DEFINITION:

Space science encompasses all of the scientific disciplines involved in space exploration and studying phenomena occurring in outer space, such as space medicine and astrobiology.

It includes:

• Astronomy including astrophysics, stellar astronomy, planetary science, galactic astronomy, extra-galactic astronomy and physical cosmology
• Scientific studies coming from Space Exploration (manned and unmanned ones)
• Astronautics including space medicine
• Astrobiology

(Source: https://en.wikipedia.org/wiki/Outline_of_space_science )