Firing up QinetiQ's ion engines

摘要

QinetiQ's electric engines, known as T5 ion thrusters, are providing high-precision drag compensation for the GOCE (Gravity and steady-state Ocean Circulation Explorer) spacecraft launched in March by the European Space Agency (ESA). GOCE is the first spacecraft to be launched as part of ESA's living planet program, which is investigating the impact that human activity is having on the Earth. The strength of the Earth's gravitational field diminishes with altitude, so GOCE's orbit skirts the outer reaches of the atmosphere at about 260 to 280 km above the Earth. Because of that, the spacecraft experiences small but significant disturbances in its motion from atmospheric drag. GOCE's ultra-sensitive measurements of the Earth's gravitational field depend on the ability of QinetiQ's engines to maintain the spacecraft's orbit by finely controlling its altitude and speed.