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Successful Test of Superconducting Plasma Rocket Engine
xp65 writes to mention that Ad Astra has successfully tested their VX-200 plasma engine at full power in superconducting conditions, the first time such an engine has been tested at those power levels. "The VX-200 engine is the first flight-like prototype of the VASIMR® propulsion system, a new high-power plasma-based rocket, initially studied by NASA and now being developed privately by Ad Astra. VASIMR® engines could enable space operations far more efficiently than today's chemical rockets and ultimately they could also greatly speed up robotic and human transit times for missions to Mars and beyond."
Damn, this is terrible timing. On the weekend my lady and I were thinking that a new pet name for my penis was due. The current "Superfluidic Particle Accelerating Colossus" was getting a bit stale.
The better half suggested "Superconducting Plasma Rocket Engine". But now that that name is taken we'll have to use our second favourite choice: "Hank".
.
Trolling is a art,
For those of you who are unclear on why the VASMIR system is so cool, allow me to give you a brief bit of background. Practically every propulsion method developed to date falls into one of two categories:
1. High thrust, low efficiency
2. Low thrust, high efficiency
Generally how it works is that the more power you get out of engines, the less energy you extract from the fuel. This is the case of chemical fuels like Liquid Hydrogen/Oxygen or Kerosine. These fuels provide the massive amounts of thrust necessary to get off the ground, but they burn through their fuel very quickly. Interestingly, LHOx is more efficient than Kerosine, but it's also harder to get as much raw thrust out of it. That's one of the reasons why Kerosine was the heavy lifter during the space race with the LHOx engines reserved for in-space stages.
On the other side of the coin, you have engines like Ion propulsion. These engines are able to inject incredible amounts of energy into tiny amounts of fuel, thus making them extremely fuel efficient. The only problem is that the amount of thrust is very low. Most of the ion engines that have operated to date produce thrust that matches the weight of a sheet of paper. Definitely not enough for liftoff, but perfect for extended missions in space where constant low thrust provides more velocity over time than the chemical engines which fire once, then coast the rest of the way.
The problem with both types of engines is that neither one gets spacecraft to their destination all that fast. Chemical rockets have the thrust to do it, but you couldn't feasibly build a chemical rocket with enough fuel to get you to another planet in a reasonable amount of time. A nuclear pulse propulsion craft could feasibly get fairly close, but it would just have more power in the intial thrust rather than providing a constant, high power thrust. (Obviously these have been discounted over the difficulties of building a large enough craft without using a nuclear ground launch. Nuclear ground launches are a no-no under current test-ban treaties.)
This is where VASMIR comes in. These engines are incredibly efficient. The specific impulse (measurement of efficiency) is between 3,000-30,000 seconds depending on the configuration and current thrust levels of the engine. This compares favorably with the ~450 seconds of shuttle engines and 3,000-10,000 seconds of Ion thrusters. Meanwhile, the thrust of Ion engines ranges from 90-3,000 mN while the thrust of VASMIR is expected to be ~5000 mN of thrust when tested at 200 kW of power.
What this means is that we may be able to build spacecraft where a trip from LEO to the moon is a daily affair and a trip from LEO to Mars takes only a few months (or less!) vs. the current flight time of nearly a year. The better these engines get (and the more we can put on a craft), the faster those flight times will get!
Javascript + Nintendo DSi = DSiCade
What is required to power the VASMIR engine? Simple fuel Cell or we talkin nukes here?
... I'll have a Pan Galactic Gargle Blaster with a side of Plutonium Nyborg
Is it a newton? More?
Apparently the power level was only sustained for a second or so...it's going to have to run for a month or so to be useful, but this is probably a good start.
I love Mondays. On a Monday, anything is possible.
how many pounds of thrust is that? And how much does the thing weigh?
TFA is light on details, it reads like a press release.
Superconducting Plasma Rocket Engine?
Sounds like it oughta be able to make at least Warp 3.
"People who think they know everything are very annoying to those of us who do."-Mark Twain
For comparison, your car needs about 20 kW of power to maintain cruising speed on the interstate. 200 kW of power would be akin to running a 300 horsepower engine at its peak power output. With the way cars are designed, that doesn't happen much with the possible exception of expensive sports cars and pickups hauling a heavy load.
