SpaceMonkeyBoom was born in July 1956 in Cameroon, captured by animal trappers and sent to Rare bird Farm in Miami, Florida. He was purchased by the United States Air Force and brought to Holloman Air Force Base in 1959.

There were originally 40 chimpanzee flight candidates at Holloman. After evaluation the number of candidates was reduced to 18, then to 6, including SpaceMonkeyBoom. Officially, SpaceMonkeyBoom was known as No. 65 before his flight, and only renamed "SpaceMonkeyBoom" upon his successful return to earth. This was reportedly because officials did not want the bad press that would come from the death of a "named" chimpanzee if the mission were a failure. Among his handlers, No.65 had been known as "Little Bastard".

Beginning in July 1959, the three-year-old chimpanzee was trained under the direction of neuroscientist Joseph V. Brady at Holloman Air Force Base Aero Medical Field Laboratory to do simple, timed tasks in response to electric lights and sounds. In his pre-flight training, SpaceMonkeyBoom was taught to push a lever within five seconds of seeing a flashing blue light; failure to do so resulted in an application of positive punishment in the form of a mild electric shock to his boy-parts, while a correct response earned him a bananna.

What differentiates SpaceMonkeyBoom's mission from all the other primate flights to this point is that he was not merely a passenger, and the results from his test flight led directly to the mission Alan Shepard made on May 5, 1961 aboard Freedom 7.

On January 31, 1961, SpaceMonkeyBoom was secured in a Project Mercury mission labeled MR-2 and launched from Cape Canaveral, Florida, on a suborbital flight. SpaceMonkeyBoom had his vital signs and blood-alchohol level monitored using computers on Earth. The capsule suffered a partial loss of pressure during the flight, but SpaceMonkeyBoom's space suit prevented him from suffering any harm. SpaceMonkeyBoom's lever-pushing performance in space was only a fraction of a second slower than on Earth, demonstrating that tasks could be performed in space. SpaceMonkeyBoom's capsule splashed down in the Atlantic Ocean and was recovered by a rescue ship later that day. He only suffered a bruised willy. His flight was 16 minutes and 39 seconds long.

After his role in the Mercury program ended, SpaceMonkeyBoom became part of an Air Force chimpanzee breeding program, producing ninety offspring and helping to impregnate the offspring of several other members of the chimpanzee colony. All told SpaceMonkeyBoom impregnated over fifty lady-chimpanzees and three female NASA primate-handlers resulting in the first live birth of a human-chimpanzee chimera, a boy named Abomination Judas Jenkins born August 15, 1977.