By Robert B. Voas, Ph.D., Head, Training Office, NASA Spacecraft Center; John J. Van Bockel, Training Office, NASA Manned Spacecraft Center; Raymond G. Zedekar, Training Office, NASA Manned Spacecraft Center; and Paul W. Backer, McDonnell Aircraft Corp.


This paper presents a second report on the ability of the pilot to operate the space vehicle and perform all associated space-flight functions during Mercury flights. As with the previous paper, the analysis is directed toward establishing the capability of the man to perform in the weightless environment of space with essentially the same proficiency which he demonstrated under the more normal terrestrial conditions. The results of the analysis of the MR-3 flight indicated that the pilot was able to perform the space-flight functions, not only within the tolerances required for the successful completion of the mission, but within the performance levels demonstrated in fixed-base trainers on the ground under essentially optimal environmental conditions. From the first manned Mercury-Redstone flight, it was concluded that the performance data were essentially in keeping with the previous experience with manned aircraft flying zero-g trajectories. That is, the pilot was able to operate the space vehicle and perform other flight functions while exposed to the unusual environmental conditions of space, including a 5-minute period of weightlessness, without a detectable reduction in performance efficiency. As in the MR-3 flight, the astronaut's communications to the ground provide one source of data, while the telemetred records of vehicle attitude under manual control provide a second source, and a third source is the narrative description of the activities and events given by the pilot during the postflight debriefing. Not available for this report are the onboard pictures of the astronaut, since the film was lost with the spacecraft. This paper attempts to evaluate the performance of the pilot on the MR-4 mission, to compare the observations made by Astronaut Shepard and Astronaut Grissom of the earth and sky, as seen from space, and to compare their evaluations of the Mercury training devices.

The Astronaut's Flight Activities Plan

Three major differences between the MR-4 and MR-3 flights which are of significance to the astronaut's activities can be noted. First, spacecraft no. 11 (MR-4) differered from spacecraft no. 7 (MR-3) in that spacecraft no. 11 had available the centerline window which permits a view directly in front of the spacecraft. Through the window, the astronaut is able to see 33° in a vertical direction and approximately 30° horizontally. With the spacecraft in the orbit attitude, which is -34° with the small end down, two thirds of the window is filled with the earth's surface and the upper one-third views space above the horizon. The size and location of this window provided an opportunity for better examination of the earth's surface and horizon than was possible through the 10-inch-diameter porthole available to Astronaut Shepard. The second variation from the MR-3 flight was in the checkout of the various reaction-control systems (RCS). During the MR-3 flight, Astronaut Shepard made use of the manual proportional and the fly-by-wire control systems, whereas during the MR-4 flight, Astronaut Grissom made use of the manual propartional system and the rate command system.

The third variation between the MR-3 and MR-4 flights was a slight reduction in the number of flight activities following the retrofire period on the MR-4 flight. The flight programs for Astronaut Shepard and Astronaut Grissom are compared in figure 6-1. Each begins with essentially the same launch period during which the astronaut monitors the sequential events and reports the status of the onboard systems approximately every 30 seconds. In both flights, the turnaround maneuver was performed on the autopilot with the astronaut monitoring the autopilot action. Immediately after the turnaround, both Astronaut Shepard and Astronaut Grissom selected the manual proportional control mode and attempted to make a series of maneuvers: one each in pitch, yaw, and roll using the spacecraft attitude and rate indicator as a reference. After these three basic maneuvers, the astronaut shifted to an external reference. During this period, Shepard used the periscope, whereas Grissom used the window. Each reported what could be seen through these observation systems. In addition, Grissom made a 60° left yaw maneuver to the south.

Manual Control Summary

Figure 6-1.   Manual control summary for the MR-3 and MR-4 flights.

Following this period on external reference, the retrofire maneuver started. This maneuver commenced with the countdown from the ground to the retrosequence. From the retrosequence to the start of retrofire, there is a 30-second period during which the astronaut brings the vehicle into the proper attitude for retrofiring. This is followed by a retrorocket firing period of approximately 20 seconds. Both Astronaut Grissom and Astronaut Shepard controlled the spacecraft attitude during this period using the instrument reference and the manual proportional control system.

Following retrofire, Astronaut Shepard attempted to do a series of maneuvers using the fly-by-wire system and the spacecraft instruments as a reference. This series of maneuvers was omitted for Astronaut Grissom's flight; instead, he switched to the rate command system and returned to the window reference for further external observations. During this period both Astronaut Shepard and Astronaut Grissom made a check of the HF communications radio system.

The next mission phase began at approximately T +6 minutes 40 seconds with the astronaut pitching up to reentry attitude. At this point, both Astronaut Shepard and Astronaut Grissom looked for stars, Shepard using the small porthole on his left and Grissom using the large centerline window. Neither astronaut was able to see any stars at this time.

