The Explorers' Club, № MLXIII

Operation AXIOM: The Space Race—The 50th Anniversary of the Helios Project, Part I
10 December 1974: Helios 1 (Helios-A prior to launch) lifted off from Florida's Cape Canaveral Air Force Station atop a Titan III-Centaur rocket, bound for close approaches to the Sun; the two Helios probes were built in West Germany & carried ten scientific instruments; Helios 1's perihelion was within Mercury's orbit; some instruments were damaged by the Sun's heat (21 September 1975).

Commentary: The primary mission ended after eighteen months; the last telemetry from Helios 1 was received on 10 February 1986.

The Helios probes were the first non-American/non-Soviet-built objects to leave Earth orbit.

Semper exploro.