The Molniya-M launch vehicle essentially is a basic Soyuz launch vehicle with an additional third stage. Molniya multi-stage boosters offered new possibilities for exploring the Moon, Venus, Mars and the nearest planets of the Solar System. The first two stages - the four strap on boosters of the first stage and the second core stage - are based on the R-7 ICBM, but reinforced for the heavier upper stages. The new third stage was 2.66 m in diameter. The third stage used engines developed for the R-9 ICBM. The fourth is equipped with an orientation and stabilization system (SOIS) and a jettisonable engine section. This section had to start in weightlessness, provide a low thrust to settle the propellants in the main stage so that the main engine could ignite. The stage was based on the existing Vostok third stage, with two tanks of 600 mm cross section, and a single S1-5400 Lox/Kerosene engine. The first successful launch took place on February 12, 1961 and successfully sent "Venera-1" on a journey to Venus. On November 1, 1962 "Mars-1" was successfully launched to Mars. Both these spacecrafts were the first to escape earth's gravity to reach their respective planets.