23 May

2003: On 23 May 2003, the Mars Express launch window opened and would last for four weeks. A launch window is the period of time when it is possible to launch a spacecraft so it can start its mission successfully and as planned.

However, just before the spacecraft was due to leave Toulouse, France, for its trip to the Baikonur Cosmodrome in Kazakhstan, engineers discovered a fault in one of the electronics modules.

In view of the estimated time needed to correct the fault, the launch date was initially put back from 23 May to 6 June, still within the launch window. However, thanks to the skill and dedication of the engineering team, the job was completed sooner than expected and the launch date was brought forward.

With the green light given, Mars Express was fuelled - an operation that took about a week. It was then attached to Fregat, the Soyuz upper stage rocket booster, and mated with the Soyuz rocket. The whole system was rolled out to the pad four days before launch.

On 2 June 2003, the Soyuz rocket lifted off from Baikonur, and Mars Express was on its way.