NSSDCA/COSPAR ID: 1971-012D
Calsphere 4 was a US Air Force radar calibration sphere launched from Vandenberg AFB aboard a Thor Burner rocket along with a DMSP satellite and Calsphere 3 and 5.
Launch Date: 1971-02-17
Launch Vehicle: Thor-Burner II
Launch Site: Vandenberg AFB, United States
Mass: 1 kg
Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office