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Plasma power: The VX-200 rocket being tested at Ad Astra Rocket Company’s facilities in Houston. The total power produced by the engine is distributed between its two electromagnetic stages; both are firing in the image.
Ad Astra Rocket Company
TR: You are developing a propulsion system for deep space missions. What recent advances have you made, and what milestones have you reached?
FCD: We are 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.
TR: What is the next step in development of the engine?
FCD: The next step is to actually build the flight unit, which will be ready to launch October 2013. 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.]
TR: Do you have a vehicle for the system after the ISS work?
FCD: We are already in discussions with SpaceX and Orbital Sciences, the two companies that already have access to the space station [through contracts with NASA], so we can develop the interface in either one of those vehicles. We will make a decision, selecting one of those two probably at the end of next year.
TR: There are arguments that the private sector needs government money to succeed. How are you handling funding?
FCD: It's always a struggle to continue to get investment, but the way we do it is by meeting our milestones. The one we met [last week] will give us ammunition to seek more private investment. It would also be nice to have government funding. When we created the company, it was an experiment in NASA privatization, and the premise was that we would privatize the project and let the private sector mature the technology to the point where NASA would pick it up again, and that time has arrived. So we are always looking for a contract from NASA that would alleviate our need for private investment.
Nanotubes promise better ion-propulsion efficiency.
NASA's new ion-propulsion system could be ready for launch as soon as 2013.
Nice interview. It feels good to see such passion for space exploration. The human species is naturally curious. We have exploration in the genes. I found this argument by Mr. Diaz rather interesting:
Absolutely. Rockets are not a new invention. Reliable rockets were built in World War II, and they were perfected by NASA in the 50s and 60s, and other countries as well. Also, the technology for rocket propulsion is not rocket science anymore. However, we do need advanced propulsion, which is a completely untapped area of research; very little work has been done, and we need to move into that realm because we are not going to get to Mars on chemical rockets. It is going to be too fragile and too dangerous [of a mission] for chemical rockets.
I very much agree with this. Chemical rockets must go. Too dangerous and expensive. But are magnetoplasma rockets the solution to the solar system colonization problem? I'm not so sure and here is why.
As Mr. Diaz observed, rockets are not a new invention. A rocket is a rocket. They are all based on the same basic principle of propulsion. A spaceship powered by non-chemical rockets still has to carry fuel and/or propellant on board. This puts a severe limit on both speed and travel distance. The problem with any kind of rocket is that you have to spend as much time accelerating as you spend decelerating. And the faster you travel, the more fuel you're going to need to carry for acceleration and deceleration. Finally, it's a good bet that magnetoplasma rockets will be just as expensive as traditional rocket technology because it's also going to require complex control and containment machinery and subsystems. Complexity implies lower reliability.
The only way for the space transportation industry to free itself from the technological shackles of the baby-boomer century is to abandon rocket propulsion altogether. Obviously, this will not happen any time soon if the industry is forced to rely on 20th century physics for a solution. But that's what you get for thinking inside the box and your technology is only as advanced as your thinking. Well, thinking outside the box is what I've been doing. And I mean, way outside the box. I have excellent cause to suppose that physics is about to undergo a radical paradigm shift that will forever transform the way we travel and generate power.
A reevaluation of our understanding of the causality of motion leads to the inescapable conclusion that we are immersed in an immense lattice of energetic particles. Soon, we'll use the lattice for both propulsion and clean energy production. We'll have vehicles that can go almost anywhere at tremendous speeds and negotiate right angle turns without slowing down and without incurring any damage due to inertial effects. Floating cities, earth to Mars in hours, New York to Beijing in minutes... That's the future of energy and travel.
My advice to all policy decision makers in the global transportation arena is to take a careful look at the writing on the wall and prepare yourselves for the coming changes.
The Problem with Motion
The big problem seems to be energy storage. Since VASIMR uses electrical energy to energize the plasma, the question remains where the electrical energy will come from. A little poking around reveals that they are considering solar power and nuclear power for a potential martian voyage.
Solar power would obviously be problematic for voyages to Mars. Also I would be concerned about the panels failing, and leaving humans stranded in space. Nuclear would work, but then I don't understand why we would need VASIMR, instead of a nuclear thermal system, which have already been developed.
Sorry if I've misunderstood the issue.
Nuclear would work, but then I don't understand why we would need VASIMR, instead of a nuclear thermal system, which have already been developed.
Solid-core nuclear thermal has an exhaust velocity of ~12,000m/s as an absolute maximum. NERVA, (which you are alluding to), tops out at ~8000m/s using hydrogen.
VASIMR gets ~29,000m/s in high-thrust mode, and ten times that in high impulse mode.
The amount of deltaV you have is directly proportional to the exhaust velocity. This means that your propellant efficiency is determined by exhaust velocity, the faster your propellant flies out the back the less you need.
To get NTR into the efficiency range of VASIMR means going to open-core designs. Even then, NTR can't match VASIMR in high-impulse mode.
(For scale, the space shuttle main engines get 4400m/s and you can't do much better.)
NERVA had an ISP of ~825s in a vacuum. Vasimir, when fully implemented, has a reported ISP of 30,000s to 50,000s.
Very interesting and promising technology for deep space propulsion.
On the commercial is chepaer front, the REAL issue, as identified by Mike Griffin a few weeks ago, is "What Commercial Sector?"
The CURRENT problem is that until orbital space tourism becomes commonplace, there will not be the economies of scale to significantly reduce launch costs. The commercial space launch business is currently tiny, (about 1 launch per year per firm) and these startups are struggling to survive.
Of course, they are quite willing to canabalize our manned space exploration program in order to stay in business.
In another decade the picture may be very different, but for now, NASA is the only real ticket beyond LEO.
I find it interesting that the post critical of privatespace referenced a SpaceReview article written by a Lockheed Martin drone in direct competition with same.
Funny, actually.
We still need something that can take us far out into the solar system.
Nuclear particle propulsion, ion plasma propulsion and other non-renewables cannot do the job.
Solar sails using solar winds/particles would work if could effectively control direction in space.
We need renewable propulsion. Here is one example that uses the collection of cosmic particles as resuable propulsion accelerating mass.
http://nlspropulsion.net/Documents/propulsion_poster.pdf
Dr. Diaz is on the right path but feel further improvements need to be made on his technology to achieve renewable propulsion in space.
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Gaetano Marano
246 Comments
>>> NOT all the "commercial space" is interesting like the VASIMR and (surely) NOT "cheaper" than "old.space" >>>
.
as clearly explained in my comment to this Technology Review article [ http://www.technologyreview.com/business/22869/ ] NOT all the "commercial space" is interesting like the VASIMR and (surely) NOT "cheaper" than old.space hardware
in fact, the new.space cargo-to-ISS will cost between $60M to $95M per ton, that is a price HIGHER that the (already very high) Shuttles and EELVs cargo payloads costs, as explained here:
http://www.ghostnasa.com/posts/042moneywasted.html
and here: http://www.thespacereview.com/article/1447/1
in other words, the "new.space" companies can't "save" NASA then NASA (absolutely) can't rely on them to replace the Shuttles, Ares, Orion, etc.
it's only a big and sad illusion... like the Ares-1
.
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