By IANS
New York : The long-running Ulysses mission, which was launched to study the sun’s poles and its influence on surrounding space, is coming to an end.
After more than 17 years in space – almost four times its expected lifetime – the mission is finally running out of power and is likely to finish sometime in the next month or two, a release by the European Space Agency (ESA) said.
A joint mission by ESA and NASA, Ulysses was launched in 1990 from a space shuttle. The data it sent has forever changed the way scientists view the sun and its effect on the space surrounding it.
Ulysses, which is in a six-year orbit around the sun, has a path that carries it out to Jupiter’s orbit and back again.
The further it moves away from the sun, the colder the spacecraft becomes – with a drop to two degree centigrade meaning the freezing of its hydrazine fuel.
This has so far been avoided as Ulysses carries heaters to maintain the required on-board temperature. But this power supply – from the decay of a radioactive isotope – has been steadily dropping.
Now, the spacecraft no longer has enough power to run all of its communications, heating and scientific equipment simultaneously.
“We expect certain parts of the spacecraft to reach 2ºC pretty soon,” Richard Marsden, ESA’s Ulysses project scientist, has been quoted as saying in the release.
This will block the fuel pipes, making the spacecraft impossible to manoeuvre.
The project team sought to solve the problem by temporarily shutting off the main spacecraft transmitter, releasing 60 watts of power that could be channelled to the science instruments and the heater.
When data was to be transmitted back to Earth, the team planned to turn the transmitter back on. Unfortunately, during the first test of this method in January, the power supply to the radio transmitter failed to turn back on.
The spacecraft has thus lost its ability to send large quantities of scientific data back to Earth and is facing the gradual freezing of its fuel lines – marking the beginning of the end of a highly successful mission.