I have a Fischer CAP-O-MATIC space pen which I've have longer than all of the cars I've owned. I think I bought some time around 1996. It hasn't been used frequent enough to need a refill but it's never failed to write. The only problem is a small bit of ink will crust up on the tip which you can wipe off or just accept a dot where you first placed the pen down on paper.
https://www.jetpens.com/blog/The-Best-Pressurized-Ink-Pens/p...
They don't write as nicely as fountain or gel pens, but when you need to write on receipt paper or a waxed carton, they will work.
You can put the Fisher Space Pen refills in any pen that takes a Parker ballpoint refill.