|
 |
 advertisement
| |
|
|
|
|
|
Rocket Engines of the Future
By Ray Villard
Special to space.com
posted: 06:56 am ET
28 September 1999
|
antimatter_enginesNASA engineers are developing a radically new type or rocket engine that harnesses the power of stars to cut travel time to Mars, for example, from the current nine months down to three months. Called the gas-dynamic mirror engine, it traps and heats gas to temperatures as sizzling hot as those found at the core of the sun. That's hot enough to allow for nuclear fusion by combining lighter atomic nuclei into heavier nuclei. Within a few months, a six-foot long model of the engine will be fired-up by injecting a superheated gas confined between powerful magnets at either end of the engine. Within a couple of years, the engineers hope to achieve a sustained nuclear fusion reaction in the hot plasma. Attempts to build fusion reactors on earth for generating electricity have been bedeviled by the fact that some of the plasma always leaks out. But this becomes an advantage for fusion-powered rocket engines. The plasma that leaks out produces a thrust that propels the spacecraft. The trick is to sustain a fusion reaction while tapping a little of the gas for thrust. A second engine under development uses a different method to achieve fusion. Powerful laser beams zap BB-sized fuel pellets to create hot plasma contained in a metal shell. The fuel pellets would be zapped by antimatter inside an even more advanced engine imagined. This would eliminate the need for a bulky laser apparatus the spacecraft would otherwise need to carry. Antiprotons, which contain the opposite electrical charge of normal protons, can be manufactured today in particle accelerators and stored as fuel inside powerful magnetic fields. Such engines could catapult a robotic probe to the nearest star to our sun, Alpha Centauri, with a travel time of only 200 years. Though that sounds long, it is a quick hop relative to the 168,000-year journey it would take for a conventional chemical-rocket engine.
|
|
|
|
|
