Communication With Earth
In normal operation the spacecraft transmits a continuous 200 kbit/s data stream of photographs and other measurements via the NASA Deep Space Network of ground stations. SOHO's data about solar activity are used to predict solar flares, so electrical grids and satellites can be protected from their damaging effects (mainly, solar flares may produce geomagnetic storms, which in turn produce geomagnetically induced current creating black-outs, etc.).
In 2003 ESA reported the failure of the antenna Y-axis stepper motor, necessary for pointing the high gain antenna and allowing the downlink of high rate data. At the time, it was thought that the antenna anomaly might cause two to three week data-blackouts every three months. However, ESA and NASA engineers managed to use SOHO's low gain antennas together with the larger 34 and 70 meter DSN ground stations and judicious use of SOHO's Solid State Recorder (SSR) to prevent total data loss, with only a slightly reduced data flow every three months.
Read more about this topic: Solar And Heliospheric Observatory
Famous quotes containing the words communication with and/or earth:
“We ought to celebrate this hour by expressions of manly joy. Not thanks, not prayer seem quite the highest or truest name for our communication with the infinite,—but glad and conspiring reception,—reception that becomes giving in its turn, as the receiver is only the All-Giver in part and infancy.”
—Ralph Waldo Emerson (1803–1882)
“We all agree now—by “we” I mean intelligent people under sixty—that a work of art is like a rose. A rose is not beautiful because it is like something else. Neither is a work of art. Roses and works of art are beautiful in themselves. Unluckily, the matter does not end there: a rose is the visible result of an infinitude of complicated goings on in the bosom of the earth and in the air above, and similarly a work of art is the product of strange activities in the human mind.”
—Clive Bell (1881–1962)