On display in the Research and Development Gallery at the National Museum of the U.S. Air Force. The Air Force Research Laboratory (AFRL) produced a Pulsed Detonation Engine (PDE) in the 2000s using off-the-shelf automotive components. Shockwaves from controlled detonations of the fuel-air mixture provided a peak thrust of about 200 lb at around 125 decibels through four tubes at the back. After AFRL's five-year joint effort with Innovative Scientific Solutions Inc. (ISSI), Pete Siebold flew the first manned PDE flight in this modified Rutan Long-EZ "Borealis" on 31 Jan 08 at Mojave.