Following this period of observation, the reentry began. Astronaut Shepard used the manual proportional control mode and rate instruments to control the reentry; whereas Grissom used the rate command control mode and rate instruments during this period. Since the reentry oscillations caused no discomfort or concern, little control was exercised by either astronaut.

Although Astronaut Grissom had been relieved of some of the attitude maneuvers that were required of Astronaut Shepard between the retrofire and the reentry period, his program was still a full one. These full programs resulted from the decision to make maximum use of the short weightless flight time available during the Redstone missions.

Attitude Control

The curves of figure 6-2 are the attitudes of pitch, yaw, and roll maintained by Astronaut Grissom throughout the flight. The shaded area in the background indicates the envelope of attitudes maintained during 10 Mercury procedures trainer runs the week prior to the MR-4 flight. As described in paper 2 of this volume there was a malfunction of the manual proportional control system. This malfunction resulted in Astronaut Grissom's receiving less than the normal amount of thrust per control stick deflection. This anomaly in the performance of the manual proportional control system resulted in the first three maneuvres being performed somewhat differently from those on the trainer, though generally still within the envelope of the trainer runs. The pitch and yaw maneuvers overshot the 20° desired attitude, and the time to make each maneuver was somewhat increased. This longer maneuvering time in pitch and yaw, plus the time required to remove residual roll rates, prevented the attempt to make the roll maneuver. It is interesting to note that Astronaut Shepard on his flight was also pressed for time at this point and cut the roll maneuver short, rolling only 12° instead of 20°. Following these three attitude maneuvers, Astronaut Grissom made a left yaw maneuver of approximately 60°, using the manual proportional control mode and window reference. This maneuver was performed approximately as it was during the trainer sessions.

Flight Attitudes Graph

Figure 6-2.   The MR-4 flight attitudes with four trainer runs in the background.

Both Grissom and Shepard maintained the attitude of the spacecraft manually during the firing of the retrorockets. During the critical period of approximately 20 seconds in which the retrorockets were firing, the attitudes were held very close to the proper retroattitude of 0° in roll and yaw and -34° in pitch. The accuracy with which Astronaut Grissom held these attitudes is shown by the curves in figure 6-3 with the envelope of trainer runs in the background. The permissible attitude limits inside of which the retrorockets can be fired are shown as the extents of the ordinate scale labels. Outside of these limits, the retrorocket firing sequence would be interrupted until all the attitudes returned to within the permissible limits. Attitude control performance during this period was well within the limits required for a safe landing from orbit in the planned recovery area. The pilot stated during the debriefing that controlling attitude during the retrofire for the MR-4 flight appeared to be about equal in difficulty to the procedures trainer. For the training runs, using the fixed-base trainer, retrorocket-misalignment levels were selected which simulated misalignment torques equal to approximately 60 percent of the available reaction control system control torque. Since it is not possible to measure the retrorocket misalignment torques actually encountered during the flight, the performance of the system and of the pilot cannot be evaluated in detail. In addition, the pilot's assessment of the retrofire difficulty level may be a result of reduced effectiveness of the manual proportional control system, rather than large retrorocket-misalignment torque levels.

Attitude Control Graph
Figure 6-3.   Attitude control during MR-4 retrofire period.

Following the retrofire period, Astronaut Grissom shifted to the rate command control and maintained the spacecraft attitude at -34° pitch and 0° roll and yaw until T +6 minutes 34 seconds, at which time he pitched to the proper reentry attitude. The attitude control during this period is well within the envelope demonstrated during the fixed-base trainer runs. During the reentry, the pilot made use of the rate command system, which provides automatic rate damping to ±3 deg/sec if the stick is maintained in the center position. This system appeared to work well and no control action was required of the pilot to damp rates.

In summary, the pilot was able to accomplish the majority of the planned attitude maneuvers, despite the malfunction of the control system. This fact, together with the excellent control performance during the critical retrofire portion of the mission, provides an indication that pilot's control performance was not degraded during the approximately 5 minutes of weightless flight.

Flight Voice Communications

Ninety-four voice communications were made by Astronaut Grissom between lift-off and impact. (See appendix.) As in Astronaut Shepard's flight, these voice communications provide an indication of how well the astronaut was able to keep up with the mission events, how accurately he was able to respond to novel and unusual events during the flight. In general, the astronaut made all of the normal reports during the launch and reentry at the times appropriate to the event. His instrument readings relayed to the ground showed general agreement with telemetred data. In addition to the standard vioce reports of spacecraft events and instrument readings, Astronaut Grissom made a number of unscheduled reports of the unique events of the flight. He reported and described the unique view through the centerline window and the problem with the attitude control system.

