Image from Pioneering Efforts in Space.

Gordo

Mission Information:

On December 13, 1958 the U.S. Army launcehd a squirrel monkey named Gordo aboard JUPITER AM-13. This flight provided useful data for Army and Navy medical research on manned space flights. Gordo made the flight with no adverse effects, but could not be recovered because the floatation mechanism of the rocket's nose cone failed.