When rockets shoot up toward the sky, they don't really go straight up into outer space. Instead, they'll begin to pitch downrange to limit gravity drag and prevent too much stress on the spacecraft.
That's exactly what happened with the Falcon 9 rocket during its Formosat-5 mission in August 2017, leaving a huge hole in the ionosphere in its wake. The good news is that the hole only lasted for up to three hours, but it was still kind of equivalent to a localized magnetic storm.
Falcon 9 Creates Ionosphere Hole
Again, rockets curve their trajectory just a tiny bit for the reasons mentioned above, but in the case of the Falcon 9 in question, its payload was so light it instead took a vertical path. This, in effect, punctured a hole in the plasma of the ionosphere, given that the vehicle traveled straight up. It also caused unique, circular shockwaves.
Here's what happened: after about five minutes of reaching an altitude of 300 kilometers, Falcon 9 created circular shockwaves instead of the more typical V-shaped ones caused by near-horizontal trajectories most rockets take. These said circular shockwaves are, says a new study, the largest of their kind to have come from a rocket launch.
Minutes later, an "ionosphere hole" opened up as a result of the Falcon 9's exhaust plumes depleting plasma levels in an area 900-kilometer wide. The hole in and of itself wasn't much of a big deal, it should be noted. However, these types of vertical trajectories have the potential to affect and even alter modern GPS systems, which can disturb the way people navigate on Earth.
Impact On GPs And Navigation
Of course, navigation can always make slight adjustments in order to offset the alterations caused by disturbances in the ionosphere, but for something like, say, self-driving systems which rely on GPS and are becoming more and more popular, the impacts of rocket-caused errors in the GPS can be much more significant.
Space companies, SpaceX included, will have to be mindful of their rocket launches moving forward so as to prevent this from happening.
"Human are entering an era that rocket launches are becoming usual and frequent due to reduced cost by reusable rockets," says the study's lead author Charles C.H. Lin. This, along with the development of more capable rockets, "will gradually affect the middle and upper atmosphere more, and that is worthwhile to pay some attention to."
