A review of the research accomplished in 2009 in the System - Level Design , Analysis and Simulation Tools ( SLDAST ) of the NASA 's Airspace Systems Program is presented . This research thrust focuses on the integrated system - level assessment of component level innovations , concepts and technologies of the Next Generation Air Traffic System ( NextGen ) under research in the ASP program to enable the development of revolutionary improvements and modernization of the National Airspace System . The review includes the accomplishments on baseline research and the advancements on design studies and system - level assessment , including the cluster analysis as an annualization standard of the air traffic in the U.S. National Airspace , and the ACES - Air MIDAS integration for human - in - the - loop analyzes within the NAS air traffic simulation .