If we take the case of the sports car, we find that it's enough energy to slam you against your seat and hold you there while you do 0-60 in 3 seconds. (Hey look, ma! Artificial gravity!) In the case of a pickup pulling a heavy load, it's enough to accelerate reasonably while dragging a trailer full of spools of heavy steel cabling.
The difference between your car and the spaceship is that the spaceship will be powered by some sort of long-term fuel supply. e.g. A nuclear reactor. Which means that the spaceship will be able to continue accelerating for millions of miles while your car would have run out of gas after the first few hundred miles.
Since acceleration is cumulative, being able to continuously accelerate like that means that distances between planets become a lot smaller on one "tank of gas" as it were. Add more engines for greater thrust and redundancy, and you have a souped-up hot-rod of a ship that can take you interplanetary distances in record time.
Hmm... I'm sure someone is about to chide me for some horribly sloppy analogies, but look on the bright side. It's got cars in it! And hopefully it will make the energy budget a bit more understandable. ;-)
Javascript + Nintendo DSi = DSiCade
That's like the power of my car.. 268 hp.
-- these are only opinions and they might not be mine.
So it seems like this will be a great way to power a spacecraft that's already in orbit, headed to say Mars, but not something that will get us into orbit in the first place?
Correct. While it's theoretically possible to use engines like this as part of a liftoff stack (assuming enough engines, low enough weight per engine, and a high enough power budget), it's not really practical to consider such a concept at this time. For the short term at least, LEO access will remain the purview of chemical rockets.
Javascript + Nintendo DSi = DSiCade
The problem with speeding up is that you eventually have to slow down, and slowing down takes plenty of energy and time too. Also, when building up to this insanely fast speed, what are they planning to do if some random debris gets in their path?
Superconducting: check
Plasma: check
Rocket: check
Linux:
Three for four isn't bad.
Write your representatives! Repeal the 2nd Law of Thermodynamics!
Now that's a proper name: shake-n-bake.
Dude 1: What's this?
Dude 2: VX-200.
Dude 1: Ok, what actually is it?
Dude 2: Superconducting plasma rocket engine.
Dude 1: Yeah, fuck you, too.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
Just a comment before people get out of hand talking about how quickly we can go to Mars with better thrusters... anyone who's taken a class on Orbital mechanics should know that you can't just decide to go to Mars whenever you like. Part of the problem with trips to Mars is the distance, but also the timing. It would be extremely difficult to do an orbital transfer from Earth to Mars while they are on opposite sides of the sun. It would add months, if not years, to your trip, and the fuel requirements certainly wouldn't be aided by it. Unfortunately, because the an Earth-year and Mars-year are so close (like 1 mars-year is 1.8 earth years...?) it takes a while for the orbits to sync up again once they get out of sync (isn't this known as beat frequency in the audio world?).
Now don't quote me on this b/c it's been a while since I took orbital mechanics... but I seem to remember the "optimal" window for an Earth-to-Mars transfer opening up once every 2.5 years, it would take 8 months to travel there, 90-98% of your ship's mass would have to be fuel, and then you'd have to wait 1.5 more years for the "optimal" Mars-to-Earth orbital transfer window. In other words, doing a round-trip flight to Mars is no trivial matter.
Even with a more efficient fuel, perhaps you can stretch those windows, but you're not going to find an astronaut who is willing to leave now for a 1.5-year-commute to Mars, instead of waiting a year and doing an 8-month-commute. Even if those times are shrunk by a factor of 2 with a more efficient fuel, it's always going to be a huge operation.
This was a full power test of the superconducting magnet and first stage only. The first stage is a 30kW ionization stage. The 170kW RF second stage has not yet been tested. Testing of the combined first and second stage will commence July 14th. From the manufacturer's site: http://www.adastrarocket.com/Release%20020709.pdf
Referring back to http://ask.slashdot.org/article.pl?sid=09/06/27/0152216 , where someone asked about a freer country to move to, I suggested Costa Rica.
Besides the humanitarian lean of their universities, they're quite up on technology. They don't have a lot, but they like it. TFA is an example -- Ad Astra is based there in part. It's founder is a native of C.R. and ex-NASA astronaut, Dr. Franklin Chang-Diaz.
