spacedaily is reporting that the ESA (European Space Agency) is in the process of evaluating a new propulsion system named SABRE (Synergistic Air-Breathing Rocket Engine).
"Reaction Engines has announced the biggest breakthrough in aerospace propulsion technology since the invention of the jet engine. Critical tests have been successfully completed on the key technology for SABRE, an engine which will enable aircraft to reach the opposite side of the world in under 4 hours, or to fly directly into orbit and return in a single stage, taking off and landing on a runway.
SABRE, an air-breathing rocket engine, utilises both jet turbine and rocket technology. Its innovative pre-cooler technology is designed to cool the incoming airstream from over 1,000C to minus 150C in less than 1/100th of a second (six times faster than the blink of an eye) without blocking with frost. The recent tests have proven the cooling technology to be frost-free at the crucial low temperature of -150C"
lowering the cost to orbit opens the door to a greater human presence in space