Everyone knows the parable: NASA spent millions developing a pen that writes in zero gravity while the Soviets just used a pencil. This episode dismantles that urban legend, showing that pencils were a genuine safety hazard in early spacecraft, that NASA abandoned its own pen project over cost, and that a private inventor named Paul C. Fisher risked roughly $1 million of his own money to solve the problem and then sold pens to both rival space agencies.

The conversation explains why floating graphite fragments and flammable wood were unacceptable in sealed, oxygen-rich capsules packed with exposed wiring, then digs into the engineering of the AG7 pen patented in 1965: a hermetically sealed cartridge pressurized with nitrogen to about 45 psi, a tungsten carbide ball machined to plug the tip, and a thixotropic ink that stays a gel until the r ...