ESA tests P80

A prototype of the P80 rocket motor, which will power the

(ESA) small launcher Vega, has been tested at the

.

The motor delivered a mean thrust of about 190 tonnes for a nominal duration of 111 seconds, roughly a third of the thrust delivered by each of Ariane 5’s -the ESA’s heavy launch vehicle- solid booster stages.

More than 600 parameters were recorded during the firing test to monitor the performance of the motor. Initial analysis confirms that the measurements are fully in line with predictions.

Once the data recorded during the test have been analysed and the engine has undergone post-test inspection, this firing is expected to complete qualification of the P80 in readiness for Vega's maiden flight, scheduled to take place by the end of 2008.

‘The qualification of the P80 motor is a cornerstone,’ said Stefano Bianchi. ‘It is the biggest mono-segment, filament-wound-case solid-fuel rocket motor ever developed and this takes us a step closer to the Vega maiden flight. We can proceed - as from today - with increased confidence.’

The P80 is about 12m high, 3m in diameter and is loaded with 88 tonnes of solid propellant. Unlike previous motors of this size, it contains a single propellant segment, instead of several segments cast separately before being mated together.

The P80 uses a steerable nozzle, with a simplified architecture made up of fewer elements, fabricated from composite material. The nozzle also includes complex-formed cast metal parts and a new thermal insulation material. The nozzle joint is more flexible than on previous engines, allowing thrust vector control by means of electromechanical actuators. This is an additional technological improvement on a motor of this size, which usually needs to employ a more complex hydraulic system.

As solid propellant rockets cannot be shut down once ignited, the test engine was equipped with cutters to break open the casing and stop the test in the event of a malfunction.

The P80 will now be disassembled for detailed inspection, with some components being returned to Europe for examination and analysis.