NASA Working on Antimatter Rocket for Missions to Mars
Is science fiction destined to become just science?
Most self-respecting starships in science fiction stories use antimatter as fuel for a good reason – it’s the most potent fuel known. While tons of chemical fuel are needed to propel a human mission to Mars, just tens of milligrams of antimatter will do (a milligram is about one-thousandth the weight of a piece of the original M&M candy)….
The NASA Institute for Advanced Concepts (NIAC) is funding a team of researchers working on a new design for an antimatter-powered spaceship that avoids this nasty side effect by producing gamma rays with much lower energy….
When antimatter meets matter, both annihilate in a flash of energy. This complete conversion to energy is what makes antimatter so powerful. Even the nuclear reactions that power atomic bombs come in a distant second, with only about three percent of their mass converted to energy.
Antimatter rockets have significant advantages over nuclear-powered spacecraft, including improved safety, efficiency and speed:
The Reference Mission spacecraft would take astronauts to Mars in about 180 days. "Our advanced designs, like the gas core and the ablative engine concepts, could take astronauts to Mars in half that time, and perhaps even in as little as 45 days," said Kirby Meyer, an engineer with Positronics Research on the study.
Advanced engines do this by running hot, which increases their efficiency or "specific impulse" (Isp). Isp is the "miles per gallon" of rocketry: the higher the Isp, the faster you can go before you use up your fuel supply. The best chemical rockets, like NASA’s Space Shuttle main engine, max out at around 450 seconds, which means a pound of fuel will produce a pound of thrust for 450 seconds. A nuclear or positron reactor can make over 900 seconds. The ablative engine, which slowly vaporizes itself to produce thrust, could go as high as 5,000 seconds.
Although one of the drawbacks to antimatter rockets is its high cost of development, we wonder if that can’t be mitigated by passing the hat around to the millions of science-fiction fans around the world, who have dreamed of anti-matter-powered rockers for years.
(Via Rawstory.)
