Gordo

Gordo, also known as "Old Reliable," was a squirrel monkey launched aboard the U.S. Army's Jupiter AM-13 mission on December 13, 1958. Telemetry data confirmed he survived the flight and experienced weightlessness, but the recovery capsule's parachute failed and he was lost at sea.

Gordo was among the earliest primates launched on a suborbital trajectory by the United States, but not the first. Earlier V-2 rocket flights in the late 1940s carried monkeys named Albert, though those flights did not reach space altitude and the animals did not survive.

Gordo's Jupiter AM-13 flight was part of a U.S. biological testing program to evaluate whether living organisms could withstand launch acceleration, weightlessness, and reentry forces. His telemetry data provided evidence that a primate could survive the physical stresses of spaceflight.

Gordo's 1958 flight preceded the May 1959 mission of Able (a rhesus monkey) and Baker (a squirrel monkey), who became the first primates to survive a spaceflight and be successfully recovered. Gordo's loss underscored the recovery-system challenges that NASA and the Army would solve in subsequent missions.