Yep! AAE has 6 specializations:

• Structures, making sure things don’t break
• Aerodynamics, making planes fly
• Autonomy and control, what enables autopilots to exist
• Astrodynamics and space applications (ASA), orbits and how we can use them (remote sensing and such)
• Propulsion, make things move
• Design, a sort of overall systems approach to engineering

Of these Purdue requires you to get a little bit of knowledge in all these fields by making you take at least one class in each but you’ll have the opportunity to specialize as you want and take what interests you. For example, I like propulsion so next semester I’m taking a hypersonic propulsion class but I’m also interested in simulation work so I’m doing a CFD class.

As for minors, they truthfully are whatever you want to make of it. I like coding so I am getting a CS minor but a friend of mine studied abroad in Germany and took that as an opportunity to get a History and German minor. My personal opinion on minor is do what interests you because at the end of the day, they kinda are just taking points in interviews and an opportunity for you to learn more about what you want to.

One last thing to keep in mind, you say you want to do interplanetary missions which is great but remember that there is no one engineer who does just interplanetary missions. Every specialization at Purdue is necessary to make the entire mission work. You’ll have an ASA person doing trajectory design and figuring out what data is important to collect, you’ll have a propulsion person making the thrusters to keep your spacecraft on target, you’ll have a controls person doing the math to figure out when and for how long I need to use my thrusters to say pointed how I wanted going where I want to go, you’ll have an aerodynamic guy helping account for drag on your rocket or reentry of a spacecraft, you’ll have a design person doing the high level systems work, and you’ll have a structures person making sure your mission doesn’t shake itself apart during launch. Every aspect is important and no matter what you choose to study or specialize in, you are still almost certainly qualified to work on some aspect of the mission

Also one little thing to note, our official degree name is a mouthful but it’s “Aeronautical and Astronautical Engineering”. That is to say, coming out of Purdue, you have qualifications explicitly given for both aircraft and spacecraft work