LOL, is Dean Karr and others bragging about UA again?! 
PM me for specifics on my own S’s experience in aero w/ internships.
Agree with absolutely everything that has been said above: stellar GPA, eye-catching and relevant resume, ECs, research, networking, interviewing well, making connections, finding your own opportunities to pursue, apply far/wide, be willing to relocate.
The only thing I’d like to add is insight on the decision to pursue co-ops vs internships. Co-ops usually are with only 1 company (the same company) for all rotations, so you have to choose wisely, I think, if that’s your route. Internships are usually only during the summer months, and if you’re lucky, you’ll have 3 (can be different ones!) during your college years for a wider range of experience. So, do you want to go wide (internships) or go deep (co-ops)? Co-ops almost certainly lead to a job offer at the end of it, but so can internships. Again, I would choose wisely w/ co-ops - I think they kind of lock a student in too much. It is easy when you’re 18 or 19 to grab whatever co-op is available, but there will be pressure on the student to accept a job offer from the same company at the end. IMO, internships are better ways to try before you buy, so to speak.
Then, you need to consider housing, if the co-op is not in the same general area as the campus. If you’re in a dorm, you need to move out each co-op semester (and notify housing by a certain deadline prior to moving)…if you have an apartment, you need to consider that expense if it is left empty while you co-op.
A student needs to think about a co-op very early (like early FR year is not too early!), and pursue a co-op very diligently and plan carefully, IMO, whereas an internship is much more flexible and you can pick one up whenever it suits you. At UA, co-ops in certain branches of engineering are nearly non-existent, because of class schedules and only certain courses being offered in fall/spring semesters only. This is the case w/ aero at UA, but I have heard that UA will work w/ specific aero students if they find their own co-op (because UA does not have co-ops for them). Not sure what ‘work with’ means - but they appeared very accommodating and flexible when my S inquired about how to fit in an aero co-op back when he was a FR. (S did not do a co-op, but went the internship route instead.) Schools are of course going to be flexible, because let’s face it: it looks good to have their students placed in co-ops and internships.
Both are great experiences, OF COURSE…but you can see where I’m leaning with my advice… Good luck with your decision, Rdtsmith! 