The sun, from 93 million miles away, fires solar flares, coronal mass ejections and other space weather events. These "solar storms" can send highly energized particles heading toward Earth. Some of them disrupt the satellites that people rely on to watch TV and Internet purposes.
Intensive charged particles from the sun and may have caused some recent satellite
malfunctions, scientists say. (Photo : NASA)
The team's research is published in the journal Space Weather.
Scientists from MIT investigated the space weather conditions to understand the high-speed disturbances in space, which caused 26 failures in eight geostationary satellites operated by the London-based company Inmarsat.
Geostationary satellites orbit at the same rate as the Earth's rotation, which allows the satellites to maintain a constant location relative to the planet throughout their lifetime.
Study found that most of the problems, from 1996 to 2012, overlapped with high-speed particle activity during declining phases of the solar cycle.
Highly reactive electronics onto these satellites are covered with layers of protective shielding. But, this armor is worn-out by radiation in due time, degrading its components and performance.
The scientists believe that this particle flux may have accumulated in the satellites over time, which created internal charging and damaged the amplifiers inside the orbiting objects.
"Once you get into a 15-year mission, you may run out of redundant amplifiers," study researcher Whitney Lohmeyer, a graduate student at MIT's Department of Aeronautics and Astronautics, said in a statement.
"If a company has invested over 200 million in a satellite, they need to be able to assure that it works for that period of time. We really need to improve our method of quantifying and understanding the space environment, so we can better improve design."
Space weather can be much more vibrant than expected by the models engineers use when crafting the satellites, explained Kerri Cahoy, a co-author of the study and an assistant professor of aeronautics and astronautics at MIT.
Image Credit: Thinkstock.com
"There are many different ways that charged particles can wreak havoc on your satellite's electronics," Cahoy said in a statement.
"The hard part about satellites is that when something goes wrong, you don't get it back to do analysis and figure out what happened."
Some assumptions about the Space weather risks must be revised, Lohmeyer and Cahoy's findings suggested.
Researchers often consider geomagnetic disturbances when measuring the susceptibility of the spacecraft to space weather, according to a statement from MIT.
However, most of the amplifier failures happened during times of low geomagnetic activity that would usually be regarded safe, Lohmeyer said.
"If we can understand how the environment affects these satellites, and we can design to improve the satellites to be more tolerant, then it would be very beneficial not just in cost, but also in efficiency," Lohmeyer added. - DESIGN & TREND.
0 comments:
Post a Comment