"The Molniya 8K78 (Russian: \u041C\u043E\u043B\u043D\u0438\u044F, meaning \"lightning\") was a modification of the well-known R-7 Semyorka rocket and had four stages. The 8K78 resulted from a crash program by the Korolev Bureau to develop a booster for launching planetary probes. A larger third stage was added along with a fourth stage (Blok L) that was designed to fire in-orbit to send the payload out of LEO. The basic R-7 core was also structurally strengthened and given more powerful engines."@en . . .