The Italian-built San Marco 4 spacecraft was part of a cooperative space effort between the Italian Space Commission (CRS) and NASA. The scientific objective of this flight was to measure the diurnal variations of the equatorial neutral thermosphere density, composition, and temperature for correlation with simultaneous Atmospheric Explorer C data. Studies of the physics and dynamics of the lower thermosphere were included. Read more
The San Marco 4 satellite, also known as 'San Marcos C-2', was launched on the 18th February 1974
San Marco is the name of five Italian satellites put into orbit from 1964 to 1988 as part of the San Marco Project, designed by Professor Luigi Broglio and officially established in 1962 with the signing of a space cooperation agreement between Italy and USA. All five satellites were launched by Scout carriers provided free of charge by the United States. All have now been deorbited.