NASA Plans Test of New Plasma Drive

Sallust writes "Flightglobal has an interesting article about the testing of a new electrically powered plasma engine called the Vasimir. It's being developed by former astronaut Franklin Chang-Diaz and promises to greatly reduce the time and fuel required for interplanetary journeys. According to the article: 'The Vasimir involves the injection of a gas such as hydrogen into an engine that turns it into a plasma. That plasma is then energised further using radio signals as it flows through the engine, a process controlled by electromagnetic waves from superconducting magnets. Accelerated and heated through this process the plasma is focused and directed as exhaust by a magnetic nozzle. Vasimir is many times more efficient than conventional chemical rockets and far less fuel is needed.' The developers are finalising an agreement with NASA to fit a scaled-down version of the engine to the ISS to conduct operational tests. There is also a concept video on YouTube suggesting a journey time for a manned craft to Mars on the order of 60-70 days."

Comments

Yes, attach it to the ISS

[BigDaddyOttawa]

What could possibly go wrong?

Re:Yes, attach it to the ISS

[oldspewey]

It's okay as long as they remember to leave the parking brake on.

Re:Yes, attach it to the ISS

[freddy_dreddy]

I think the point here is to exploit the recent discovery of water on Mars. With conventional fuels you have to take the return-charge with you. Concepts like these allow them to harvest Hydrogen on Mars for the return trip, which is pretty useful. The painful detail (apart from the complexity) is the mechanism for braking - you're f*d if that fails.

Re:Yes, attach it to the ISS

[Amouth]

actualy because this design heats the gas to a plasma state then uses EM waves to move it to create thrust - the idea could be used on just about any gas - your effeciency would be how much energy goes into heating it to a plasma state and keeping it there.

this is a great idea because they could design one engine and while the gas is consumed it could be replaced by any gas - and electricity is the true source of the power to run the engine..

we already know what gasses are readly avaliable on mars - design one to run on say H to get there (assume Hyrdogen is the easiset to heat to plasma sate) but have the engine also able to run on the gasses from Mars.. then when it gets there refill the tanks.. carge up the batteries (or use a nuke power source on the thing) and come on back - or keep going.

think of a ship with this type of drive.. then think about adding say a Bussard collector http://memory-alpha.org/en/wiki/Bussard_collector (i know we would have to invent a bussard collector but the idea is not that hard)

if this works they way the say it does - it is going to be one of the best propultion advances for traversing our solar system.

and with us having probes leaving our system - the data from there might show that there is a good ammount of particals in the space between systems.. if that is true then you could use this to send probes to other systems. sure it would take awhile but i bet they can alwasy make improvements.

Re:Yes, attach it to the ISS

[oldspewey]

Careful, you might end up buried partway in a cliff with a plasma drive hanging out your rear bumper.

Actually, the (supposedly) true story of the Rocket Car Legend is a rather interesting read.

Re:Yes, attach it to the ISS

[Omega996]

yeah, designing and building a bussard collector isn't that hard, it just needs something that can generate a magnetic field that doesn't diminish as the inverse square of the distance, since your magnetic or electrostatic funnel would have to be huge to pull in enough material to be worthwhile (even inside the heliopause). unless you're planning on not using a vehicle with any live crew or any sort of electronic equipment. I'm sure the difficulty of initiating and sustaining a proton-proton fusion to generate plasma is just a quick fix (no doubt you've already figured out the materials and fuel source for your carbon-nitrogen-oxygen fusion catalyser), as are the problems associated with getting the ramjet to speeds above the solar wind (unless the vehicle is making a quick one-way trip into the sun).

not much to do there, at all. You should get right on it, and we'll be heading toward Mt. Lookitthat within a few months. *rolleyes*

Re:Yes, attach it to the ISS

[Omega996]

flamebait? fuck off, you ingnorant moderators.

as for amouth - you really seem to have no idea how tenuous the intersteller medium (or solar wind, for that matter) is. at one astronomical unit, there are only about 7 protons per cubic centimeter. The further one goes from the sun, the more tenuous the solar wind gets. by the time you've passed the heliopause, the particle density is roughly one per cubic centimeter. Since even at earth distances the solar wind is so thin, your 'jet intake' (the actual collection radius of your "scoop) will have to be several hundred kilometers wide to bring in enough fuel to be useful. There is drag involved with such a scoop - both from the particles entering the scoop, as well as drag from the galactic magnetic field. You still have to provide power for the magnetic field, and if you're not fusing the material from the solar wind, you have to provide power to run your microwave heater to turn the fuel into plasma. there isn't enough material in between planets (or stars, for that matter) to be used as fuel for anything less than a technology-as-magic level.

