The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is a grating spectrometer, sensitive to ultraviolet and visible wavelengths of light with a spectral range of 290-490 and 540-740 nm and 0.6 nm spectral resolution. The TEMPO instrument is in geostationary orbit at 91˚ W longitude (about 22,000 miles above Earth's equator). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete East-to-West scan of the field of regard hourly during daylight hours.
By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, aerosols, and other constituents important for understanding air quality and the chemistry of Earth's atmosphere.
The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health.
TEMPO was built by Ball Aerospace & Technologies Corp. (now BAE Systems Inc.) and launched on April 7, 2023, on a SpaceX Falcon 9 rocket from Florida's Cape Canaveral Space Force Station. TEMPO is attached to the Earth-facing side of the commercial Maxar Technologies-manufactured communications satellite Intelsat 40e.
The instrument beamed back its first Earth images on August 2, 2023. The TEMPO mission is a collaboration between the Smithsonian Astrophysical Observatory and NASA, supported by the NASA Science Mission Directorate. TEMPO serves as the North American component of an international geostationary constellation for air quality measurements.