NASA programs previously used pencils (for example a 1965 order of mechanical pencils[3]) but because of the substantial dangers that broken-off pencil tips and graphite dust pose in zero gravity to electronics and the flammable nature of the wood present in pencils[3] a better solution was needed. NASA never approached Paul Fisher to develop a pen, nor did Fisher receive any government funding for the pen's development.[3] Fisher invented it independently, and then asked NASA to try it. After the introduction of the AG7 Space Pen, both the American and Soviet (later Russian) space agencies adopted it.
 
http://en.wikipedia.org/wiki/Space_Pen