The satellites that we put into space to orbit the Earth and explore distant worlds are comprised of highly sensitive electronics. With that in mind, they demand unique shielding mechanisms to protect them from threats like geomagnetic storms and high-speed solar winds.
For the longest time, scientists have thought that geomagnetic storms posed a higher risk for satellite damage than high-speed solar storms, but a new study published this week in the journal Space Weather finds that the opposite could be true.
Image Credit: NASA
“Until now we thought that the biggest risk to orbiting satellites was geomagnetic storms,” explained Professor Richard Horne, the lead author of the study.
“Our study constructed a realistic worst-case event by looking at space weather events caused by high-speed solar wind flowing away from the Sun and striking the Earth. We were surprised to discover just how high electron radiation levels can go.”
The researchers analyzed several years’ worth of satellite data and were quickly astounded by just how long electron radiation levels could linger following a high-speed solar wind event. Intriguingly, it wasn’t uncommon for these high electron radiation levels to persist for five or more days at a time.
Citing the researchers, the longer the high electron radiation levels stick around, the worse off a satellite’s onboard electronic systems will be. Prolonged exposure can charge a satellite’s electronics up to potentially hazardous levels, sometimes even enough to cause damage.
As for why this is more dangerous than a geomagnetic storm, Professor Horne explains it best:
“Fast solar wind is more dangerous to satellites because the geomagnetic field extends beyond geostationary orbit and electron radiation levels are increased all the way round the orbit – in a major geomagnetic storm the field is distorted, and radiation levels peak closer to the Earth.”
The researchers go on to explain that thicker aluminum shielding could be employed to protect satellites’ sensitive electronics from high-speed solar storms. Based on their calculations, it would be ideal for satellites to utilize aluminum shielding that was at least 2.5mm thick. Today, satellites use much thinner shielding, which may not hold up to a high-speed solar wind event.
The research highlights some serious concerns with modern satellites and underscores the importance of building safety systems capable of protecting the sensitive instruments we install on them. It should be interesting to see how space agencies and commercial satellite companies respond to the results of this study.