Reaction Engines has begun testing of the Pre-cooler for the Skylon spaceplane. It is now fully integrated into the B9 test stand with the Viper jet engine, has finally begun this month after a number of delays shaking down the system. The initial tests have gone very well and represent a good start to the test campaign which will last several months.
The flow thorough the Pre-cooler has been found to be aerodynamically stable without any significant structural deflection or vibration.
They have just successfully completed the first phase of the pre-cooler test program.
Pre-cooler installed at the B9 Test Area.
Its major innovation is the Sabre engine, which can breathe air like a jet at lower speeds but switch to a rocket mode in the high atmosphere.
Reaction Engines Limited (REL) believes the test campaign will prove the readiness of Sabre’s key elements.
This being so, the firm would then approach investors to raise the £250m needed to take the project into the final design phase.
They hope to have positive results from the testing by July, 2012.
The test stand will not validate the full Sabre propulsion system, but simply its enabling technology – a special type of pre-cooler heat exchanger.
Sabre is part jet engine, part rocket engine. It burns hydrogen and oxygen to provide thrust – but in the lower atmosphere this oxygen is taken from the atmosphere.
The approach should save weight and allow Skylon to go straight to orbit without the need for the multiple propellant stages seen in today’s throw-away rockets.
Helium is pumped at high pressure through the module’s nickel-alloy piping.
The helium enters the system at about minus 170C. The ambient air drawn over the pipes by the action of the jet should as a consequence dip rapidly to around minus 140C.
Sensors will determine that this is indeed the case.
The helium, which by then will have risen to about minus 15C, is pushed through a liquid nitrogen “boiler” to bring it back down to its run temperature, before looping back into the pre-cooler.
“It is important to state that the geometry of the pre-cooler is not a model. That is a piece of real Sabre engine,” said Mr Bond.
“We don’t have to go away and develop the real thing when we’ve done these tests; this is the real article.”
The manufacturing process for the pre-cooler technology is already proven, but investors will be looking to see that the module has a stable operation and can meet the promised performance.