Which is great until a pencil snaps and you have a small piece of graphite floating around and it gets in some equipment and shorts it out and causes a fire.As the joke goes, when developing the space program the US spent hundreds of thousands of dollars (government kickbacks to a favorable company I'm sure) developing a pen that writes in zero-gravity... the Soviet Union simply used a pencil...
of course that could be because that was the apex of their technology.
But the story is a myth, in reality NASA got in trouble for wasting tax payers money buying mechanical pencils.
https://www.scientificamerican.com/article/fact-or-fiction-nasa-spen/