The S5.80 is a liquidpressure-fedrocket engine burning N2O4/UDMH with an O/F of 1.85. It is used for crew-rated spacecraft propulsion applications. It is currently used in the Soyuz-TMA-M spacecraft propulsion module KTDU-80, and its sibling, the S5.79 rocket engine, is still used as the main propulsion of the ZvezdaISS module.
The S5.80 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 engine, without the pressurization system or propellant 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).
11D426: Used as the main orbit correction engine of the Soyuz-T it was part of the integrated propulsion module KTDU-426 which was the big innovation introduced with that series. It enabled using fewer engines, increasing the reliability and reducing the weight of the spacecraft using a dual string redundant pressurization and propellant feed system for the main propulsion and the reaction control system. Since the latter could be used to de-orbit the spacecraft, it eliminated the need for backup orbital correction engine like the KTDU-35 required.
S5.80: An evolution of the 11D426 and S5.79 it is used on the KTDU-80 propulsion module that has been a staple of all Soyuz since the Soyuz-TM and Progress since the Progress-M. It has slightly reduced thrust but improved specific impulse, while improving engine life over the 11D426.
^ abcde"Двигатели 1944-2000: Авиационные, Ракетные, Морские, Промышленные" [Aviadvigatel 1944-2000: Aviation, rocketry, naval and industry] (PDF) (in Russian). pp. 75–81. Retrieved 2015-07-25.
^ abBrügge, Norbert. "Spacecraft-propulsion blocks (KDU) from Isayev's design bureau (now Khimmash)". B14643.de. Archived from the original on 2015-06-02. Retrieved 2015-06-02.
^ abcPillet, Nicolas. "Le système de propulsion du vaisseau Soyouz" [The propulsion system of the Soyuz spacecraft] (in French). Kosmonavtika.com. Retrieved 2015-07-14.
^ abRKK Energia (June 1999). "3.17. Комбинированная Двигательная Установка (КДУ) (Combined Propulsion System)". Soyuz Crew Operations Manual (SoyCOM) (ROP-19) Final. NASASpaceFlight.com. pp. 122–129.
^Chertok, Boris (May 2009). "Chapter 18 — Birth of the Soyuzes". Rockets and People Vol. 3 — Hot Days of the Cold War(PDF). Volume 3 (NASA SP-2006-4110). NASA. p. 562. ISBN 978-0-16-081733-5. Retrieved 2015-07-15.