I really want a career in international relations, but I also want a career in the space industry. Is there any way I can balance that out?
Major in international business and work in private sector aerospace, perhaps?
There are international relations issues involving space. There is an Outer Space Treaty that governs the use of space by various nations. Probably are dicey issues involving how space satellites can be used. So theoretically these interests can be combined.
https://en.wikipedia.org/wiki/Outer_Space_Treaty
Why not go to a school where you can learn both then decide once you’ve take classes. You may like one better or the other not as much after getting more in depth in the classes
Take a look at this website. It lists international space agencies and companies. Do some research and figure out what they are looking for in employees. I would bet that they are all looking for students with STEM backgrounds. You might get lucky and spot an internship or a contact who could help you. Space, by definition, is international. You just need to do a little work to find an interesting direction.