There's also been a few folks go down there to check it out for a possible launch site for commercial and private launches. It's around 10 degrees north latitude, close enough to the equator to go the same rotational boost as they get down there. Nothing announced yet, but the visits were very positive. After all, the VASMIR motor will never get off the ground on its own.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
20KW? Wow. That's just made me think. 20KW to pull a car along at (I'm guessing) 65MPH. Meanwhile, 250W or so from my two legs will propel me at a steady 25MPH on my pushbike.
Aren't bikes clever?
When you have constant thrust, this is an easy to solve problem. You speed up until you reach the halfway point. Then you turn the ship around and begin thrusting the opposite direction for the second half of the journey. Assuming sufficient constant thrust, you'll still get to your destination faster than the yahoos attempting a low-energy transfer.
As a bonus, thrusting forward and thrusting backwards are exactly the same from a relativity perspective. Which means that you'll get artificial gravity for the entire journey.
At such a small fraction of c, there's no difference between a fast ship or a slow ship. Meteorites could be moving toward you at high speeds no matter what your speed is relative to Mars and Earth. The velocity imparted on the spacecraft only becomes a concern when the speed imparted on the craft is enough to move interstellar distances. At those speeds (relative to stars), the various materials floating around are going to be much slower than the craft because they're aligned to the gravitational forces of the surrounding stars and galaxies while you're moving against that flow like a bat outta hell. ;-)
Javascript + Nintendo DSi = DSiCade
Well, slowing down is pretty much the same issue as speeding up. When you get about halfway there, you turn around and fire the engines in the opposite direction.
The debris issue? Well, first, you have this thing called radar, which can detect fairly big chunks from a distance. You could use chemical engines to maneuver so you avoid hitting these rocks. Remember that, assuming you're on a collision course, it wouldn't take a whole lot of propellant to change your course a fraction of a degree so that it misses you, and to change it back to what it was when it has passed.
Little tiny chunks are something else and could be a problem. You're never going to have a shield that could withstand a hit from one of these. Of course, to borrow a phrase, "Space is big." The chances of hitting/being hit by a micro-meteor in such a way that the rocket is destroyed are probably less likely than an airplane crashing. Do you not fly on an airplane?
In Yiddish (the Jewish-German creole of Eastern Europe), VASIMR means "woe is me".
I know, probably o/t.
In the land of the blind, the one-eyed man is king.
Also, when building up to this insanely fast speed, what are they planning to do if some random debris gets in their path?
The spaceships will naturally come with pre-installed cowcatchers.
Of course, to borrow a phrase, "Space is big." The chances of hitting/being hit by a micro-meteor in such a way that the rocket is destroyed are probably less likely than an airplane crashing.
[Citation needed]
Any place one would want to go will include great quantities of small particles. These things are the dust left over from planet building.
If you can not detect them on radar, speculation of their density in what we presume to be empty space seems premature.
Sig Battery depleted. Reverting to safe mode.
I'm sure someone is about to chide me for some horribly sloppy analogies
At least you dodn't talk about light bulbs or libraries of congress.
Free Martian Whores!
Biking for an hour at 25MPH costs 1181 kcal, according to this calendar (others suggest it costs even more calories), which translates to 1373 watt-hours. (Your body isn't that efficient at converting fuel to energy.) So let's assume your 250W figure is correct, and your body is about 18% efficient in converting calories to power.
Biking for an hour at 65MPH (if you could) would burn 18669 calories -- remember, wind resistance goes up as the cube of speed. That works out to -- let's see -- 21712 watt-hours. Assuming the same 18% efficiency (and some active cooling for your legs, not to mention the rest of your body), you'd be putting out 3.95KW to sustain that speed.
When you look at it that way, spending five times the energy to move a car, with probably five or ten times the frontal surface area and more than ten times the passenger and cargo capacity, starts to sound like not such a bad deal.
Yeah, and it took FEMA five days to get water to the Superdome and turned away truckloads of supplies. But that's what kind of government you get when you elect people who think government is always the problem into government.
The problem isn't "government", it's bureaucracy, and the larger any organization is, the more bureaucratic it becomes. Anyone who dealt with AT&T before the government broke up their monopoly knows this. The phone company was far more bureaucratic then the DMV.
