VASIMR Discussions

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Gravity_Ray

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I don’t want to mess with Jakethesnake's VASIMR update tread, but I really want to talk about this technology.

1. I really want to see Bolden move NASA towards massive funding of this technology and also nuclear power to provide the power VASIMR needs to get to the 200-kilowatt engine, the VX-200.

2. NASA should be giving Ad Astra a contract with some money for additional testing to get this technology to level 7 ASAP.

3. I really want to see NASA make this a demonstration mission for the ISS after the Russian re-boost contract with the ISS is finished.

4. Talk about a natural fit for building a space ship in space (preferably in high Earth orbit) maybe in a LaGrange point. This is the ship that we should be building (and I want the first one to be named Enterprise). This ship is perfect for our NEO encounters and also the first trip to Mars in a decade or so.

5. Is Chang Diaz the best astronaut scientist out there or what?

Bring on the discussions.
 
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sftommy

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Promising technology;
Argon plasma jets, no node erosion, but still need to solve the heat problem associated with magnetic containment. Same problem with mag-lev launch technologies; the heat generated by the magnets. Navy seems to have found some way around it as their next generation projected aircraft carriers are said to have mag-lev launchers.

About to show my engineering ignorance, but why doesn't the heat energy just get recycled back into power systems? In VASIMR or mag-lev launch technologies? Seems like a not insurmountable problem?
 
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Gravity_Ray

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Thanks rockett

Gotta love JSC.

What does it mean when in one sentence it says "NASA/JSC is planning to purchases services from Ad Astra", but in the next paragraph it says "The Government does not intend to acquire a commercial item.."

This is the kind of technology that NASA should be fostering. Going to Mars with chemical rockets is just not that smart. Time in space is not very good for life.
 
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rockett

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Gravity_Ray":33kmm21f said:
What does it mean when in one sentence it says "NASA/JSC is planning to purchases services from Ad Astra", but in the next paragraph it says "The Government does not intend to acquire a commercial item.."
Well Ray, I would suspect (not being a lawyer) that it means they don't intend to buy the engine, just a demonstration of it's capabilities. While true, it would be sent to the ISS, they are not committing to purchasing the finished product.
Gravity_Ray":33kmm21f said:
This is the kind of technology that NASA should be fostering. Going to Mars with chemical rockets is just not that smart. Time in space is not very good for life.
I agree with you there, and I do question their lack of commitment, but that seems to be the modus operandi of this NASA administration. Check it out, talk it up, but commit to nothing...
 
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rcsplinters

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Ray, here's another link:

http://www.spaceflightnow.com/news/n1006/01vasimr

The regulars won't find much of interest in that article but some might find the background to be useful. It does make the point about the importance of the 1kg/kw barrier. From my reading that is the key technological and engineering challenge. The thing that so many overlook is that such a power source may have some significant ground application as well. When we talk about the costs of space flight, folks like to leave the spinoffs out of the equation. Such a lightweight power source could be very significant spinoff.

I agree that these technologies show vastly more promise for investment than flight to LEO. Personally, I would like to see the results from a mission planner in regards to the timeline particularly with time on site versus in transit relative to planet positions. Would the mission still be as sensitive to planet position or would the technology enable trajectories that limit us to missions of a very specific duration as a result of planet alignment. I'd also like to see how such technology would impact capabilities once in LEO. Silly as it might sound, with greater ability to manuver in orbit, we might find a means to capture and slow space junk only to release it to burn and then match trajectory to capture another piece, rinse and repeat.

Personally, I don't expect a lot of practical application of VASIMR till the power requirements are managed. Once that's accomplished, then we really might have an example of a "game changer".
 
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Gravity_Ray

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Another thing I got from this article is what a difference a strong personality makes in a private Endeavour versus a public Endeavour.

For example what Chang Diaz and Ad Astra did with $20 million in less than 5 years is amazing. They basically brought this technology from a 2 to a 6. For that much money NASA can do maybe one study on safety in about the same time frame. This is repeated over and over again with people like Musk and Bigelow. This proves that a private company can do much more with much less than any public Endeavour in the field of space travel.

