Telstar 2, primarily a communications satellite, carried an experiment designed to measure the energetic proton and electron distribution in the Van Allen belts.

Telstar 2 differed from Telstar 1 by employing provisions for scientific information to be transmitted in real time via the microwave telemetry system so that telemetry could be obtained after the 2 years timer had turned off the VHF beacon.

[2] The satellite was launched into space on May 7, 1963, on a Delta-B rocket from the Cape Canaveral Air Force Station in Florida, United States.

The European receiving station for Telstar 2 was built in Brittany, France, near the village of Pleumeur-Bodou, at which the 340-ton pivotally mounted antenna sits under a 50-meter diameter radar dome.

The transmissions were not continuous, being restricted to 25–30 minutes, since the low orbit of the satellite made it difficult for the receiving and transmitting antennas to pick up its signal.