A miniature plasma thruster could one day power satellites, and could potentially increase their maneuverability and prevent them from crashing into each other, researchers say. The shoebox-sized prototype, called the Mini-Helicon Plasma Thruster, is much smaller than other rockets of its kind and runs on gases that are much less expensive than conventional propellants. As a result, it could slash fuel consumption by 10 times that of conventional systems used for the same applications [Science Daily].
The system doesn’t use a chemical reaction to provide power, as most rockets do, but instead uses electrical power to accelerate a propellant. The thruster uses nitrogen gas, which is pumped through a quartz tube wrapped in a coiled antenna and surrounded by magnets. Radio frequency power, transmitted to the nitrogen from the antenna, turns the gas into plasma, or electrically charged gas. The magnets help produce the plasma, and guide and accelerate it through the system [Wired News].
MIT rocket scientist Oleg Batishchev released a video on YouTube of a “fun” prototype fashioned by his crew from a glass bottle (acting as the quartz tube) and a Coke can (replacing the antenna). Apparently it actually worked in the MIT vacuum chamber, producing a (very small) amount of thrust. “This shows that this is a robust, simple design,” argues Batishchev. “An even simpler design could be developed” [The Register].
The small prototype is based on a more powerful technology called Variable Specific Impulse Magnetoplasma Rocket (VASIMR), which uses argon gas as its propellant. NASA hopes to test the VASIMR system aboard the the International Space Station in 2012, as a step towards using the propulsion technology to bring down the cost of transporting space cargo.
In the very long run, plasma engines could even bring humans to Mars, astronaut Chris Ferguson recently explained. Conventional engines would be hard-pressed to propel a rocket to the red planet because of the staggering amount of fuel required in proportion to the rocket’s weight, Ferguson said. “We’re as good as we can get with an internal combustion engine, and it’s not good enough,” Ferguson said [Philadelphia Inquirer].
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Image: Oleg V. Batishchev