Pilot Observations

The major sensory observations made by the pilots during the MR-3 and MR-4 flights were those of vision, auditory phenomena, vibration, angular acceleration, linear acceleration, weightlessness, and general orientation.


On the MR-4 flight, Astronaut Grissom used the centerline window for the bulk of his external observations, whereas Astronaut Shepard primarily used the periscope. The major areas of observation are listed as follows:

Earth's surface.– Astronaut Grissom was hampered in his attempts to identify land areas due to extensive cloud coverage. He was, however, able to make some observations as evidenced by the following quotations from the postflight debriefing sessions: "... The Cape is the best reference I had. ... I could pick out the Banana River and see the peninsula that runs on down south, and then on down the caost of Florida. I saw what must have been West Palm Beach... and it was a dark brown color and quite large. I never did see Cuba. High cirrus blotted out everything except an area from about Daytona Beach back inland to Orlando and Lakeland to Lake Okeechobee and down to the tip of Florida. Beyond this the Gulf of Mexico was visible."
Astronaut Shepard was less hampered by cloud formations during his flight. His observations through the periscope were reported as follows in the postflight debriefing sessions: "... The west coast of Florida and the Gulf coast were clear. I could see Lake Okeechobee. I could see the shoals in the vicinity of Bimini. I could see Andros Island... Tampa Bay.... There was an abrupt color change between the reefs, in the area of Bimini and the surrounding water."

Clouds.– Because of shortage of time and/or high cirrus clouds that obscured any underlying vertical cloud formations, neither Astronaut Shepard nor Astronaut Grissom was able to report cloud heights during the MR-3 and MR-4 flights.

Horizon.– Astronaut Grissom described the horizon as "very smooth as far as I could see... a blue band above the earth, then the dark sky. It is very vivid when you go from the blue to the dark.... The blue band appears about a quarter of an inch wide."
Astronaut Shepard viewed the horizon through the small 10-inch-diameter porthole. He described his view as follows: "... There was only one haze layer between the cloud cover and the deep blue.... It was a little hazy, or what looked like haze; so there was no real sharp definition between clouds, haze layer, or the horizon and sky."

Sky.– Astronaut Grissom reported that the sky was very black and that the transition from blue to black was very rapid during the launch phase.
Astronaut Shepard on the MR-3 flight had the impression that the sky was a very dark blue rather than black.

Stars.– The high contrast between the cabin interior light intensity and external areas for both suborbital flights made it very difficult for either pilot to locate stars. Astronaut Shepard did not see any stars during his flight. Astronaut Grissom was not able to locate any stars during the scheduled external observation period of his flight; however, he did locate what appeared to be a star late in the powered phase of the flight. Subsequent investigations indicate that he saw the planet Venus.

Sun.– The sun never posed a great problem for either of the astronauts during the suborbital missions. It entered the cabin either directly or reflected during both flights. Unlike Shepard, Astronaut Grissom did have some minor difficulties with sunlight. His statements were: "The sun was coming in bright at 0.05 g and I think I would have missed it if I hadn't known that it was due and coming up.... I looked real close and I did see it.... It comes in pretty much as a shaft of light with everything else in the cockpit dark."

Use of earth reference for attitude control.– Both astronauts expressed confidence that it would be possible to determine rates and attitudes by the use of their respective available reference devices. Astronaut Shepard said, "Qualitatively, I noticed nothing that would prevent it [periscope] from being a good backup for the instruments, for attitude reference and for control."
Astronaut Grissom's comments on the window as a means of reference were: "When I had zero roll on the instruments, I had zero roll out the window. When I was looking at the Cape, then I had a good ready yaw reference and then it [yaw rate] was quite apparent, and I could control on that basis."

Other visual phenomena.– Neither pilot was able to observe the launch vehicle at any time during the flights. At tower separation, the periscope has not as yet extended so Shepard was not able to observe the tower jettisoning. However, the centerline window provided Grissom with a direct view of this operation. His comment is as follows: "I didn't see any flame, but I could see it go and I could see it for a long time after it went. I could see the little tail-off and it occurred to me that it went slightly off to my right."

Both pilots were able to observe through the periscope some portions of the retropackage after it had been jettisoned. Astronaut Grissom's comment was: "Right after retrojettison, I saw something floating around. It actually looked like a retromotor at one time, and these floated by a couple of times."
Astronaut Shepard's comment was: "I heard the noise and saw a little bit of the debris. I saw one of the retropack's retaining straps."

During the reentry phase, Astronaut Grissom reported observing what he describes as shock waves. His report was: "I'm fairly certain it was shock waves off the shield of the capsule. It looked like smoke or contrail really, but I'm pretty certain it was shocks."

