When NASA first started sending astronauts into space, they realised that the ball-point pen would not work at zero gravity.
A million dollar investment and two years of tests resulted in a pen that could write in space, upside down, on almost any surface and at temperatures ranging from below freezing to over 300°C.
When confronted with the same problem, the Russians used a pencil.
‘Things should be made as simple as possible, but not any simpler" - Albert Einstein.
