But to achieve the required performance, Kosberg had to develop a staged combustion engine, a then extremely aggressive feat.

Only M. V. Melnikov of OKB-1 had designed a staged combustion engine before, the S1.5400, and it used a different propellant mix with significantly less thrust.

While the UR-200 project was in direct competition to the R-36 and was cancelled in favor of the latter, it did have a few test launches and thus was a proven design.

[3][5][6] When Chelomey started his super heavy ICBM UR-500 (8K82) project, he originally intended to use multiple UR-200 modules as a first stage.

When this concept proved not viable, and the multi-body that was finally used was settled on, they had to search for new propulsion on the first stage.

But it could be adapted as a heavy launch vehicle that could perform important missions for the Soviet moonshot, and so the Proton-K (8K82) was born.

The second stage was enlarged, and the RD-0208/9 were revised as the RD-0210 and RD-0211 by uprating them slightly and significantly increasing the burning time.

The orbiter was identical to the Venera 9 bus, and the lander was the first man made object to reach the surface of Mars.

It consisted of an orbiter based on the Mars 2 design, and a lander which was sent the first pictured from the surface of Venus.