The spacecraft surveyed the sun’s environment in the four dimensions of space and time and presented ground breaking results. The data provided by Ulysses proved that the Sun’s magnetic field is conducted through the Solar System by a more complex way than previously thought. It was found that particles ejected from the lower latitudes of the Sun can ascent to high latitudes and vice versa. These dangerous particles could even reach other planets, which is not good news for astronauts and satellites that could be affected by them.
“Ulysses has taught us far more than we ever expected about the Sun and the way it interacts with the space surrounding it,” said Richard Marsden, ESA’s Ulysses Project Scientist and Mission Manager. ESA and NASA came up with a joint decision to end the mission last year due to the weakening of Ulysses and frozen fuel lines. However, the satellite persevered and was shut down only a year later.
The scientists working on Ulysses found that by burning the thrusters every two hours, warm fuel would circulate around the frozen fuel lines, keeping the spacecraft functioning. This workaround allowed for Ulysses’ extended time in space.
Another reason that contributed to the shut down of Ulysses was the increase in demands associated with the 70 meter-diameter Deep Space Network ground stations used to maintain operation with the spacecraft. Furthermore, since Ulysses has traveled further from Earth, the data bit rate during communications has reduced to a level at which the input energy outweighs the resultant output.
“We expected the spacecraft to cease functioning much earlier. Its longevity is a tribute to Ulysses’s builders and the people involved in operations over the years,” says Paolo Ferri, Head of the Solar and Planetary Missions Division at ESA’s European Space Operations Centre in Darmstadt, Germany. As of the shut down, Ulysses has become a man-made ‘comet’ that will continue to orbit the Sun.
TFOT has previously written about other NASA satellites such as the Kepler Telescope, which will look for Earth-sized planets, which orbit stars at distances where temperatures permit liquid water to endure on their surface – a region often referred to as the “habitable” zone. You can also check out our article on space garbage, which is exactly what Ulysses has become and IBEX, another NASA program that collects data on solar wind.