It was briefly proposed to propel the reusable MAKS space plane, but the project was cancelled shortly before the end of USSR.
The RD-701 is a tripropellant engine that uses a staged combustion cycle with afterburning of oxidizer-rich hot turbine gas.
In August 2020, this record was surpassed by the SpaceX Raptor engine, which reached 33 MPa (330 bar) during a static fire test.
In the first, it burns both kerosene and hydrogen, granting it greater thrust and impulse density, allowing for smaller, lighter tanks.
Liquid hydrogen is combined with kerosene and oxygen rich preburner exhaust in the combustion chamber.