Storms from the Sun The Emerging Science of Space Weather (2002) / Chapter Skim
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8. A Tough Place to Work
8. A Tough Place to Work
Pages 117-136
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From page 117... ...
Another subset of those 600 satellites gathers scientific data for government agencies, watching clout! patterns, whale migration, ozone holes, ant!
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From page 118... ...
ciramatically, according to Christopher Kunstaclter, senior vice president of U.S. Aviation Underwriters, a major satellite insurance company.
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States, claims that about 5 percent of all spacecraft failures can be attributer! to the environment; the cause of another 10 percent of mishaps is "unknown." According to Alan Tribble, who has been teaching courses on space weather effects since 1992, that figure for environmental failures might be as high as 25 percent, if you account for the long-term clegraciation of solar cells ant!
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Satellite companies regularly reconstruct in fine detail the exact sequence of events before a spacecraft anomaly or failure. But such data ant!
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in the primary attitude control circuit that kept the spacecraft orientec!
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space environment.
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in the Earth's space environment. Though it was not necessarily the sort of change that could kill a satellite instantly, Baker notes, the sustainer!
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Acceleratecl to damaging speeds in the radiation belts around Earth, these particles can pierce a spacecraft and its components, literally punching holes through them. SEUs usually involve changes to the memory of a satellite's computer circuits, sometimes locking up the electronic brain temporarily in the same way a terrestrial computer can crash.
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. The Hubble Space Telescope is a famous victim of single-event upsets, though many satellites (inclucling the Global Positioning System for navigation)
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Deputy project scientist Kenneth Sembach toic! Space.com that the FUSE engineers "chose the best they coup!
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permanent damage to their solar cells, ant! one of the GOES weather satellites lost six years off of its clesignec!
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spends roughly $500 million per year to mitigate the effects of the space environment. Those effects range from outright failures, to the loss of service time due to satellite degradation, to time spent correcting computer failures or satellite positioning.
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decision makers from all branches of the military, civilian science agencies, ant! industry to conduct a national Space Weather Architecture Stucly.
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Since then I think the level of awareness of space environmental impacts is up substantially, but I feel confident that operators are still weak in knowledge 13: about how to handle a space environment-causec! anomaly." Tschan remembers an occasion when there was a partial raclio blackout ant!
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From page 131... ...
Others may be aware but do not have the money to do anything about it. "I believe that military leaclers are more aware of space environmental effects than they have ever been," saic!
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AT&T also collected! $132 million in insurance claims for the loss of the satellite.
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"Huncirecis of satellites have functioned! normally for close to a clecacle, providing an incredible financial rate of return for their operators," notes one industry insider who prefers to remain anonymous.
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From page 134... ...
Add in that the number of reported satellite anomalies traditionally doubles in years of major magnetic activity, according to Allen, and the current solar cycle could get interesting. "A catastrophe is more likely for civilian systems since there are more of them and most have newer designs," Chris Tschan notes.
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From page 135... ...
"I think space weather is a credible problem but not the only one to worry about," notes Alan Tribble, author of one of the only textbooks on space weather effects. "I clon't feel that there are many glaring vuinerabilities in the average satellite, whether commercial or military.
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From page 136... ...
"Satellite operators will purposely carry extra capability on the fleet of satellites they operate, so if failures occur they can shift traffic to backup capacity on other satellites. We all have spare tires in our cars since no one knows how, at a reasonable cost, to build a flat-proof tire that lasts 40,000 to 80,000 miles." "It's very difficult to quantify how susceptible things are to space weather failure," Tribble adds.
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