It was retired from service in favour of the modernised Proton-M, making its 310th and final launch on 30 March 2012.

Like other members of the Universal Rocket family, the Proton-K was fuelled by unsymmetrical dimethylhydrazine and nitrogen tetroxide.

This avoids the need for low-temperature–tolerant components, and allowed the rocket to sit on the pad fully fuelled for long periods of time.

The Russian Government paid for the cleanup of residual propellant in spent stages that impact downrange.

Proton components were built in factories near Moscow, then transported by rail to the final assembly point near the pad.

The first-stage guidance system was open-loop, which required significant amounts of propellant to be held in reserve.

Blok D upper stages were used on forty flights, the majority of which were for the Luna and Zond programmes.

Due to its rushed development, the Proton K launch vehicle had a low success rate initially.