"DISCOVER-AQ is collecting data that will prepare us to make better observations from space, as well as determine the best mix of observations to have at the surface when we have new satellite instruments in orbit . NASA is planning to launch that satellite instrument, called TEMPO, in 2017."
Source: James Crawford, the mission's principal investigator at NASA's Langley Research Center in Hampton, Va., commenting on a multi-year NASA airborne science mission that is on its way to California to help scientists better understand how to measure and forecast air quality globally from space.