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Plasma Propulsion Could Cut Time To Mars in Half
NEW ROCKET TECHNOLOGY COULD CUT MARS TRAVEL TIME
An agreement to collaborate on development of an advanced rocket technology that could cut in half the time required to reach Mars, opening the solar system to human exploration in the next decade, has been signed by NASA's Johnson Space Center, Houston, TX, and MSE Technology Applications Inc., Butte, MT.
The technology could reduce astronauts' total exposure to space radiation and lessen time spent in weightlessness, perhaps minimizing bone and muscle mass loss and circulatory changes.
Called the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), the technology has been under development at Johnson's Advanced Space Propulsion Laboratory. The laboratory director is Franklin Chang-Diaz, a NASA astronaut who holds a doctorate in applied plasma physics and fusion technology from the Massachusetts Institute of Technology, Cambridge.
Chang-Diaz, who began working on the plasma rocket in 1979, said, "A precursor to fusion rockets, the VASIMR provides a power- rich, fast-propulsion architecture."
Plasma, sometimes called the fourth state of matter, is an ionized (or electrically charged) gas made up of atoms stripped of some of their electrons. Stars are made of plasma. It is gas heated to extreme temperatures, millions of degrees. No known material could withstand these temperatures. Fortunately, plasma is a good electrical conductor. This property allows it to be held, guided and accelerated by properly designed magnetic fields.
The VASIMR engine consists of three linked magnetic cells. The forward cell handles the main injection of propellant gas and its ionization. The central cell acts as an amplifier to further heat the plasma. The aft cell is a magnetic nozzle, which converts the energy of the fluid into directed flow.
Neutral gas, typically hydrogen, is injected at the forward cell and ionized. The resulting plasma is electromagnetically energized in the central cell by ion cyclotron resonance heating. In this process radio waves give their energy to the plasma, heating it in a manner similar to the way a microwave oven works.
After heating, the plasma is magnetically exhausted at the aft cell to provide modulated thrust. The aft cell is a magnetic nozzle, which converts the energy of the plasma into velocity of the jet exhaust, while protecting any nearby structure and ensuring efficient plasma detachment from the magnetic field.
A key to the technology is the capability to vary, or modulate, the plasma exhaust to maintain optimal propulsive efficiency. This feature is like an automobile's transmission which best uses the power of the engine, either for speed when driving on a level highway, or for torque over hilly terrain.
On a mission to Mars, such a rocket would continuously accelerate through the first half of its voyage, then reverse its attitude and slow down during the second half. The flight could take slightly over three months. A conventional chemical mission would take seven to eight months and involve long periods of unpowered drift en route.
There are also potential applications for the technology in the commercial sector. A variable-exhaust plasma rocket would provide an important operational flexibility in the positioning of satellites in Earth orbit.
Several new technologies are being developed for the concept, Chang-Diaz said. They include magnets that are super-conducting at space temperatures, compact power generation equipment, and compact and robust radio-frequency systems for plasma generation and heating.
Coordinated by Johnson's Office of Technology Transfer and Commercialization, the Space Act Agreement calls for a joint collaborative effort to develop advanced propulsion technologies, with no money exchanged between the two parties. Such agreements are part of NASA's continuing effort to transfer benefits of public research and development to the private sector.
before some idiot straps one to four wheels and tries to break mach 2 on the salt flats?
And better yet: How long after leaving the line before same fool disintegrates the car and is strewn over fifty square miles of ground?
.sig: Now legally binding!
Well, this is definitely a boost for the hopes of manned exploration of Mars, which means that this technology will almost certainly not be used to it's full potential.
It constantly astounds me that world governments, with all the obvious environmental problems, refuse to whole-heartedly endorse space programs. Certainly, the lack of participation of nations in the shape of Russia (although their space program is/was generally good) is understandable, but the U.S. and other prosperous countries need to take some leadership here.
An Internation Space Station is a good start, but the political infighting regarding the development of it is discouraging. We need governments to realize that, with 6 billion people on the earth, that we don't have the resources to maintain an acceptable standard of living infinitely.
Traveling to another planet to explore, in a precursor to either inhabitation or mining, would be an even better use of this technology. I for one hope that world governments wake up (and that waking up is continigent upon public sentiment) and realize that right now is the time to radically advance our exploration of space.
Scythe
Scientific American ran a really detailed article a few months back on Mars missions. It discussed several propulsion systems, including this plasma thingee.
Rush down to your local blood center and donate some of your plasma!
count to ten
XML causes global warming.
It's not that simple. Sure its easy to say "launch today with today's tech," but consider the factors involved in a longer voyage...
You have to have enough consumables to keep your crew alive for a long period of time: air, food, and water. The longer the voyage, the more mass you will have to take in order to provide for your crew, and thus the more fuel you will need to propel the extra mass...
You would need a tremendous amount of fuel using conventional propulsion methods, and the cost would be prohibitive (note we don't already have a mars mission underway!).
Doug
Venn ist das nurnstuck git und Slotermeyer? Ya! Beigerhund das oder die Flipperwaldt gersput!
But if I want to be on Mars ASAP, which technology is going to get me there first? Conventional, tried-and-true, already-exists rockets? Or untested, not-yet-mature, haven't-built-one-yet technology?
Just launch a damn ship NOW.
You are advocating precisely the same approach that took us to the moon six times...and then no more, in almost thirty years.
Why? Because they were in a hurry. Because they wanted to hit Kennedy's arbitrary deadline. Because it was a stunt, strictly for prestige value. So instead of investing in infrastructure, they slapped together the quickest solution they could.
If you want to go to Mars once, use conventional solutions and launch now. If you want to keep going there, over and over without end...if you want to make it more than a stunt...be patient, develop the technology to support it, do it right.
Furthermore, conventional solutions, which accelerate only at the beginning and end, take time proportional to the distance. Constant-acceleration takes time proportional to the square root of the distance. This allows you to go not only to Mars but anywhere in the solar system.
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You are in a twisty little maze of open source licenses, all different.
To clarify this point for those who were too busy learing C++ in school to read any Einstein:
As an object with mass approaches the speed of light, the ammount of force required to accelerate approaches infinity.
Therefore the speed of light (represented as "c") is not only theoretically impossible for a passenger vehicle to reach, but before you even get up to that speed you will reach a point where more acceleration is Not Worth The Trouble.
On top of that, there are troublesome issues of time deceleration and lots of other hard math problems that lead one to desire a better way of getting from point A to distant point B than getting a rocket to go "really really fast". Some serious thought and lots of bad sci-fi has been applied to this problem, but so far with few promising conclusions.
Information wants to be anthropomorphized.