NASA is celebrated for space probes and Mars missions. But one of the agency's next big projects could also make a major contribution to public health.
The U.S. space agency, along with agencies in Europe and South Korea, is making plans to launch a fleet of air pollution sensors into space. The sensors, which are being built by NASA, the European Space Agency and the South Korean government, are meant to monitor and track pollutants from orbit. Scientists hope NASA's contribution to the project, called TEMPO, will provide a more accurate picture of how dangerous particles crisscross the Earth.
"Air pollution is really a global pollution," Barry Lefer, a NASA scientist and project manager for TEMPO, told The Huffington Post. "Pollution from the U.S. travels to Europe, pollution from Asia travels to the U.S. And satellites are the best way to see the long-range transportation of pollution."
The final product, which scientists say will be a "constellation" of pollution-tracking satellites, is still years away. But NASA plans to kick off the first phase of the project in May, when it will begin collecting air pollution data from the Korean peninsula in order to fine-tune its satellite-based pollution monitors.
NASA has been collecting pollution data for decades, but its old instruments are becoming outdated. They're also not always accurate, in part because they don't directly measure pollutants. Instead, they look at light bouncing off particles in the atmosphere. Each type of particle reflects light differently, producing a series of "spectral fingerprints" that scientists can use to tell one substance from another.
While distinguishing between different pollutants is difficult, experts say the real challenge is producing high-resolution data that would let scientists determine exactly where air pollution is coming from. NASA's new satellites can collect pollution data at the county level, promising a more detailed picture of pollution sources than previous satellite data could provide.
"What's gotten better is the finer resolution," Lefer said. With earlier satellites, "we could see the city and the rural area, and we would be averaging the two. Now, with the new satellite imagers, we get better spatial resolution."
While NASA has been using satellites to measure and track air pollution since the 1970s, most environmental organizations in the U.S. and Asia rely on ground-based sensors to monitor pollution. But these sensors can't be everywhere at once, and groups like the Environmental Protection Agency are often left with large gaps in data.
"One of problems with EPA monitoring is you only have data where there’s a monitor," Lefer said. "A satellite can see where they’re not monitoring properly."
Ground-based sensors are also unable to track pollution over long distances, like across oceans and from one continent to another. The new mission, Lefer said, is meant to provide "a powerful new understanding of air pollution and how it's being transported across the globe."
A huge amount of money is also spent on studying our home planet. Barry Lefer, NASA scientist
Every year, air pollution is responsible for more than 150,000 deaths in the U.S. and more than 2 million deaths in the Western Pacific region, which includes China and South Korea, according to NASA. Scientists at NASA hope that putting sophisticated air pollution monitors in space will help environmental agencies around the world improve their efforts to curb pollution.
"There are different ways we’ve tried to... make this useful to the general public, use this for the good and improve the public's health," Lefer said.
Critics of NASA in Congress argue that the agency's Earth-focused missions need to be kept in check. In 2015, Rep. Lamar Smith (R-Texas), chairman of the House Committee on Science, Space and Technology, introduced legislation to defund NASA's Earth Science program. Missions focused on the Earth, Smith argued, come “at the expense of the other science divisions and human and robotic space exploration.”
But efforts to explore the Earth and protect the health of its occupants remain a central part of NASA's mission, Lefer said.
"NASA is still the nation's space agency. We’re interested in going to Mars, we're interested in the cosmos," he said. "But a huge amount of money is also spent on studying our home planet."