NASA’s Ulysses became the first spacecraft to orbit the Sun over its polar regions.
Ulysses launched in October 1990 as a joint mission of NASA and the European Space Agency. Reaching a high-inclination solar orbit required a gravity assist from Jupiter. During its 1992 encounter, Jupiter’s gravity redirected the spacecraft out of the ecliptic plane, allowing it to pass over the Sun’s north and south polar regions.
Ulysses made three major polar passes, beginning in 1994–1995, followed by later passes in 2000–2001 and 2007–2008. It measured the solar wind, magnetic field, cosmic rays, and dust at latitudes no earlier spacecraft had sampled.
Unlike missions focused on viewing the Sun from near the ecliptic, Ulysses explored how solar activity varies with latitude. Its mission formally ended in 2009 after the spacecraft could no longer maintain sufficient hydrazine fuel for thermal control.