page_title: Mercury-Redstone 2
section_title: Mission
hierarchical_section_title: Mercury-Redstone 2 / Mission
caption_attribution_description: English: A three-year-old chimpanzee, named Ham, in the biopack couch for the MR-2 suborbital test flight. On January 31, 1961, a Mercury-Redstone launch from Cape Canaveral carried the chimpanzee "Ham" over 640 kilometers (400 mi) down range in an arching trajectory that reached a peak of 254 kilometers (158 mi) above the Earth. The mission was successful and Ham performed his lever-pulling task well in response to the flashing light. NASA used chimpanzees and other primates to test the Mercury capsule before launching the first American astronaut Alan Shepard in May 1961. The successful flight and recovery confirmed the soundness of the Mercury-Redstone systems.
context_page_description: Mercury-Redstone 2 was the penultimate test flight of the Mercury-Redstone Launch Vehicle prior to the first manned American space mission in Project Mercury. It was launched at 16:55 UTC on January 31, 1961 from LC-5 at Cape Canaveral, Florida. Mercury spacecraft No. 5 carried a chimpanzee named Ham on a suborbital flight, landing in the Atlantic Ocean 16 minutes and 39 seconds after launch.
context_section_description: Mercury spacecraft No. 5 contained six new systems that had not been on previous flights: environmental control system, attitude stabilization control system, live retrorockets, voice communications system, "closed loop" abort sensing system, and a pneumatic landing bag.
  Six chimpanzees (four female and two male) and 20 medical specialists and animal handlers from Holloman Air Force Base, New Mexico, where the chimps lived and were trained, were moved into quarters behind Hangar S at Cape Canaveral, Florida on January 2, 1961. The six chimps were trained in Mercury simulators for three weeks. The day before the flight, two chimps were chosen for the mission: one primary, Ham, and one backup, a female chimp named Minnie. The competition was fierce, but Ham was full of energy and good humor. Ham was named in honor of Holloman Aerospace Medical Center. Ham was from Cameroon, Africa, (original name Chang, Chimp No. 65) and was purchased by the USAF July 9, 1959. He was 3 years 8 months old at launch.
  At 12:53 UTC, January 31, 1961, Ham was inserted into the spacecraft. The countdown was then delayed almost four hours because of a hot inverter, and several other minor problems.
  At 16:55 UTC the MR-2 lifted off. One minute after the launch, computers reported that the flight path angle was at least one degree too high and rising. At two minutes, the computers predicted a 17 g (167 m/s²) acceleration. At 2 minutes 17 seconds into the flight, the Redstone's liquid oxygen (LOX) fuel was depleted. The closed-loop abort system sensed a change in engine chamber pressure when the LOX supply was depleted and fired the launch escape system. The abort signaled a Mayday message to the recovery forces.
  The high flight angle, and the early abort, caused the maximum velocity of the spacecraft to be 7,540 ft/s (2,298 m/s) instead of the planned 6,465 ft/s (1,970 m/s). The retrorockets had been jettisoned during the abort and therefore could not be used to slow down the spacecraft. All of this added up to an overshoot of the planned landing area by 130 miles (209 km) and an apogee of 157 miles (253 km) instead of 115 miles (185 km).
  Another problem occurred at 2 minutes and 18 seconds into the flight, when cabin pressure dropped from 5.5 to 1 lb/in² (38 to 7 kPa). This malfunction was traced later to the air inlet snorkel valve. Vibrations had loosened a pin in the snorkel valve and allowed the valve to open. Ham was safe in his own couch spacesuit and did not suffer any ill effects from the loss of cabin pressure. His couch spacesuit pressure remained normal, and suit temperature stayed well within the 60 to 80 degrees Fahrenheit (16 to 26 °C) optimum range.
  Because of over-acceleration of the launch vehicle and the boost from the escape rocket, a speed of 5,857 mph (9,426 km/h) was reached instead of the 4,400 mph (7,081 km/h) planned. At apogee Ham's spacecraft was 48 miles (77 km) farther downrange than planned. Ham was weightless for 6.6 minutes instead of the 4.9 minutes that were planned. The spacecraft landed 422 miles (679 km) downrange after a 16.5-minute flight. He received 14.7 g (144 m/s²) during reentry, almost 3 g (29 m/s²) greater than planned.
  Ham performed his tasks well, pushing levers about 50 times during the flight. Onboard cameras filming Ham's reaction to weightlessness showed a surprising amount of dust and debris floating around inside the capsule during apogee. 
  The spacecraft splashed down about 12:12 pm. EST, out of sight from recovery forces. About 12 minutes later, the first recovery signal was received from the spacecraft. Tracking showed it was about 60 miles (96 km) from the nearest recovery ship. Twenty-seven minutes after landing, a search plane sighted the capsule floating upright in the Atlantic. The search plane requested that the Navy send its rescue helicopters from the closest ship carrying them.
  When helicopters arrived they found the spacecraft on its side, taking on water, and submerging. Upon water impact, the beryllium heat shield had bounced against the capsule bottom, punching two holes in the 
caption: Ham before the launch of Mercury-Redstone 2
exif: {}