ESA/NASA · solar mission ended
Ulysses
Ulysses, an ESA–NASA mission, was the first spacecraft to fly over the Sun's poles, studying the solar wind for 18 years.
- Launch
- 6 October 1990
- End of mission
- 30 June 2009
- Distance from Earth today
- 270.4 million km1.808 AU · light: 15 min 2 s
- Distance from the Sun today
- 279.9 million km1.871 AU
Trajectory
Trajectory: JPL Horizons vectors (spacecraft -55) every 15 days, projected onto the ecliptic; compressed distance scale.
Mission timeline
- Deployed from Space Shuttle Discovery (STS-41)
- Jupiter gravity assist lifts the orbit out of the ecliptic
- Mission ends after more than 18 years
Targets: Sun, Jupiter
About the mission
Every planet and earlier probe stayed close to the plane in which the planets orbit, so the Sun's polar regions had never been studied directly. Ulysses solved this by flying to Jupiter first and using its gravity to swing into a steeply tilted orbit around the Sun with a period of about six years. That orbit carried it over both solar poles several times, at both quiet and stormy phases of the solar cycle, showing how the solar wind and magnetic field change with latitude. Planned for five years, it worked for more than eighteen before its power ran too low in 2009.