 Interested in these activities, the teenage Mueller wanted to be an aeronautical engineer but discovered that where he could afford to go to school, the Missouri School of Mines and Metallurgy (now Missouri University of Science and Technology) in Rolla, Missouri, there was no aeronautical engineering department.They did offer mechanical engineering, so he enrolled in that program but found it discouraging and switched to electrical engineering.Mueller assumed he would end up working in industry and so, in his senior year, went on a tour of various suitable companies.