Hypersonic propulsion using supersonic combustion ramjet (scramjet) technology offers the possibility of very high speeds and fuel efficiencies. The technology has the potential to put numerous defense and civilian aerospace applications within reach during the next couple of decades.
The Defense Advanced Research Projects Agency (DARPA) completed its Autonomous Airborne Refueling Demonstration program this month, showing that unmanned aircraft can autonomously perform in-flight refueling under operational conditions.
