The countdown began at 8:30 p.m. the previous night, with Shepard entering the spacecraft at 5:15 a.m. ET, just over two hours before the planned 7:20 launch time. At 7:05 a.m., the launch was held for an hour to let cloud cover clear - good visibility would be essential for photographs of the Earth - and fix a power supply unit; shortly after the count restarted, another hold was called in order to reboot a computer at Goddard Space Flight Center. The count was eventually resumed, after slightly over two and a half hours of unplanned holds, and continued with no further faults.
It was at this time that Astronaut Alan Shepard spoke his famous words of prayer...which became known as "The Astronauts Prayer" or "Shepard's Prayer"
“Dear Lord, please don’t let me f--- up”
Shepard was now able to take manual control of the spacecraft, and began testing whether he was able to adjust its orientation. The first thing he did was position the spacecraft to its retrofire attitude of 34 degrees pitch (nose of spacecraft pitched down 34 degrees). He then tested manual control of yaw, motion from left to right, and roll. When he took control of all three axes, he found that the spacecraft response was about the same as that of the Mercury simulator; however, he could not hear the jets firing, as he could on the ground, due to the levels of background noise.
The secondary objective was to make observations of the ground from the spacecraft; returning the spacecraft to automatic control, Shepard found that he was able to distinguish major land masses from clouds easily, and could make out coastlines, islands and major lakes, but had difficulty identifying cities. He had problems working with the spacecraft periscope - early Mercury capsules had a small periscope rather than a viewing window - and had to abandon an attempt to change optical filters on it.
Under automatic control, the spacecraft had developed a slight movement as it passed through peak altitude; Shepard now switched into the "fly-by-wire" mode, where the pilot used a controller to order the automatic system to fire the rockets for the desired positioning, rather than manually controlling the individual jets. Adjusting roll and yaw, he found the pitch position was around ten degrees too shallow - 25 degrees rather than the desired 35 for reentry - and as he began to correct it, the timed retrorockets fired to send him into reentry. The retrorocket pack - strapped atop the heat shield and so requiring release before reentry - was successfully jettisoned, but the confirmation light failed, requiring Shepard to activate the manual override for the jettison system before it confirmed that the rockets were fully released.
Shepard resumed fly-by-wire control after retrofire, reporting that it felt smooth and gave the sensation of being fully in command of the craft, before letting the automatic systems briefly take over to reorient the capsule for reentry. He then kept control until the g-forces peaked at 11.6g during re-entry; he held the capsule until it had stabilized and then relinquished control to the automated system. The descent was faster than anticipated, but the parachutes deployed as planned, a drogue at 21,000 ft, and a main parachute at 10,000 ft.
Splashdown! Freedom 7 tilted over on its right side about 60 degrees from an upright position, but did not show any signs of leaking; it gently righted itself after a minute, and Shepard was able to report to the circling aircraft that he had landed safely and was ready to be recovered.
The flight lasted 15 minutes, 22 seconds and the spacecraft traveled 302 miles from its launch point, ascending to 116.5 miles, after reaching speeds of 5,180 mph.. Freedom 7 splashed down at coordinates: 27.23°N 75.88°W.
"The first plane ride was in a homemade glider my buddy and I built. Unfortunately we didn't get more than four feet off the ground, because it crashed."
Not only did Ol'Shepard not F__K Up, but he later commanded mighty Saturn V rocket on the Apollo 14 mission, piloting the lunar lander to the most accurate landing of all the Apollo missions. That day, Alan became the fifth and oldest person to walk on the Moon, and the only astronaut of the original Mercury Seven to have stepped foot on the Moon.
Blue skies, Commander Shepard