The cabin pressure inside Freedom 7 sealed off at 5.5 pounds per square inch, [353] as programmed. 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. The trajectory, similar to that of the MR-BD flight, was only one degree off course, which meant a variation of slightly more than a mile in peak altitude. After engine cutoff, 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.
After tower separation, which occurred two minutes and 32 seconds after launch, Shepard disarmed the retrorocket-jettison switch and advised Slayton that his capsule was free from the booster. At three minutes the automatic attitude control system about-faced the capsule to a heatshield-forward position for the remainder of the flight. Momentary oscillations climaxed the turnaround maneuver, whereupon the automatic thrusters cut in for five seconds to steady, or "damp," the capsule into its proper attitude. Now almost at the top of his suborbital trajectory, Shepard went to work on his most important task, determining whether an astronaut could control his spacecraft's attitude.
He began to switch the control system to manual, one axis at a time. First he took over pitch, which he was able to adjust by moving the handcontroller in his right grip forward or backward to give the spacecraft the proper up or down attitude. His first action was to position the spacecraft in the retrofire attitude, tilted 34 degrees above a local horizontal mark. The pitch indicator on Freedom 7 was scribed at 45 degrees, as earlier studies had proposed, but more recent investigations had indicated that 34 degrees was a better angle.
While Shepard was in control of pitch, the automatic system was controlling yaw, or left and right motion, and roll, or revolving motions. When Shepard assumed control of all three axes, he was pleased to find that the feel was about the same as in the procedures trainer, the Mercury simulator. Although he could control his ship well, he was unable to hear the spurting control jets above the noise of his radio. He encountered one small problem while using his hand controller: when he moved his hand to yaw, the wrist seal bearing of his suit bumped into his personal parachute. To make the proper displacement, he had to push hard.28
When he tried to carry out another of his flight objectives, observing the scene below him, Shepard immediately noticed that the periscope had the medium gray 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. [355] 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 gray slide. He first tried to estimate the span of his terrestrial vision. The periscope, located two feet in front of him, had two settings, low and high magnification. On low at the 100-mile altitude, there theoretically should have been a field view of about 1900 miles in diameter, and on high, a segment 80 miles in diameter. Shepard was able to distinguish clearly the continental land masses from the cloud masses. He first reported seeing the outlines of the west coast of Florida and the Gulf of Mexico. He saw Lake Okeechobee, in the central part of Florida, but could not see any city. Andros Island and the Bahamas also appeared in the scope. Later Shepard would remark that Earth displays flashed before him in his air- lubricated free-axis trainer had been most valuable in helping him to distinguish land masses passing beneath the spacecraft.
As Shepard sped over the peak of his trajectory, now under fully automatic attitude control, he began to notice a slow pitch rate. At this point his flight plan dictated that he switch to the fly-by-wire mode of operation, wherein the astronaut operated the handcontroller to change the position of the capsule, using the hydrogen peroxide jets of the automatic system to effect the changes rather than those of the manual system. Thus Shepard would manually position Freedom 7 for the retrofire that was scheduled to occur shortly after attaining the zenith of his trajectory at 116.5 miles. The astronaut switched to fly-by-wire, but as he started to make a yaw and roll maneuver he noticed that the spacecraft pitch position was low, being 20 to 25 degrees rather than the desired 34 degrees for retrofire attitude. Although he could not remember exactly whether he made a yaw or roll maneuver, he did immediately begin to work on his pitch problem. Then the retrorockets fired, creating a noise that was easily heard but was not as loud as the sound of the ALFA trainer jets. This provided what later astronauts on orbital missions described as "a comforting kick in the pants." Pieces of debris, including a restraining strap, flashed by the capsule portholes as the retropack was jettisoned. Glancing back to the control panel, Shepard saw no confirming sequence light, but Slayton radioed his telemetered knowledge of retropack jettison. So the astronaut pushed the manual override; finally the reluctant light appeared. This was the only failure of an event-sequence light during the MR-3 mission.
While riding down the reentry curve toward a water landing, Shepard again assumed the fly-by-wire mode of control. He later reported that the feel of fly-by-wire was very similar to that of the trainers. Although he had a tendency to overcontrol in the fly-by-wire mode, he had the pleasant feeling of being in full command, for a few minutes at least, of his spacecraft's attitude. Then Shepard allowed the automatic system to regain control and stabilize the spacecraft for reentry. [356] The periscope automatically retracted when Freedom 7 began its plummet into Earth's atmosphere.
On the way down, Shepard tried to look out the awkwardly placed ports to observe the stars. He saw nothing, not even the horizon. These futile attempts at star-finding got him behind in his work. As he commented later, this was the only time during the flight when he did not feel "on top" of the situation and ready for anything. The feeling of indecision passed quickly. He immediately reported when the .05-g light came on, the indication that the g-load buildup was about to commence. He was surprised that the light flashed and zero g ended about a minute ahead of the time he had come to expect from his simulated experience in the procedures trainer. As the reentry 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.
Shepard was supposed to give an altimeter reading between 80,000 and 90,000 feet, but since his rate of descent was faster than he expected, he became worried over the deployment of the drogue parachute and forgot to report his altitude. 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. Once his fall was broken the periscope extended, giving a view of the trailing and reassuring drogue. The opening of the air-inlet snorkel valve to accept ambient air pressure at 15,000 feet struck Shepard as coming a trifle late. 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, but one considerably less violent than he had received in centrifuge simulated training. "I was delighted to see it," Shepard remarked with considerable understatement. And well he might be, for at that stage of the flight most of the critical moments had passed. Freedom 7 had closely followed its assigned trajectory and the recovery forces were standing by for its pickup.
