The SKYLON vehicle
SKYLON is the successor to Britain’s HOTOL spaceplane concept, being developed by Reaction Engines Ltd (REL). It is an unpiloted fully reusable aircraft-like vehicle capable of transporting 12 tonnes of cargo into space and is intended as a replacement for expensive expendable launchers in the commerical market.
The SABRE engines have a dual mode capability. In rocket mode the engine operates as a rocket engine. In air-breathing mode the liquid oxygen flow is replaced by atmospheric air, increasing the installed specific impulse 3-6 fold.
The vehicle takes off and lands using a relatively conventional retractable undercarriage. By special attention to the brake system it has proved possible to achieve an acceptably low undercarriage mass. However, a heavily reinforced runway will be needed to tolerate the high equivalent single wheel load.
At the start of the take-off roll the vehicle weighs 275 tonnes, whilst maximum landing weight is 55 tonnes. At take-off the vehicle carries approximately 66 tonnes of liquid hydrogen and approximately 150 tonnes of liquid oxygen for the ascent.
The ground handling operations will be carried out using a standard aircraft tractor and a bonded goods cargo building permitting overhead loading and protection from the elements. For safety and operational simplicity the cryogenic propellants are loaded subcooled without venting of vapour. Cryogen loading is automatic through services connecting in the undercarriage wells whilst the vehicle is stood on the fuelling apron.
Credits: Reaction Engines Ltd och spacefuture.com