Drogue parachute deployment was observed by both pilots. Shepard observed this event through the periscope and Grissom through the centerline window. Astronaut Shepard reported: "The drogue [parachute] came out at the intended altitude and was clearly visible through the periscope."
Astronaut Grissom observed: "The drogue [parachute] came right out. I could see the canister go right on out and the drogue deploy."

Main parachute deployment was obvious to both pilots. Astronaut Grissom was afforded the best view of the parachute through the centerline window. Astronaut Grissom reported: "I could see the complete chute when it was in the reefed condition and after it opened I could see, out the window, 75 percent of the chute."
Astronaut Shepard's comment was: "Then at 10,000 feet, of course, the antenna canister went off, and you could see it come off and pull the main chute with it and then go off in the distance. You could see the chute in the reefed condition. The it dereefed." When asked, "Did you see the chute at full inflation?" he replied, "Yes, I would say probably three fifth of the chute area; over half, anyway."

Astronaut Grissom observed the reserve parachute canister in the water through the periscope after it had jettisoned.

Astronaut Grissom was not able to locate any of the recovery ships or search aircraft in the recovery area. He reported during the debriefing, "I didn't see any airplanes out the 'scope until after I had hit, but I saw the choppers through the 'scope after the impact."

Auditory Phenomena

The noise encountered by both pilots did not at any time reach a disturbing level. The major mechanical functions of the spacecraft were audible to both astronauts. Their reports of the various functions are as follows:

Shepard observed: "Sounds of the booster [launch vehicle], the pyros [pyrotechnics] firing, the escape tower jettisoning, and the retros firing could be heard. All these sounds were new; although none of them was really loud enough to be upsetting, they were definitely noticeable. I remember thinking I did not hear the noise of the manual jets firing. I was aware of the posigrade firing and of just one general noise pulse."

Grissom reported: "At no time did we have any annoying sound level. You can hear the escape rocket fire, the posigrades, and you can hear the pitch and yaw jets fire, and that's about it."

Both astronauts reported that they heard the retrorocket package jettison and heard the firing of the drogue-parachute mortar. However, only Shepard recalled hearing the antenna mortar firing.


The vibrations encountered by Astronaut Grissom during the MR-4 flight were less than those experienced by Astronaut Shepard on the MR-3 flight. This was primarily a result of (1) an improved fairing between the spacecraft and the launch vehicle and (2) added sound attenuating material in the couch. Vibration was experienced only during the launch phase of both flights. The astronauts' reports of the vibrations encountered and their effects are as follows. Shepard's comments were: "From the period of about 45 to 50 seconds after lift-off and through about a minute and a half there was some vibration. I could feel vibrations building up, and the sound level came up a little bit until at one point, I'm not sure whether it was at max q [maximum dynamic pressure] or not, there was enough vibration in the capsule [spacecraft] that there was a slightly fuzzy appearance of the instrument needles. Then, after we got through the max q, everything smoothed out." The degradation of vision associated with this vibration was not serious.

Grissom observed: "I called out vibrations as soon as they started and they never did get very bad at all. I was able to see the instrument panel and see the instruments clearly all the time and to transmit quite clearly."

Angular Acceleration

Astronaut Grissom reported that he was able to discern angular accelerations during spacecraft turnaround and retrofire. He did not think that he could feel the accelerations produced in controlling the spacecraft.

Astronaut Shepard had much the same experience on the MR-3 flight. He was also able to feel the angular accelerations during periods when there were high torques acting on the spacecraft.

Linear Accelerations

Both pilots were aware of the linear accelerations connected with the main functions of the spacecraft, such as posigrade firing at spacecraft seperation, retrorocket firing, reentry, drogue parachute deployment, main parachute deployment, and impact. In addition, Astronaut Grissom was able to identify the deployment of the landing bag. He stated, "I could feel it [the landing-bag deployment], but it was just a slight jar as the thing dropped down."

Astronaut Shepard stated that the landing-bag shock was so slight that he did not notice it.


Both pilots experienced approximately the same sensations during the weightless phase of the flight. They both had to make a special effort to notice the weightless condition. Astronaut Shepard made these observations concerning his flight: "I said to myself, 'Well, OK, you've been weightless for a minute or two and somebody is going to ask you what it feels like.'... In other words, I wasn't disturbed at all by the fact that I was weightless. I noticed a little bit of dust flying around, and there was one washer over my left eye. ... I was not uncomfortable and I didn't feel like my performance was degraded in any way. No problems at all."

Astronaut Grissom's primary cue to the weightless condition was also a visual one, as is indicated by his comments during the debriefing: "... At zero-g, everything is floating around. I could see washers and trash floating around. I had no other feeling of zero-g; in fact, I felt just about like I did at 1 g on my back or sitting up."