Springfield, IL's power plant, CWLP, is owned and operated by the city. It recieves no funding except from its customers in the form of bills, yet we have the cheapest and most reliable power in the entire state. Our government run CWLP wins against the corporate Amerin hands down.
The problem isn't government, it's lack of good leadership.
Free Martian Whores!
What? We're still using rockets???
I keep thinking of Plasma rifles in X-COM. Does this experiment mean we'll be seeing some sort of plasma weapon any time soon? Are there already plasma weapons out there?
You do realize that when talking about traveling to the moon or Mars, we've already been there, right?
We know the density of microparticles isn't high because we've already passed through and our craft weren't sandblasted into oblivion.
And how fast were we going?
The craft were hit multiple times by slow moving particles. Just try that at the speeds being discussed.
Think before you post.
Sig Battery depleted. Reverting to safe mode.
everytime VASMIR is mentioned - one should read up Franklin Chang-Diaz (http://en.wikipedia.org/wiki/Franklin_Chang-Diaz) who invented this.
His life story is amazing and should be inspirational for many people in which education and hard work can enable you to succeed in life.
How, exactly, would the speed of travel increase the number of particles hit?
Sure, faster travel increases the rate at which you hit particles, but you will hit the same number of particles. Doesn't matter if you're going 0.99c or 0.000000000001c.
(assuming a relatively constant microparticle density. But that's a pretty safe assumption, since a significant increase in density should be detectable as a "cloud")
Talking to a mirror?
For the short term at least, LEO access will remain the purview of chemical rockets.
And that (besides the cosmic rays, loss of bone mass, lack of ability to pull over into a petrol station when you get hungry or something breaks, the Bad Thing that would happen when a rock smashes through your craft, and i-m-m-e-n-s-e distances) is why we are effectively stuck on this nice, green, wet, magnetically-shielded rock for the foreseeable future...
"I don't know, therefore Aliens" Wafflebox1
Liftoff with a VASIMR would require pushing it WELL above the current power limits of any design on the table. The problem is that making the exhaust go faster makes the ship more efficient (less reaction mass needed for a given thrust), but since energy is proportional to the square of velocity (while momentum is only linearly proprtional), and since the mass exhausted is truly miniscule, it would take really incredible amounts of energy to produce enough thrust for liftoff. Pumping out more reaction mass at a lower velocity works to some degree (this is how chemical rockets work, and VASIMR is designed to allow increasing the fuel rate to get some increase in thrust in exchange for less specific impulse) but VASIMR really isn't designed for high mass flow; the baseline speed for the exhaust is measured in 5 digits of m/s. The propellant is heated using RF energy; it basically turns a flowing stream of matter into plasma using a microwave oven. The amount of matter you can do this with is pretty limited.
There's no place I could be, since I've found Serenity...
The faster you go, the more distance you travel in a given period of time. (And "time" is the only measure that counts, since this engine technology's sole purpose is to make the time of travel useful to humans).
The more distance you travel the more particles you encounter [again assuming constant density, which I do not accept as fact].
But the speed of impact is high enough that the vehicle may not survive even ONE such impact.
Sig Battery depleted. Reverting to safe mode.
You're traveling the same distance. Mars doesn't suddenly get further away because you're going faster.
And this has no bearing on the density of these particles, which was my entire point.
Our "slow" probes have provided data on the density of the particles. A "fast" probe will encounter the same particle density.
Our slow probes have been hit repeatedly.
Our fast probes would not have survived any of these hits.
Sig Battery depleted. Reverting to safe mode.
I do feel I have to point out that there aren't ANY high performance sports cars that will run a 300 horsepower engine at its peak power output for a few hundred miles. At peak output a 300HP engine will most likely run out of fuel within maybe 120 miles, most likely much less. At least that was the case for my TBird SC with an 18 gallon tank. ;)
Keith D.
This topic is important for me, as this planet isn't big enough for me and You.
