I love using the Fisher Space Pens.
They’re really reliable and can be used in just about any weather condition that I might find myself in. Most of the time, the most extreme condition that my space pens are required to work in is either writing using a wall as a backing for my notebook, or writing upside down in rare cases.
But I realized something when I was opening a new refill today…
I was just looking at the packaging of one of my Fisher Space Pen Refills and noted that the pen is only good down to -30° F.
Temperature in space is a very cold -454.81° Fahrenheit.
So, in essence, the space pen couldn’t be used unprotected in space by an astronaut in a space suit.
It could be used in zero gravity, but just not in deep space.
It’s unimportant to most people, so that’s why I put this into the Semi-Useful Knowledge category. LOL