SPACE: ARTEMIS SATELLITE REACHES OPERATIONAL ORBIT.

• Position: Brief Article

Following a malfunction of the Ariane 5 upper stage, Artemis was left in a lower than intended orbit, and it was even feared at the time that the entire mission might be lost. However, it was finally saved through the use of experimental technologies fitted to the satellite. Novel, unplanned use of the ion propulsion technology built into Artemis was the key to this success. The system was used to raise the satellite's orbit from 31 000 km to 36 000 km. This is a much slower process than using a conventional apogee boost motor - a bit like using an outboard motor to drive an ocean liner!

After being placed in a safe parking orbit under thrust from its conventional chemical-powered apogee boost motors, the satellite's small ionic motors took over in February 2002 and, at an average of 15 kilometres a day, Artemis rose in spirals towards geostationary orbit. Needless to say, there were incidents and unexpected problems on the way, as engineers strove to make a system do a job for which it had not been designed.

Artemis has now taken up its operational...