Researchers using a NASA air-quality satellite estimate that Southaven power plant emissions of nitrogen oxides from the natural gas turbines that power SpaceXAI’s data centers have run far above the level the state permit anticipates. Their estimate is roughly 19 times higher on average since February 2026. The Daily Memphian reported on the study Saturday, Nov. 14.
The paper, titled “Quantifying AI data center nitrogen oxide (NOx) emissions from space,” was written by Kevin D. Gauld and Daniel J. Varon of the Massachusetts Institute of Technology and Nicholas Balasus and Daniel H. Cusworth of Carbon Mapper. It was first posted Aug. 23 on arXiv, an online preprint server where papers appear without formal peer review. The authors last revised it on Oct. 19.
What the Southaven Power Plant Emissions Study Found
The researchers used NASA’s TEMPO instrument, which sits in a fixed orbit over North America and measures nitrogen dioxide (NO2) in the air during daylight hours. They tracked the area around the plant, which the study calls the SpaceXAI Colossus 2 power plant, from August 2025 to August 2026. The Daily Memphian identifies its address as 2875 Stanton Road in Southaven.
According to the paper’s abstract:
Local average NO2 levels rose sharply after the plant began operating in late 2025.
The satellite first detected nitrogen oxide (NOx) emissions from the site in December 2025, at an estimated 530 kilograms per hour, plus or minus 220.
Emissions kept rising through August 2026 and averaged about 870 kilograms per hour, plus or minus 165, after February 2026.
That is roughly 19 times the approximately 47 kilograms per hour expected under the facility’s March 2026 permit, which covers 41 turbines operating with “best available control technology.”
At the permitted level, emissions would be too small for the TEMPO analysis to detect at all.
The authors calibrated their satellite estimates against continuous emission monitoring data from other U.S. power plants. They based the expected permit level on Mississippi Department of Environmental Quality (MDEQ) records. The study says MDEQ approved a permit to construct 41 permanent turbines on March 11, 2026, and that the turbines are designed to use selective catalytic reduction pollution controls.
Why Nitrogen Oxides Matter
Nitrogen oxides come mainly from burning fuel. They help form ground-level ozone, or smog, and can irritate the lungs. The Daily Memphian’s report says the study found the plant could have released smog-forming chemicals at a rate clearly visible from space, and could have contributed significantly to local air emissions. The paper says this is the first time NOx pollution from AI data center power generation has been measured with atmospheric observations.
The study estimates emissions from the plant. It is not a reading from ground-level air monitors in Southaven, and it doesn’t determine whether any air-quality standard was violated.
Permit Fight Continues
The study comes days after the MDEQ Permit Board voted Nov. 10 to uphold the SpaceXAI/MZX Tech air permit, after an evidentiary hearing in which residents raised concerns about noise, utility bills and pollution. Agriculture Commissioner Andy Gipson cast the lone vote against it. The plant supplies electricity to the company’s data centers in Southaven and Memphis.
The paywalled excerpt of the Daily Memphian article did not include a response from SpaceXAI or MDEQ. DeSoto County News will update this story if either responds to the study’s findings.
