Luna 2

Goals
Luna 2, originally named the Second Soviet Cosmic Rocket, was the sixth Soviet attempt to send a probe crashing into the Moon. But it was the first successful attempt for any nation, making the Luna 2 probe the first human-made object to reach the surface of another celestial body. The spacecraft carried sensors to study interplanetary space and sodium gas to enable Earthbound observers to follow its progress.

Accomplishments
Luna 2 was the first object of human origin to make contact with another celestial body. The spacecraft scattered spherical emblems of the Soviet Union on the lunar surface. The spacecraft's sensors found no evidence of a lunar magnetic field or radiation belt.

Key Dates
Sept. 12, 1959: Launch | 06:39:42 UT
Sept. 14, 1959: Lunar Impact | 23:02:23 UT

In Depth
After an aborted launch on Sept. 9, the Ye-1A probe, also known at the time as the Second Soviet Cosmic Rocket, successfully lifted off on Sept. 12 (Sept. 13 Moscow time).

When the spacecraft reached about 97,000 miles (about 156,000 kilometers) from Earth, it released one kilogram of sodium gas on Sept. 12 in a cloud that expanded to about 400 miles (650 kilometers) in diameter and was clearly visible from the ground.

Three days later, Luna 2 achieved escape velocity (the speed and direction required to travel beyond Earth’s gravity). This sixth Soviet attempt at lunar impact was much more accurate than its predecessors, and the spacecraft reached the surface of the Moon at 23:02:23 UT on Sept. 14, 1959, becoming the first object of human origin to make contact with another celestial body.

The probe collided with the moon at approximately 30 degrees north latitude and 0 degrees longitude on the slope of the Autolycus crater, east of Mare Serenitatis.

Luna 2 (as it was renamed in 1963) deposited Soviet emblems on the lunar surface carried in 9 x 15-centimeter metallic spheres. The spacecraft’s magnetometer measured no significant lunar magnetic field as close as 55 kilometers to the lunar surface. The radiation detectors also found no hint of a radiation belt

Spacecraft
Launch Vehicle: 8K72 (no. I1-7b)

Spacecraft Mass: 860 pounds (390.2 kilograms) with upper stage

Spacecraft Instruments

three-component magnetometer
six gas-discharge counters
piezoelectric detector
scintillation counter
ion traps

- Credit: NASA