Airports around the world have once again plunged into chaos of red screens and canceled flights. Airbus and EASA They have ordered an unprecedented technical stoppage of 6,000 A320 aircraft to apply a patch that prevents “data corruption in the ELAC computer.” Behind this technicality lies a disturbing reminder that all of our digital technology is at the mercy of the Sun. The more advanced, miniaturized and efficient our infrastructure is, the more vulnerable it becomes to space weather.
Anatomy of a “bit flip”. On October 30, a JetBlue Airbus A320 covering the route between Cancun and Newark made a sudden downward pitch without the pilots commanding it. A manufacturer inquiry revealed that the culprit had been a high-energy particle: a neutron generated by the interaction of the solar wind with the atmosphere that impacted a memory cell of the ELAC (Elevator Aileron Computer) computer with enough energy to change the voltage of a microscopic transistor from 0 to 1.
This phenomenon known as a “bit flip” caused the L104 version of the Airbus software to interpret that the plane was in a dangerous situation (such as a stall). The computer did what it was programmed to do: “save” the plane by lowering the nose to gain speed. But the problem was not the hardware itself, but rather the software logic, which in this version does not have the necessary immunity to discard corrupt data. Hence, it does not affect all aircraft, and the solution is to apply a patch.
The price of Moore’s law. 30 years ago, transistors were macroscopic bricks that required a lot of energy to alter. Today, microprocessors in airplanes (as well as those in cars and cell phones) have transistors on the nanometer scale. They are so sensitive that a minor solar storm, like the one on October 30, which was classified as G1, has the potential to wreak havoc that we previously only expected from catastrophic solar stormslike the Carrington event.
It is the price that we pay for Moore’s law– As transistors become smaller and operate at lower voltages, less power is required to disturb their state.
A precedent called Qantas 72. While the JetBlue Flight 1230 case has ended up affecting an unusual number of aircraft, industry veterans have had a déjà vu. In 2008, Qantas Flight 72 (an Airbus A330) experienced a similar nightmare over the Indian Ocean. The plane abruptly lowered its nose twice without warning, throwing passengers against the cabin roof.
The Australian ATSB investigation concluded that one of the aircraft’s inertial reference units had been hit by cosmic rays, causing it to take an angle of attack of 50 degrees. The difference is that today we have thousands more planes in the sky, more dependent on automation, and operating under a 25 Solar Cycle which is proving to be more active than anticipated.
Beyond airplanes. The Sun had already sent us a warning about its new maximum in 2022, when SpaceX lost 38 of 49 Starlink satellites just released. Not due to electronic failures, but thermodynamic ones. A solar storm increased the density of air in the Earth’s atmosphere, slowing satellites in low orbit until they fell. It was a minor storm, but enough to cost millions of dollars.
The satellites are more exposed to solar radiation and are especially sensitive to geomagnetic storms. On Halloween night 2003, the Sun played trick-or-treating, causing a 30-hour crash in the FAA’s WAAS system, which is vital to GPS landing accuracy. If that were to happen today, with the current reliance on GNSS for everything (from Uber to banking transactions), the impact would be incalculable.
Will there be another Carrington event? The most disturbing thing about the technical report on the A320 is that the triggering event was a level G1 geomagnetic storm, classified as minor. The scale goes up to G5, classified as extreme. In 1859, the Carrington Event fried telegraph networks around the world.
If a storm of that magnitude hit the Earth today, we wouldn’t be talking about updating the software of 6,000 airplanes. We would be talking about the possible loss of entire GPS constellations, massive physical damage to the electrical grid and a paralysis of global transportation for weeks or months.
We’ve built a civilization on extremely fragile silicon scaffolding, and our host star has a bad temper. Hence, space meteorology has ceased to be a scientific curiosity and has become a first-rate mission to predict solar storms and prepare satellites, astronauts and electrical infrastructure on the ground for any possibility. Today was a software patch, tomorrow we may need to rethink how we harden all of our technology.
Image | ESA, Airbus
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