A "space odyssey" is a descriptive term for a journey into outer space. If you're looking for alternative synonyms to describe this kind of adventure, you could use terms such as "galactic quest," "stellar voyage," or "cosmic expedition." Other options to depict an exciting journey through the vastness of space could include "astral adventure," "interstellar expedition," or "celestial journey." Each of these phrases evokes a sense of wonder and exploration, drawing inspiration from the vastness and mystery of the universe. Ultimately, the term you choose will depend on the tone and style you want to convey in describing the journey into space.