PERIOD OF FLIGHT
I include as part of the flight period the time from insertion into the spacecraft on the launching pad until the time of recovery by the helicopter, The voice and operational procedures developed during the weeks preceding the launch were essentially sound.
The countdown went smoothly, and no major difficulties were encountered with the ground crews, the control-central crew, and the pilot. There has been some comment in the press about the length of time spent in the spacecraft prior to launch, some 4 hours 15 minutes to be exact. This period was about two hours longer than had been planned. A fact that is most encouraging is that during this time there was no significant change in pilot alertness and ability. The reassurance gained from this experience applies directly to our upcoming orbital flights, and we now approach them with greater confidence in the ability of the pilots, as well as in the environmental control systems.
Our plan was for the pilot to report to the blockhouse crew primarily prior to the T-2 minutes on hard wire circuits, and to shift control to the Center by use of radio frequencies at T-2 minutes. This shift worked smoothly and continuity of information to the pilot was good. At lift-off I started a clock timer in the spacecraft and prepared for noise and vibration. I felt none of any serious consequence. The cockpit section experienced no vibration and I did not even have to turn up my radio receiver to full volume to hear the radio transmissions. Radio communication was verified after lift-off, and then periodic transmissions were made at 30-second intervals for the purpose of maintaining voice contact and of reporting vital information to the ground.
Some roughness was expected during the period of transonic flight and of maximum dynamic pressure. These events occurred very close together on the flight, and there was general vibration associated with them. At one point some head vibration was observed. The degradation of vision associated with this vibration was not serious. There was a slight fuzzy appearance of the instrument needles. At T+1 minute 21 seconds I was able to observe and report the cabin pressure without difficulty. I accurately described the cabin pressure as “holding at 5.5 p. s.i. a.” The indications of the various needles on their respective meters could be determined accurately at all times. We intend to alleviate the head vibration by providing more foam rubber for the head support and a more streamlined fairing for the spacecraft adapter ring. These modifications should take care of this problem for future flights.
I had no other difficulty during powered flight. The training in acceleration on the centrifuge was valid, and I encountered no problem in respiration, observation, and reporting to the ground.
Rocket cutoff occurred at T+2 minutes 22 seconds at an acceleration of about 6 g. It was not abrupt enough to give me any problem and I was not aware of any uncomfortable sensation. I had one switch movement at this point which I made on schedule. Ten seconds later, the spacecraft separated from the launch vehicle, and I was aware of the noise of the separation rockets firing. In another 5 seconds the periscope had extended and the autopilot was controlling the turnaround to orbit attitude. Even though this test was only a ballistic flight, most of the spacecraft action and piloting techniques were executed with orbital flight in mind. I would like to make the point again that attitude control in space differs from that in conventional aircraft. There is a penalty for excessive use of the peroxide fuel and we do not attempt to control continually all small rate motions. There is no aerodynamic damping in space to prevent attitude deviation, but neither is there any flight-path excursion or acceleration purely as a function of variation in spacecraft angles.
At this point in the flight I was scheduled to take control of the attitude (angular position) by use of the manual system. I made this manipulation one axis at a time, switching to pitch, yaw and roll in that order until I had full control of the craft. I used the instruments first and then the periscope as reference controls. The reaction of the spacecraft was very much like that obtained in the air-bearing trainer (ALFA trainer) described previously in the paper by Astronaut Slayton. The spacecraft movement was smooth and could be controlled precisely. Just prior to retrofiring, I used the periscope for general observation.
The particular camera orientation during my flight happened to include many clouds and is not as clear for land viewing. This photograph shows the contrast between land and water masses, the cloud cover and its effect, and a good view of the horizon. There appears to be a haze layer at the horizon. This haze is a function not only of particles of dust, moisture, and so forth, but also of light refraction through atmospheric layers. The sky itself is a very deep blue, almost black, because of the absolute lack of light-reflecting particles. We are encouraged that the periscope provides a good viewing device as well as a backup attitude-control indicator and navigation aid.
