Richard Varvill, technical director and one of the founders of Reaction Engines believes the Skylon spaceplane project is now reaching its final stages. After decades of withdrawn government support and huge technical hurdles, the tide has turned in favour of high-tech manufacturing and, more importantly, human space travel. A recent study into the Skylon’s ability to carry passengers suggests that a trip to orbit in an upright seat, for stays of up to 14 days, would cost around $500,000. Compared with the plans of some groups, Skylon’s space tourism ambitions are still relatively modest. However, the team is also looking to include an upper stage that would move out of low Earth orbit and, if successful, the project could have far wider significance.
Reaction Engines has been undergoing internal preparations for significant events, which are to be covered in their September update. UK officials will meet next week at a special two-day workshop next week, which will investigate how it can be developed commercially.
Heat it up: Pre-cooler uses thin-wall tubes
The Skylon is based around a synergistic air-breathing rocket engine (SABRE) that uses jet propulsion to reach the edge of the Earth’s atmosphere before switching to rocket power to get into orbit. The first phase of SABRE requires air from the atmosphere to be cooled before being compressed into the engine and burned with hydrogen, while the second phase draws on liquid hydrogen and a small supply of liquid oxygen to propel the plane into space at speeds of Mach 25.
The breakthrough for Reaction Engines has been in the development of its pre-cooler system. At Mach 5, SABRE will need to cope with gases entering at temperatures reaching 1,000 degrees celcius. The pre-cooler uses thousands of small-bore thin-wall tubes, each around the width of a human hair, to drop the air temperature to -150degrees celcius in just 30ms. Back when Skylon was still a concept, the required heat exchangers for this type of pre-cooled jet engine were impossible to make, but with improvements in materials and manufacturing techniques, Varvill believes the technology has turned a corner. If all goes well, we’re hoping to run tests by the middle of 2011 in front of a Viper jet engine.