| E-1 No.3 | |
| Mission Type: | Lunar impactor |
| Operator: | Soviet space program |
| Mission Duration: | Failed to orbit |
| Manufacturer: | OKB-1 |
| Programme: | Luna programme |
| Previous Mission: | Luna 1958B |
| Next Mission: | Luna 1 |
| Launch Rocket: | Luna 8K72 |
| Launch Site: | Baikonur 1/5 |
Luna E-1 No.3, sometimes identified by NASA as Luna 1958C,[1] was a Soviet spacecraft which was lost in a launch failure in 1958. It was a 361kg (796lb) Luna E-1 spacecraft, the third of four to be launched,[2] all of which were involved in launch failures. It was intended to impact the surface of the Moon, and in doing so become the first man-made object to reach its surface.
The spacecraft was intended to release of sodium, in order to create a cloud of the metal which could be observed from Earth, allowing the spacecraft to be tracked.[3] Prior to the release of information about its mission, NASA correctly identified that it had been an attempted Lunar impact mission.[1]
Luna E-1 No.3 was launched on 4 December 1958 atop a Luna 8K72 carrier rocket,[4] flying from Site 1/5 at the Baikonur Cosmodrome.[5] Modifications to correct the vibration issue on previous launches by installing dampers on the LOX feed lines worked and the booster completed the strap-on burn successfully. However, the launch was another failure as the core stage lost thrust at T+245 seconds. Engine performance fell to 70% and it began deviating from its flight trajectory. The AVD system terminated thrust and the booster fell 4,200 km (2,609 miles) downrange. Investigation found that a gear of the core stage hydrogen peroxide pump was improperly lubricated and failed during flight, causing loss of turbopump performance and engine thrust.[4]