The China Aerospace Science and Technology Corporation is beginning advanced research on hybrid combined cycle engines that can takeoff from an airport’s landing strip and fly straight into orbit. The hybrid space plane’s combined cycle engines would use turbofan or turbojet engines to takeoff horizontally from a landing strip. Once airborne, the engine then shifts to ramjet propulsion and, as speed increases, adjusts into a scramjet engine with supersonic airflow. At the scramjet stage, the hybrid spaceplane would enter hypersonic flight in ‘near space’, the part of the atmosphere between 20km to 100km above sea level. Finally, the hybrid spaceplane would use its rocket motors to push out of near space and into orbit.
Zhang Yong, a CASTC engineer, claimed that China will master the spaceplane’s technologies in the next three to five years, and a full-scale spaceplane would then enter service by 2030.
CASTC’s rapid research timeline suggests that the reports in 2015 of a Mach 4 test flight for a recoverable drone testbed for a combined cycle ramjet/turbofan engine were accurate. And China also has the world’s largest hypersonic wind tunnel, the Mach 9 JF-12, which could be used to easily test hypersonic scramjets without costly and potentially dangerous flight testing at altitude.
Concepts currently appear to look similar to the UK Reaction engines skylon spaceplane.
Combined Cycle Engine
The combined cycle engine shares the same inlet and exhaust nozzle for both the turbojet/turbofan and ramjet. In the upper diagram, the air intake ramps behind the ramjet spike direct airflow into the turbo core. In the bottom diagram, the air intake ramps gradually block off air flow to the turbo core, redirecting air into the ramjet combustion engine for high supersonic (Mach 3.0-Mach 4.0). Chinese combined cycle engines like this blueprint would be paired with a scramjet (presumably via changing the ramjet) and a separate rocket motor to create a hypersonic space plane.
SOURCES- Popular Science