Sorry I am late to respond. He majored in physics, minored in astronomy and declared a second major in the arts. The grad school told him ‘we were waiting for someone like you!’ (yes were all were surprised). You guessed it, he took an junior level engineering class one summer at a local university. He also worked in engineering internships for four summers at a large aerospace company so he was exposed to lots of engineering on the job. He prepared himself in engineering in every way possible while he was an undergrad. At grad school, he had to take one undergrad class in an area of engineering that he had not been exposed to. He commented often in grad school that he ‘had to learn’ some of the background material and he used all the resources available to him to master it. So I may have made it sound simple, of course it wasn’t, but it is certainly is attainable if you plan to use your summers to get engineering experience and have the drive and initiative to learn the stuff on your own that you do not know.