February 23, 2009

MIT Develops More Cost-Efficient Rocket Technology

Scientists at the Massachusetts Institute of Technology (MIT) are developing a rocket aimed at keeping satellites that orbit the Earth on their proper track.

The Mini-Helicon Plasma Thruster is a newly designed, smaller rocket that experts say operates on cheaper gas than the current propellants typically used for maintaining a satellite's orbit.

In fact, it is the first rocket to run on nitrogen, the most abundant gas in Earth's atmosphere.

"It could slash fuel consumption by 10 times that of conventional systems used for the same applications," said Oleg Batishchev, a principal research scientist in the Department of Aeronautics and Astronautics at MIT and project leader for the new system.

Scientists have been working on a new propulsion system to replace the traditional chemical rocket technology that has carried man into space for years. Due to the large amounts of fuel these rockets use, financial concerns have prompted scientists to design a more cost-efficient system as more private companies start working in space.

Engineers have been busy designing alternative, non-chemical rockets where an external source of electrical energy is used to accelerate the propellant that provides the thrust for moving a craft through space.

The Mini-Helicon has three general parts: a quartz tube wrapped by a coiled antenna, with magnets surrounding both. The gas of interest is pumped into the quartz tube, where radio frequency power transmitted to the gas from the antenna turns the gas into a plasma, or electrically charged gas.

Batishchev said the plasma beam exhausted from the tube is what provides the thrust that propels the rocket, adding that the exhaust velocity is some 10 times higher than the velocity from the average chemical rocket, requiring less propellant.

NASA and the European Space Agency have used similar technology in the past, including NASA's Deep Space 1, which involved the flyby of a comet and asteroid.

"The Mini-Helicon is one exciting example of the sorts of thrusters one can devise using external electrical energy instead of the locked-in chemical energy," said Manuel Martinez-Sanchez, director of the SPL and a professor in the Department of Aeronautics and Astronautics.

The MIT team expanded on a previous larger-scale rocket idea by former astronaut Franklin Chang-Diaz.

"The idea was that a rocket based on the first stage of Chang-Diaz's system could be small and simple, for more economical applications," said Batishchev, who noted that the team's prototype would fit in a large shoebox.

"This shows that this is a robust, simple design. So in principal, an even simpler design could be developed," he said.

However, Batishchev acknowledged that it could be years before the technology could be used commercially, in part due to certification policies through NASA and other agencies.


Image 1: The prototype of a new plasma rocket is tested in the lab of Department of Aeronautics and Astronautics principal researcher Oleg V. Batishchev at MIT. Donna Coveney/MIT

Image 2: Department of Aeronautics and Astronautics graduate student Taylor Matlock, center, principal research scientist Oleg V. Batishchev, left, and Dan Stiurca, junior in electrical engineering and computer science, right, work on adjusting a prototype of a new plasma rocket. Donna Coveney/MIT

Image 3: Principal research scientist Oleg V. Batishchev


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