Space weather was in the news this month when SpaceX reported that they had lost 40 out of 49 Starlink satellites from a recent launch due to a solar geomagnetic storm.
This article will answer the question “What is space weather and how does it affect satellites?”
It all starts with the Sun.
Activity on the Sun (e.g. sunspots, solar flares, coronal mass ejections) can result in the Sun sending electromagnetic emissions, charged particle radiation and magnetized plasma towards the Earth. This creates a type of weather referred to as space weather which can cause three different types of “storms”: radio blackout storm, solar radiation storm, and solar geomagnetic storm.
Periods of intense space weather can affect a satellite in the following ways: causing malfunction of, or damage to its electronics; changing its orbit; and disrupting communications with ground stations.
Solar radiation storms increases the concentration of charged particles reaching and surrounding the Earth. These charged particles are detrimental to satellite electronics and systems. The higher the concentration of charged particles, the higher the likelihood of satellite malfunction or damage.
Solar geomagnetic storms are also detrimental to satellite electronics and systems. Additionally, these storms can heat the atmosphere causing it to expand into the orbital path of low earth orbit satellites. This increases the drag on satellites which slows them down and can cause them to move into a different orbit which would need to be corrected. In some cases the change in orbit causes the satellite to reenter the atmosphere and burn up. This is what caused the failure of the Starlink satellites.
Radio blackout storms can interrupt communications between satellites and ground stations. In some cases this may disrupt services (e.g. GPS) being provided to customers on the ground.
Satellite manufacturers continue to develop new technologies and procedures to protect electronics and systems from the effects of space weather. However, space weather represents an ongoing threat to satellites operations.
The world’s economy and our day-to-day life is heavily dependent upon satellites for communications (e.g. television), navigation (e.g. GPS), and earth observation (e.g. weather). An extreme space weather event can cause damage which would be globally disruptive and take many years to recover from.
Recognizing the importance of understanding and predicting space weather, governments have established space weather prediction services. For example, in the United States NOAA provides space weather prediction services which are available to the public. Space weather prediction services monitor the Sun’s activity and issue warnings to satellite operators (and other organizations that may be affected by space weather) in advance of forecasted storms. These advance warnings allow satellite operators to warn their customers of potential service disruptions so customers can prepare accordingly. It also gives satellite operators the opportunity to place their assets into a “safe mode” to better weather the storm. An example space weather status dashboard from NOAA is shown below.
Should we be worried? Yes, a little bit…
Additional information for the curious
Organizations tracking solar activity:
- NOAA Space Weather Prediction Center
- ESA Space Weather Coordination Centre
- International Space Environment Service
- Solar and Heliospheric Observatory
The following is an infographic on space weather from ESA that goes into a little more technical detail.
The SpaceX press release on the space weather event is below.
