The Ulysses spacecraft, which was launched way back in 1990, has been visiting the planets of the solar system for some 17-years, but now the Ulysses looks like it is doomed. A critical error has occurred in the mechanism that prevents the fuel from freezing, and that means the Ulysses is soon to be heading to spacecraft heaven.
The Ulysses was the first spacecraft to ever pass over the north and south poles of the Sun, but amazing feats of pole to pole travelling were nothing compared to the three comet tails it successfully navigated. The lessons scientists have learnt regarding solar wind and interstellar dust have proven to be invaluable. Unfortunately then, the circuitry has now become defective, which means there is no way to supply power to the machinery that prevents the hydrazine power source from freezing. Once the hydrazine falls below the 2° Celsius freezing point, it's going to be game over for old Ulysses, as there will be no way to control the sky skipper. We imagine it's showing a RROD as we speak, which makes us unbearably sad. We just wanted to say thanks for all the indispensable scientific information, great times, good laughs and the terrific name. Cheers, you will be missed, Ulysses. [New Scientist]