Elon Musk’s rocket launch in Aug could have affected aviation, military navigation systems, says report
28 Mar 2018
Aviation and military navigation systems around the globe could potentially have been affected by the launch of business magnate Elon Musk’s Falcon 9 rocket carrying Taiwan’s FORMOSAT-5 satellite into orbit last August.
"The unusual trajectory the SpaceX Falcon 9 rocket took when delivering a Taiwanese satellite into orbit last August created an atmospheric shock wave four times bigger than the area of California,” says an American Geophysical Union blog.
Most rocket-induced shock waves are V-shaped when viewed from space as rockets tend to follow a curved trajectory after launch. However, Falcon 9’s trajectory was nearly vertical as it was carrying a light payload of only one satellite, Taiwan’s FORMOSAT-5 Earth-observing satellite. That trajectory created a circular atmospheric shock wave as opposed to a V-shaped one.
According to Charles Lin, a geophysicist at the National Cheng Kung University in Taiwan and lead author of a new study describing the unusual launch in Space Weather, a journal of the American Geophysical Union, “we’ve seen many cases of a rocket-produced disturbance, but there’s never been something that perfectly circular and with that large area.”
The FORMOSAT-5, Taiwan’s first self-made satellite, was originally scheduled to be launched with several others but was delayed because of a Falcon 9 launch pad explosion in September 2016. And by the time the launch was rescheduled, FORMOSAT-5 was the rocket’s only cargo.
With such a light payload, Falcon 9 traveled nearly vertically after its launch from California’s Vandenberg Air Force Base on August 24, 2017. The rocket delivered the satellite to its intended altitude of 720 km.
In the new study, Lin and his colleagues used GPS signals to determine how the FORMOSAT-5 launch affected the upper atmosphere. They found Falcon 9’s vertical trajectory created a circular shock wave above western US that had never before been seen from a rocket launch.
The shock wave circular was also the largest Lin had ever seen – roughly four times the area of California. Besides creating a gigantic shock wave, the launch created a hole in the ionosphere above California. Water vapour in the rocket’s exhaust reacted with the ionosphere’s charged particles to create a hole in the plasma layer that took up to two hours to recover, says the AGU blog.