'Luna 2' (E-1A series) was the second of the
Soviet Union's Luna program spacecraft launched in the direction of the
Moon. Being the first spacecraft to reach the surface of the Moon, it impacted the lunar surface west 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,
Cherenkov detectors, and
micrometeorite detectors. There were no propulsion systems on Luna 2 itself.
Scientifically, Luna 2 is most famous for making the discovery of the
solar wind, via its hemispherical ion traps designed by
Konstantin Gringauz. Luna 1 had provided the first evidence of this phenomenon; on Luna 2, Gringauz changed the four sensors to a tetrahedral arrangement, instead of planar, to get better measurements of the plasma flux.
After launching 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 Putredinis region, is roughly estimated to have occurred at 0 degrees longitude, 29.1 degrees N latitude. Some 30 minutes after Luna 2, 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 the Moon having
radiation belts.
Luna 2 and the Van Allen Radiation Belt
Luna 2 showed time variations in the
electron flux and
energy spectrum within the
outer belt.
Luna 2 was instrumented with a three component fluxgate
magnetometer, similar to that used on Luna 1, but with the dynamic range reduced by a factor of 4 to -750 to +750
nanoteslas (gammas) so that the quantization uncertainty was -12 to +12 nT. The spacecraft spin period was 840 seconds about the major axis, and there was a precession with a period of 86 seconds. The sampling rate of the instrument was approximately once per minute. According to the Principal Investigator, the errors associated with the experiment zero levels and spacecraft fields were such that the accuracy was approximately 50 to 100 nT. The spacecraft gave results similar to those of Luna 1 in the Earth's radiation belts and, upon impact, placed an upper limit of 100 nT on the lunar magnetic field at the surface.
USSR pennants

Elements of the USSR pennants, delivered by Luna 2 to the moon
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 to scatter these elements around on impact. Each pentagonal element was made of
stainless steel and had the 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 impacted the moon 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.
Cultural References
The song "LUИIK 2" appears on the album "Planet Reverb" by '
Jetpack (musician)'. It features Russian dialogue and space sound effects portraying the journey of the craft. The album liner notes dedicate it to "the men and women of the Soviet space program".
See also
★
Soviet space program
★
Sinus Lunicus
★
List of artificial objects on the Moon
External links
★
Zarya - Luna 2 chronology
★
Soviet Spacecraft Pennants