Most people around knife and edc gadgets know the SpacePenPocket, but Fisher also makes some pretty conventional ballpoint pens using their famous gas-pressured refill.
They come in several variants, including my three here : all matte black (military style with no markings and also marketed by RiteInTheRain), conventional black and gold, chromed with gripping serrations. You press the whole cap to click the writing tip out, you don´t need to twist it.
These are slim, lightweight and tough ballpoints that give you the unique and smooth writing experience of the gas-driven ink. Prolonged writing is more comfortable than with a conventional refill. That is more meaningful to me in daily life than the possibility of getting an alien autograph with it in outer space.
It is, by the way, an urban MYTH that the Russians used a simple lead pencil in their space programs, because of the danger that a broken-off pencil tip poses in zero gravity (inhaling it without intent) and the flammable nature of the wood present in pencils. Not a good idea !