Re:Yes, attach it to the ISS

[nacnud75]

The Environmental Control and Life Support System (ECLSS) planned for the ISS will use recycled water and split it into Oxygen and Hydrogen. The Oxygen is used to support the crew while the hydrogen is dumped. A VASIMR might be able to use this hydrogen to reboost the station, reducing the need for ISS resupply with toxic propellants.

Makes me happy

[SSIlver2002]

It's stuff like this that makes me happy and brings a huge smile to my face. It also makes my imagination go wild! I hope something like this gets implemented sooner than later.

plasma exit velocity?

[oldspewey]

Neither summary nor TFA give any indication of the velocity of plasma exiting the engine. How does it compare with chemical rocket? Ion drive?

Re:plasma exit velocity?

[Intron]

We can guess that it is similar to the DS-1 Ion drive which propels Xenon ions at 30 km/sec.

Re:plasma exit velocity?

[wurp]

This sounds a lot to me like it *is* an ion drive. I didn't RTFA, but a plasma is characterized by a separation of the electrons from the nuclei. The only difference between that and an ion drive is that not necessarily all electrons are stripped from the atom in an ion drive.

I don't know how (or if) you would distinguish between ionic hydrogen and a hydrogen plasma (hydrogen atoms have only one electron...)

In both cases you give the propellant momentum with either electric or electromagnetic force, and both are much more efficient than chemical rockets. I would also expect both to have miniscule thrust compared to chemical rockets, and hence only be appropriate for navigation when you already have orbital or superorbital velocities.

Re:plasma exit velocity?

[DarthVain]

More importantly how does it compare to twin ion engines? The empire wants to know!

QIE - Quad Ion Engines, now with the added benefit that they don't look like bowties. Under utilized as the name isn't very catchy...

Re:plasma exit velocity?

[bodino]

Wiki - the source of all knowledge - has some good details.

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

Re:plasma exit velocity?

[AKAImBatman]

VASIMR (Variable Specific Impulse Magnetoplasma Rocket) is a variation on the Magnetoplasmadynamic thruster (MPDT) that has been in development for a decade or two. These thrusters are coveted for their rare combination of high specific impulse (i.e. efficiency) and thrust to weight ratio (power). Such a combination makes them ideal for manned missions, as they allow space craft to fly under constant, high powered thrust. This is the "holy grail" of space travel because it cuts down the TIME in flight significantly. Thus the summary's mention of a 90 day flight time to Mars. (Normal flight time using a minimal Hohmann Transfer is ~1.5 years.)

Obviously, the exact thrust numbers depend upon the rocket. However, the VASIMR rockets have a range of specific impulses from 3,000 to 30,000 seconds. You can see how that compares to Ion Thrusters here. Chemical rockets tend to top out at 500 seconds and thus don't even place when compared to VASIMR or Ion thrusters. The only reason why we want to keep using chemical rockets once we have better thruster technology is that all these new technologies lack the thrust to weight ratio to get a rocket off the ground. i.e. They are only good for space travel. Atmospheric flight need not apply.

Re:plasma exit velocity?

[HRogge]

Ion drives use electromagnetic fields to accelerate particles with an accelerator. Most times they use heavy atoms like xenon.

VASIMIR makes plasma from light elements like hydrogen and then use electromagnetic fields to heat the plasma... by controlling the temperature you can change the thrust/momentum the engine creates.
(at least that's what I heared).

Re:plasma exit velocity?

[avandesande]

From wiki:

Current VASIMR designs should be capable of producing specific impulses ranging from 3,000 to 30,000 seconds (jet velocities 30 to 300 km/s). The low end of this range is comparable to some ion thruster designs. By adjusting the manner of plasma production and plasma heating, a VASIMR can control the specific impulse and thrust. VASIMR is also capable of processing much higher power levels (megawatts) than existing ion thruster electric propulsion designs. Therefore it can provide orders of magnitude higher thrust, provided a suitable power source can be provided.

