My course lectures will cover the basics and fundamentals in nuclear astrophysics and cosmology. The ultimate goal is to explore what we are made of, why and how the universe began and evolved, and whether we are alone in the universe. For this goal I will lecture on nuclear physics in explosive nucleosynthesis in the Big-Bang universe, supernovae and neutron star mergers. In the near future, humans will surely develop their activities in space. We need to be prepared by studying how and when the atomic nuclei that make up our life were created, and what important roles they have played so far in the evolution of the universe, galaxies, and stars.