At about this point, as I have indicated publicly before, I realized that somebody would ask me about weightlessness. I use this example again because it is typical of the lack of anything upsetting during a weightless or zero-g environment. Movements, speech, and breathing are unimpaired and the entire sensation is most analogous to floating. The NASA intends, of course, to investigate this phenomenon during longer periods of time, but the astronauts approach these periods with no trepidation.
Control of attitude during retrofiring was maintained on the manual system and was within the limits expected. There was smooth transition from zero gravity to the thrust of the retrorocket and back to weightless flying again. After the retrorockets had been fired, the automatic sequence acted to jettison them. I could hear the noise and could see one of the straps falling away in view of the periscope. My signal light inside did not show proper indication so I used the manual backup control and the function indicated proper operation.
After retrorockets were jettisoned, I used a combination of manual and electric control to put the spacecraft in the reentry attitude. I then went back to autopilot control to allow myself freedom for some other actions. The autopilot control functioned properly so I made checks on the high frequency voice link for propagation characteristics and then returned to the primary UHF voice link. I also looked out both portholes to get a general look at the stars or planets as well to get oblique horizon views. Because of the sun angle and light levels I was unable to see any celestial bodies. The Mercury Project plans are to investigate these phenomena further on later flights.
At an altitude of about 200,000 feet, or at the edge of the sensible atmosphere, a relay was actuated at 0.05 g. I had intended to be on manual control for this portion of the flight but found myself a few seconds behind. I was able to switch to the manual system and make some controlling motions during this time. We feel that programming for this maneuver is not a serious problem and can be corrected by allowing a little more time prior to the maneuver to get ready. We were anxious to get our money’s worth out of the flight and consequently we had a full flight plan. However, it paid off in most cases as evidenced by the volume of data collected on pilot actions.
The reentry and its attendant acceleration pulse of 11 g was not unduly difficult. The functions of observation, motion, and reporting were maintained, and no respiration difficulties were encountered. Here again, the centrifuge training had provided good reference. I noticed no loss of peripheral vision, which is the first indication of “gray out.”
After the acceleration pulse I switched back to the autopilot. I got ready to observe parachute opening. At 21,000 feet the drogue parachute came out on schedule as did the periscope. I could see the drogue and its action through the periscope. There was no abrupt motion at drogue deployment. At 10,000 feet the main parachute came out and I was able to observe the entire operation through the periscope. I could see the streaming action as well as the unreefing action and could immediately assess the condition of the canopy. It looked good and the opening shock was smooth and welcome. I reported all of these events to the control center and then proceeded to get ready for landing.
I opened the faceplate of the helmet and disconnected the hose which supplies oxygen to its seal. I removed the chest strap and the knee restraint straps. I had the lap belt and shoulder harness still fastened. The landing did not seem any more severe than a catapult shot from an aircraft carrier. The spacecraft hit and then flopped on its side so that I was on my right side. I felt that I could immediately execute an underwater escape should it become necessary. Here again, our training period was giving us dividends. I could see the water covering one porthole. I could see the yellow dye marker out the other porthole and, later on, I could see one of the helicopters through the periscope.
The spacecraft righted itself slowly and I began to read the cockpit instruments for data purposes after impact. I found very little time for that since the helicopter was already calling me. I made an egress as shown in the training movie; that is, I sat on the edge of the door sill until the helicopter sling came my way…. The hoist itself was uneventful. At this point, I would like to mention a device that we use on our pressure suits that gives watertight integrity. There is a soft rubber cone attached to the neck ring seal of the suit. When the suit helmet is on, this rubber is rolled and stowed below the lip of the neck ring seal bearing. With the helmet off, this collar or neck cone is rolled up over the bearing and against the neck of the pilot where it forms a watertight seal. The inlet valve fitting has a locking flapper valve. Thus the suit is waterproof and provides its own buoyancy.