At a meeting in Baltimore next month, the FAA will take a fresh look at research dedicated to softening the sonic boom of supersonic aircraft. Supersonic flight over land in the U.S. is not permitted, largely due to the impact of the loud sonic boom associated with it. But several projects delving into supersonic flight have sought to mitigate the boom — largely through advanced aerodynamics — in hopes of reversing the rule. At least part of the mandate of the Baltimore meetings will be to increase public awareness of technological advances that could reduce the boom to a whisper. According to the FAA, "Recent research has produced promising results for low-boom intensity, and has renewed interest in developing supersonic civil aircraft that could be considered environmentally acceptable for supersonic flight over land." Previous FAA meetings on the subject took place in October 2008 and March 2009 — in Chicago and Palm Springs, California, respectively.