Circling Earth at an altitude of more than 22,000 miles are a host of satellites that give us access to some of the things we love most: the Internet, mobile phones and premium TV.
But space is a hostile environment, even for a chunk of metal. Our communications satellites are under attack from solar flares and coronal mass ejections that occur in the sun’s atmosphere, sending charged particles hurtling toward Earth.
Earth’s atmosphere protects those of us on the ground from these charged particles, but our communications satellites are not so lucky. They spend their lives in what is known as geosynchronous orbit -- far beyond the Earth’s atmosphere -- and are therefore vulnerable to the effects of what is known as space weather.
Engineers protect satellites from destructive space weather by providing layers of special shielding over sensitive electronic equipment, and by building in backup components that can be turned on if original components break.
This engineering strategy mostly works, and very few people have experienced an interruption in their communications service because of a broken satellite, Whitney Lohmeyer, a graduate student at MIT’s Department of Aeronautics and Astronautics, said in an interview with the Los Angeles Times.
But she suggests that learning more about how space weather affects satellites could lead to better satellites.
“We have great communication, but why wouldn’t you want it to be better?” she said.
In a new paper published in the journal Space Weather, Lohmeyer worked with MIT assistant professor Kerri Cahoy to analyze the space weather conditions under which components of geostationary satellites failed.
Looking at 26 equipment failures that occurred over 16 years, the team found that satellite failures were most likely to occur during the declining phase of the the 11-year solar cycle, when the satellites were affected by high-energy electron activity. Right now, the sun is at the peak of the solar cycle, which means we’re about to head into the declining phase again.
[Updated, 9:08 a.m. PDT, Sept. 18: In an email to the Los Angeles Times, Lohmeyer wanted to make it clear that the 26 “failures” she studied were technically component anomalies. “It is like a part in your car breaking,” she wrote. “While still important, it is not the satellite as a whole that is failing.”]
But, as Lohmeyer noted, it is not a black-and-white situation.
“These high-energy electrons are not necessarily the result of an immediate [coronal mass ejection] or solar flare that happened in the past week,” she said. “There is more to the equation, and that’s what we want to fill in.”
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