The NIAC research is a preliminary study to see if the idea is feasible. The new design will use positrons, which make gamma rays with about 400 times less energy. Previous antimatter-powered spaceship designs employed antiprotons, which produce high-energy gamma rays when they annihilate. Even the nuclear reactions that power atomic bombs come in a distant second, with only about three percent of their mass converted to energy. This complete conversion to energy is what makes antimatter so powerful. When antimatter meets matter, both annihilate in a flash of energy. Anti-electrons have a positive charge, so scientists dubbed them 'positrons'. For example, normal electrons, the familiar particles that carry electric current in everything from cell phones to plasma TVs, have a negative electric charge. 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.Īntimatter is sometimes called the mirror image of normal matter because while it looks just like ordinary matter, some properties are reversed. High-energy gamma rays can also make the engines radioactive by fragmenting atoms of the engine material. They penetrate matter and break apart molecules in cells, so they are not healthy to be around. Some antimatter reactions produce blasts of high energy gamma rays. However, in reality this power comes with a price.

Image right: A spacecraft powered by a positron reactor would resemble this artist's concept of the Mars Reference Mission spacecraft.

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). Most self-respecting starships in science fiction stories use antimatter as fuel for a good reason – it’s the most potent fuel known.

What is antimatter