Over more than 17 years of observations above and below the poles of the Sun, the ESA/NASA Ulysses mission has made fundamental contributions to our understanding of the Sun itself, its sphere of influence (the heliosphere), and our local interstellar neighbourhood. The mission provided the first-ever map of the heliosphere in the four dimensions of space and time.

The heliosphere expands well beyond the outer fringes of the Solar System, where it meets and interacts with material (dust, gas and cosmic rays) of interstellar origin. Ulysses was the first mission to perform direct measurements of interstellar dust and gas, and to study galactic cosmic rays in unprecedented detail.