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Ulysses Goes into Retirement
After eighteen years of service, the Ulysses spacecraft will be relieved of its duties studying our sun on June 30, 2009. It accomplished much in helping us understand the sun, plus it united astronomers from the European Space Agency (ESA) and NASA during this cooperative mission.
The craft was originally launched aboard STS-41 (Shuttle Discovery) in October 1990. In order for the craft to achieve a high enough altitude above the sun, Ulysses was aimed towards Jupiter, whose gravitational field sent Ulysses whizzing toward the sun. This path also allowed Ulysses the opportunity for a bonus study of the gas giant's magnetosphere.
After the Jupiter flyby, the craft went on to explore the sun's poles, including a study of the solar winds and magnetic field strength--a task that no other craft had ever undertaken. The results of the magnetic field strength tests were particularly important: scientists learned that highly energetic particles spewed by the chaotic sun can travel farther than expected and even migrate to the poles. This means that certain areas of the sun which scientists had formerly not considered as particularly dangerous may pose a risk to astronauts and satellites.
The craft continued collecting data longer than NASA scientists had planned, but now the mission is not so cost-effective. Consequently, all systems will be shut down and Ulysses will become a mere artificial "comet," orbiting the sun like the ghost of its old self.
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