General Orientation

Neither pilot experienced any unexpected disorientation. Astronaut Shepard, in fact, experienced no disorientation at any time as is indicated by his statements during the debriefing.

Astronaut Grissom, on the other hand, experienced a slight pitching forward sensation at launch-vehicle cutoff. His comment was: "... Right at BECO [booster-engine or launch-vehicle cutoff] when the tower went, I got a little tumbling sensation. I can't recall which way it was that I felt I tumbled, but I did get the same sort of feeling that we had one the centrifuge. There was a definite second of disorientation there. I knew what it was, so it didn't bother me." Most of the astronauts have experienced this sensation during this period on dynamic centrifuge simulations. Grissom further commented: "Prior to retrofire, I really felt that I was moving; I was going backwards. ... When the retros fired, I had the impression I was very definitely going the other way."

Training Program Evaluation

The Mercury astronaut training program was described by Astronaut Slayton in the report on the Mercury-Redstone flight 3 (ref. 1). As a result of the two suborbital flights, a preliminary evaluation of some portions of the training program are possible. The pilots' comments on some of the more important phases of training are given in this section.

General Comments

Astronaut Shepard reported that he felt sufficiently trained for the mission. He felt that the training produced a "... feeling of self-confidence as well as the physical skills necessary to control the vehicle." He did not believe that any areas of training had been neglected. He reported, "... that as a result of the training program, at no time during the flight did I run into anything unexpected." With regard to items in the training program which might be omitted, Astronaut Shepard reported, "All the training devices and phases we experienced were valuable." However, since he felt that the physiological symptoms associated with weightlessness and other space flight environmental conditions were not going to be a problem, he believed the time devoted to weightless flights and disorientation devices could be reduced.

Astronaut Grissom stated after the flight that he felt least well prepared in the recovery portion of the mission. He also felt that additional practice on the air-lubricated free-attitude trainer during the last 2 weeks prior to the mission would have been desirable. This simulator is at NASA-Langley Air Force Base, Va., and not available to the astronaut who must remain close to the launch site just prior to the flight. Astronaut Grissom also felt he should have had more time at the planetarium and for map study. Like Astronaut Shepard, he did not feel any of the training phases were unnecessary, but that the time on some trainers could be reduced.

Weightless Flying

Astronaut Shepard reported that "... The weightless flying is valuable as a confidence-building maneuver." Astronaut Grissom agreed that the training was valuable and that he would not want to be without it. Both reported that the flights in the F-100 airplanes in which they experienced 1 minute of weightlessness, while strapped in the seat, were most similar to their Redstone-Mercury flight experiences. Shepard felt that the amount of weightless flying could have been reduced.

Fixed-Base Procedures Training

Both pilots felt this was a very valuable trainer, particularly when tied into the Mercury Control Center simulations. Astronaut Shepard made less use of the procedures trainer than he might otherwise have because of the difference in the panel arrangement between the trainer and the early model of the spacecraft which he flew. Shepard felt that the computer attitude simulation provided and accurate reproduction of the flight dynamics. Grissom was not able to make a good evaluation of this portion of the simulation due to the malfunction of the control system on his flight.

Shepard stressed the importance of accurate timing of events in the procedures trainer, noting that a small time inaccuracy had momentarily disturbed him during the flight. Grissom suggested that where possible, sound cues associated with mission events should be added to the simulation.

Air-Lubricated Free-Attitude Trainer

Both pilots felt that the air-lubricated free-attitude (ALFA) trainer, a moving-base trainer which provides angular-acceleration cues as well as a simulation of both the window and periscope views of the earth, was very good for developing skill in the attitude control task. It was more valuable to Grissom since the spacecraft he flew had the centerline window. The angular response of the ALFA trainer appeared to be accurate to Shepard and he felt that this trainer was a necessary addition to the fixed-base training. As already noted, Astronaut Grissom felt that more practice in the ALFA trainer with the pilot using the window reference would have been desirable. He felt that the horizon simulation which, at present, is only an illuminated band should be improved. Both pilots reported that the simulated periscope view employing a projected earth map was very valuable.


Both pilots felt that the centrifuge provided valuable training for launch and reentry periods. Shepard reported that simulated accelerations of the centrifuge during retrofiring were far more jerky and upsetting than those occurring during the flight. "... which were very smooth." Grissom agreed that the centrifuge simulations were more difficult than the flight. The centrifuge had prepared him for a slight momentary vertigo sensation which he experienced just after cutoff of the launch-vehicle engine.

