TEMPO

TEMPO is attached to the Earth-facing side of the commercial communications satellite Intelsat 40e in geostationary orbit, from where it observes air quality over North America. 
Credit: MAXAR

The Satellite and the Science

TEMPO is part of NASA’s Venture Class Missions program, a set of low-cost space probes, as well as the Earth System Science Pathfinder (ESSP) program of Earth observatories. TEMPO flies aboard the commercial communications satellite Intelsat 40e, which was launched in April 2023. The Maxar-built spacecraft is in a geostationary orbit, staying above precisely the same spot on Earth’s equator. This vantage point allows TEMPO to observe variations in air quality across the whole of North America on an hourly basis.

TEMPO consists of a spectrometer designed to measure ultraviolet and visible light. By observing sunlight reflected and scattered off the Earth’s surface and atmosphere, the instrument collects information that can be used to derive the amounts of key atmospheric components such as nitrogen dioxide, ozone, and aerosol particles. The mission looks at air quality with unprecedentedly high resolution capable of distinguishing details in cities.

TEMPO is the first space-based mission designed to provide hourly reports on air quality, which in turn is essential for researchers and public officials tracking air quality. The CfA | Harvard & Smithsonian is the scientific and instrument operations lead on the project, which includes collaborators from NASA, multiple federal and state agencies, and other research institutions in the US, Canada, Mexico, Korea, and Europe. TEMPO is the North American component of a constellation of Earth-observation satellites tracking air quality.