Luna 10

Did You Know?

• Luna 10 was part of the E-6S series and had an on-orbit dry mass of 540 kg.
• Its scientific instruments included a triaxial magnetometer, a meteorite detector, and devices for solar-plasma studies.
• The spacecraft carried oscillators programmed to play 'The Internationale' for the 23rd Congress of the Communist Party, but a missing note forced controllers to play a rehearsal tape instead.

The flight

Luna 10 lifted off for the Moon on March 31, 1966, at 10:48 GMT. After tweaking its path the next day, it slipped into lunar orbit on April 3, completing its first lap three hours later (early on April 4 in Moscow). A 245-kilogram science package then detached from the main spacecraft, which was circling the Moon in an orbit ranging from 218 to 621 miles high, tilted 71.9 degrees from the lunar equator. The probe kept going for 460 orbits around the Moon, sending back 219 batches of data before its radio fell silent on May 30, 1966. It eventually hit the lunar surface, though no one knows exactly when. On November 8, 1966, Alexander Vinogradov and his team at the USSR Academy of Sciences announced that Luna 10’s gamma ray spectrometer had picked up radiation from uranium, thorium, and potassium on the Moon. This let them match lunar mare rock to Earth’s basalts and the highlands to Earth’s ultramafic rocks. Natural nuclear reactions accounted for 10 percent of the Moon’s surface gamma radiation; cosmic rays caused the other 90 percent. Luna 10 also found that meteoroids in its immediate orbital zone were 100 times denser than in interplanetary space.