Luna E-1 No.2

Luna E-1 No.2,^[1] sometimes identified by NASA as Luna 1958B,^[2] was a Soviet spacecraft which was lost in a launch failure in 1958. It was a 361-kilogram (796 lb) Luna E-1 spacecraft, the second of four to be launched.^[3] It was intended to impact the surface of the Moon, and in doing so become the first man-made object to reach its surface.

E-1 No.2

A replica of an E-1 spacecraft
Mission type	Lunar impactor
Operator	Soviet space program
Mission duration	Failed to orbit
Spacecraft properties
Manufacturer	OKB-1
Launch mass	361 kilograms (796 lb)
Start of mission
Launch date	11 October 1958 (1958-10-11)
Rocket	Luna 8K72 s/n B1-4
Launch site	Baikonur 1/5
Luna programme ← Luna 1958A Luna 1958C →

The spacecraft was intended to release 1 kilogram (2.2 lb) of sodium, in order to create a cloud of the metal which could be observed from Earth, allowing the spacecraft to be tracked.^[4] Prior to the release of information about its mission, NASA correctly identified that it had been an attempted Lunar impact mission.^[2]

Facing continued political pressure to beat the US, Sergei Korolev lost his temper and exclaimed "Do you think only American rockets explode!?" Once again, he knew that the Pioneer 1 probe was set for launch on October 11, but again decided to wait. Just like with the attempt in August, the US Moon shot failed to attain orbit.

Luna E-1 No.2 was launched on 12 October 1958 atop a Luna 8K72 carrier rocket, flying from Site 1/5 at the Baikonur Cosmodrome.^[1] As the Pogo oscillation issue on Luna E-1 No.1 could not be adequately resolved due to the rushed launch schedules, a couple of stopgap measures were tried including disabling the propellant utilization system at T+85 seconds and throttling the engines down to reduce structural loads on the stack. The booster flew until T+104 seconds when it exploded once again from vibration rupturing the propellant lines.^[4]