Re:plasma exit velocity?

[Dancindan84]

Google 'microwave plasma balls' and you will get the idea.

I'm completely in awe that I didn't get a single porn site on the front page doing that search.

Re:plasma exit velocity?

[rk]

(Normal flight time using a minimal Hohmann Transfer is ~1.5 years.)

I think you forgot to divide by two. The duration of the whole Hohmann Earth/Mars transfer orbit is about this long, but you only use half of it to get there.

Re:plasma exit velocity?

[Intron]

Let's see, a kiloton of TNT = 4 x 10^12 joules all released in a fraction of a second.

A megawatt of power for 30,000 seconds (8 hours) = 3 x 10^10 joules, so no nuking here.

Also, unless I misunderstand this, you don't get more energy as thrust than you can put in as electricity. So to get that megawatt of power out, you need a megawatt of electricity in. Solar panels will only get you 1300 W / m^2 with 100% efficiency at the Earth's orbit. I guess you need a really long extension cord.

Re:plasma exit velocity?

[AKAImBatman]

Good catch. So 8.5 months for a one-way trip vs. 3 months. I'll take the VASIMR any day of the week. :-)

Re:plasma exit velocity?

[Profane MuthaFucka]

A more fuel efficient way to nuke things from orbit is to haul the nuke to the target in a wagon pulled by a horse.

I think you're mixing up specific impulse with thrust.

Re:plasma exit velocity?

[Anonymous Coward]

The VASIMIR isn't new... it was developed by NASA over 10 years ago, but the power-thrust/mass ratio didn't justify funding it. It just sounds like someone who wouldn't let it die. You're right, this is an ion drive with the difference that the net fuel charge is zero, as opposed to a true ion drive which ionizes a neutral fuel (usually a noble gas like Xe or Ar) and uses the excess charge repulsion to generate thrust. This disassociates neutral hydrogen using RF coils, so no charge is introduced, but the reactive plasma is used to generate an Isp. The plasma propulsion effect is much more charge than heat. Your goal is to minimize heat release. Thermal expansion on sparse plasmas in deep space doesn't generate much thrust (we're talking PV cooling), it just causes a cooling problem, trying to keep the propulsion system properly controlled (thermally).

Re:plasma exit velocity?

[Omega996]

an ion drive takes atoms of an element and strips off some of the electrons in order to make the particle charged (ions). These charged particles are then directed through an aperture with an opposing charge, accelerating them. When an ion with a positive charge comes in contact with a free electron, it captures it, and the atom reverts back to a charge-neutral state.

a plasma is a gas that is energetic enough that the positively-charged nuclei and negatively-charged electrons circulate in a gas. As long as the energy levels are high enough, the nuclei will not capture the free electrons. the amount of charge carried in a plasma is a function of the ratio of ions and electrons versus neutral particles in the gas.

Re:plasma exit velocity?

[mi]

However, the VASIMR rockets have a range of specific impulses from 3,000 to 30,000 seconds.

This is the part I don't get, but you probably do. Why would I lower the exhaust speed, instead of lowering the mass?

The distances a spacecraft can travel in a given time are limited by the mass of "stuff" it can throw back multiplied by the speed, with which it is thrown. So, one would think, the most efficient engine would be throw "stuff" out as fast as it can, and if lower thrust is desired at times, it would throw less of it instead of throwing the same amounts at lower speed...

Or is varying the amount at will simply too difficult today and requires another 10 years of research?

Re:plasma exit velocity?

[Phil Karn]

I assume you meant "power in the exhaust", not "energy as thrust"?

Re:plasma exit velocity?

[GleeBot]

Actually, the main reason to have a variable Isp (specific impulse) engine is because there's a direct trade-off between Isp, and energy.

Note that momentum transfer increases linearly with velocity and mass, but kinetic energy increases linearly with mass and with the square of velocity. Thus, to make a given amount of mass go faster requires a lot more energy.

A more concrete example: You want to impart a total impulse of 2MV. You can either get it throwing out a mass M at 2V (mass efficient), or by throwing out a mass 2M at V (energy efficient).

