Solar probe is back from the brink

日期:2018-01-08 01:15:08 作者:柯攵 阅读:

By Charles Seife in Washington DC A spacecraft that spun out of control earlier this year should soon be back in action. The Solar and Heliospheric Observatory (SOHO) lost power after NASA and the European Space Agency (ESA) lost contact with it in June. Its hydrazine fuel froze and its instruments were exposed to the harsh temperatures of space. But early last month, controllers on the ground re-established contact. Giving a progress report in Washington DC last week, Francis Vandenbussche, who heads the ESA team trying to recover SOHO, said that one of three pipes containing hydrazine has now thawed: “Absolutely, we will have recovered before the end of October.” Once all the pipes are thawed, mission controllers should be able to start SOHO’s propulsion system, orient the craft’s solar panels towards the Sun, and fix its decaying orbit. The bad news is that some of the instruments may have been damaged by the extreme cold and heat of space—and some important data have already been lost for good. According to Joe Gurman, a SOHO project scientist with NASA, the loss of a continuous stream of data on the Sun’s seismology has ruined plans to get a clear understanding of the very low-frequency rumbles that rock the solar interior. “You need continuity for long-baseline modes of vibration,