Artemis 2 atmosphere hole: did it break GPS, and does it close?

The hole is in the ionosphere, not in the air you breathe or the ozone layer. The ionosphere is the layer of Earth’s atmosphere that starts about 30 miles (50 kilometers) up and is full of electrically charged particles. It sits between the ground and the satellites that run GPS, which orbit around 12,550 miles (20,200 kilometers) up, so every navigation signal has to pass through it.

A “hole” here means a patch where the number of free electrons suddenly drops. Rockets cause this in two ways. The rocket’s supersonic climb sends a shock wave upward that pushes the charged gas aside. And when engines fire high up, the exhaust reacts with the charged gas. An earlier modeling study explained the chemistry in plain terms: water, hydrogen and carbon dioxide in the exhaust swap charge with oxygen ions, and the new ions quickly recombine and stop being charged. The result is a dent in the layer, which scientists call an ionospheric depletion.

This is also not the ozone hole. Scientists who studied an earlier rocket-made gap stressed that these ionospheric holes are nowhere near as serious as the ozone problem, though they admit the effects are still poorly understood.

It was the strongest rocket disturbance measured so far. The team at National Cheng Kung University in Taiwan says the Artemis II effect was up to ten times more intense than the disturbances seen after SpaceX’s Starship test flights, even though Starship produces roughly twice the liftoff thrust of NASA’s Space Launch System (SLS).

The researchers found two separate holes. One trailed the SLS core stage, the 212-foot main body of the rocket. The other came from two burns of the rocket’s upper stage that fired more than an hour after liftoff, around 115 miles (185 kilometers) up, to push the Orion capsule out of Earth orbit and toward the moon.

Here is the surprise. The upper-stage burns left the bigger mark, not the roaring launch itself. That is because they happened inside the ionosphere, where the gas is thin and easy to disturb.

The study counts three distinct disturbance events from the one mission:

• the launch itself, which sent shock and gravity waves upward;
• the Apogee Raise Maneuver, a burn that stretched Orion’s orbit and spread a disturbance across about 50 degrees of longitude;
• the trans-lunar injection burn the next day, which sent Orion on its way to the moon.

The authors say this is the first time one space mission has produced three ionospheric disturbances over the same region during successive orbital maneuvers. Their paper is a preprint in the journal Geophysical Research Letters, so it has not yet gone through final peer review.

No real GPS outage has been documented. The study measured how much the ionosphere changed and worked out that the change was equivalent to positioning errors of several meters. That is a calculated effect at the ground stations, not a list of phones or cars that failed.

Why would charged gas move your location at all? A GPS receiver works out where it is by timing signals from four satellites. When the electron count in the ionosphere changes, those signals arrive slightly faster or slower than expected, and the receiver’s position estimate shifts.

Study co-author Charles Lin, an earth science professor at the university, says a couple of meters of error is enough to make an autonomous car think it should change lanes. He also flagged drone positioning as a concern. Those are the systems that need lane-level or better accuracy. The study looked only at fixed ground stations, not at phones or cars.

How scientists spotted it from the ground

The team did not launch any special instrument. It reused about 3,500 fixed GNSS ground stations across the Americas, many of them run by US scientific groups to track the tiny movements of tectonic plates. GNSS covers GPS and the other satellite navigation systems, and the team used GPS, GLONASS and Galileo signals logged every 30 seconds.

By comparing how long signals took to reach thousands of receivers, the researchers built a moving map of the ionosphere and watched the rocket’s dent spread across the continent. One limit: denser station networks give sharper pictures, so the 3,100-mile figure reflects where receivers happen to be.

Yes, these holes heal on their own, and fast compared with natural disruptions. Severe solar storms can upset GPS for days. Rocket-made holes are far more short-lived.

There is a track record. After Starship blew up about 93 miles above the Earth on November 18, 2023, a team from Russia and France checked data from some 2,500 ground stations. They found a hole running between Mexico’s Yucatan peninsula and the southeastern US, and it closed after 30 or 40 minutes. In July 2023, a Falcon 9 launch was followed by a “bleeding” aurora that lasted 20 minutes, and a rocket carrying a US Space Force satellite punched a hole that quickly recovered. Modelers have also studied two Falcon 9 launches from Vandenberg, carrying the Jason-3 and FORMOSAT-5 satellites, and found the FORMOSAT-5 hole was far bigger and lasted longer.

The public summaries of the Artemis II study do not give an exact closing time, so we cannot say how many minutes its holes lasted.

Artemis II was a test. NASA is now working toward Artemis IV, which aims to land astronauts on the moon, and a longer-term Moon Base program. Lin says rocket launches have always disturbed the ionosphere, but his team had never seen this kind of effect from the orbital maneuvers of a mission heading beyond Earth. With many more moon and Mars missions planned, he expects these space weather effects to grow.

That matters most for anything that needs to know its position to within a meter or two, like the self-driving cars and drones Lin mentioned.