Is the energy generated from matter-antimatter annihilation useful?

[anj16]

I understand that when matter and antimatter come in contact with each other, they annihilate to generate either gamma rays or other particles such as pions, electrons, etc. So my question is, how do we use the gamma rays or the particles to say move a spaceship from one point to another? (?generate momentum?)

 

[DennisN]

So my question is, how do we use the gamma rays or the particles to say move a spaceship from one point to another? (?generate momentum?)

Before that question is considered, I'd suggest you consider these questions:

1. How is antimatter produced?
2. How much antimatter has been produced by scientists up until today?
3. How is antimatter stored?

Try to google for it, or try reading

http://en.wikipedia.org/wiki/Antimatter

Check out e.g. "Preservation" and "Cost".