Participation in Spacecraft Checkout Activities at the Launch Site

Both pilots felt that this portion of their preparation was particularly essential. During this period, they were able to familiarize themselves with the unique features of the actual spacecraft they were to fly. Grissom summed up the value of this training as follows: "It is good to get into the flight capsule [spacecraft] a number of times; then on launch day, you have no feeling of sitting on top of a booster [launch vehicle] ready for launch. You feel as if you were back in the checkout hangar–this is home, the surroundings are familiar, you are at ease. You cannot acchieve this feeling of familiarity in the procedures trainer because there are inevitably many small differences between the simulator and the capsule [spacecraft]."


Air-Ground Communications for MR-4

The following table gives a verbatim transcription of the communications between the spacecraft and the ground during the MR-4 flight. The call signs listed in the second column identify different elements of the operation. The spacecraft is identified as "Bell 7" for Liberty Bell 7. The astronaut communicator in the Blockhouse is identified as "Stony." "Cap Com" is the astronaut communicator in the Mercury Control Center. "Chase" is an astronaut in an F-106 airplane. "ATS" stands for "Atlantic Ocean Ship," a Mercury range station aboard a ship which had been moved in close to the landing area for this flight. "Hunt Club" is the designation given to the recovery helicopters. "Card File" is the designation of a radio-relay air-plane which relayed the spacecraft communications to the Mercury Control Center.

