Revolutionary GOCE spacecraft benefits from QinetiQ precision

QinetiQ's electric engines are playing a crucial role on a revolutionary spacecraft to be launched today (14.21 GMT Monday) from the Plesetsk cosmodrome in Northern Russia.

The electric engines, known as T5 ion thrusters, are providing high-precision drag compensation for the dart-shaped GOCE spacecraft being launched by the European Space Agency (ESA) to map the Earth's gravitational field.

GOCE is the first spacecraft to be launched as part of ESA's living planet programme which is investigating the impact that human activity is having on the Earth. By measuring the Earth's gravity, GOCE will contribute significantly to our understanding of the Earth's structure, ocean circulation and climate change.

The strength of the Earth's gravitational field diminishes with altitude, so GOCE's orbit skirts the outer reaches of the atmosphere at just 200-300 kms (125-185 miles) above the Earth. As a result the spacecraft experiences small but significant disturbances in its motion from atmospheric drag. QinetiQ's electric engines act as cruise control for the spacecraft, continuously compensating for this atmospheric drag and quite literally preventing the spacecraft from falling out of the sky.

"In order to achieve its very challenging mission objectives, the GOCE spacecraft is based on cutting-edge technology, making it a jewel of innovations," commented Volker Liebig, Director of Earth Observation Programmes at ESA. "It has been designed to fly at an extremely low orbital altitude, just 250km (155 miles) above Earth. For this reason it has an eye-catching aerodynamic shape and will actively compensate for the air drag by using the finely controlled thrust of QinetiQ's ion engine."

QinetiQ's T5 ion thrusters are around ten times more efficient than rocket thrusters that have traditionally been used to propel spacecraft, requiring only 40kgs of propellant for the whole 30-month GOCE mission. The thrusters use the inert gas xenon as their propellant ensuring they are also more environmentally friendly than conventional thrusters that use volatile chemical propellant.

"This important space mission would not be possible without the precision provided by the QinetiQ's electric engines," commented Mary Carver, Managing Director of QinetiQ's Integrated Systems business. "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."

Mary Carver added: "In the next few years 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, an even more advanced electric propulsion system that has been designed for use on the ESA BepiColombo mission to Mercury.