If I understand this correctly (and some one will correct me if I am wrong), the reason why a VSIMR engine is preferable to a chemical engine is the fact that due to much smaller amounts fuel needed a VSIMR engine can be turned on to full half way to destination to accelerate and turned on the rest of the way to decelerate. If you were to do that with a chemical rocket about 90% of your mass would be fuel and you will basically be able to get to Mars plant a flag and come back. This is EXACTLY what we do not need to do. So a space ship with a VSIMR engine can get around much better AND when it gets there the mission will be much more meaningful.

I actually agree with you about a more powerful nuclear reactor needed to generate more power, but even a smaller nuclear reactor such as a RTG (Radioisotope Thermoelectric Generator) can be used for a cluster of VASIMR engines. A space ship can for example have a cluster of 3 or 6 (100 Kilowatt) VASIMR engines. Of course less but larger engines will simplify things and therefore be safer.

I also like your application for a VSIMR rocket to clean up space junk. I suspect a robotic ship can do that and you can probably make some good money from various companies that need satellite orbits that are currently too dangerous to use.
 
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James_Bull

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NASA's space propulsion research has to be focused on a megawatt class VASIMR engine AND a space capable nuclear reactor. Realistically speaking, it really is the only we're going to get manned flight out of the Earth's gravity well. Mars and even the Jovian moons could become within reach. Personally I was very happy when Constallation program was cancelled. It was very short sighted and would have completed devasted technology development for 15 years... What private companies have done with tech projects that were all cancelled to fund Steroid Apollo is absolutely incredible. But now they need and will get a lot more money.
Now we may have a chance to see man exploring the solar system within our lifetimes. :)
 
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rcsplinters

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I'm not so sure I buy into the private company is better argument. I do believe that persons of vision are essential in any organization. Remember Von Braun's employer was none other than the good ole US government. I know guys that saw him in action and each said he was smart, full of charisma and an unequaled program planner. Which brings me to this.

Remember that these technologies are not going to be ready to take us out of orbit for many many decades. We are still going to need huge rockets to get us to orbit, 100 tons or more (which is why I want Constellation. I don't think we go anywhere without Ares V). We're going to need another huge pop to get us out of orbit , very quickly anyway. Where these technologies would come to play would be after those two events have taken place, sort'a like fifth gear on a car. Go fast, less fuel, no heavy acceleration. However, once we are on our way, I really wish some mission planner would do some detailed work on what a Mars mission or a Martian Moon mission might look like. Do we accelerate halfway and turn around? Do we accelerate a lot more than half way and use the atmosphere slow down. What does this buy us in terms of mission length, transit times. Would it make a rescue mission of sorts possible? Once we're there, do we have to have another chemical booster to get back out of orbit or is the gravity there low enough to make VASIMR type propulsion practicial to leave?

I have a bunch of questions like that for LEO operations as well. What could we do in LEO with a low impulse long duration motor? Does that open up some capability we don't have today? Maybe the paradigm of putting a human in orbit shifts dramatically. We launch them with 6 hours of supplies and transfer them to a tug which never lands. The tug might take a week to move from "staging" orbit to something 300 - 400 miles up or higher. This would start to make human to LEO with a single stage much more practical. That said for a VASIMR tug, you'd still need a massively heavy lift capability which needn't be man rated (have to get it up there in the first place). Those guys would have to be stocked for weeks or months. What do missions like that look like?

It would be cool to see some detailed mission designs which presume such capability exists.
 
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Valcan

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RCS,

Something like the tug has been discussed here a few times before.

I think people need to stop thinking of LEO as the destination for the ships and stations and start thinking of it as the place to build and assemble such things then with tugs boost them to higher orbits and paths.

Or as ive said before....we need a space capable drydock for construction and repair.
 
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aaron38

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rcsplinters":27ohsqph said:
I'm not so sure I buy into the private company is better argument.
I'll make this argument in it's behalf. Right now if a nation wants a space program, they need to R&D, build and operate their rocket all by themselves. And that's not very efficient. Immagine if air travel was that way, if each nation's airlines only used airplanes designed and built by that nation's government.

Did Air India have to research, design, build, flight test and safety rate their own jumbo jet? No, they just buy them from Boeing and Airbus. For this planet to sucessfully colonize space, what we can't do is reinvent the wheel a hundred times over. So now if India wants a space program, they can just buy a couple Bigelow modules and some SpaceX flights and they're in business. They can focus on what they want to DO in space, not how to get there.

