On 10 July 1958, a partial test version of the Luna 8K72 was launched without the Blok E upper stage but with the core and strap-ons of the 8K72 which had thicker-gauge tank walls and the AVD malfunction detection system.

Almost immediately at liftoff, the Blok D strap-on suffered an engine malfunction and broke off the booster, impacting on the pad and exploding.

This accident, which caused considerable damage to Site 1/5, was traced to high frequency combustion instability in the strap-on RD-107 engines, something that would become a persistent problem on R-7 launches over the next two years.

Despite a number of technical issues, the pad crews managed to get the booster ready on the 17 August 1958, but Korolev instead decided to let the US flight go first on the reasoning that the Luna probe had a shorter trajectory to travel and would reach the Moon first.

This failure was traced to the resonant vibration issue that occurred on Sputnik 3 last spring and thought corrected, but the addition of the Blok E stage increased the length of the booster and moved its center of gravity.