Back in the Saddle, Again (April 29, 2004)
Hi-res TIF image (1.8M).
This one-day video clip does not show spectacular solar storms, huge solar prominences, or any of the particularly engaging features that we have come to expect from SOHO for its pick of the week. But the clip is greeted with a great deal of enthusiasm from astronomers and sun study enthusiasts of the world. Why? Because it means that, after a week of troubles with system shutdowns and no images, SOHO is taking images again and is back to normal operations. The slight shaking seen in the movie marks the thruster firings that were required to put SOHO back to the planned orbit and configuration. Like a car that is beyond its manufacturer's warranty, SOHO needed a visit to the repair shop (so to speak) and is now fully recovered. It took hard work and imaginative problem solving on the part of a dedicated support team of engineers and scientists to solve a new problem with the spacecraft: one of its hardware safety features had started to produce spurious emergency triggers and had to be disabled. A new software protection has been added as a compensation. As a bonus, in this clip we do see an earth-directed coronal mass ejection that begins at 7:13 UT on April 27 just above the Sun's central area.
Like it or not, after more than eight years, SOHO is operating beyond the mission design lifetime of four years. Its last of three gyroscopes failed in 1998, but a software solution was created to guide SOHO without them. Its high gain antenna motor drive lost some of its movement capability after a problem was encountered last year. Nevertheless, there is nothing on the horizon that poses a serious problem for the spacecraft for many years to come. Though a couple of the instruments have begun to show signs of wear, almost all are operating at full capacity. The sturdy spacecraft was amazingly well designed, and built with lots of redundancies. SOHO continues to provide us with images and data available nowhere else in the world. It patiently continues to build an unparalleled database of an entire 11-year solar cycle that will be mined by scientists for years to come. So there is good reason for all the cheers you may hear in the background. As the famed cowboy Gene Autrey used to sing, We're back in the saddle again. Let the music play!
SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.
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