Husband wants to invest in space x

My husband wants to invest $5,000 in space x through a private placement (start engine)
I’m a little nervous but I know nothing about investing and stocks. He wants to use his credit card to invest . That’s why I’m nervous because we’ve been working on getting our debt down and as soon as we’re getting somewhere , he wants to use it again. But anyways, I need advice. Is investing in space x a good idea ?