Scientists this summer are taking to the air in an ambitious effort to better understand the chemistry, behavior, and health impacts of wildfire smoke. The flights in an instrument-packed C-130 airplane belonging to the National Science Foundation will be followed in 2019 by flights on a NASA DC-8 research jet by scientists with NASA and the National Oceanic and Atmospheric Administration. The two planes will fly through plumes of wildfire smoke, with a focus on the western United States, where wildfires have grown bigger and more intense. Researchers are saying it's the most comprehensive effort ever to understand wildfire smoke.