KTDU-80

The KTDU-80 (Russian: Корректирующе-Тормозная Двигательная Установка, КТДУ) is the latest of a family of integrated propulsion system that KB KhIMMASH has implemented for the Soyuz since the Soyuz-T. It integrates main propulsion, RCS and attitude control in a single system pressure fed from a common dual string redundant pressurized propellant system. The common propellant is UDMH and N₂O₄ and the main propulsion unit, is the S5.80 main engine. It generates 2.95 kN (660 lbf) of thrust with a chamber pressure of 0.88 MPa (128 psi) and a nozzle expansion of 153.8 that enables it to achieve a specific impulse of 302 s (2.96 km/s). It is rated for 30 starts with a total firing time of 890 seconds. The integrated system without the pressurization nor tanks weighs 310 kg (680 lb) and is an integrated unit that is 1.2 m (47 in) long with a diameter of 2.1 m (83 in).

Description

The KTDU-80 system integrates a dual string redundant propellant and pressurization system, a main propulsion system (the SKD), an RCS (the DPO-B) and an attitude control system (the DPO-M). All the propulsion elements are pressure fed rocket engines burning UDMH and N₂O₄ with a common supply of pressurized propellant. Mechanically, the KTDU-80 is separated in two sections: