Ulysses Mission

The Ulysses Mission is the first spacecraft to explore interplanetary space at high solar latitudes. Ulysses is both a study of the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) of the USA. The spacecraft and spacecraft operations team is provided by ESA, and the launch and the spacecraft, radio tracking, and data management operations are provided by NASA. Scientific experiments are provided by investigation teams in both Europe and USA.

This spacecraft was launched on October 6, 1990. It was originally proposed as a dual spacecraft mission to explore the regions over the Sun's north and south poles. In order for the spacecraft to reach these high solar latitudes, it was aimed close to Jupiter so that Jupiter's large gravitational field would accelerate Ulysses out of the ecliptic plane to high latitudes. This cannot be done with any man made launch.

Ulysses landed on the planet of Jupiter on February 8, 1992. Since that day on, it has traveled to higher latitudes with maximum Southern latitude of 80.2 degrees. This was achieved on September 13,1994. Then in June through September of 1995, Ulysses traveled through high northern latitudes. These high latitude observations are being obtained during the quiet portion of the 11-year solar cycle.

The primary mission of Ulysses is to characterize the heliospheric as a function of solar latitude. The heliospheric is the vast region of interplanetary space occupied by the Sun's atmosphere and dominated by the outflow of the solar wind. The periods of primary scientific interest were when Ulysses was at or higher than 70 degrees latitude at both the Sun's south and north poles. On June 26, 1994, Ulysses reached 70 degrees south. There it began a four-month observation from high latitudes of the complex forces at work in the Sun's corona.

Scientists have long studied the Sun and the Earth using Earth based sensors but no other previous spacecraft had reach such a higher latitude. Now with Ulysses, high latitude data is available.

Ulysses spacecraft carried a suite of instruments out to Jupiter where that planet's gravity pulled the spacecraft into a trajectory that carried it over the Sun's South Pole in the fall of 1994. Such instruments were the magnetometer, solar wind plasma experiment, solar wind ion composition instrument, unified radio instrument, energetic particle instrument, low-