balloon satellite

4 satellites and probes

Spacecraft	Launch	Operator	Launch vehicle
Echo 2	January 25, 1964	National Aeronautics and Space Administration	Thor-Agena B
Beacon 2	August 15, 1959	—	Juno II
Vanguard Balloon	April 14, 1959	—	Vanguard
Beacon 1	October 23, 1958	—	Juno I