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Concept art, shows the VASIMR engine powering a moon mission.  (Source: Ad Astra)

The VASIMR engine is of an electric rocket design. This type of rocket is trickier to perfect, but performs better than a chemical rocket, with increased speed, lower costs, and better safety.  (Source: Ad Astra)

A VASIMR engine is shown here in action, generating plasma thrust.  (Source: Ad Astra)

Ad Astra envisions a rich market of spaceflight applications.  (Source: Ad Astra)
Former NASA astronaut turns heads with his innovative engine

Commercial space flight is very expensive.  As a result of its reliance on chemical boosters, the cost of flying a single pound into space aboard the space Shuttle to approximately $5,000 to $6,000.  The cost of launching space missions to far-away bodies such as the Moon or Mars grows exponentially higher -- it is estimated that the cost of sending one pound sent to the Moon is around $200,000.  These extreme costs have put longer manned commercials spaceflight out of reach, with the commercial space industry instead turning to a few luxury tourism startups.

While much of this fuel is expended on launch, some is also expended in the vacuum.  And as longer missions are attempted, the need for more efficient rockets operating in the vacuum increases.

A new engine, named VASIMR, could provide exactly the solution needed.  Developed by former astronaut Franklin Chang Diaz, the engine could change a lot about how we interact with space.  The new rocket, driven by plasma, is able to use cheaper fuels like neon, argon, or hydrogen, while providing finer control over thrust and specific impulse -- two key parameters that determine a rocket's movement and speed.  The new rocket is also much safer and more reliable than traditional chemical rockets, reducing the risks associated with space flight.

The engine exhausts plasma, a fourth state of matter along with solids, liquids, and gases.  Plasma is essentially ionized gas.  It is typically created via either low pressure or extremely high heat (10,000° C or more).  Plasma consists of a mix of electrons and positively charged gas ions.

No known material can contain plasma, so VASIMR instead uses magnetic fields for containment.  It uses radio frequency waves to ignite and throttle the rocket precisely.  The rocket is capable of long burns, with its long term goal being to produce enough sustained thrust and impulse to reach Mars in under three months.

The new engine is the flagship technology of Mr. Diaz's startup, Ad Astra Rocket Company.  After three decades of development at NASA, MIT, and elsewhere, the rocket engine is finally approaching commercial readiness.  The rocket recently passed a momentous milestone -- 200 kilowatts of power, the amount necessary for the company to start developing its flight version.

According to Mr. Diaz, "[Ad Astra is] getting ready to fly the VASIMR engine on the International Space Station (ISS). It is a 200-kilowatt plasma rocket, the most powerful rocket ever built to fly in space, and the prototype is being tested on the ground in our facilities in Houston. We have been gradually ramping up the power over many months, and our goal is to reach 200 kilowatts, which is the power level the rocket will run at on the ISS, and we achieved that today. We actually reached 201 kilowatts. It was a very exciting moment because it happened right when we were in the meeting, and I kept getting text messages."

The rocket will be first tested in space in October 2013, aboard the International Space Station.  Describes Mr. Diaz, "We will install it on the ISS and test it there. After the test is finished, we will use it commercially to reboost the space station [to a higher altitude] to provide the drag compensation. [Currently the ISS requires periodic boosts to get it to the right orbit for space shuttle or Progress dockings.]"

Ad Astra is trying to convince NASA to enter a greater contractual relationship with it to lower costs manned and unmanned space missions, via use of the VASIMR engine.  Given the shaky state of NASA's Shuttle-successor, Orion, that certainly seems possible.  Founder Diaz believes that using commercial bidding and innovation are key to NASA and other international space organizations lowering their costs, as well as the key to getting other commercial entities involved in the space industry.

Mr. Diaz explains, "The agency really transformed the world in space with the achievements of the moon landings, but the whole world changed, and NASA didn't change. NASA remained in the glory days of the past, and 40 years have gone by, and NASA is still the same NASA as the 1960s. And I don't mean it in a bad way. It was so wonderful what was done, and people were completely fascinated by it. But a new opportunity has been created because NASA's fascination with its own past in the present has created a gap, a hole, which is perfect for the private sector to move into.

"The private sector is going to fill the void in rapid access to low earth orbit, allowing NASA to be NASA, to do what NASA was really meant to do, which is look forward to the frontier. Let the private enterprise build the base camp now that we know how to do it, and NASA can go conquer the summit."

The startup is in talks with two space tourism companies -- SpaceX and Orbital Sciences -- to create the body to house the VASIMR engine and finish a contract-ready rocket, which would incorporate efficient chemical boosters to reach orbit and then fire the VASIMR to continue its spaceflight.  Both of these organizations have the advantage of access contracts to the ISS -- Ad Astra is currently trying to figure out which best meets its needs.



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Power =/= Thrust
By Amiga500 on 10/7/2009 9:29:19 AM , Rating: 2
What is the thrust rating?!?! How efficiently is the input power converted to useable thrust?




