Extra Year in Engineering

I’m in my second year of aerospace engineering, and I dropped two courses last semester and which were pre requisites for two courses this semester. I have to take four courses in summer school. I’m thinking about just taking and extra year. I still plan to do coop and might want to do my masters and was wondering if it will look bad when applying if i split up my third year courses and take some of my third year courses next year and some the year after. Should I just do all my third year courses together the year after next?