Luna (rocket)
The Luna 8K72 vehicles were carrier rockets used by the Soviet Union for nine space probe launch attempts in the Luna programme between 23 September 1958 and 16 April 1960. Like many other Soviet launchers of that era the Luna 8K72 vehicles were derived from the R-7 Semyorka design, which is also the basis for the modern Soyuz rocket.
The first flight of a Luna 8K72 (September 1958), which was to launch the Luna E-1 No.1 probe, ended 92 seconds after launch when the rocket broke up from longitudinal vibration, causing the strap-ons to separate from the vehicle, which then crashed downrange.
The second flight of a Luna 8K72 (October 1958), which was to launch the Luna E-1 No.2 probe, ended 104 seconds after launch when the rocket again disintegrated from vibration.
The third flight of a Luna 8K72 (December 1958), which was to launch the Luna E-1 No.3 probe, ended 245 seconds after launch when the Blok I core stage shut down from loss of engine lubricant.
The resonant vibration problem suffered by the 8K72 booster was the cause of a major argument between the Korolev and Glushko design bureaus over the cause and solution to it. It was believed that the vibrations developed as a consequence of adding the Blok E upper stage to the R-7, shifting its center of gravity.