Simulating solar storms for satellite operator training

Threats from space aren’t always obvious, but statistically, it’s only a matter of time before one of them happens. One of the most concerning for many space experts is a massive solar storm, like the one that literally lit telegraph paper on fire when it hit back in 1859.

In the last 150 years, our technology has improved by leaps and bounds, but that also means it’s much more susceptible to damage if another event like the “Carrington Event,” as the storm in 1859 is called. Estimates for potential damage range into the trillions of dollars, with full economic recovery taking well over a decade if something isn’t done to mitigate the damage beforehand.

As part of that preparedness, the European Space Agency (ESA) has started requiring the operational crew of new satellites, which would be on the frontlines of any solar storm catastrophe, to simulate how they would handle such an event, as described in a recent press release focused on one of those simulations.

To be blunt, the best they can do is damage control. There is no good outcome for a satellite in the event it is in the direct path of a solar storm. The most it can hope for is to get through the event still functional and with only a little bit less fuel than intended, due to using that fuel to enhance its orbit-keeping as the atmosphere swelled from the storm and slowed the satellite down.

In this particular example, the Sentinel 1-D team had to deal with a simulated solar storm just after the planned launch of their spacecraft, which is currently scheduled for November 5th. Sentinel 1-D is part of ESA’s Copernicus Programme to monitor Earth’s surface in radar and provide updated maritime and land conditions. The simulation its team had to go through was laid out in three stages.

First, the satellite was hit by an X45-class solar flare, which was traveling at the speed of light, with basically no warning for the operations team whatsoever. That flare, which was comparable to one around Halloween 2003 that knocked out power to some people on the ground as well as disrupted GPS accuracy, causing flights to be rerouted, especially those that were flying over the poles. In this simulated case, the solar flare portion of the storm knocked out GPS once again, making it difficult for the Sentinel 1-D team to position where they were.

A few minutes after the solar flare arrived, the satellite was bombarded with high energy particles traveling near the speed of light. While the appearance of the solar flare allowed for some warning that this would occur, it is difficult to defend against these particles, which have a tendency to flip “bits” in critical pieces of satellites like electronic memory and communications systems. This could cause permanent damage to the system, corrupting its memory of frying part of its circuitry.

But that isn’t the largest danger—about 15–18 hours after the particle storm, the bulk plasma of a coronal mass ejection would arrive. This caused a swelling of Earth’s atmosphere by up to 400%, creating massive drag for the newly launched satellite.

But also, critically, for all other satellites in its neighborhood who might not have enough fuel to deal with that sudden increase. This created a series of choices for the Sentinel 1-D team—how to best avoid collisions in this newly chaotic environment. The probabilities of those collisions were changing so rapidly that it’s hard to make a well-informed choice—and every choice of what to avoid or to ignore could have impacts on other potential collisions later on.

Such simulations offer the operational team a chance to understand first-hand what those choices are, and what the realistic expected outcome of such a scenario would be. The press release didn’t report on how the Sentinel 1-D team fared as a result of the simulation, but again, the best they could have hoped for was damage mitigation.

The simulation was held at ESA’s mission control center (ESOC) in Darmstadt, Germany, and represents what will soon become standard practice for future satellites going forward, as the agency begins to focus more on space safety. Whether other space-oriented organizations take the same precautionary approach might one day determine how much of our orbital infrastructure survives a catastrophic event which will, one day, almost certainly happen.