RD-170 engine for Energia and Zenit rockets
Often referred to as the "most powerful rocket engine in the world," RD-170 was designed to propel the first stage of the super-heavy Energia rocket. As part of a reusable transportation system, RD-170 was designed to fire as many as 10 times. A similar engine designated RD-171 was intended for the first stage of the Zenit medium-lift rocket.
Previous chapter: First stage of the Zenit rocket
Green structures are gimbal mechanisms designated 2D4100 and built at KB Arsenal in Leningrad (now St. Petersburg). They tilt combustion chambers steering the rocket along its flight trajectory.
Torturous development of the RD-170/171 series continued from 1976 to 1987, presenting some of the most serious challenges before engineers at Moscow-based NPO Energomash led at the time by Valentin Glushko. The first test firing of the engine took place on Aug. 25, 1980. Between 1981 and 1983, various problems plagued test firings. One of the botched tests at NPO Energomash test facility on the outskirts of Moscow reportedly ended with a massive explosion that sent a heavy metal cover of the troubled engine's turbopump several miles away concluding with an impact on the runway of Moscow's main international airport in Sheremetievo!
However in the end, all problems were resolved and one of the engines made 18 full-length firings logging a total of 2,520 seconds on the test stand.
The engine was first used on the Zenit rocket in 1985 and then on Energia in 1987. On Dec. 5, 2013, NPO Energomash conducted 1000th firing of the RD-171M engine at the company's test bench, NIK-751.
In 2017, Director General of RKK Energia Vladimir Solntsev referred to a "simplified" and "cheaper" version of the RD-171 engine in connection with Soyuz-5 (Sunkar) project. Solntsev hinted that this "optimization" of RD-171 would be achieved by abandoning features that allowed reusability of the engine. The engine would also incorporate some of the engineering soluations that had already been tested on RD-180 and RD-191 engines, NPO Energomash said. Some of the engine components were expected to be manufactured using 3D printing.
The new version apparently received designation RD-171MV. At the time, NPO Energomash promised to begin the live firings of the new engine in 2019 and roll out the first engine in 2021.
On July 19, 2017, the company announced that it began production of the RD-171MV and RD-0124M engines.
Next chapter: Second stage of the Zenit rocket
Writing and photography by Anatoly Zak
Last update: July 23, 2017
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RD-170 during assembly in 1980s.
A scale model of the RD-170 engine. Copyright © 2001 Anatoly Zak
A possible depiction of the RD-171MV engine.