A massive solar storm could knock out GPS, disrupt flights, crash the power grid — and we’re not prepared for it, recent tests show.

In May 2024, U.S. government agencies ran a first-of-its-kind emergency drill simulating a severe solar storm. Led by NASA, NOAA, FEMA, and the Johns Hopkins Applied Physics Lab, the exercise tested how the country would respond to a space weather catastrophe.

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Solar storms happen when the Sun releases massive bursts of energy — flares, radiation, and magnetic fields — that slam into Earth’s atmosphere. The most extreme events, like the famous Carrington Event of 1859, can fry electrical systems, knock out communication satellites, and cause widespread blackouts.

Today, with everything from planes to phones relying on GPS and electricity, the impact could be far worse.

Inside the Space Weather Exercise

The emergency exercise, formally known as the 2024 Space Weather Tabletop Exercise, was designed to simulate a real-time response to an escalating solar storm scenario over several days. Participants from over 50 U.S. federal and state agencies — including NASA, NOAA, FEMA, the Department of Energy, and the Department of Defence — were tasked with reacting to a fictional but scientifically plausible sequence of solar eruptions.

One scenario imagined an eight-day space weather crisis unfolding in early 2028, with NOAA tracking a volatile solar region aimed at Earth. To raise the stakes, astronauts aboard the Orion spacecraft and on the lunar surface were added to the mix, representing real Artemis mission conditions. Agencies were asked to evaluate whether they had protocols in place to protect satellites, power grids, astronauts, and infrastructure during such a crisis — and many found themselves lacking.

These eruptions impacted satellites, ground infrastructure, and critical communications. The simulation exposed key vulnerabilities: agencies lacked synchronised communication protocols, there were delays in getting actionable warnings to the public, and infrastructure operators were often unsure how to protect sensitive systems. The findings highlighted an urgent need for faster decision-making frameworks, improved forecasting tools, and more public outreach to prepare for future solar threats.

Here’s what could go wrong during a major solar storm:

  • Satellites & Space Tech: The radiation could damage satellites, knock out communication links, and even endanger astronauts in orbit.
  • GPS & Navigation: Satellite navigation systems could go offline — affecting everything from Google Maps to aviation and shipping.
  • Power Grids: Electrical transformers could be overwhelmed, causing widespread outages that take weeks to fix.
  • Flights & Communication: Radio blackouts could ground planes and disrupt emergency communications.

The Sun goes through 11-year activity cycles. Right now, Solar Cycle 25 is reaching its peak. Scientists at NOAA say solar activity has already been much stronger than predicted.

In fact, May 2024 saw the most powerful solar storm in over 20 years, rated G5 (extreme). NASA even had to temporarily shut down or “safe mode” some of its satellites to protect them.

That storm was just a warning shot. Experts warn that bigger storms are possible — and that we’re not fully prepared. The drill’s final report makes it clear: without better coordination, tech upgrades, and public awareness, the next big solar storm could lead to a national emergency.