And conversely SpaceX doesn't have to worry about mission planning, just like Boeing doesn't have to worry about day to day operations of an airline.

I want the government efforts out there on the bleeding edge, pushing the envelope. Once they figure out how to do something, they pass the baton and move on to the next challenge. NASA's role is now to get to the moon and start using all that water we just found.

But someday water extraction will be handed off to a private company and NASA moves on again. I don't see us getting there any other way.
 
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Gravity_Ray

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aaron38":3fvqp0e7 said:
I want the government efforts out there on the bleeding edge, pushing the envelope. Once they figure out how to do something, they pass the baton and move on to the next challenge. NASA's role is now to get to the moon and start using all that water we just found.
A VASIMR space ship (tug boat) what ever you want to call it is exactly the kind of new technology that needs to be supported by NASA. I am very happy to see JSC supporting Ad Astra with funds to move this technology into production and testing in space.

Deep space should now be the arena of NASA not LEO.

I understand the need for Congress to have a goal; it’s like a baby learning to hold a bottle on his own. Since Congress appears so stupid that technological advancement in space is too complicated of a goal for them, this kind of Space Ship would be a good way to keep the little idiots happy. If they want a goal, then tell them the goal is to build the Space Ship Enterprise on a 5 year mission to explore our solar system with a crew of people along with robotic support powered by an RTG and pushed along with a VASIMR engine (or cluster of engines).
 
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sftommy

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Remember Von Braun's employer was none other than the good ole US government.
I also remember Von Braun's other employer was none other than Adolf Hitler

....we need a space capable drydock for construction and repair.
I agree, launch small (or large for that matter), assemble (or repair) into larger structures in orbit. The larger Bigelows may provide the first "hangers" to do that and I suspect if it were brought up, somebody there has already done preliminary drawings.

I'd like to see a Lunar shuttle theoretical study built around the VASIMR working out of NEO to a lunar orbit on an ongoing basis. Sounds like a practical challenge to have something like that going or under serious development in the 2020s.
 
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docm

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Bigelow does indeed have a concept for a refueling/assembly for placement at L1. This is where he plans to assemble his land-able lunar base.
 
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aaron38

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Gravity_Ray":28ouvxkl said:
A VASIMR space ship (tug boat) what ever you want to call it is exactly the kind of new technology that needs to be supported by NASA. I am very happy to see JSC supporting Ad Astra with funds to move this technology into production and testing in space.
Right. NASA should be pushing hard to get that technology developed and flying. After the ISS test runs, I want to see that lunar tug built ASAP, because that is the space infrastructure needed to dramatically cut the cost of cargo delivery to the Moon.

But I don't want NASA in the freight hauling business either. So once the lunar tug is functional, hand that batton off and move on to the next challenge. Private industry can then handle building more and running day to day operations. Building infrastructure is NASA's job.
 
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docm

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Aviation Week....

Vasimr Prototype Makes New Strides

HOUSTON — Ad Astra Rocket Co., led by former NASA astronaut Franklin Chang-Diaz, reports new strides in the performance of its experimental 200-kw. Variable Specific Impulse Magneto-plasma Rocket (Vasimr), the VX-200, which the company is developing as a commercial propulsion source for a range of future deep space and possible near-Earth missions.
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Earlier this week, Ad Astra completed a six-month round of testing in which it dramatically improved the timing and performance of the startup of the VX-200’s 30-kw. first stage. Other testing in the company’s large vacuum chamber verified efficiencies of greater than 50% in the conversion of electricity to thrust through 112 kw., with combined first- and second-stage operations.
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During follow-on testing over the first six months of this year, Ad Astra reduced the first-stage startup time from 6 sec. to 60 millisec. At the same time, engineers improved the success rate of the ignition process from 50% to 99% through characterizations of the electronic circuitry and software adjustments.

The latest round of testing mapped the efficiency of dual-stage operations through 112 kw. at 55%, closely matching predictions. “Anything over 50 percent is good,” Chang-Diaz says.

The efficiency predictions climb to 60% at 200 kw., or full thrust.
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orionrider

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Just found this about the HTRE, the only nuclear reactor actually flight-tested by the USA (1957): http://www.megazone.org/ANP/tech.shtml
If the article is accurate, the reactor had a mass of 5 tons for 35 MW of (raw) power :shock:
That is much lighter and powerful than I thought. The data I had seen until now was about very small (<100kw) designs, like the ones discussed in the link from Boris.

