Although the general objectives of each Mercury flight were similar, there were many specific differences. One of the most important medical variables from flight to flight was the normal physiological differences between pilots. Preflight, inflight and postflight comparisons for a particular individual could be made in some detail, but only general comparisons between astronauts were possible.
The stresses of space flight were well tolerated by MA-7 astronaut Scott Carpenter. All flight responses were considered to be within acceptable physiological ranges. Specifically, the heart rate response to nominal exercise demonstrated a reactive cardiovascular system. An abnormal electrocardiogram (ECG) tracing was recorded during reentry and is believed to have resulted from the increased respiratory effort associated with straining to continue speech during maximum reentry acceleration. No disturbing body sensations were reported as a result of near-weightless flight. Astronaut Carpenter felt that all body functions were normal.
Astronaut Carpenter also tested foods specially packaged for the properties of fluids in the gravity-free environment, and took photographs and photometric readings of the stars. The heavy schedule of experiments and manual capsule maneuvering exercises seriously taxed his ability to perform and, the manual maneuvering of the spacecraft resulted in a higher than anticipated fuel expenditure. The status of the fuel supply made it necessary for Aurora 7 to undertake a long period of drifting flight during the third orbit to conserve fuel.
Although the early fuel loss caused concern, results from the fuel-conserving procedure developed to bring Mercury 7 safely back to Earth proved useful in planning rest and sleep periods for astronauts on the longer manned missions of the future.