Thread Removed - reposted as a poll
I'd say either physics or mechanical. Aerospace engineering is essentially a subset of mechanical, so you'd probably be picking up some of the more "traditional" or more specialized classes that have been foregone for the topics deemed important for an aerospace engineer. Physics would give a broad sense of the other areas of physics (profound, I know) that aren't thought much about in your area of engineering. Another option is just to take additional classes that you're interested in (from whatver department they might be in) without declairing a second major.
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