Schirra's nine-hour mission was designed to test spacecraft engineering and conserve fuel rather than push endurance records, and he executed it almost flawlessly, landing his Mercury capsule within five miles of the recovery ship USS Kearsarge in the Pacific. The mission proved NASA could fly precise, efficient missions after the more turbulent flights of Mercury astronauts John Glenn and Scott Carpenter earlier that year.
Wally Schirra approached the Sigma 7 mission almost like a test pilot doing a systems check rather than an explorer venturing into the unknown, and that was exactly the point. After Scott Carpenter's Aurora 7 flight in May 1962 burned through fuel reserves and overshot its splashdown zone by 250 miles, NASA needed to prove the Mercury capsule could be flown with discipline and precision.
Schirra spent much of the flight in a deliberately spare, businesslike mode, minimizing unnecessary maneuvers and letting the capsule drift when possible to save fuel — an approach some engineers later called 'chimp mode' complaints aside, it worked beautifully. He experienced the first case of a well-documented and calm view of Earth from orbit, radioing back matter-of-fact descriptions of weather patterns and geography.
The near-perfect splashdown, just 4.8 nautical miles from the target and in clear view of recovery forces, was a dramatic improvement over previous flights and gave NASA confidence heading toward the longer Mercury-Atlas 9 mission the following year and, eventually, Gemini and Apollo.
Key people: Wally Schirra