Ulysses mission to study the sun predicted to end in 2008
Monday, 25 Feb 2008 15:35
Artist's impression of the Ulysses spacecraft
Science In Focus
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Ulysses, the mission to study the sun and its influence on surrounding space, is likely to come to an end in the next few months.
The mission, jointly-controlled by Nasa and the European Space Agency (ESA), has lasted for more than 17 years in space - over three times its expected lifetime.
Ulysses was launched in 1990 from the spaceshuttle Discovery and was the first mission to study the space environment surrounding the sun's poles.
It is currently in a six-year orbit of the sun, which takes it to Jupiter's orbit and back.
The farther it travels from the sun, the colder the spacecraft becomes. If it falls to 2C the spacecraft's hydrazine fuel will freeze.
Although Ulysses is powered by the decay of a radioactive isotope, this is coming to an end and it no longer has enough power to run its communications, heating and scientific equipment simultaneously.
"I remember when we got those first pictures of Ulysses floating out of the space shuttle Discovery's payload bay back in October of 1990 and thinking we had a great five years ahead of us," said Ed Massey, Ulysses project manager at Nasa's Jet Propulsion Laboratory.
"I never dared think that we would be receiving invaluable science data on a near continuous basis for more than 17 years. Ulysses has set the bar on solar science data collection quite high."
Scientists are hoping to run the spacecraft for the next few weeks in its reduced capacity.
"We will squeeze the very last drops of science out of it that we can," said ESA project scientist and mission manager Richard Marsden.
"Ulysses is a terrific old workhorse. It has produced great science and lasted much longer than we ever thought it would."