This book is based on the author's varied experience: ¿ Missile design and management at RAFAEL, the Israeli Armament Development Authority, ¿ Teaching and research projects carried out by his graduate students and himself in Israel (Technion and Tel Aviv universities), the US (University of California, Berkeley) and Canada (Mc-Gill University), ¿ His experience as consultant in Israel for 34 start-ups and high-tech companies. Through his courses the author provided his students the foundation for future careers, as many of them have become leading figures in Israeli high-tech industries. The book is structured as a textbook for students in Mechanical or Aeronautical engineering, but it can also be used as a reference book for engineers working in related fields. Reuven Eshel was born in Haifa on November 12, 1936 and married on June 17, 1962 to Ruth (born Ratner), they have 3 Children and 8 grandchildren. He had a B.Sc. (Cum Laude) in Mechanical and Nuclear Engineering, Technion, Israel, a D.Sc. (Direct Path) in Mechanical Engineering, Technion, Israel, a graduation of RAFAEL Management school and a graduation of arbitrators-course, Association of Israeli Arbitrators. Numerous professional experiences have characterised his working life, from 1997 to 2020 he worked as Consultant to 34 Hi-Tech industries and institutions in Israel and Slovenia. He was elected as "Excellent lecturer" at the Technion in 1975, Chosen as best lecturer of the M.E. department, Technion in 1980, was Honor member of Pie-Tau-Sigma, Berkeley Chapter, USA in 1981, Chosen as best lecturer at the M.E. department, Technion in 1993, 1995, 2006, Chosen as member of the New York Academy of Science in 1997, in 2019 he won the Prize for life achievements (1958 to 2019) at RAFAEL - Armament Development Authority, and Rafael company. He published 2 books about Contributions of Israeli Academia to Industry and 85 publications on management, technology, and technological history, and also 25 confidential books, and 180 technical reports for RAFAEL.