spacetoday.net: Yohkoh spacecraft in safe mode

Posted: Mon, Jan 7, 2002, 10:12 AM ET (1512 GMT)
The Yohkoh spacecraft, a Japanese spacecraft designed to monitor the Sun, went into safe mode last month and may not be recovered, according to some recent reports. The spacecraft first encountered problems December 14, during an annular eclipse of the Sun. The spacecraft went into a safe mode during the eclipse to conserve power, and also began to drift slightly. Since Yohkoh was out of contact with controllers during the eclipse, they could not monitor the roll or correct for it. By the time communications were reestablished with the spacecraft, Yohkoh's solar panels had lost their lock on the Sun, depriving the spacecraft of power and draining its battery. Controllers have shut down Yohkoh's scientific instruments as they attempt to restore power to the spacecraft and correct its orientation, but they are unsure whether they will be able to accomplish this task. The spacecraft, launched in 1991, monitors the Sun at x-ray wavelengths using instruments contributed by Japan, the US, and the UK.