This article that I put below is a publication I made a few years ago in the blog of NoSoloIngenieria. It was a project of some friends from my career in which I participated from time to time. I have tried to put it as is, although I could not resist editing it slightly. It is about the famous legend of the special pen that, according to some stories, NASA had to develop so that their astronauts could write in space. I hope you like this curious story.