The KTDU-425 was a former Soviet liquid fuelled engine designed
Aleksei Isaev
Aleksei Mikhailovich Isaev (also Isayev; Russian: Алексе́й Миха́йлович Иса́ев; October 24, 1908, in Saint Petersburg – June 10, 1971, in Moscow) was a Russian rocket engineer.
Aleksei Isaev began work under Leonid Dus ...
of the
Isayev Design Bureau. It was mainly used on the
4MV bus, which employed it as its main propulsion system. The first version which was the KTDU-425 (11D425), which had a thrust of 18.85kN was first used in 1971 for
Mars-2,
Mars-3 as well as the failed M-71C (
Kosmos 419
Kosmos 419 (russian: Космос 419 meaning ''Cosmos 419''), also known as 3MS No.170 was a failed Soviet spacecraft intended to visit Mars. The spacecraft was launched on 10 May 1971, however due to an upper stage malfunction it failed to dep ...
) probe.
This was soon replaced by the KTDU-425A, which had a thrust of 18.89kN. This version was employed on the remaining 4MV and
5VK
The 5VK planetary probe (short for 5th-generation Venus-Comet probe) is a designation for a common design used for Soviet unmanned probes to comet 1P/Halley and Venus. It was an incremental improvement of earlier 4MV probes used for Mars and Venu ...
probes built, as well as
Phobos 1 and 2.
Variants
* KTDU-425 (11D425) - First version of the KTDU-425. Employed in 1971 on M-71 Probes. Thrust: 18.85Kn, Specific Impulse: 312s, Burn time: 520s.
[{{Cite web , title=Spacecraft-propulsion blocks from Isayev Design bureau (Khimmash) , url=http://www.b14643.de/Spacerockets/Specials/KB-Isayev_KDUs/index.htm , access-date=2022-04-17 , website=www.b14643.de]
* KTDU-425A (11D425A) - Improved version of KTDU-425. Employed between 1973 and 1989. Thrust 18.89Kn, Specific Impulse: 315s, Burn time: 560s.
References
Soviet Mars missions
Soviet Venus missions