This is a myth, using a pencil in space isn't clever or thrifty, it's a disaster waiting to happen. The graphite from pencils breaks off in small fragments while writing and the fragments can create shorts in electronics and to top it off they're also flammable. None of those are properties you want to bring into a spacecraft.

After Fisher, the pen company, spent their own couple millions to develop a pen that could write in zero gravity, they convinced NASA to use it, and a few years later the Soviets bought 100 of them for their own space program.

NASA was never involved in the development of the space pen, though they supposedly had their own effort that was quickly abandoned as it got expensive. Before that they also used pencils.

The pen is just a better writing implement in space. It cost $3 in the 60s, with wide availability.

Fischer made the space pen as a commercial product, all R+D entirely at their own expense. NASA just bought some of the pens from them.

That's just a myth, you know: https://www.scientificamerican.com/article/fact-or-fiction-n...