Luna 2

Luna 2 (Russian: Lunik II| Space Rocket II) was the second of the Luna program of spacecraft launched in the direction of the Moon. The first spacecraft to land on the Moon, it impacted the lunar surface east of Mare Serenitatis near the Aristides, Archimedes, and Autolycus craters. Luna 2 was similar in design to Luna 1, a spherical spacecraft with protruding antennae and instrument parts. The instrumentation was also similar, including scintillation counters, geiger counters, a magnetometer, and micrometeorite detectors. The spacecraft also carried Soviet pennants. There were no propulsion systems on Lunik II itself.

After launch and attainment of escape velocity on September 13 1959, Luna 2 separated from its third stage, which travelled along with it towards the Moon. On September 13 the spacecraft released a bright orange cloud of sodium gas which aided in spacecraft tracking and acted as an experiment on the behavior of gas in space. On September 14, after 33.5 hours of flight, radio signals from Luna 2 abruptly ceased, indicating it had impacted on the Moon. The impact point, in the Palus Putredinus region, is roughly estimated to have occurred at 0 degrees longitude, 29.1 degrees N latitude. Some 30 minutes after Lunik II, the third stage of its rocket also impacted the Moon. The mission confirmed that the Moon had no appreciable magnetic field, and found no evidence of radiation belts at the Moon.

Lunik II and the Van Allen Radiation Belt

Lunik II showed time variations in the electron flux and energy spectrum within the outer belt.