  Stony 0:01 1 Lift-off.
1 Bell 7 0:03 4.5 Ah, Roger. This is Liberty Bell 7. The clock is operating.
  Cap Com 0:08 3 Loud and clear, Jose, don't cry too much.
2 Bell 7 0:11 1.5 Oke-doke.
  Bell 7 0:18 2.5 OK, it's a nice ride up to now.
  Cap Com 0:20 1 Loud and clear.
3 Bell 7 0:21.5 1.5 Roger.
  Bell 7 0:28 8.5 OK. The fuel is go; about 1 1/2 g's; cabin pressure is just coming off the peg; the O2 is go; we have 26 amps.
  Cap Com 0:36.5 2.5 Roger. Pitch [attitude] 88 [degrees], the trajectory is good.
4 Bell 7 0:39 2 Roger, looks good here.
  (1) 0:54 6.5 OK, there. We're starting to pick up a little bit of the noise and vibration; not bad, though, at all. 50 secs, more vibration.
5 Bell 7 1:01.5 6.5 OK. The fuel is go; 1 1/2 g's; cabin is 8 [psi]; the O2 is go; 27 amps.
  Bell 7 1:08.5 0.5 And...
  Cap Com 1:09 1 Pitch is...
6 Bell 7 1:10 0.5 4 [g], 5 [g]...
  Cap Com 1:11 2 Pitch [attitude] is 77 [degrees]; trajectory is go.
7 Bell 7 1:13 9.5 Roger. Cabin pressure is still about 6 [psi] and dropping slightly. Looks like she's going to hold about 5.5 [psi].
8 Bell 7 1:23 0.5 Eh...
  Cap Com 1:23.5 0.5 Cabin...
9 Bell 7 1:24 1.5 Believe me, O2, is go.
  Cap Com 1:26 3 Cabin pressure holding 5.5 [psi].
10 Bell 7 1:29 1.5 Roger, roger.
  Bell 7 1:31 15.5 This is Liberty-Bell 7. Fuel is go; 2 1/2 g's; cabin pressure 5.5; O2 is go; main [bus] 25 [volts], isolated - ah, isolated [bus] is 28 [volts]. We are go.
  Cap Com 1:46.5 3 Roger. Pitch [attitude] is 62 [degrees]; trajectory is go.
11 Bell 7 1:49.5 3 Roger. It looks good in here.
  Bell 7 1:56 18.5 Everything is good; cabin pressure is holding; suit pressure is OK; 2 minutes and we got 4 g's; fuel is go; ah, feel the hand controller move just a hair there; cabin pressure is holding, O2 is go; 25 amps.
  Cap Com 2:15 1.5 Roger, we have go here.
12 Bell 7 2:16.5 0.05 And I see a star!
  Cap Com 2:17 1.5 Stand by for cutoff.
13 Bell 7 2:23 2 There went the tower.
  Chase 2:24.5 1.5 Roger, there went the tower, affirmative. Chase.
14 Bell 7 2:26 4 Roger, squibs are off.
  Cap Com 2:31.5 0.5 Roger.
15 Bell 7 2:33 9.5 There went posigrades, capsule has separated. We are at zero g and turning around and the sun is really bright.
  Cap Com 2:42.5 4.5 Roger, cap. sep. [capsule separation light] is green; turnaround has started, manual handle out.
16 Bell 7 2:47 13.5 Oh boy! Manual handle is out; the sky is very black; the capsule is coming around into orbit attitude; the roll is a little bit slow.
  Cap Com 3:01 0.5 Roger.
17 Bell 7 3:02 8.0 I haven't seen a booster anyplace. OK, rate command is coming on. I'm in orbit attitude, I'm pitching up. OK, 40... Wait, I've lost some roll here someplace.
  Cap Com 3:10.5 3.5 Roger, rate command is coming on. You're trying manual pitch.
18 Bell 7 3:15.5 3 OK, I got roll back. OK, I'm at 24 [degrees] in pitch.
1 Bell 7 3:20.5 4 Roger, your IP [impact point] is right on, Gus, right on.
19 Bell 7 3:24.5 3 OK. I'm having a little trouble with rate, ah, with the manual control.
  Cap Com 3:28 0.5 Roger.
20 Bell 7 3:31 4 If I can get her stabilized here, all axes are working all right.
  Cap Com 3:36 3 Roger. Understand manual control is good.
21 Bell 7 3:40.5 3 Roger, it's - it's sort of sluggish, more than I expected.
22 Bell 7 3:45 1.5 OK, I'm yawing.
  Cap Com 3:47.5 1.5 Roger, yaw.
23 Bell 7 3:50 1 Left, ah.
24 Bell 7 3:51.5 4 OK, coming back in yaw. I'm a little bit late there.
  Cap Com 3:57.5 2 Roger. Reading you loud and clear, Gus.
25 Bell 7 3:59.5 2 Lot of stuff - there's a lot of stuff floating around up here.
26 Bell 7 4:02 12 OK, I'm going to skip the yaw [maneuver], ah, or [rather the] roll [maneuver] because I'm a little bit late and I'm going to try this rough yaw maneuver. About all I can really see is clouds. I haven't seen any land anyplace yet.
  Cap Com 4:15 3.5 Roger, you're on the window. Are you trying a yaw maneuver?
27 Bell 7 4:18.5 5.5 I'm trying the yaw maneuver and I'm on the window. It's such a fascinating view out the window you just can't help but look out that way.
  Cap Com 4:25 1.5 I understand.
28 Bell 7 4:29.5   You su, ah, really. There I see the coast, I see.
  Cap Com 4:30.5 1.5 4+30 [elapsed time since launch] Gus.
  (1) 4:33 4.5 4+30 [elapsed time since launch] he's looking out the window, A - OK.
29 Bell 7 4:37.5 3.5 I can see the coast but I can't identify anything.
  Cap Com 4:42 2 Roger, 4+30 [elapsed time since launch] Gus.
30 Bell 7 4:44 4 OK, let me get back here to retro attitude, retro sequence has started.
  Cap Com 4:48 3.5 Roger, retro sequence has started. Go to retro attitude.
31 Bell 7 4:52 4 Right, we'll see if I'm in bad, not in very good shape here.
  Cap Com 4:57 3.5 Got 15 seconds, plenty of time, I'll give you a mark at 5:10 [elapsed time since launch].
32 Bell 7 5:01.5 2.5 OK, retro attitude [light] is still green.
  Cap Com 5:05 6 Retros on my mark, 3, 2, 1, mark.
