When NASA first planned to send up astronauts, they quickly
discovered that ball-point pens would not work in zero gravity.
To combat the problem, NASA scientists spent a decade and $1.2
billion to develop a pen that writes in zero gravity, upside down,
underwater, on almost any surface including glass and at temperatures
ranging from below freezing to +300 C.
Confronted with the same problem, the Canadians used a pencil.