Many commercial flights may need to be rerouted or grounded to prevent passengers from being exposed to space radiation from solar flares, according to new research.
Radiation at flight altitudes
Researchers at the Surrey Space Centre (SCC) found that radiation exposure at typical flight altitudes of 5-9 miles could trigger faults in aircraft electronics, posing a risk to flight safety. A major solar storm in November 2025 caused radiation levels to briefly rise to nearly 10 times normal flight conditions at high altitudes, based on measurements led by SCC.
The strongest solar storm on record, which occurred in 1956, could have exposed passengers to the equivalent of a year's worth of flight-related cosmic radiation. As the atmosphere provides protection from the sun's radiation, commercial flights expose passengers to significantly more radiation than at ground level.
Recent incidents highlight risks
In October 2025, a JetBlue flight from Cancún to Newark made an emergency landing in Florida after a sudden drop in altitude, injuring 15 people. Following this, Airbus temporarily grounded 6,000 A320 aircraft after discovering the plane had a vulnerability to 'intense solar radiation' in a flight control computer.
Dr Fan Lei, Senior Research Fellow at the SCC, said: 'The recent Airbus A320 grounding linked to cosmic radiation shows that space weather is not a theoretical risk; it is already affecting aviation.' He added: 'As aircraft systems become more advanced and increasingly reliant on electronics, understanding and preparing for these events will be critical to maintaining flight safety.'
Single Event Upsets and polar routes
The study highlights how high-energy particles from space can interfere with onboard electronics, causing Single Event Upsets (SEUs) – small errors that can accumulate and disrupt critical systems. In many cases, these disruptions may present a greater operational challenge than radiation exposure to passengers and crew, by increasing pilot workload and the risk of in-flight problems. In extreme scenarios, SEUs could increase from a few per hour to thousands.
The biggest risks are on polar flight routes, including those between London Heathrow and Vancouver International Airport in Canada, where the Earth's magnetic shielding is weakest. However, during severe geomagnetic storms, these effects can extend much further south, including over the UK.
Proposed aviation radiation scale
The findings highlight a gap in current aviation safety frameworks, which mostly focus on routine radiation exposure without fully accounting for extreme space weather events. To help the aviation sector respond more effectively, the research team has proposed a new atmospheric radiation scale designed specifically for aviation, providing clearer thresholds for when action should be taken. It proposes increased monitoring as well as rerouting or grounding flights during severe events.
Professor Keith Ryden, leader of the Space Environment and Protection research team at the Surrey Space Centre, said: 'At the moment, there is no consistent way for the aviation sector to assess and respond to extreme space weather risks. We've introduced a clearer, aviation-specific radiation scale to help support more informed decision-making in aviation, helping operators act quickly to protect passengers, crew and critical onboard systems.'
Such delays may leave passengers frustrated if stuck at the airport, but a few hours in duty-free or an airport bar may well be preferable to the alternative – a terrifying incident like the one that occurred last October.