RE: Power =/= Thrust
By Amiga500 on 10/7/2009 9:30:55 AM , Rating: 1
Ach... after a moments digging...

... 5 Newtons.

Not a real landmark day for space exploration just yet!


RE: Power =/= Thrust
By MozeeToby on 10/7/2009 11:12:48 AM , Rating: 5
5 Newtons that can be run continiously for weeks, months, or years is absolutely news. Look at it this way, if you have a 500 kg probe and a motor that can produce 5 N for 6 months, the final velocity of that probe is 150000 m/s.

That's quick enough to get a probe past Pluto in less than a year, without gravity assists (presumably it would be much faster with them). It's more than enough to revolutionize our unmanned missions.


RE: Power =/= Thrust
By Chernobyl68 on 10/7/2009 12:33:00 PM , Rating: 2
I don't know what its fuel consumption is, but since it uses much simpler gases as fuel (as opposed to more dangerous chemicals in chemical rockets) means it could be easily refueled on the space station if the need arose.


RE: Power =/= Thrust
By stromgald30 on 10/7/2009 1:26:26 PM , Rating: 2
While what you're saying is true, VASMR engines do bring about many of the other issues that already exists with current ion thrusters, specifically the warm-up time (no last minute escapes with this engine), the high EM field (can't put this thing anywhere near computer boxes), and the high likelihood of building up a significant electrical charge on the vehicle (which can also disturb on-board electronics).

So, yes it's safer from a toxicity or blow you out of the sky standpoint, but it's not necessarily safer from an overall mission standpoint.


RE: Power =/= Thrust
By jimwhd on 10/7/2009 2:42:34 PM , Rating: 2
quote:
While what you're saying is true, VASMR engines do bring about many of the other issues that already exists with current ion thrusters, specifically the warm-up time (no last minute escapes with this engine), the high EM field (can't put this thing anywhere near computer boxes), and the high likelihood of building up a significant electrical charge on the vehicle (which can also disturb on-board electronics). So, yes it's safer from a toxicity or blow you out of the sky standpoint, but it's not necessarily safer from an overall mission standpoint.


Couldn't the electrical charge on the vehicle be discharged in the same manner that is used in commercial aircraft via a "static wick"?


RE: Power =/= Thrust
By Ringold on 10/7/2009 3:16:42 PM , Rating: 2
My understanding, at least as told to me by a flight instructor back in the day, is that those "static wicks" disperse the charge in to the air behind the aircraft. No air in space?


RE: Power =/= Thrust
By Hogger1 on 10/8/2009 8:18:02 AM , Rating: 5
"But there is an Air n Space Museum." Homer S.


RE: Power =/= Thrust
By bug77 on 10/7/2009 5:17:57 PM , Rating: 2
Not to mention that "no known material can contain plasma". Still, a whole new way to look at space flight cannot be a bad thing.


RE: Power =/= Thrust
By stromgald30 on 10/8/2009 5:25:22 PM , Rating: 2
You don't have to contain plasma and deliver it on-board. Plasma is created from electricity and inert gas (Argon, Xenon, etc). The inert gas can be delivered on-board much more easily than chemical propellants.


RE: Power =/= Thrust
By MrPoletski on 10/12/2009 6:29:18 AM , Rating: 2
How will you end up with a significant electrical charge building up?

what is doing the charging, bearing in mind that this fuel plasma will not come in contact with any part of the ship because it is electromagnetically contained - and hence no charge from it will conduct to the ship either.

Ion drives will charge your ship because you are deliberately ionising matter that you make no real effort to prevent from contacting the ship.

Also, when you are not thrusting, what is to stop you holding some superhot plasma ready to go? It will cost energy, sure, but it'd certainly be worth doing in the case of anticipating possibly needing an emergency burn.


RE: Power =/= Thrust
By stromgald30 on 10/12/2009 1:15:08 PM , Rating: 2
Plasma contains a mix of ions. When you heat almost any gas to the temperatures of plasma, it ionizes. However, unlike ion drives, both positive and negative ions are exhausted together, so there's no need for neutralizing the charge at the exhaust with a cathode.

One of the biggest issues with the VASIMR is the fact that there is a tendency for the plasma ions to follow the magnetic field lines around to the front of the engine (you can't have a magnetic monopole). This would charge up the ship if the ions are cool enough or damage it, if they're still in plasma form. It never comes up in laboratory tests because the way the test cells are set up prevents this problem. It's not an insurmountable engineering problem, just one that requires space trials and careful usage of the engine.

Holding plasma in the chamber is possible, but I'd be more concerned with damage to the engine rather than power (since this thing is supposed to used 24/7). Think of shooting water through a pipe. If the water's fast enough, it won't go into any 90 degree branches off the straight pipe. However, if you try to just hold the water in the pipe or slow the flow, it will expand/fill areas you don't want it to get to. The magnetic field to contain and accelerate the plasma isn't perfect. There will be weak spots. Holding plasma for long periods would be asking for trouble in stray plasma molecules contacting the inside of the chamber.

