an interesting fact
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 Celsius.
Confronted with the same problem, the Israelis used a
pencil.