Four-stage LV Molniya (rocket R-7 + stage I + stage L carrying payload). Launch mass of LV Molniya - 305 t 228x800 (26 713 bytes)

The outlook for developing a multi-stage launch vehicle based on rocket R-7 offered new possibilities for exploring the Moon and the nearest planets of the Solar System - Venus and Mars.
The Government Decree on "Space Exploration Plans" of June 4, 1960 enacted to develop a four-stage launch vehicle for missions to Mars and Venus.
The new four-stage launch vehicle was derived from rocket P-7. Stage II of rocket P-9 using the engine designed by S. A. Kosberg was employed (with certain modifications) as stage III (stage I). Stage L designed by OKB-1 was used as stage IV. In stage IV a closed-cycle liquid-propellant engine 11D33 also designed by OKB-1.
The stage L PU ignition should be performed in space environment after a 1.5- hour flight in the Earth orbit, not immediately upon completion of stage III operation. Therefore, for this period it was necessary to provide stage L with the stabilization and attitude control system, as well as capabilities to burn the engine in space environment. A control system for stages I and L designed by NII headed by N. A. Pilyugin was also provided on stage L.
An automatic interplanetary station for a mission to Venus has been developed in the second half of 1960.
The first successful launch of LV carrying the automatic interplanetary station took place on February 12, 1961. The automatic station with upper stage L was placed into orbit. It flied around the Earth and was the first in the world to escape for Venus over the Equatorial Africa. This station was named as "Venera-1".
On November 1, 1962 an automatic interplanetary station was first successfully launched to Mars. The station was named as "Mars-1".

Transportation of four-stage launch vehicle carrying the automatic interplanetary station

Installation of four-stage launch vehicle carrying the automatic interplanetary station to the launch pad

In a period from October 1960 to March 1964, a series of LV accidents occurred because of a failure to ignite the stage L engine. Through analyzing the accidents their cause was revealed. It was a design error resulting in a failure to ignite the stage IV (stage L) engine.
Stage L was provided with an individual engine ignition unit which truss structure accommodated the attitude control and stabilization system and the engine automatics including storage batteries. The control system, 70s before the stage L engine ignition, had to switch power supply of the attitude control and stabilization system from the engine ignition batteries to batteries of stage L. However, power was not switched and stage к was uncontrollable for 70s. The stage operation would be successful if angular disturbances did not change its position beyond limits, power at that moment being switched from the stage L control system. With the disturbances beyond limits, gyroscopes came against stops and the engine of stage L could not be ignited. The error that caused so many troubles was eliminated. On April 24, 1964 the automatic interplanetary station was launched to Venus and without critical comments regarding the launch vehicle.
It should be noted that stage L was first injected from a transfer in space environment. Its flight conditions, environment, exposure to different factors were unknown. There was much to discover, to encounter for the first time, but there was no place to learn and nobody to teach. Lessons were learned only from our own experience. This accounts for a large number stage L failures. An additional difficulty was that stage L was launched over the Atlantic, in the Guinean Gulf region. To receive telemetry form stage IV in real time was impossible at that time. Information was transmitted from the ships of the Command and Measuring Complex only in records and with a long delay.
On April 23, 1965 this launch vehicle delivered active data relay satellite Molniya-1 to the artificial Earth satellite orbit for purpose of developing a radio communication line between Moscow and Vladivostok. On May 1, 1965, via this satellite, citizens of the Far East were watching on their TV sets a direct transmission of the Military Parade and demonstration at the Red Square in Moscow. Since that event, LV was named "Molniya".