Solar Wind Observations Over the Poles of the Sun (SWOOPS)

Instrument Summary

The primary mission of the Ulysses spacecraft was to characterize the heliosphere as a function of solar latitude. The heliosphere is the immense magnetic bubble containing our solar system, solar wind, and the entire solar magnetic field. It was the first mission to study the Sun from both poles. During its operation, Ulysses made nearly three complete orbits of the Sun.

Ulysses was a joint mission between NASA and the European Space Agency (ESA), launched on October 6, 1990. ESA provided the spacecraft and operations team, while NASA oversaw launch, radio tracking, and data management operations. After more than 18 productive years of charting the unexplored regions of the Sun’s poles, Ulysses ceased operations on June 30, 2009.

The objectives of the SWOOPS investigation were (1) to characterize bulk flow parameters and conditions of the solar wind as a function of solar latitude; (2) to investigate radial variations of solar wind properties between Earth and Jupiter; and (3) to investigate the solar wind interactions with the Jovian magnetosphere. The instrument consists of two sensor systems. Electrons in the energy range between 1 and 900 eV are measured by a 120 degree spherical-section electrostatic analyzer. The solar wind ion analyzer makes three-dimensional measurements of solar wind ions with energies in the range between 257 eV and 35 keV per charge. It consists of a 105 degree spherical-section electrostatic analyzer.