My son is a baby Aero and considered Astro. First off, the programs only differ by about 15%. Between the Core curriculum and common engineering classes, the differences across all engineering programs is not huge and even less so between Aero and Astro.
What does that mean for you? You can go, take some classes, talk to the staff of each and decide for yourself. You could probably even take core and base engineering classes through your sophomore year and still be positioned to graduate without nailing it down. If you validate a bunch, you may need to get creative - my son has two Aero specific classes in addition to Aero 210 (which is core) this semester as a Doolie because he validated several classes. So don't feel rushed to make a decision. You have time to get there and settle in. The departments will have open houses and you can meet staff and upperclassman, ask questions about the program and figure out what you want to do from there.
Being engineering programs, either one will set you up for similar careers. If you know you really want to pursue Space Ops, then Astro is a better fit, but Aero (or any other engineering) is not precluded from Space Ops. If you want to fly, there is not much of a difference. If you want acquisitions, then one lends itself to airplanes vs boosters/satellites better, but again neither is precluded from the other - I was boosters as a EE. I imagine the difference really would only come into play if you wanted to go into research. In which case, you likely will pursue a graduate degree and that degree will need to be in the specific field of your research.
So you are pretty safe choosing the one that appeals to you more. The more you enjoy it, the less painful it will feel.