sentences:  The likely reason for the spacecraft failure was the leakage of fuel and oxidizer vapors through the improperly designed PTFE check valve to the common pressurization system.During interplanetary cruise, the vapor mix had accumulated in feed lines and pressurant lines, resulting in explosion and their rupture after the engine was restarted for routine course correction.A similar problem later crippled the Akatsuki space probe in 2010.