First published April 12, 1977; part of a 7-stamp commemorative set.
This particular one is from April 20, 1977.
This Cuban stamp is commemorating the 20th anniversary of the first artificial satellite (“XX Aniversario del Satélite Artificial 1957–1977”).
I’d appreciate it if someone could write in the comments a theory about what kind of satellite this is. Thanks 😊
The smaller inset image is a reproduction of a Polish stamp (“POLSKA- międzynarodowy rok geofizyczny 1957–1958 ”) from 1957–1958 about the International Geophysical Year.











