Czechoslovakia  1961
Luna 1, Luna 3
Two stamps from a set of six devoted to space research. At left is Luna 1, intended to hit the Moon but which missed and became instead an artificial asteroid orbiting the Sun. On the right is an elegant engraving of Luna 3, with a somewhat stylized view of the far side of the Moon. These two were the only stamps in the set featuring Moon probes.

Stanley Gibbons catalogue numbers:
60h  –  1212
1.60k  –  1213