Super 'sun-hot' plasma rocket in fullbore bench test triumph


Posted in Space, 5th October 2009 12:13 GMT



A radical, highly fuel-efficient plasma rocket whose interior operates at temperatures close to those found inside the sun has passed a key test milestone. Trials of the space drive aboard the International Space Station are expected within the next few years.


The superpowered rocket design is known as the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), and it is under development by former NASA astronaut and physicist Franklin Chang Díaz at his spinout company Ad Astra Rocket. Last week the experimental VX-200 test rig - which is partly British made - reached its full rated 200 kilowatt power, an achievement described by the firm as a "highly coveted milestone".

VASIMR works by turning Argon reaction mass into terrifically hot plasma - nearly as hot as "the interior of the sun" according to Ad Astra - and blasting it out of the engine's rocket nozzle. Because the argon is ejected with such terrific speed, a VASIMR-propelled ship would get a lot more poke out of a given amount of propellant than one driven by everyday chemical rockets.

One downside is that the amount of thrust produced is small in comparison to the plasma drive's mass, meaning that VASIMRs couldn't lift themselves out of Earth's atmosphere. The plasma drive would outspeed chemical rockets not by pushing harder, but by pushing for much longer, so achieving a much higher velocity over time. Another snag is that significant amounts of electrical power are required, the generation of which is an issue in space.

For relatively easy missions close in to the Sun, VASIMRs could run usefully on solar panels, the mainstream means of generating electricity in spacecraft. Solar-powered plasma drives, Chang Díaz says, could save fuel over chemical ones doing tasks such as maintaining the ISS in orbit, or driving ships between the Earth and Moon.

Solar VASIMR would also, according to the veteran astronaut's calculations, be of use on a Mars mission. However he has suggested in the past that a solar-powered Mars mission would be "technically feasible but operationally fragile", adding that "as their robotic precursors have done, future human interplanetary spacecraft will rely on nuclear power to explore the far reaches of the solar system and beyond".

The greater power offered by nuclear reactors would make for much more puissant interplanetary ships. If small dustbin-sized reactors (of the same class nowadays used in submarines) could be employed, Chang Díaz believes that VASIMR ships could reach Mars in just 39 days, a huge improvement over chemically-propelled craft which would have to coast almost all the way and take six months. (The concept vid above shows a longer trip using slightly different assumptions, but still very fast compared to a conventional ship). Manned missions to the moons of Jupiter or other destinations in the outer Solar System would also become realistic with nuclear VASIMR.

The use of nuclear power in space is actually fairly routine, but it has occurred mostly in top-secret spy satellites and so hasn't caused much debate. Anti-nuclear protests have occurred when such tech has been used in civil craft.

For now, though, Chang Díaz and his team at Ad Astra are focused on building a flight-rated version of their technology, the VF-200-1. This is already underway, and the successful VX-200 fullbore trial has made engineers confident that it will work. Plans call for the VF-200-1 to be tested in space aboard the ISS in 2013.

“This latest achievement is a fitting tribute to the outstanding Ad Astra team. I am proud and honored to have the opportunity to work alongside this superb group of individuals who turn dreams into reality," says Chang Díaz.

I like this part - a developmental effort by a non-government entity. I really believe more efforts like this are not only what's necessary to spur space exploration, it's the correct way to do it.

IBOTGC

(In Before "Only The Government Can")

Sweet. When can we get phased plasma rifles in the 40W range? I can't wait to tapco fuck up one of those things.

This could mean realistic mining of the asteroid belt and sourcing fuel offplanet.

Imagine the number of jobs that could be created in the private sector to build equipment/ ships/ storage etc. to facilitate that....  REAL economic recovery.

Solar sail outbound, plasma drive inbound could work real well.

This new drive totally changes the math on the amount of time it would take to get to Mars. There was  a pretty good writeup on this subject a couple months ago in Aviation Week and Space Technology.
New engine could be a major game changer.

I'd love to see someone go after the refined metals in the asteroid belt!




This could be good in other areas as well. Advances in controlling superheated plasma

for rockets could lead to advances in other areas... Like fusion power!




 

Government will never allow this to happen.  The government view of space is that "the people own it".  In world where collectivism is heralded and where self interest is demagogued, major technological breakthroughs will not be allowed to be profiteered.

Can anyone elaborate on the part in red?  Is he implying that the Mars rovers Spirit and Opportunity have nuclear materials on them?  I hadn't heard that....I thought they were entirely solar/battery powered.

OK so what the hell is a dustbin and why would anybody keep their dust in a bin anyways?

He's talking about the various interplanetary deep space probes.

As a kid who was born in the beginning of the 70's and has idolized astronauts his whole life, I can't fathom anybody that doesn't think that American's birthright is not space exploration and settlement.  We are a country of pioneers.  It is only recently that we've becomed hobbled by socilaist ideals and perverse concepts of fairness.  We need to have manned mining operations in the asteroid belt and bases on the moon and Mars.  Time for us to prove to the world once again what is possible with hard work and perseverance.

Spirit and Opportunity are indeed solar powered.

My guess is he's talking about other interplanetary missions (Vikings 1+2, Voyagers 1+2, Galileo, Ulysses) that flew with RTGs.

Not the rovers, but spacecraft like the Voyagers.

They are solar/battery, but Mars is right at the edge of where Solar makes sense at all. And Mars has a roughly 24h day just like earth, so depending on the latitude, you're getting 12 hours or less of sunshine. And IMO, the Mars rovers would have been nuclear/RTG powered if there wouldn't have been political hassles to doing so. The higher energy density of a nuclear RTG, or even a full-blown reactor also just gives more power per pound than even the best cost-is-no-object solar panels which is good from a sicience standpoint.

From the viewpoint of Aerospace engineers and NASA, more power = more insturments = more science.

The original Viking landers were RTG powered. And despite how long the rovers lasted past their design specs,  the cold and dust of the Martian environment did take it's toll on the rover's solar panels and the batteries. The rovers were even "rescued" more than once by Martian windstorms that dusted off the panels, allowing NASA/JPL to eek a few more percentage points of power out and do some more exploring. The other huge benefit of operating in Mars-space and further out from the sun is that a nuclear power plant's waste heat actually helps keep the spacecraft functional so the valves in thruster systems keep working, camera platform gears from seizing up, and the electronics from doing truly weird things, etc.

Besides the main RTG, the Voyager probes actually have Plutonium pellets scattered about their chassis at strategic points to increase their reliability in the outer Solar System. The heat from the radioactive decay is conducted through the probe's structure to keep vital components a few degrees warmer than the probe would naturally want to cool to.

The VASIMR thrusters can work with any electrical source, so in theory, Mars orbit and inward, solar would "work", however VASIMR would need a nuclear power plant to work WELL. The power to weight ratio of even the best solar panels made from hideously expensive rare-earth metals does not stack up, even if it were to be used in Earth-orbit space, or inward towards the sun. For power-intensive applications in space when repair is millions of miles away, (i.e. no help is coming) trying to deal with solar-only is a big challenge.

The upcoming Mars rover (Mars Science Laboratory, "Curiosity") will be powered by a radioisotope thermoelectric generator.  It also weighs 900kg vs 185kg each for Spirit and Oppertunity, and the power system will last for 14 years (NASA publically plans to support the system for only 2 years).

Kharn

Potato Batteries thats what they need, grow em on mars.