Instruments on the Mars Express orbiter:
1. MARSIS: ground penetrating radar to locate, for example, water and ice
2. HRSC: providing accurate and detailed images of the surface and atmosphere
3. OMEGA: mapping the surface composition of Mars
4. SPICAM: finding out why the Martian
atmosphere is so oxidising
5. PFS: studying the composition of the atmosphere
6. ASPERA: looking at how the solar wind erodes the Martian atmosphere
7. MaRS (no corresponding hardware): using data transmission for science
8. Beagle 2: searching for evidence of past or present life.