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

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.