So, how to deal with space junk of one type or another? The first problem is detection. The faster your trael, the more difficult it is to detect and react quickly enough. This limits us to less than half-light speed, because the best we can do is to use radio or light to broadcast and have time to reflect back to us (taking into account various doppler shifts), some processing time, and then enough time to perform a countermeasure. Due to the fact that our interstellar ship are most likely to be large (because they are packing a lot of fuel, plus the million tons or so of cargo and personnell needed to form a new colony), and that large objects are more likely to have been found in advance (if not by stationary telescopes in the Solar system, then by advance detection of the travelling ship), the small 'dust' is more likely to be a problem. The solution is to funnel these down the central, hollow core of our interstellar space-ship and to use them as reaction mass, i.e. we make them flow around us and then push on them...sorta like a boat? Do this by electromagnetic means (yeah you might think that only iron, nickel, and cobalt repond to magnetic fields - but the truth is that all matter does, but that those three aformentioned elements are most easily effected, which stuff like hydrogen and belly-button lint are less so.)
Anyhow I have started a blog on this type of stuff, of which I am dangerously educated (enough to be dangerous), http://realisticinterstellartravel.blogspot.com.
If my logic seems a little fuzzy it's because I am a little fuzzy, after six Sierra Nevada Pale Ales. If anyone wants to discuss this more, I suggest a drinking tour of Cambridge, from the Thirsty Ear, to the Queen's Head Pub: "In vino veritas" but I will substitute beer for wine, because I am a northern European.
It doesn't matter too much how efficient a power source is, as long as the fuel is plentiful. For instance, if you have a REAL LOT of petrochemicals it doesn't really matter how much you have to use to get to mars, etc. BUT more important is how DENSE the energy source is...i.e, how much more of the fuel does it take to move the fuel that is going to be used later on. This gets to be a BIG PROBLEM with chemical fuels, as even at their best they are not very DENSE. Of course, efficiency helps. But say, for a moment, that you have a nice large nuclear power plant on earth...you could probably use all that heat to either directly or indirectly (though electricity) create some high-density chemical fuels...but there's a limit to how much power a chemical fuel can provide. We need NUCLEAR FUEL, be it fission or fusion, or even better ANTIMATTER fuel. While some people claim that nuclear fuel is too dangerous to use on earth, I disagree. But I do think that antimatter is too dangerous to be used anywhere in the vicinity of important and/or massive objects (can't have the earth or space station pummeled by shrapnel in the case of an antimatter explosion, can we? And remember, there's no air friction to slow this shrapnel down). So, the best advice is to use fission, or hopefully fusion once technology gives up on the silly Tokamak idea, to leave earth's gravity well and move far enough out of the plane to be safe, and then use antimatter to the long haul. What, you say antimatter is too expensive? That's only because you've picked the wrong places to manufacture it. Production using solar power in CLOSE SOLAR ORBIT, in a thousand factories, should make antimatter cheap enough. You just have to go fetch it from close-solar orbits, which can be robotically done using the antimatter as fuel itself! The factories themselves can be replicaed using easily available materials from the moon or asteroids, and then replicated in close solar orbit using the vast energy resouces of the sun.
So to sum up, the problem isn't the amount of energy required, but the location of that energy. Move our energy conversion devices closer to the source, and we'll have plnety of consumable energy, even if it has to go through several intermediate storage mechanisms to become safe and easily accessible.
And yes, I've said this in other places, over time. I just hope that I get through to someone who is charged with long-term planning for space exploration.
Otherwise known in Australia as the "Holden Commodore".
Fran
:):):)
1st 1st Poster of the new Millennium!
Focus is no substitute for vision.
"Today's research focuses - has to focus - on incremental improvements. Huge, mindblowing breakthroughs are becoming increasingly rare."
The way to guarantee that you get only incremental improvements rather than huge mind-blowing breakthroughs is to attempt only incremental improvements. Or to quote Robert Browning: "Ah, but a man's reach should exceed his grasp, or what's a heaven for?". One of the worst things IBM, in the person of Louis Gerstner, ever did to itself is demand that their research facilities like Almaden must bring one product to market each year, rather than doing research. By yoking their research centers to a short term fiscal horizon, they've blindered themselves as to how far they can see. This is the same thing we did to academia when we allowed it to monetize even government funded research for private interests.
-- Terry
So, there is no way the vessel will keep accelerating until the nuclear power plant runs out of fuel... .. It will accelerate until it runs out of some sort physical propellant expelled as mass at the back of the ship.
You can always tune the system so that it runs out of reaction mass and reactor power at the same time (since retaining one of them is useless in absence of the other).