By Xinhua
Beijing : The Ulysses solar probe, after 17 years of studying the sun and solar system, is about to die by freezing to death, NASA and the European Space Agency have announced.
The satellite had long outlasted the five-year mission it began in 1990, but it continued to transmit useful data on solar winds.
More recently, its plutonium power source had slowly weakened and its fuel was freezing as the probe made a wide circle of the sun, traveling as far as Jupiter.
In January, engineers tried a longshot maneuver to heat up the fuel. Instead, their effort backfired and hastened Ulysses’ death by several months.
The US$250 million probe was a joint European-NASA project. After being released from orbit by astronauts on the space shuttle Discovery in October 1990, Ulysses made nearly three full, wide circles of the sun from above and below its poles. It also circled over Jupiter’s poles, logging a nearly 10 billion kilometers overall.
When the satellite recently started to fail, the probe had just finished examining the sun’s north pole for a third time.
What made it unique and crucial to science was its orbit and perspective, providing astronomers with a three-dimensional look at the sun and the whole solar system.