April 5, 2010 Magnetic Disturbance - Peak Dst 0 nT

Science Center Objects

Space Weather Events of April 5, 2010 and the Galaxy 15 satellite

On April 5, 2010, 09:48 UT the Galaxy 15 Intelsat communications geostationary satellite ceased responding to controllers on the ground. Months later, Intelsat continues to re-establish contact with the satellite, but it has begun to drift and the satellite, designed to operate through 2022, might end up being completely lost. The probable cause of the problem were a series of relatively small but unusual solar and geommagnetic events that commenced some 2 days earlier. On April 3, during relatively quiet solar conditions, a flare was observed near an active region on the surface of the Sun. Soon thereafter, a moderate-size coronal mass of hot plasma and tangled magnetic-field lines was ejected towards the Earth. Two days later, this ejection was detected by the ACE monitoring satellite situated between the Earth and the Sun. In response, NOAA’s Space Weather Prediction Center issued a forecast for slightly elevated levels of geomagnetic activity and space-weather disturbance. USGS magnetometers operated at ground-based observatories recorded the arrival of the coronal mass ejection on April 5, 2010, 08:45. A magnetic storm unfolded over the course of the next day, but USGS storm-time disturbance measures (Dst) showed that it never became very large. What was unusual about this event was a very abrupt magnetic-field reconfiguration, a magnetic substorm, that occurred just prior to the loss of contact with the Galaxy 15. USGS magnetic observatories in Alaska, California, Arizona, and Hawaii, as well as those operated by the Canadians, France, and New Zealand, showed that substorm activity was largely confined to eastern-Pacific longitudes – the same longitudinal position of the Galaxy 15. The substorm accelerated charged particles from the tail of the Earth’s magnetosphere. This probably caused a buildup of static electric charge on the Galaxy 15, which, when discharged either temporarily upset or permanently damaged electronic components in the satellite. Events like this normally occur during large magnetic storms, and we can expect an increase in their frequency during the up-and-coming solar maximum in 2013. That the Galaxy 15 anomaly occurred during modestly disturbed space-weather conditions highlights the necessity for both continuous real-time monitoring, such as that coordinated between the USGS and NOAA, and scientific research so that the hazardous effects of space-weather disturbance can be mitigated.

Prepared on July 28, 2010
Last Updated 2014-10-06 17:16:45 by Jeffrey J. Love