The main scientific objective of project Mercury was to determine man's capabilities in a space environment and in those environments to which he will be subject upon going into and returning from space. A few of the basic flight problems included: The development of an automatic escape system, vehicle control during insertion, behaviour of space systems, evaluation of pilots capabilities in space, in flight monitoring, retrofire and re-entry manoeuvres and landing and recovery.

The name "Freedom Seven" was Alan Shepard's choice. "Freedom" because it was patriotic and "Seven" because it was the seventh Mercury capsule produced. It also represented the seven Mercury astronauts. To help relieve any tension Shepard might have built up before his flight, Glenn pasted a little sign on the spacecraft instrument panel, reading "No handball playing here." This bit of levity hearkened back to their training days.

At T-15 minutes it was necessary to hold the count again to make a final check of the real-time trajectory computer. A small electrical part had a problem and this resulted in an hour and twenty six minute delay. Shepard was on top of the Redstone for so long now that he had to urinate. "Gordo!" he said, talking to Gordon Cooper, a fellow Mercury Seven astronaut and principal pre-launch communicator. "Go, Alan." "Man, I got to pee." "You what?" "You heard me. I've got to pee. I've been up here forever."

Shepard wanted to be let out but there wasn't time to reassemble the White Room. Thinking that he could be up there for hours, he told them he was going to do it in his suit. Unfortunately, there was no urine collection system and the medics were concerned he would short-circuit the leads. "Tell 'em to turn the power off!" Alan snapped. Cooper, with a chuckle in his voice said, "Okay, Alan. Power's off. Go to it."

Shepard couldn't hold back any longer and the liquid pooled in the small of his back. His heavy undergarment soaked up the urine, and with 100 percent oxygen flowing through the suit he was soon dry. The countdown resumed.

At T- minus two minutes and forty seconds and counting, Shepard heard that dreaded word again, "Hold". There was a little computer problem. Getting frustrated, he yelled, "I've been in here more than three hours. I'm a hell of a lot cooler than you guys. Why don't you just fix your little problem and light this candle?"

They fixed the problem and the countdown proceeded until lift-off at 9:34 am EST on 5/5/1961. Because of his excitement, Shepard said he failed to hear much of the closing countdown, with the exception of the firing command. During this period his pulse rate rose from 80 per minute to 126 at the lift-off signal. "You're on your way, Jose!" Deke Slayton shouted. "Roger, lift-off, and the clock has started," Alan called out.

Shepard saw the umbilical cable supplying pre-launch electrical power to the Mercury-Redstone and its supporting boom fall away. He raised his hand to start the elapsed-time clock that ticked off the seconds of the flight. The ride continued smoothly for about 45 seconds; then the rocket, capsule, and astronaut began vibrating. Conditioned to these circumstances, Shepard realized that he was passing through the transonic speed zone, where turbulence built up. The buffeting became rugged at the point of maximum aerodynamic pressures, about 88 seconds after lift-off; Shepard's head and helmet were bouncing so hard that he could not read his panel dials.

Pressed by 6 g at two minutes after launch, Shepard still was able to report "all systems go." The Redstone's engine shut down on schedule at 142 seconds, having accelerated the astronaut to a velocity of 5,134 miles per hour, close to the nominal speed. After engine cut-off, Shepard heard the tower-jettison rocket fire and turned his head to peer out the port, hoping that he might see the smoke from the pyrotechnics. There was no smoke, but the green tower-jettison light on his panel assured him that the pylon was gone. Shepard strained in his couch under an acceleration that hit a peak g load of 6.3. Outside the capsule the shingle temperature reached 220 degrees F, but inside the cabin the temperature was only 91 degrees. The astronaut was hardly perspiring in his pressure suit at 75 degrees.

When he tried to observe the scene below him, Shepard immediately noticed that the periscope had the medium grey filter in place. While waiting on the pad, he had used this filter to eliminate the glare of the intermittently bright sunlight and had planned to remove the filter when he retracted the periscope, just before launch. But being otherwise occupied at the time, he had forgotten to make the change. During spacecraft turnaround he tried to remove the filter, but as he reached for the filter knob the pressure gauge on his left wrist banged into the abort handle. He carefully pulled his hand away. After that he forgot about the intensity filter and observed the wondrous sights below through the grey slide. "What a beautiful view!"

While riding down the re-entry curve toward a water landing, Shepard again assumed the fly-by-wire mode of control. As the re-entry loads began to build up to a peak of 11.6 g, the oscillations also increased moderately. As soon as the highest g point had passed and the spacecraft had steadied, Shepard left fly-by-wire and cut in the automatic control system. As the altimeter dial slipped past 40,000 feet, the astronaut braced and listened closely for the drogue mortar to fire. He gave the Cape a reading of 30,000 feet, and 9000 feet later the drogue snapped out without a kick. The antenna canister atop the spacecraft blew off as planned at 10,000 feet, pulling the main parachute with it. Shepard clearly saw and felt it in its initial reefed and partially unfurled condition, which prevented the lines from snapping. Within seconds it spread to its 63-foot diameter, giving the astronaut a reassuring jolt.

Freedom 7 splashed and listed over into the water on the astronaut's right side, about 60 degrees from an upright position. The chutes cast loose automatically on impact to prevent dragging. As the water sloshed over the ports, the spaceman saw the fluorescing dye spreading over an ever increasing area. Shepard quickly checked the spacecraft interior to see if any leaks had resulted from impact. There were none; it was dry. Now slowly Freedom 7 came to an upright position, taking about a minute's time, and Shepard jubilantly reported to Card-file 23, the communications airplane, that he was all right. From beginning to end the flight mission had been almost perfect.