Soyuz TMA-10 ferried part of the Expedition 15 crew to and from the International Space Station. Space Tourist Simonyi joined for a short duration mission, returning to Earth on Soyuz TMA-9. During reentry, the Service Module failed to fully separate from the Descent Module, triggering a harsh, steep reentry and landing. Investigators misidentified the cause of the failure, leading it to reoccur on Soyuz TMA-11.