||This article needs additional citations for verification. (September 2007)|
|Mission type||Lunar Science
|Launch date||September 12, 1959 at 06:39:42 UTC|
|Mission duration||33.5 hours|
|Mission highlight||Lunar impact (see below)|
|COSPAR ID||1959 Xi 1|
|Mass||390.2 kg (860.2 lb)|
September 14, 1959, 21:02:24 UTC
|Magnetometer (magnetic fields)
Geiger counter (radiation environment)
Scintillation counter (magnetospheric studies)
Luna 2 (E-1A series) was the second of the Soviet Union's Luna programme spacecraft launched to the Moon. It was the first spacecraft to reach the surface of the Moon. On September 14, 1959 it successfully impacted with the lunar surface east of Mare Imbrium near the craters Aristides, Archimedes, and Autolycus.
Launch was scheduled for September 9, but the Blok I core stage was shut down after it failed to reach full thrust at ignition. The booster was removed from the pad and replaced by a different vehicle, delaying the flight by three days. Luna 2, like Luna 1, took a direct path to the Moon with a journey time of around 36 hours. This was dictated by the fact that the Earth-Moon gravitational system forced it to follow a curved trajectory, and launch had to occur from the side of the Earth opposite the Moon. Its journey time had to be, therefore, 12 hours, 36 hours or 60 hours in order to ensure that the Moon was above the horizon in the Soviet Union.. Luna 2 hit the Moon about 800 kilometres from the centre of the visible disk 1959 September 13 at 21:02:24.
Luna 2 was similar in design to Luna 1, a spherical spacecraft with protruding antennas and instrument parts. The instrumentation was also similar, including scintillation counters, geiger counters, a magnetometer, Cherenkov detectors, and micrometeorite detectors. There were no propulsion systems on Luna 2 itself.
Van Allen Radiation Belt 
USSR pennants 
The spacecraft also carried Soviet pennants. Two of them, located in the spacecraft, were sphere-shaped, with the surface covered by identical pentagonal elements. In the center of this sphere was an explosive for the purpose of slowing the huge impact velocity. This was designed as a very simple way to provide the last necessary delta-v for those elements on the retro side of the sphere to not get vaporized. Each pentagonal element was made of stainless steel and had the USSR Coat of Arms and the Cyrillic letters СССР (Russian; it translates into English as USSR) relief engraved on one side, and the words СССР СЕНТЯБРЬ 1959 (English: USSR SEPTEMBER 1959) relief engraved on the other side. The third pennant was located in the last stage of the Luna 2 rocket, which collided with the moon's surface 30 minutes after the spacecraft did. It was a capsule filled with liquid, with aluminium strips placed into it. On each of these strips the USSR Coat of Arms, the words 1959 СЕНТЯБРЬ (English: 1959 SEPTEMBER) and the words СОЮЗ СОВЕТСКИХ СОЦИАЛИСТИЧЕСКИХ РЕСПУБЛИК (English: UNION OF SOVIET SOCIALIST REPUBLICS) were engraved.
On September 15, 1959, the premier of the USSR, Nikita Khrushchev, presented to the American president Dwight D. Eisenhower a copy of the spherical pennant as a gift. That sphere is located at the Eisenhower Presidential Library and Museum in Abilene, Kansas.
See also 
- Soviets 'Lunik' Hits The Moon 1959/9/14 on YouTube
- Zarya - Luna 2 chronology
- Soviet Spacecraft Pennants