Mercury-Atlas 5
| Mission Insignia | |
|---|---|
| |
| Mission Statistics | |
| Mission Name: | Mercury MA-5 |
| Call Sign: | MA-5 |
| Number of Crew Members: |
1 |
| Launch: | November 29, 1961 15:08 UTC Cape Canaveral Complex 14 |
| Landing: | November 29, 1961 18:29 |
| Duration: | 3 hours 20 minutes, 59 seconds |
| Number of Orbits: |
2 |
| Apogee: | 147.4 miles |
| Perigee: | 99.5 miles |
| Distance Traveled: |
50,892 mi |
| Peak G Forces: | 7.6 g |
| Crew Picture | |
 | |
| Enos the Chimp | |
Mercury-Atlas 5 was an unmanned spaceflight of the Mercury program. It was launched on November 29, 1961 with Enos the chimp aboard. The craft orbited the Earth twice and splashed-down off the coast of Puerto Rico, a territory associated with the United States in the eastern Caribbean. Enos was unharmed.
By November, 1961, the Soviets had launched two men into orbit and the United States still had not orbited a chimp. Some NASA leaders opposed the chimpanzee flight. NASA headquarters questioned the wisdom of MSC wasting time on another unmanned Mercury mission, when the Soviet's had already flown two successful manned orbital flights. NASA Headquarters Public Affairs Office finally issued the following statement, "The men in charge of Project Mercury have insisted on orbiting the chimpanzee as a necessary preliminary checkout of the entire Mercury program before risking a human astronaut."
The flight used Mercury spacecraft # 9 and Atlas # 93-D. On February 24, 1961 spacecraft # 9 arrived at Cape Canaveral. It took 40-weeks of preflight preparation. This was the longest preparation time in the Mercury program. The mission of spacecraft # 9 kept changing. It had been first been configured for a suborbital instrumented flight, then for a suborbital chimpanzee flight, then a three-orbit instrumented mission, and finally for the orbital flight that Enos flew.
MA-5 was planned as a close approximation of the upcoming MA-6 manned orbital mission. Mercury-Atlas 5 would be launched from Complex 14 at Cape Canaveral on a heading 72.51 degrees east of north. Orbital insertion of the Mercury spacecraft would occur 480 miles from Cape Canaveral. The altitude would be 100 miles and the speed would be 25,695 feet per second. Retrofire was planned to take place at 4 hours, 32 minutes, and 26 seconds after launch. The spacecraft would land 21 minutes and 49 seconds after retrofire. Reentry temperatures should reach 3,000 degrees F on the heatshield, 2,000 degrees on the antenna housing, 1,080 degrees on the cylindrical section, and 1,260 degrees on the conical section. The spent Atlas sustainer engine should reenter the atmosphere after 9 1/3 orbits.
On October 29, 1961, three chimps and 12 medical specialists moved into quarters at the Cape to prepare for the flight. The name given to "Enos," the chimp selected to fly the MA-5 mission, in Greek or Hebrew means "man".
On November 29, 1961, about five hours before launch, Enos and his spacesuit-couch were inserted in the spacecraft. During the countdown, various holds took 2 hours and 38 minutes. Liftoff came at 15:08 UTC. The Atlas launched the MA-5 spacecraft into an orbit of 99 miles by 147 miles.
The turnaround and damping maneuver consumed 6 pounds of the 61.5 pounds of control fuel aboard. After that, through the first orbit the thrusters used only 1.5 pounds of fuel to maintain a correct position.
At the end of the first orbit, ground controllers noticed the capsule clock was 18 seconds too fast. As it passed over Cape Canaveral a command was sent to update the clock to the correct time.
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