For the first time, a European space probe is to fly to Mars and land on the planet by the end of 2003. “Mars Express” shall investigate whether there was once water on our neighboring planet Mars and whether life was formed at that time. At 150 million euros, this will be the most cost-effective mission ever undertaken. This has been made possible by the use of proven technologies and developments of the comet probe “Rosetta” and “Mars 96”.