicule, as was the multiverse model of quantum physics. Even rockets working in the vacuum of space was bashed by some in the mainstream.
There is often groupthink and "best practices" of the time, and going against those can get one labelled as a crackpot. Humans naturally protect their turf.
I've been labelled such myself for claiming that human grokkability is more important than shear parsimony in terms of "productive" programming code, in debates among certain academics. (I'm not claiming all academics.)
The problem is that "parsimony" is easier to measure than human grokkability, but being easier to measure does not make a factor more important. My detractors seem to mistake ease-of-measurement for importance.
Humans have to read and maintain the code, not machines nor mathematicians. (At least machines processing the code is usually not the bottleneck.)
They claim that "emergent" benefits appear if one follows parsimony, but so far have not shown this the case. Their case is very indirect, seemingly claiming that if you follow parsimony, you'll filter out "bad" programmers, and academically gifted programmers would replace them and be many times more productive, justifying their higher salaries. This has been tried before without lasting benefits. Companies also value people skills, writing skills, UI skills, domain skills, and other things that "raw" academics are not necessarily better at. Those not in the field often don't understand the value of those aspects.
Plus, I suspect they want the industry to value academics more, and are thus biased by their wallet to push for academic-centric development. Thus, protecting their turf.
Did I wander into a tangent here?
Table-ized A.I.
Did I wander into a tangent here?
Yes, but you are right! 8-)