NASA launches TEMPO, a new space-based air quality monitoring instrument

A new NASA instrument for monitoring air pollution has hitched a ride on a SpaceX Falcon 9 rocket. The instrument, TEMPO, will provide “the most extensive view of air pollution” over North America, said Xiong Liu, TEMPO’s deputy principal investigator, at a press briefing two days before the launch.

Unlike most existing earth-observing instruments, TEMPO, which launched on the morning of April 7, will sit in geostationary orbit, aboard the Intelsat 40E communication satellite. Because this orbit matches the rotation of the earth, TEMPO will be able to capture how pollutants such as nitrogen dioxide, ozone, and formaldehyde change on an hourly basis across an area stretching from Mexico City to the oil sands of Canada.

Most other earth-observing satellites sit at a lower altitude and are out of sync with Earth’s rotation. As a result, their instruments can only collect air quality data once per day at any given location. TEMPO, a UV-visible spectrometer, will also be able to provide a much finer picture of how air quality varies between locations, as it will be capable of resolving different pollution sources sitting less than 5 km apart.

TEMPO is the newest addition to the US’s growing air quality monitoring network. The instrument will be used in tandem with ground-based air quality monitors operated by the Environmental Protection Agency and with short-term measurements collected by scientific researchers. Combined, the data can help craft a more complete picture of how air pollution is changing both spatially and over time. They will also assist in improving existing air quality models.

“Better models allow us to develop more applications of the data—more predictive tools—and put that actionable information into the hands of decision makers at every level,” said Karen St. Germain, director of NASA’s earth science division, at the press briefing. Government agencies “will be able to add TEMPO data in, to approve air quality modeling [and] public health alerts,” St. Germain said.

These agencies include the EPA and the National Oceanic and Atmospheric Administration. Both are part of the TEMPO Early Adopters program, which is made up of 300 US government agencies, scientific researchers, and international partners that will get an early look at TEMPO data before it becomes available to the public.

TEMPO should reach its final orbital altitude approximately 3 weeks following its launch date. According to St. Germain, it is one of four earth-observing instruments that NASA plans to launch this year.