In the first case, you use 1/2 M (2V)^2 = 1/2 M 4V^2 = 2MV^2 energy, while in the second case, you use 1/2 2M V^2 = MV^2 energy, or half as much, for the same total impulse. This only gets worse the bigger the velocity difference gets.

Often, the limiting factor in electric propulsion technologies like these is the power supply, not the thruster. Generally, to get the max Isp all the time you'd need a power supply so massive (like a nuclear reactor) as to completely throw off the mass fraction.

So generally, the way these systems are proposed to be operated is with a fixed power budget, and switched between mass efficient, low thrust mode (for long term delta-V), and mass inefficient, high thrust mode (for certain maneuvers).

Re:plasma exit velocity?

[marco.antonio.costa]

In most ion drives there is interactions between the electrodes and the propellant, reducing reliability and maximum input too, I believe.

In the VASIMR the electrodes and propellant are completely separate by the containing magnetic field, which also means that the temperature of the plasma, thus propellant speed, is only limited by the power used to heat it, up to fusion temperatures, which is hellishly cool.

This gets my geek insticts completely haywire, sorry for the fanboyish post. :P

Nice to see fact moving faster than fiction

[CRCulver]

Who knows if this thing will work out, but it would be amusing if it did. In histrilogy beginning with Red Mars , Kim Stanley Robinson had interplanetary journeys being trimmed down to such short lengths only a couple of hundred years from now, and KSR's work tried hard to be scientifically plausible.

Re:Nice to see fact moving faster than fiction

[spun]

Fact is often capable of moving faster than fiction, it just takes a collective decision to make it so. We could have been to Mars already, just like we could be feeding everyone in the world. We just don't care enough.

Re:Nice to see fact moving faster than fiction

[rubenerd]

You're absolutely right. Collective will of corporations, governments and people (land, labour, capital and enterprise for those economically inclined) towards a single goal in the past has resulted in amazing things being achieved. Alas it's just too uncommon for all three groups to be interested in the same things at the same time, because they have different priorities and perceived needs.

What I'm hoping for now is that with the shrinking of the world there is a huge opportunity for corporations, governments and people to work together regardless of their geographic location quite unlike any other period in our collective history.

Optimistically, together we can achieve so much. Realistically, I think we're still more interested in spending our land, labour, capital and enterprise resources on killing each other over differences such as religion, resource allocation and political ideology.

As a terribly politically incorrect end note though, the jet turbine engine was created as a direct result of war. Who knows, a new cold war may have people racing to other planets, comets or solar systems instead of our moon. It's interesting to think about: how much of our progress is just making sure someone else doesn't do it first?

All they have to do now...

[fiannaFailMan]

...is optimize the plasma conduits, although they'd better make sure not to divert too much power away from the main deflector array, I'd hate to have to reconfigure that thing yet again.

Re:All they have to do now...

[fm6]

And this is superior to simple (relatively non-lethal) copper wires because...?

Re:All they have to do now...

[lgw]

You can only put so much current through a busbar. What do you do when a solid copper bar 4 inches across won't carry the power you need? Eventually the size and mass of the busbar required make scaling up in power impractical. For drives, weapons, computer cores, and the like it makes sense.

Of course, that doesn't explain why the bridge consoles exploded regularly - that's just lowest-bidder construction.

Re:All they have to do now...

[SlowMovingTarget]

I can think of a number of reasons:

1. It's harder to run out of magnetic fields than it is to run out of copper.
2. Exploding Plasma is way cooler than non-exploding copper. I suppose you could make copper plasma, but see number 1.
3. The old Constitution class used copper wiring, but the space rats and non-corporeal vampiric fart-wraiths kept chewing through it (begin dramatic STOS music). With plasma conduits, the whole ship is one big giant bug zapper.
4. EPS conduits can also predict pregnancy when you pee on them. I'd like to see your copper wire do that!

cool

[ionix5891]

all is left now is for someone to come up with a warp drive :p

horray!

[nawcom]

we will bring the name of Jeebus to Mars before the Apocalypse that Revelations speaks of begins.

*runs away after starting un-needed religious flamewar*

Electrically powered engine?

[SupremoMan]

I can see the Big Oil putting a stop to this ASAP!

But the radio signals

[Anonymous Coward]

...have to be playing Magic Carpet Ride

Re:But the radio signals

[actionbastard]

No they will be playing, 'Heavy Metal'. by Don Felder. That way you'll get to experience the 'Awesome Bewbage'.

