Complex sentence: Luna 3, or E- 2A No.1 was a Soviet spacecraft launched in 1959, the third space probe to be sent to the neighborhood of the moon, and this mission was an early feat in the spaceborne exploration of outer space.
Split into simpler sentences: Luna 3, or E- 2A No.1 was a Soviet spacecraft launched in 1959. The third space probe to be sent to the neighborhood of the Moon, and this mission was an early feat in the spaceborne exploration of outer space.