I don't mean to come off as bashing the new technology, I just know of some limitations and think that it will not completely replace the current chemical engines.


RE: Power =/= Thrust
By MrPoletski on 10/13/2009 5:26:34 AM , Rating: 2
Would be nice if it could use helium, the by product of nuclear fusion.

Then this engine could be combined with a fusion reactor (when we get them working proper) for super space age fun!


RE: Power =/= Thrust
By Amiga500 on 10/7/2009 12:41:49 PM , Rating: 2
(In my opinion) the real problem is not travel in space - simple inertia takes care of that. You get there eventually.

The real problem is getting out of the earth's gravity well.

An ion engine that can feasibly replace the chemical rocket on a 3rd stage of a launch vehicle would be groundbreaking. Unfortunately, this isn't there yet.


RE: Power =/= Thrust
By JasonMick (blog) on 10/7/2009 1:15:59 PM , Rating: 2
Combine this thing with a space elevator and you're good to go.

...of course a space elevator is going to take a bit longer, but there has been a lot of good progress in that front as of late, too.


RE: Power =/= Thrust
By kattanna on 10/7/2009 1:24:06 PM , Rating: 5
quote:
...of course a space elevator is going to take a bit longer, but there has been a lot of good progress in that front as of late, too.


since im still laughing, we have at least another 50 years

;>)


RE: Power =/= Thrust
By EricR on 10/7/2009 3:33:09 PM , Rating: 2
quote:
5 Newtons that can be run continiously for weeks, months, or years is absolutely news. Look at it this way, if you have a 500 kg probe and a motor that can produce 5 N for 6 months, the final velocity of that probe is 150000 m/s. That's quick enough to get a probe past Pluto in less than a year, without gravity assists


Hmm,

150000 m/s (or 335540 mph) = Don't blink or you'll miss it!


RE: Power =/= Thrust
By Etsp on 10/7/2009 4:40:51 PM , Rating: 5
That's 93 miles per second. It's likely you'll miss it even if you don't blink!


RE: Power =/= Thrust
By MrPoletski on 10/12/2009 6:08:19 AM , Rating: 2
93 miles per second...

Well, only 186,123 miles/s to go then...;)


RE: Power =/= Thrust
By Morro on 10/7/2009 8:55:37 PM , Rating: 2
Ok, for 500kg probe traveling at 150000 m/s and having thrust of about 5N and acceleration of 0.01 m/s^2 (F/m) will result in kinetic energy increase of about 750kW per second. Not bad for 200kW engine ;)


RE: Power =/= Thrust
By Morro on 10/7/2009 8:57:13 PM , Rating: 2
I meant KJ per second, as you can guess..


RE: Power =/= Thrust
By Hyperion1400 on 10/8/2009 10:19:51 AM , Rating: 2
Deep space kinetic energy weapons anyone? >:)

"Opps, sorry China, we were trying to puss that 2 kilometer wide asteroid into to orbit to try and harvest it. It slipped, honest!"


RE: Power =/= Thrust
By 91TTZ on 10/7/2009 4:05:28 PM , Rating: 2
quote:
5 Newtons that can be run continiously for weeks, months, or years is absolutely news. Look at it this way, if you have a 500 kg probe and a motor that can produce 5 N for 6 months, the final velocity of that probe is 150000 m/s.


But how would you power it? This engine made 5 newtons at 200KW. RTG's are usually the powerplant of choice, but their power output is low, usually only a few hundred watts for a device weighing a hundred pounds or so. This engine would require almost a thousand times more power.


RE: Power =/= Thrust
By manofhorn on 10/7/2009 10:41:10 AM , Rating: 2
and am i really missing something here, or is 200kw just over 250 horsepower? THAT'S the most powerful rocket ever built to fly in space?


RE: Power =/= Thrust
By Amiga500 on 10/7/2009 10:47:04 AM , Rating: 2
No, well.

Thats kinda what I was asking.

200kW/250hp is the power rating at the engine crankshaft so to speak.

I was wondering what the 'power rating' at the wheel hubs were.


RE: Power =/= Thrust
By MozeeToby on 10/7/2009 11:20:52 AM , Rating: 3
It has the highest Delta V of any rocket in space, not highest power. A chemical rocket will produce much, much more thrust but can only run for a very short time and requires a lot of fuel to power it. This thing produces very little thrust (5 N) but can run for months and uses very little fuel. Having to take less fuel further increases the efficiency since you don't need to haul as much fuel with you.

The practical upshot of all that is very slow accelleration but a very high top speed, much higher than is possible with chemical rockets. Or, alternatively, the ability to stabalize a satellite/space station orbit without having to constantly send up more rocket fuel to do so.


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