2017-03-31 Fri

The Luna 10 was the first ever spacecraft to not only reach the vicinity of the moon but also to go into orbit around it. It was launched on 31st March 1966 at 10.48 UT by Union of Soviet Socialist Republics (USSR). It was launched in a way that the spacecraft would come around on its first orbit while the 23rd Congress of the Communist Party of the Soviet Union would be convening its morning session.

Few of the primary objectives to launch it were: achievement of the first lunar orbit, gaining experience in orbital operations, studying the lunar environments, etc.

It was a Ye-6S spacecraft with a fueled mass of about 1350 kg attached to a cylindrical pressurized 245 kg lunar orbiter module; it was 1.5 meters tall and 75 cm in diameter at the base. Since it was battery powered it had a limited lifetime.

On 1st April, Luna 10 fired its rockets and entered lunar orbit on 3rd April 1966 at 18:44 UT. It completed its first orbit on April 4, Moscow time. It operated for 56 days, covering 460 lunar orbits and 219 active data transmissions before the batteries were depleted and radio signals were discontinued on May 30, 1966. It is almost sure that the spacecraft must have collided with the moon by now.

At the Communist Party Congress, the "Internationale" (live broadcast from Luna 10 as it rounded the Moon) was played over loudspeakers for the assembled delegates on the morning of 4th April. It was revealed 30 years later that it was a recording from Luna 10 from the previous night, used because the controllers did not trust a live broadcast and because in a session earlier that morning it was discovered that a note was missing in the transmission from the solid-state oscillators programmed to reproduce the notes of the song.

Salpost (post of Sierra Leone) issued this 24000 Livre Egyptienne souvenir stamp sheet of Lunar 10 in 2016.