What hasn't been mentioned yet is the problem Fisher solved with the "Space Pen": Normal ball point pens need gravity to pull the ink down towards the ball at the bottom; they would not write for extended periods of time against or even without gravity. According to the Wikipedia page ball point pens were popularized in the U.S. only in the 1950s by Marcel Bich through the now ubiquitous Bic brand. They were as much bleeding (or hopefully not bleeding!) edge technology as space travel itself. The "Space Pen" had a pump mechanism which could pressurize the ink reservoir, thus forcing the ink towards the ball.
Of course, chalk is not subject to the complications of fluid dynamics under zero gravity ; there is no flow of substance but just abrasion, which works under about all conditions which does not melt, evaporate or otherwise compromise the two surfaces involved.