Separation of the orbital module is critical for a safe landing; without separation of the orbital module, it is not possible for the crew to survive landing in the descent module. This is because the orbital module would interfere with proper deployment of the descent module's parachutes, and the extra mass exceeds the capability of the main parachute and braking engines to provide a safe soft landing speed. In view of this, the orbital module was separated before the ignition of the return engine until the late 1980s. This guaranteed that the descent module and orbital module would be separated before the descent module was placed in a reentry trajectory. However, after the problematic landing of Soyuz TM-5 in September 1988 this procedure was changed and the orbital module is now separated after the return maneuver. This change was made as the TM-5 crew could not deorbit for 24 hours after they jettisoned their orbital module, which contained their sanitation facilities and the docking collar needed to attach to "Mir". The risk of not being able to separate the orbital module is effectively judged to be less than the risk of needing the facilities in it, including the toilet, following a failed deorbit.