Satellite remote sensing of atmospheric composition is becoming an increasingly important source of information in air quality management and public health surveillance. Current instruments such as MODIS, MISR, OMI, and VIIRS have provided valuable enhancements to numerous decision support activities at the local to global scales. As the stakeholders outside NASA gain experience in adopting various NASA Earth observations into their decision support activities, they also realize the limitations of these data products. For example, current satellites cannot provide high spatial-resolution PM speciation data for users to better understand the differential toxicity of PM components, therefore better design early warning systems and emissions control policy. The current satellites cannot provide tropospheric ozone data as well as gas-phase precursors such as NO2 at a high sampling frequency to characterize ozone pollution episodes. In addition, aerosol retrievals from instruments on a polar satellite are often insufficient to track the development of an air pollution event over time. Finally, as the current instruments such as MODIS and OMI approach the end of their missions, the loss of data coverage is becoming a real and serious concern for the users with operational information needs.