New, it is not

[ivanthered]

The VASIMIR has been in developement since 1979.
http://en.wikipedia.org/wiki/Variable_specific_impulse_magnetoplasma_rocket

I wonder where they will get the 200 kW to drive it from?

-------------
http://borislegradic.blogspot.com/

Re:New, it is not

[Fast Thick Pants]

Sounds like a job for a small, contained nuclear reaction.

Re:New, it is not

[qoncept]

I'm sure in 1979 they could walk in to any corner drug store and buy plutonium, but this is 2008. No, no, the only thing that could generate that kind of electricity is a bolt of lightning, but unfortunately you never know when or where it's going to strike.

Re:New, it is not

[luzr]

Actually, for ion engine, 0.5N is quite a lot.

You have to consider that these engines are meant to be ON for very long periods of time. Small acceleration accumulates to pretty big velocities if you can afford to leave engines on.

And with this engine, you can.

Re:New, it is not

[Nef]

Seriously, it's only 200 kW? That being the case, a few square meters of solar panel should do just fine, even at Mars like distances, you'd still be getting enough energy that it would be trivial ( something like 5 square meters would be sufficient at even Mars furthest distance of 2.5EE6 KM from the sun)

Yes, I know my figures aren't exact, but this is /., so I'm sure someone will come along and actually do the calculations.

Re:New, it is not

[Squiffy]

Seriously, it's only 200 kW? That being the case, a few square meters of solar panel should do just fine, even at Mars like distances, you'd still be getting enough energy that it would be trivial ( something like 5 square meters would be sufficient at even Mars furthest distance of 2.5EE6 KM from the sun)

Yes, I know my figures aren't exact, but this is /., so I'm sure someone will come along and actually do the calculations.

From the article you linked, the Earth gets 1366 Watts per square meter. 200000/1366 = 146.4.

Near Mars, which gets about half of that flux, you need about 300 square meters.

Re:New, it is not

[Squiffy]

So, a couple of 10 by 15 meter panels. That doesn't sound out of the question.

I wasn't arguing against the use of solar panels. I was correcting OP's arithmetic.

I forgot to include a treatment of the actual efficiency of the solar panels we know how to build. We can build 18% efficient panels, and we might have figured out how raise that efficiency to 50%, so the actual area would be between 300/.5 and 300/.18 (i.e. 600-1700) square meters.

Re:New, it is not

[GleeBot]

A bit simplified, but here are the basic physical relationships:

Power = Energy / Time.
Energy (kinetic) = 1/2 Mass * Velocity^2.

Force (thrust) = Impulse / Time
Impulse = Mass * Velocity.

Over a period of 1 second (Time = 1):

Energy = 50 kW * 1 second = 50 kJ = 50000 kg m^2/s^2 = 1/2 MV^2
M = 2 (50000 kg m^2/s^2) / V^2

Impulse = 0.5 N * 1 second = 0.5 kg m/s = MV
M = (0.5 kg m/s) / V

(0.5 kg m/s) / V = 2 (50 kg m^2/s^2) / V^2
V = 2 (50000 kg m^2/s^2) / (0.5 kg m/s)

V = 200 000 m/s = 200 km/s
M = 2.5e-6 kg = 2.5 mg

Summary: They're pushing a very very tiny amount of mass very very fast. For a given amount of thrust, this is very efficient in terms of mass, terribly wasteful in terms of energy.

Engine?

[jdb2]

Engine? The scaled down test version might use something "conventional" as its power source, such as an RTG. But, in order for the VASIMIR to work at full-scale, say in a human Mars mission, the power source is going need a VERY large energy density -- something not achievable with any known and tested chemical reaction. I have no idea why they call the power source the "engine" but perhaps it's to placate the environmentalist wackos who will go nuts after hearing the obvious : the "engine" or power source is a nuclear reactor. It will be interesting ( and probably funny ) to see how this plays out in the long run if NASA sticks with this technology.

jdb2

Re:Engine?

[samkass]

I think the parent poster was trying to differentiate between an RTG (like Voyager has) which relies on the natural decay of radioactive isotopes and a full-bore nuclear fission reactor which induces decay with a neutron chain reaction.

