RD-170

Several Soviet and Russian rocket engines use the approach of clustering small combustion chambers around a single turbine and pump. During the early 1950s, many Soviet engine designers, including Valentin P. Glushko, faced problems of combustion instability while designing bigger thrust chambers. At that time, they solved the problem by using a cluster of smaller thrust chambers. == Variants ==

RD-170 The RD-170 engine featured four combustion chambers and was developed for use on the Energia launch vehicle – both the engine and the launch vehicle were in production only for a short time. Energia was launched twice. Each Energia vehicle had 4 boosters, each powered by one RD-170. The engine was designed to be reused up to 10 times, with a total service life of 20 full burn durations. Dual-chamber derivative The RD-180 uses only two combustion chambers instead of the four of the RD-170. The RD-180 used on the Atlas V replaced the three engines used on early Atlas rockets with a single engine and achieved significant payload and performance gains. This engine had also been chosen to be the main propulsion system for the first stage of the now cancelled Russian Rus-M rocket. Variants of RD-191 include RD-151 in South Korean Naro-1 rocket, According to the information, new and proposed variants will be marked as: • RD-180M for crewed Atlas V rocket (Not required, current RD-180 meets crewed Atlas V requirements.) • RD-180V for Rus-M rocket. • RD-175 with 9800 kN thrust for proposed Energia-K rocket. In 2017, Director General of RKK Energia Vladimir Solntsev referred to a "simplified" and "cheaper" version of the RD-171 engine in connection with the Soyuz-5 (Sunkar) project. == Specifications ==

• 4 combustion chambers, 4 nozzles • 1 set of turbines and pumps; turbine produces approximately 257,000 hp (192MW); equivalent to the power output of 3 nuclear-powered icebreakers • Ignition: pyrophoric start-up fuel capsule (triethylaluminium) • Vacuum thrust: • Vacuum Isp: • Sea-level Isp: • Weight: • Thrust-to-weight ratio: 82 == See also ==