Celestial cruise control

The thrusters have been implemented to provide high precision drag compensation for the GOCE craft by the European Space Agency (ESA). As part of a programme to investigate the impact that human activity is having on the planet, the spacecraft will orbit the outer reaches of the atmosphere at 200-300kms above the earth. As the strength of the earth's gravitational field diminishes with altitude, the craft experiences disturbances in its motion from atmospheric drag, so Qinetiq's electric engines have been designed to continuously compensate for this factor. The T5 ion thrusters require 40kgs of propellant for the duration of the 30 month mission and are said to be around 10 times more efficient than traditional rocket thrusters. Mary Carver, managing director of QinetiQ's integrated systems business, explained: "This important space mission would not be possible without the precision provided by the QinetiQ's electric engines. Our space engineers have overcome a challenge that has been likened to compensating for the impact of an insect landing on the windscreen of a car travelling at 100mph." "In the next few years," continued Carver, "electric propulsion could make previously impossible missions into deep space a reality and extend the operational life of commercial communications satellites, reducing costs." QinetiQ is currently working with partners to qualify its T6 thruster, a more advanced electric propulsion system that has been designed for use on the ESA BepiColombo mission to Mercury. The GOCE launch, originally scheduled for today, has now been suspended until Tuesday.