<p>For your questions:
Technology not related to defense is also controlled by the export restrictions – I wouldn’t be suprised if JPL has a blanket regulation against foreign nationals working there, but you can always call and ask again. They won’t make any allowances for Caltech students that they wouldn’t for others.</p>
<p>As for entering JPL, I know that even some of the tours given to Caltech students are restricted to US citizens.</p>
<p>I don’t know of any research on the Caltech campus that requires US citizenship (though it’s possible there are a couple), so an international student would have all the opportunities as US students for doing an on-campus SURF. I’d guess that every year the SURF’s are 65% Caltech and 35% JPL. But I’m pulling those numbers from nowhere.</p>