Star Trek fans will quickly point out that
Enterprise and
Voyager are propeled using engines fueled by antimatter. Far from being unrealistic, research at Penn state University and NASA
Advanced Space Transportation Program (ASTP) is ongoing in order to create the next generation of thrusters utilizing antimatter.
To date, the highest amount of energy can be produced by annihilating antimatter with
matter.
Chemical reactions at best can provide 1x10^7
joules/kg,
nuclear fision 8x10^13 j/kg, and
nuclear fusion 3x10^14 j/kg. Matter antimatter annihilation yields 9x10^16
j/kg.
There are many technical obstacles to be addressed. First, the amount of available antimatter in production is not enough,
particle accelerators such as the ones found in
Fermilab, close to
Chicago, and
CERN, in
Switzerland, produce somewhere between 1 to 10
nanograms of antimatter annually. The process of production typically involve accelerating
protons near the speed of light and slamming it into a metal, such as
tungsten. Various
subatomic particles are produced by this collision, including
antiprotons, the simplest form of antimatter. 71 milligrams of antimatter would provide an equal amount of energy that is provided by space shuttle external tank.
The second obstacle is storage. Antimatter can not be stored in normal containers because it will instantly annihilate once antimatter makes contact with matter. One solution is using
Penning Trap, a super cold vacuum using electro magnets in order to suspend particles of antimatter. Antielectrons are difficult to store because of their mass, however, antiprotons are stored much more easily. Antimatter storage reaps several benefits, one of which is O15 production, a radioisotope used for
Positron Emission Tomography (PET) of the human brain.
------------------------------------------
References:
http://www.engr.psu.edu/antimatter/introduction.html
http://science.nasa.gov/headlines/y2000/ast29may%5F1m.htm
http://science.nasa.gov/newhome/headlines/prop12apr99_1.htm