Re:Engine?

[somepunk]

a better link.

Re:Engine?

[jdb2]

Good luck with that. Not only a nuclear reactor, but a heat exchanger, a turbine, and a generator.

Uhhhhh? Have you ever heard of nuclear thermal rockets? NASA's NERVA program? You know a nuclear reactor can heat substances other than just water. I don't know if you were trying to be funny because "a turbine, and a generator" is just stupid.

That's a lot of complexity for a space mission.

And what space mission is not complicated? There's this thing called "technology" that improves exponentially with time and better technology allows greater complexity.

There are more direct ways to generate electricity with nuclear reactions, but none are really practical for this sort of power output, that I'm aware of. I'm thinking a more straightforward application of nuclear power would work better. Something like this.

I had thought of Antimatter, but we're talking about a near term mission that uses proven and tested technology. ( for its energy source ) Maybe in 50 years we'll be using antimatter for all our energy storage needs, but that implies we'll have large supplies of Anti-Hydrogen ice. Can you tell me where I can buy some today? ( By the way, I'm not a skeptic when it comes to Antimatter based energy storage and propulsion. The problem now is that current particle accelerators are designed to study particle physics, not to produce antimatter. In fact, Robert Forward showed that if we were to build accelerators specifically designed to produce antimatter,( perhaps a special linear wake-field accelerator ) we could potentially produce at least 1 milligram per year at a cost of only around a 10 million dollars. If one where to use many accelerators in parallel that where able to produce higher energies, that amount might be up in the gram-kilogram range.)

jdb2

Re:Engine?

[luzr]

Actually, current solar power of ISS is around 100kw (350 m^2 of solar panels).

So you can perhaps power VASIMIR even using the sun.

No doubt, small nuclear reactor would be an excellent idea too, especially for Mars and further missions....

Re:Engine?

[toby34a]

It will be interesting. However, we've known for a long time that a nuclear reactor would be the best fuel source for a space vessel. Truth be told, it's probably safer to put a nuclear reactor in a spacecraft then in a submarine or aircraft carrier, and the Navy does that all of the time (and it would be more environmental... out in space, you wouldn't have the radioactivity in the oceans). Considering most sub reactors get >100 MW, 200 kW isn't a big deal, and you can power the ship off of it too.

Re:Engine?

[PeterBrett]

Good luck with that. Not only a nuclear reactor, but a heat exchanger, a turbine, and a generator. That's a lot of complexity for a space mission.

Look up the SP-100, which was an interesting NASA project designing a small nuclear fission reactor specifically for safe space use. One of the nice things about running a reactor in space is the fact that you only need radiation shielding in the direction where you've got sensitive equipment (i.e. crew). One of the bad things about running a reactor in space is trying to keep it cool.

Re:Engine?

[CrimsonAvenger]

It will be interesting. However, we've known for a long time that a nuclear reactor would be the best fuel source for a space vessel. Truth be told, it's probably safer to put a nuclear reactor in a spacecraft then in a submarine or aircraft carrier, and the Navy does that all of the time (and it would be more environmental... out in space, you wouldn't have the radioactivity in the oceans). Considering most sub reactors get >100 MW, 200 kW isn't a big deal, and you can power the ship off of it too.

Submarine reactors don't dump radioactivity into the oceans, either. The primary loop (the water moving from the reactor to the steam generators) is a closed loop. The secondary loop (the steam from the steam generators to the turbines to the condensers) is also a closed loop. The only seawater is the coolant for the condensers, which never comes in contact with the (non-radioactive) water of the secondary loop, which (non-radioactive) water never comes into contact with the (not terribly radioactive) water of the primary loop.

I agree that 200KW isn't that big a deal. What you're looking for is the highest power to mass ratio reactor you can manage. Which isn't necessarily the same as the size range for a submarine reactor, since there isn't an ocean out in space to dispose of the waste heat from the secondary loop. Getting rid of that waste heat would likely be the largest part of the mass of the reactor used to power a VASIMR.

This could be good but...

[Coraon]

Make sure you are not an ensign on this ship. Additionally if your in a red shirt it would be best to stay away from the plasma conduits. Or yellow shirt for the next generation of this engine.

energized using radio signals

[KeithJM]

That plasma is then energised further using radio signals

I'll bet they're broadcasting the plasma's college fight song to it.

