What would happen when the Sun releases a burst of energy at the Earth and thousands and thousands of satellites are in the path? More and more, it seems to be the convergence of orbital crowding, weak infrastructure and short warning times. Most recent studies on the effects of solar storms have shown that the range of error in Low Earth Orbit is reduced to a matter of days or in severe cases hours.
Solar storms are bursts of electromagnetic radiations and charged particles into space caused by eruptions like flares and coronal mass ejections (CMEs). Flares come within eight minutes and the CMEs take a day or two. The magnetic field on earth is distorted, the upper atmosphere gets heated and the satellites get dragged more when a CME hits. In May 2024, the effect caused the depletion of some spacecraft orbits that dropped hundreds of meters forcing operators to combust valuable fuel to regain altitude. The ICESat-2 satellite of NASA went into safe mode and Aqua and Aura almost faced the same fate.
A good case study was given by the same storm, which later came to be known as the Gannon event. The thermosphere temperature had reached more than 2,100 degrees Fahrenheit, the atmosphere had expanded creating heavier nitrogen particles that were lifted higher than normal, and GPS signals failed. In the U.S. Midwest, farmers reported having GPS-controlled tractors going way off course, which added to losses of more than 500 million dollars. Planes went beyond flight navigation and the onboard computers had bit flips which sent the systems into safe mode.
The dangers multiply rapidly in space. A measure of the danger of colliding in case the evasion maneuvers fail, the Collision Realization and Significant Harm (CRASH) Clock, has been reduced to 2.8days as of mid-2025 compared to previous values of 121 days in 2018. Having more than 14,000 satellites currently in Low Earth Orbit, including mega-constellations such as Starlink, even a temporary loss of control during a solar storm would trigger a space debris free-ride of collisions causing debris generation. In 24 hours, manoeuvring is no longer possible, with models indicating that there is a 30 percent risk of a collision among catalogued objects, and a 26 percent risk between a Starlink satellite.
The danger lies in ground infrastructure. Currents related to storms may be more than 100 amperes on power grids, which may put high-voltage transformers at risk or cause their destruction. According to vulnerability mapping by the USGS, the Eastern and Midwestern U.S are the most vulnerable because the local geology has led to the amplification of geoelectric fields by the resistive bedrock. The 1859 Carrington Event and Quebec blackout of 1989 are examples of past occurrences that indicate that these currents have the potential to cause hours to months of massive outages.
Making predictions is an imperative issue. Alerts are offered by NOAA Space Weather prediction center and NASA Community Coordinated Modeling Center but space weather prediction is far behind terrestrial meteorology. Such missions as Parker Solar Probe, SOHO and STEREO have enhanced CME observation and future resources, including the SWFO-L1 commissioned by NOAA, seek to offer incessant observation of solar wind. Nevertheless, as NASA Nour Rawafi warns, the Sun will do what the Sun wants… We have to start thinking big.
Resilience can be engineered but at a high cost. It can be reduced by radiation hardened electronics, redundancy, and orbital correction fuel reserves, whereas grid upgrades including Quebec billion-dollar transformer program minimize the possibility of blackouts. However, the sheer concentration of orbital traffic would imply that a few minutes of loss of control in the case of a major solar storm would be permanent. It reads grimly on the narrowing CRASH Clock: in context of megoconstellations, the gap between disruption and disaster is closing rapidly.
