S5.142

The S5.142 (AKA DST-25) is a liquid pressure-fed rocket engine burning N₂O₄/UDMH with an O/F of 1.85.[1] It is used for crew-rated spacecraft propulsion applications.[5] It was used in KTDU-80 propulsion module from the Soyuz-TM to the Soyuz-TMA-M, as the low thrust thruster (DPO-M).[3] As of the Soyuz MS, KTDU-80 does not use DPO-M anymore.[6]

S5.142

Country of origin	Russia
Date	1990-1996
First flight	1996-02-21 (Soyuz TM-23)
Designer	KB KhIMMASH
Application	attitude control thruster
Predecessor	11D427M
Status	Retired
Liquid-fuel engine
Propellant	N2O4 / UDMH
Mixture ratio	1.85
Cycle	pressure fed
Configuration
Chamber	1
Nozzle ratio	45
Performance
Thrust (vac.)	25 N (5.6 lbf)
Chamber pressure	0.88 MPa (128 psi)
Isp (vac.)	285 s (2.79 km/s)
Burn time	25,000 seconds
Restarts	300,000
Dimensions
Length	180 mm (7.1 in)
Diameter	136 mm (5.4 in)
Dry weight	0.9 kg (2.0 lb)
Used in
KTDU-80
References
References	[1][2][3][4][5][6]

The S5.142 generates 25 N (5.6 lbf) of thrust with a chamber pressure of 0.88 MPa (128 psi) and a nozzle expansion of 45 that enables it to achieve a specific impulse of 285 s (2.79 km/s).[1] It is rated for 300,000 starts with a total firing time of 25,000 seconds and can do single burns from 0.03 seconds to 4,000 seconds. Each unit weights 0.9 kg (2.0 lb).[1][5]

Versions

This engine has been used in manned Russian space program since the Soyuz TM-23.[1] There are two versions:[4]

• S5.142 (AKA DST-25): Version used as DPO-M (attitude control thrusters) on the KTDU-80 unit of the Soyuz-TM up to the Soyuz-TMA-M.[1]
• S5.142A: A version of the S5.142 adapted for the KVTK upper stage for the Angara rocket.[4]

See also

• KB KhIMMASH
• KTDU-80
• Soyuz-TMA

References

1. "ЖРДМТ от 0,5 кгс до 250 кгс" [Small thrust jet engine from 0.5 kgf to 250 kgf] (in Russian). KB KhIMMASH. Retrieved 2015-07-25.
2. "Двигатели 1944-2000: Аавиационные, Ракетные, Морские, Промышленные" [Aviadvigatel 19442-2000: Aviation, rocketry, naval and industry] (PDF) (in Russian). pp. 75–81. Retrieved 2015-07-25.
3. Pillet, Nicolas. "Le système de propulsion du vaisseau Soyouz" [The propulsion system of the Soyuz spacecraft] (in French). Kosmonavtika.com. Retrieved 2015-07-14.
4. "Основные двигатели разработки КБХМ" [The main engines produced by KbKhA] (in Russian). Retrieved 2015-07-25.
5. RKK 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.
6. Zak, Anatoly (2016-07-07). "Propulsion system for the Soyuz MS spacecraft". Russian Space Web. Retrieved 2016-07-06.

External links

• KB KhIMMASH Official Page (in Russian)