Are there studies or prototypes of large nuclear generators that could be compatible with VASIMR :?:
 
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orionrider

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One VASIMR study hypothesized using a 200-megawatt nuclear power system. The result, he [Chang Diaz] added, showed that 20 metric tons could be delivered to Mars in 39 days.
20 tons, including the VASIMR propulsion, reaction mass, the nuclear reactor and the electrical converter.
Ah, and the cosmonauts, water, food, air, and of course the vessel itself...

:| :? :( :cry:
 
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docm

Guest
The 200mw mission would require new efficient designs, but FCD has also said that as little as 12mw would shorten a Mars mission dramatically. That's much more manageable.

Interesting article today in Aviation Week....

Ad Astra Ponders Vasimr Mission To Asteroid

Ad Astra Rocket Co. is assessing a cooperative unmanned rendezvous mission to a yet-to-be-selected asteroid with a spacecraft and scientific payload powered by the experimental Variable Specific Impulse Magnetoplasma Rocket (Vasimr), according to Franklin Chang-Diaz, the seven-time space shuttle astronaut who serves as the company’s CEO and president.

Ad Astra’s efforts come against the backdrop of President Barack Obama’s recently announced plans for NASA to begin working toward a manned asteroid rendezvous, circa 2025, that would mark humanity’s first foray beyond the Moon (AW&amp;amp;ST April 19, p. 28).
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“This is all very new stuff we are discussing,” says Chang-Diaz. “The point is we have not really quite decided what to do with the second engine,” he says. “Once the first engine is up and flying, we are thinking maybe the second engine could be used in another spacecraft, a free-flyer of some sort.”
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Ad Astra was incorporated five years ago to advance the development of electric space plasma propulsion started by Chang-Diaz while he was a graduate student at the Massachusetts Institute of Technology and nurtured while he served in NASA’s astronaut corps between 1980 and 2005. Since leaving the space agency, Chang-Diaz has pursued commercial development under a series of Space Act agreements.

Ad Astra’s strategy is to graduate from the municipal power grid as a source of electricity to space solar power demonstrations. The ultimate goal is a 200-megawatt space nuclear reactor as the source of electricity to generate the plasma thrust for fast missions to Mars. The company would develop and lease the plasma rockets for missions that range from satellite-servicing and orbital debris removal to slinging spacecraft on accelerated deep space missions with scientific payloads and human explorers.
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aaron38

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I don't have a problem with a VASIMR mission to an asteroid, it's a good engine demonstration, but I don't think it's all that practical at the moment, unless the mission is to actually try to change the asteroid's orbit as a demonstration.

But I really think the Lunar Tug should be first. Doubling the 100mT launcher payload to Luna and allowing a highly integrated ice miner/fuel processor vehicle to be landed is a key technical capability we don't have at the moment.

As much as I'd love to lob Mars Direct missions every 2 years, it's not happening anytime soon. So let's get dug in on the Moon and build up the infrastructure. The work on the 200MW version can continue while the 2MW Tug validates the current design.
 
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orionrider

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unless the mission is to actually try to change the asteroid's orbit as a demonstration.
I don't believe anything Ad Astra has at the moment could have a measurable effect on an asteroid.
Even a meteoroid of only 30m across would mass 100,000 tons, compared to the 400 tons of the much larger ISS.
The VX200 engine produces a force of only 5N.

That is about what a medium hamburger with fries and ketchup exerts on your kitchen table.

;)
 
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aaron38

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Well then I say scrap the asteroid mission and focus on the Tug. It's time to invest in infrastructure that lowers long term costs.
 
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nimbus

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[youtube]http://www.youtube.com/watch?v=JOyrzUr57dE[/youtube][youtube]http://www.youtube.com/watch?v=PCAwwV-4DUo[/youtube]
[youtube]http://www.youtube.com/watch?v=lPsWfmEqORk[/youtube][youtube]http://www.youtube.com/watch?v=ptOgqQIC1-k[/youtube]
[youtube]http://www.youtube.com/watch?v=f26NClLvpWA[/youtube][youtube]http://www.youtube.com/watch?v=pvjt-eZFqVM[/youtube]
 
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