Sun to set on Ulysses solar mission on 1 July

ESA - After over 17 years of operation, the joint ESA/NASA mission Ulysses will officially conclude on 1 July this year. The spacecraft, which studied the Sun and its effect on the surrounding space for almost four times its expected lifespan, will cease to function because of the decline in power produced by its on-board generators. Ulysses has forever changed the way scientists view the Sun and its effect on the surrounding space. The mission’s major results and the legacy it leaves behind have been presented today at ESA Headquarters in Paris. "Over almost two decades of science observations by Ulysses, we have learned a lot more than we expected about our star and the way it interacts with the space surrounding it," said Richard Marsden, ESA’s Ulysses Project Scientist and Mission Manager. "There will never be another mission like Ulysses,” he continued. “Many solar missions have appeared on the space scene in recent years, but Ulysses is still unique today. Its special point of view over the Sun's poles has never been covered by any later mission, making Ulysses’s pioneering character still valid. This legendary spacecraft has served us extraordinarily well and it has certainly lived up to its mythical namesake's reputation.” "Ulysses has been a challenging mission since launch," said Ed Massey, Ulysses Project Manager at NASA's Jet Propulsion Laboratory, California, USA. "Its success required the cooperation and the intellect of engineers and scientists from around the world. The diversity of our team was one of its greatest strengths." That strength and diversity spilled over into the Ulysses spacecraft itself. The spacecraft and its suite of 10 instruments had to be highly sensitive yet robust enough to withstand some of the most extreme conditions in the Solar System, including two polar passes of the giant planet Jupiter. “The main objective of Ulysses was to study, from every angle, the heliosphere, the vast bubble in space carved out by the solar wind,” said Ed Smith, NASA’s Ulysses Project Scientist. “The heliosphere separates the solar neighbourhood from the interstellar medium. Over its long life, Ulysses redefined our knowledge of the heliosphere and went on to answer questions about our solar neighbourhood we did not know to ask." Ulysses was the first mission to survey the environment in space above and below the poles of the Sun in the four dimensions of space and time. It showed that the Sun’s magnetic field is carried into the Solar System in a more complicated manner than previously believed. Particles expelled by the Sun from low latitudes can climb up to high latitudes and vice versa, even unexpectedly finding their way down to planets. "Ulysses has been a challenging mission since launch," said Ed Massey, Ulysses Project Manager at NASA's Jet Propulsion Laboratory, California, USA. "Its success required the cooperation and the intellect of engineers and scientists from around the world. The diversity of our team was one of its greatest strengths." That strength and diversity spilled over into the Ulysses spacecraft itself. The spacecraft and its suite of 10 instruments had to be highly sensitive yet robust enough to withstand some of the most extreme conditions in the Solar System, including two polar passes of the giant planet Jupiter. “The main objective of Ulysses was to study, from every angle, the heliosphere, the vast bubble in space carved out by the solar wind,” said Ed Smith, NASA’s Ulysses Project Scientist. “The heliosphere separates the solar neighbourhood from the interstellar medium. Over its long life, Ulysses redefined our knowledge of the heliosphere and went on to answer questions about our solar neighbourhood we did not know to ask." Ulysses was the first mission to survey the environment in space above and below the poles of the Sun in the four dimensions of space and time. It showed that the Sun’s magnetic field is carried into the Solar System in a more complicated manner than previously believed. Particles expelled by the Sun from low latitudes can climb up to high latitudes and vice versa, even unexpectedly finding their way down to planets.