Falling toward the water at a rate of 35 feet per second, in contrast to the maximum rate of 6550 feet per second during the powered phase of the flight, Shepard pushed the switch to dump the remaining hydrogen peroxide fuel. Glancing at the dials, he noted another green light, indicating that the landing bag with its four-foot impact skirt had dropped down to cushion the water landing. He reported to the Cape that everything was in order before Freedom 7 dropped below the radio horizon.
The astronaut used the brief remaining time before impact to remove his knee straps, open the faceplate shield, and remove the hose connections of his pressure suit. Then came the thud of water impact, comparable to landing an aircraft on a carrier. Freedom 7 splashed and listed over into the water on the [357] 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 fluoresceing 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 Cardfile 23, the communications airplane, that he was all right.
Helicopters of Marine Air Force Group 26 were waiting. Wayne E. Koons and George F. Cox, pilot and copilot, respectively, of the primary helicopter, had watched the spacecraft for about five minutes on its descent. After splashdown, Koons quickly maneuvered his chopper into position for the retrieval exercise. Glancing at Freedom 7, Cox noted that the high-frequency antenna was not in its correct position as he hooked the cable through the recovery loop. Koons maneuvered the helicopter to lift the spacecraft partially out of the water, awaiting pilot egress. All of a sudden the high-frequency antenna pronged upward, hit and dented the bottom of the helicopter, and broke off. But no damage was done; Shepard told Koons he would debark as soon as Freedom 7's hatch cleared the water.
While Shepard worked himself into a sitting posture, Koons asked again if he was ready. Not yet, he replied; he was still removing his restraint harness and he could still see water against the ports. So the chopper raised the spacecraft further and Shepard unlocked the hatch.
The astronaut then wormed his way over the hatch sill and grappled for his "horse collar" hoisting sling. He soon grasped the line and fitted the sling under his arms. On the way up he brushed against the remainder of the high-frequency antenna, but it was flexible and did no harm. The hovering chopper had no difficulty getting Shepard aboard and in lifting Freedom 7 from the water and transporting it to the carrier Lake Champlain. When Shepard finally stepped on the carrier's deck, only 11 minutes had elapsed since the water landing. About half an hour after he had begun his free-dictation report, Shepard was called to the flag bridge to answer an unexpected telephone call from President Kennedy, who had watched the launching and followed flight details closely via television and who now congratulated the astronaut on his flight into space.29
Aboard the Lake Champlain, the immediate task was determining what shape Shepard was in after that brief but awesome excursion through space, with its accompanying high acceleration load, weightlessness, and deceleration loads. Some physiologists had feared that even a few minutes of weightlessness could cause disorientation, while some psychologists were equally apprehensive about what would happen to a space passenger's mind. But Shepard reported that he found his five minutes of weightlessness quite pleasant. In fact, he said, he was already in the weightless state before he realized it. For evidence, he cited a washer that had floated beside his left ear. The weightless Shepard had grabbed for the [358] weightless washer - and missed. Anticipating his debriefing, the astronaut had used an analogy from his professional experience to describe his sensations. The best comparison in his memory was riding in the back seat of an F-100F airplane. "It was painless," he said, "just a pleasant ride." As for any other effects of weightlessness and g stresses, Shepard had demonstrated by assuming direct pilot control that man was quite capable of functioning in space. He experienced no impairment of his faculties. He had reported to Mercury Control with perfect clarity regarding his and the spacecraft's status, and when two physicians, M. Jerome Strong and Robert Laning, made a preliminary postflight physical examination of Shepard aboard the carrier, they found him to be in excellent condition. From beginning to end the flight mission had been almost perfect. The jubilant but technically perfectionist engineers called it only an "unqualified success."30
Now there remained no possible doubt that man could function intelligently aboard the Mercury spacecraft and with relative safety in a true space environment for 15 minutes. What of the primitive spacecraft that he had inhabited? How well did it perform? The answer seemed to be, very well indeed. But could its systems be trusted to work under even more demanding conditions in orbital flights? Had all the flight preparations been adequate? These were only a few of the questions that the returning astronaut would have to answer, if only partially and indirectly, at the seemingly interminable debriefings.
28 Later, during postlaunch debriefings, Shepard stated that the decision to carry or eliminate the personal parachute on subsequent flights should be left for the prime pilot. An unidentified astronaut at the debriefing (probably Schirra) exclaimed, "Please!"
29 The "Kennedy call" was to become a standing event in all manned Mercury flights.
30 Shepard gave a most lucid account of his mission from liftoff to water impact, following his preliminary medical examination aboard the Champlain. Shepard's dictated report is contained in "Postlaunch Report for MR-3," and in the Sjoberg debriefing memo of Aug. 22. The latter document also gives questions by the debriefers and answers by the astronaut covering every aspect of the flight. Also see "Shepard and USA Feel A. OK," Life, L (May 12, 1961); Alan B. Shepard, Jr., "Astronaut's Story of the Thrust into Space," Life, L (May 19, 1961).