The RD-0243 (Russian: Ракетный Двигатель-0243, romanized: Raketnyy Dvigatel-0243, lit.
Both are liquid-fuel rocket engines, burning a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide (N2O4) oxidizer.
The RD-0244 main engine operates in the oxidizer rich staged combustion cycle, while the vernier RD-0245 uses the simpler gas generator cycle.
Since volume is at a premium on submarine launches, this module is submerged on the propellant tank.
[3] Its development period was from 1977 to 1985, having had its first launch on December 27, 1981.