SpaceX disrupted GPS by opening a hole in the ionosphere
Like skimming a rock across a pond, rocket launches tend to breach the Earth’s atmosphere at an angle. This reduces gravity drag and stress on the vehicle, which is useful when you’re trying to shoot a heavy payload into space.
In 2017, SpaceX launched a Falcon 9 rocket that didn’t do this. Instead of curving to ascend at an angle, it travelled vertically all the way through the Earth’s atmosphere. It could do this because the payload for the Formosat-5 mission was so light – only 475kg. But, like throwing a rock into a pond, this made quite a splash.
Researchers not only detected circular shockwaves around the launch, but have also determined that the rocket punched a 900 km hole into the plasma of the Earth’s ionosphere.
As Ars Technica reports, research has been published that points to the Falcon 9 rocket making giant shockwaves that spread out over a 1.8 million square km region across the western United States. This was followed by an “ionosphere hole” when exhaust plumes from the rocket depleted plasma over an area extending 900 km, which lasted for around three hours.
Like a localised magnetic storm, this disruption to the middle and upper atmosphere meant GPS signals were affected. The launch itself didn’t have that much of an impact – causing only a 1-meter error to GPS signals, but the scientists behind the report warn that further launches could cause more extensive disturbances.
At a time when reusable rockets are lowering costs, and therefore making rocket launches more frequent, there’s a concern that the analogous rise of devices that rely on GPS navigation – particularly the advent of driverless cars – could be an issue. That last thing you want is a pile up on the motorway because of a rocket launch hundreds of miles away.