GPS measurements point to changes over North America, but the report does not document user outages or navigation failures. Researchers say NASA's Artemis II launch and later rocket burns altered the ionosphere over North America, with changes that could translate into GPS positioning errors of several metres.
Researchers at Taiwan's National Cheng Kung University analysed measurements from ground-based GPS receivers. Space.com reported on 4 November 2026 that the team detected two disturbances, each extending about 5,000 kilometres across North America.
The measurements indicate possible positioning errors of several metres, but do not show that users experienced outages or that vehicles or drones were affected.
What the Artemis II GPS Measurements Show
The researchers used GPS signals to measure changes in the ionosphere, the electrically charged region of the upper atmosphere. Signals travelling from satellites to ground receivers pass through this layer. Changes in its free-electron concentration can alter how quickly a signal travels, affecting the distance calculations receivers use to estimate position.
The first disturbance followed the Space Launch System core stage after liftoff on 1 April 2026. A second was associated with two burns of the rocket's upper stage at an altitude of about 185 kilometres. Space.com reported that the second disturbance was more prominent.
The fixed GPS receiver networks used by the researchers are high-precision stations that US scientific institutions use to track small movements in Earth's crust. They helped reconstruct changes in electron concentration over the region, but did not record what happened on every GPS-enabled device.
The reported positioning errors are estimates derived from those measurements, not a log of navigation failures or safety incidents.
What Artemis II's Ionospheric Changes Could Mean for GPS
GPS and other satellite-navigation signals pass through the ionosphere before reaching receivers on Earth.
NOAA's Space Weather Prediction Center explains that a highly disturbed ionosphere can prevent a receiver from locking on to a satellite signal or cause it to calculate an inaccurate position. Its guidance describes the general mechanism; it does not verify a GPS effect from Artemis II.
Study co-author Charles Lin, an Earth science professor at National Cheng Kung University, told Space.com that an error of a couple of metres could affect an autonomous car's lane choice and drone positioning. Those are possible consequences, not outcomes observed after the launch. The study does not establish that all receivers would be affected equally.
The disturbances were reported over North America. The coverage reviewed documents no effect on UK GPS users, so the finding does not establish that anyone in Britain experienced a loss of navigation service. Its UK relevance is what it may indicate about rocket activity and systems that rely on satellite positioning.
Why Artemis II's GPS Findings May Matter Beyond the Mission
Rocket launches can disturb the ionosphere; severe solar storms can also affect GPS signals, sometimes for days. Space.com describes rocket-related effects as shorter-lived, but does not state how long the Artemis II disturbances lasted or report a GPS service warning linked to the launch.
Lin told Space.com that the upper-stage manoeuvres were unusual in an interplanetary mission and that such effects could become more significant as missions to the Moon and Mars increase. That is his assessment of future relevance, not evidence that upcoming launches will disrupt GPS. Space.com describes the GPS research as a preprint.
