Motivational letter...Part 1.....LEASE Why did I study aerospace engineering? I remember very well the day in wich I choosen aerospace enginieering. I did not like airplanes, rockets or orbiters; actually I knew anything of them. When I finished the high school my wish was to study Mathematics and Physics. So I was sure to choose a Scientific Department. My first thought was for the department of engineering, wich seemed to combine teorical approach with manual labor. On the other hand, the departments as Mathematics and Physics seemed to be too much theoreticals for me at that time. Having choosen the department, the next question was: Which is the best engineering for myself? I quickly read the early exams of mechanical and aerospace engineering; finally I have prefered aerospace engeneering beacuse mechanical engineering was specific for the engines than aerospace while I prefered more the aerodynamical sector. I can not say that choise has been wrong but if I could turn back the clock, choosing between Engineering and Mathematics would be a hard decision. During my master's degree, I followed a specialization course called ''Dynamical Systems'' in the Mathematics Dept. and I realized the meaning of rigorous mathematical approach to the problems. Then I decided to change my curriculum in order to insert courses with the same approach to the engineering problems. So, definitly, I think that if I could turn back the clock I would choose the bacherol's degree in Mathematics and after that the master's degree in Mathematics for engineering applications.