Open loop means that they’re just using a mathematical prediction of where to point the mirror at a specific time, given the relative position between the heliostat, the target and the sun. adjustments to the mirrors are typically done every 10 to 15 seconds, which is sub optimal. Closed loop means that they’re actually using Computer vision to dynamically sense the specific angles between the sun and the target and then adjust the mirrors accordingly, no mathematical model required, and the adjustments can be done tens of times per second.
I was actually a grad student at unm with Dennis Chao. Guy was bright, creative and knew how to tell a good joke. Interesting to see this still on the inter-tubes.
I work for a big national lab. Bs/ms in cs. Take a hard science major as well (make the cs a minor or double major). The best programmers/CS people I know are cross-disciplinary and are able to adapt CS approaches to hard problems in other fields.