Antimatter rocket
An
antimatter rocket is a proposed type of
rocket that uses
antimatter as its power source. There are a number of possible designs. In one, antimatter would be injected into a target of normal matter and the resulting reaction products (mostly charged particles) would be vented through a magnetic nozzle, providing thrust. A more conventional approach would be to inject the antimatter into a
tungsten block, producing heat, which could then be used to either directly heat a propellant (similar to how a
nuclear thermal rocket operates), or generate electricity to run some other propulsion mechanism. Finally, a photon rocket involves heating up such a tungsten block or other material so it incandesces could be used - a curved mirror would then be used to reflect the photons backwards and thus accelerate the spacecraft forwards.
The chief difficulty is obtaining the antimatter, and to a lesser extent storing it. A few atoms of antihydrogen have been produced using particle accelerators, but this method is too expensive to be practical at this time. An additional difficulty is that most of the energy of matter-antimatter reactions is released in the X-ray and gamma ray spectrum, which cannot be reflected by any known means. One possible solution to this challenge is the Redshift rocket.
See also: spacecraft propulsion