When NASA first started sending astronauts into space, they realised that the ballpoint pen would not work as zero gravity. $1 million investment in two years of test results in a pen that could write in space, upside down, on almost any surface and a temperature is ranging from below, freezing to 300°C. When up with the same problem, the Russians used a pencil.

I have a number of these all new but some wear to some packs