Just make sure...

[mdm-adph]

...and get the ownership rights for the drive squared away before you make the trip to Mars -- the last time this happened, the resulting legal battles (between the UN and some free-love hippie with a strange fixation for water) lasted for years.

VASIMR Info available on Atomic Rocket Page

[dlapine]

Try this Atomic Rocket website for some more information on this type of engine outside of Wikipedia. What's interesting about this type of engine is that it's capable of trading thrust (what you want to liftoff) for Specific Impulse (what you want in orbit to get best reaction mass efficiency).

This is a pretty good site for information on all types of potential/possible/theoretical propulsion systems, and what it would take to do "real" solar system space travel. That being said, space travel (even within the bounds of just our solar system) via our current level of technology bites.

As someone else noted, this type of propulsion requires about 10MW of electrical energy to function. That energy is not provided by the propulsion system. Something else has to provide it in a compact, dense and energetic form- namely a nuclear reactor onboard the craft. That's why this type of engine shows up at the "Atomic Rocket" website, even though the engine itself doesn't use any nuclear reactions. Some people might not appreciate that the exhaust is not radioactive, as the power plant is just used for electricity.

Unlike a chemical rocket, a spacecraft using this engine would be able to get to orbit with some payload, and would not resemble "a disintegrating totem pole" getting there. Unfortunately, it also requires a nuclear reactor, a VASMIR engine, a large amount (50-75% of the whole thing) of reaction mass, and probably, wings.

Re:that's all good, but..

[oldspewey]

I wonder, aggregate across the internet - how much storage, energy, and bandwidth is wasted by pointless memes?

... and on the day that the internet crosses some critical threshold in computing and storage capacity and actually becomes a self-aware entity, will it be really annoying?

Re:that's all good, but..

[grahamd0]

"I can has DESTROY ALL HUMANS? LOLZ."

[The slashdot yelling filter has not achieved the level of sentience necessary to comprehend satire.]

Re:Scotty

[Amorymeltzer]

Too soon man, too soon.

Exactly What Neds To Be Done

[reallocate]

This is exactly what needs to be done: Provide more speed.

Combine that with a cheap and reliable way to get to LEO and you have the beginnings of a real exploration of the Solar System.

It's VASIMR actually...

[marco.antonio.costa]

This is exactly what needs to be done: Provide more speed.

Combine that with a cheap and reliable way to get to LEO and you have the beginnings of a real exploration of the Solar System.

This engine looks really cool, I've been checking it out for awhile. I really think plasma engines are the tech we'll be using as propulsion.

This is a good trend for us to pursue. Truly SPACE-craft that don't have to be spectacularly and expensively launched and go thru the trouble of reentry every single mission.

Parent's right, what we need now is the most efficient and cheap means to get to space as possible; the new private space companies that are trying out with pure liquid fuel rockets and are failing miserably now could be on the right track. And hopefully the space elevator idea might come to be feasible in the next 50 years.

Then my friends, humanity will have moved OUT of it's parents house, and finally be free.

BCReason

[bcreason]

I'm waiting for the Dirt Drive . Same concept as the Vasimir but instead of throwing Hydrogen away as propellant you use Silicon, the main component of dirt.

Why use precious hydrogen that can be used to make water when you could use dirt. The Moon has dirt, Mars has dirt, most asteroids have dirt.
(Technically it's regolith, but regolith doesn't sound as cool)

I know it will take some serious engineering to make a drive that uses a solid fuel. I'm thinking vaporize it with lasers, then everything else is pretty much the same as with the Vasimir.

Advantages over Hydrogen:

• Easier to obtain
• Easier to store, no pressure vessels required.
• More compact to carry.
• Has more mass, therefore more thrust.
• Safer, non flammable and not stored under pressure. No chance for an explosion.
• Safer, wont leak away if a storage container is holed.

Gaseous Core Nuclear Reactor

[serutan]

A gaseous core reactor would radiate ultraviolet energy directly to the hydrogen, eliminating the need to generate electricity. Take a look at this article about a hypothetical design for a non-polluting, 100% reusable nuclear rocket using the Saturn V form factor that could lift 1000 tons of payload into Earth orbit and return an equal payload to a powered landing.