I believe that James Irwin took some stamps and envelopes into space on Apollo 15. He was paid by a dealer and turned over the stamps. They were not to be sold until much later but the dealer started selling them overseas. Irwin kept a few hundred for himself. NASA was not happy, they forced Irwin to turn over his stamps and suspended him from the program. I don’t remember the scandal when it happened but I’ve read the story over the years. It may be an urban legend. Does anyone else remember the story, or confirm that it’s true?
Regarding your question: if you already know the answer to this (which, from the tone of your post, seems likely), it really belongs in a trivia forum, not on the SDMB. We are primarily interested in questions of fact that the poster honestly does not know the answer to.
However, if I am completely wrong about your intent, the answer to your question can be found on this site, where I found this:
It’s also worth noting that the same idea showed up a couple of decades earlier in Heinlein’s short story “The Man who Sold the Moon”. Perhaps Irwin was inspired by Heinlein?