Ham was the name of America's first astronaut.

Ham was a male chimpanzee, 44 months old when he made his historic flight aboard the Mercury-Redstone 2 mission. The flight was launched at 11:55 am on January 31, 1961 from Cape Canaveral, Florida.

Despite some technical difficulties, this mission validated the design of the Mercury space capsule and the Mercury-Redstone launch configuration. The suborbital flight took place aboard the Mercury capsule No. 5 and was launched atop a modified U.S. Army Tactial Redstone ballistic missile.

During the flight, there were several technical problems, which caused the the rocket to overaccelerate, reaching a speed of 5,857 miles per hour, rather than the planned 4,400 miles per hour. This resulted in an apogee of 157 miles rather than the 115 miles originally planned. At this point, the capsule was already 48 miles farther downrange than programmed, and Ham endured the weightless state for 1.7 minutes longer (6.6 minutes total) than the 4.9 minutes scheduled. He landed 422 miles downrange after a 16.5-minute flight; the preplanned figures called for 290 miles and 14.25 minutes. His peak reentry g was 14.7, almost 3gs greater than planned

The nearest recovery ship was the destroyer USS Ellison, about 60 miles away. The Navy helicopter dispatched to the scene found the capsule taking on water due to cracks in the hull and an open pressure valve. After taking on 800 pounds of seawater, the helicopter crew finally managed to extract the craft from the water and bring it back to the ship.

Despite this potentially harrowing experience, Ham handled the trip very well, and was none the worse for wear after exiting the capsule. Despite a loss of cabin pressure during the trip, his flight suit performed perfectly and maintained good pressure and temperature. During the flight, Ham needed to perform a repetitive lever-pulling task. A warning light indicated that Ham would be subjected to an electric shock, prompting Ham to pull the lever, delaying the shock for 15 seconds. Ham successfully pulled the lever 50 times during the mission, receiving a shock only twice. Thus Ham not only proved that a space flight was at least possible, but also that a chimpanzee could function as an astronaut just as well as any human subject. America's first human in space, Alan Shepard, took his own flight in Freedom 7 atop Mercury-Redstone 3 on May 5, 1961.

The chimpanzee was named Ham in honor of the Holloman Aerospace Medical Center, the New Mexico facility where the chimpanzees trained and lived.