  (1)     He's in limits. [Falls in the middle of last Cap Com communication.]
33 Bell 7 5:11.5 &160; OK, there's 1 firing, there's 1 firing.
  (1) 5:12 1 Retro 1. [Cuts out Bell 7.]
  Cap Com 5:13.5 1 Roger, retro 1.
34 Bell 7 5:19 2 There's 2 firing, nice little boost. There went 3.
  Cap Com 5:21 2.5 Roger, 3, all retros are fired.
35 Bell 7 5:23.5 1 Roger, roger.
36 Bell 7 5:25.5 2.5 OK, yeh, they're fired out right there.
  Cap Com 5:29 3 Roger, retrojettison armed.
37 Bell 7 5:33.5 2.5 Retrojettison is armed, retrojettison is armed, going to rate command.
38 Bell 7 5:36 1.5 OK, I'm going to switch.
  Cap Com 5:38 3 Roger. Understand manual fuel handle is in.
39 Bell 7 5:41 3 Manual fuel handle is in, mark, going to HF.
  Cap Com 5:44.5 1.5 Roger, HF.
  Cap Com 5:52 6.5 Liberty Bell 7, this is Cap Com on HF, 1, 2, 3, 4, 5. How do you read [Bell] 7?
  (1)     I got you.
40 Bell 7 6:08 18 ... here, do you read me, do you read me on HF? ... Going back to U [UHF]... [received by ATS ship]. Boy is that... Retro, I'm back on UHF and, ah, and the jett - the retros have jettisoned. Now I can see the Cape any, oh boy, that's some sight. I can't see too much.
  Cap Com 6:25 6 This is Cap Com on HF, 1, 2, 3, 4, 5. How do you read, [Bell] 7?
41 Bell 7 6:34 3.5 Roger, I am on UHF high, how you read me?
  Cap Com 6:38 4.5 Roger, reading you loud and clear UHF high, can you confirm retro-jettison?
42 Bell 7 6:41 3.5 OK, periscope is retracting, going to reentry attitude.
  Cap Com 6:47 4.5 Roger. Retros have jettisoned, scope has retracted, you're going to reentry attitude.
43 Bell 7 6:51.5 1 Affirmative.
  Cap Com 6:56.5 3.5 Bell 7 from Cap Com, your IP [impact point] is right on.
44 Bell 7 7:00.5 3 Roger. I'm in reentry attitude.
45 Bell 7 7:05.5 0.5 Ah.
  Cap Com 7:07 2.5 Roger, how does it look out the window now?
46 Bell 7 7:09.5 4 Ah, the sun is coming in and so all I can see really is just, ah, just darkness, the sky is very black.
  Cap Com 7:14.5 3 Roger, you have some more time to look if you like.
  Cap Com 7:27 2.5 [Bell] 7 from Cap Com, how do you feel up there?
47 Bell 7 7:30 3.5 I feel very good, auto fuel is 90 [percent], manual is 50 [percent].
  Cap Com 7:33.5 3 Roger, 0.05 g in 10 [seconds].
48 Bell 7 7:37 2 OK.
49 Bell 7 7:50.5 3 OK, everything in very good, ah.
1 Bell 7 7:54 2.5 I got 0.05 g [light] and roll rale has started.
  Cap Com 7:57 1 Roger.
50 Bell 7 8:03.5 5 Got a pitch rate in here, OK, g's are starting to build.
  Cap Com 8:09 1.5 Roger, reading you loud and clear.
51 Bell 7 8:11 5 Roger, g's are building, we're up to 6 [g].
52 Bell 7 8:17 1.5 There's 9 [g].
53 Bell 7 8:19 11.5 There's about 10 [g]; the handle is out from under it; here I got a little pitch rate coming back down through 7 [g].
  Cap Com 8:32 2 Roger, still sound good.
54 Bell 7 8:34.5 3 Oh, the altimeter is active at 65 [thousand feet]. There's 60 [thousand feet].
  Cap Com 8:38.5 1.5 Roger, 65,000.
55 Bell 7 8:42 7.5 OK, I'm getting some contrails, evidently shock wave, 50,000 feet; I'm feeling good. I'm very good, everything is fine.
  Cap Com 8:49.5 2.5 Roger, 50,000.
56 Bell 7 8:52 1.5 45,000, do you still read?
  Cap Com 8:54 2.5 Affirmative. Still reading you. You sound good.
57 Bell 7 9:00.5 3 OK, 40,000 feet, do you read?
58 Bell 7 9:07 2 35,000 feet, if you read me.
59 Bell 7 9:19 7 30,000 feet, everything is good, everything is good.
  Cap Com 9:24 2.5 Bell 7, this is Cap Com. How...
  (1)     Cape, do you read?
60 Bell 7 9:28 2 25,000 feet.
61 Bell 7 9:36.5 2.5 Approaching drogue chute attitude.
62 Bell 7 9:41.5 4.5 There's the drogue chute. The periscope has extended.
  Cap Com 9:45 4 This is... we have a green drogue [light] here, 7 how do you read?
63 Bell 7 9:49.5 13.5 OK, we're coming down to 15,000 feel, if anyone reads. We're on emergency flow rate, can see out the periscope OK. The drogue chute is good.
  Cap Com     Roger, understand drogue is good, the periscope is out.
64 Bell 7 10:05.5 2 There's 13,000 feet.
  Cap Com     Roger.
65 Bell 7 10:14 25 There goes the main chute; it's reefed; main chute is good; main chute is good; rate of descent coming down, coming down to - there's 40 feet per second, 30 feet per, 32 feet per second on the main chute, and the landing bag is out green.
  (1)     Ah, it's better than it was, Chuck.
66 Bell 7 10:40.5 3 Hello, does anybody read Liberty Bell, main chute is good, landing bag [light] is on green.
  Cap Com     And the landing bag [light] is on green.
  ATS     Liberty Bell 7, Liberty Bell 7, this is Atlantic Ship Cap Com. Read you loud and clear. Our telemetry confirms your events. Over.
67 Bell 7     Ah, roger, is anyone reading Liberty Bell 7? Over.
  Card File 23     Roger, Liberty Bell 7, reading you loud and clear. This is Card File 23. Over.
68 Bell 7 10:52 4 Atlantic Ship Cap Com, this is Liberty Bell 7, how do you read me? Over.
  ATS     Read you loud and clear, loud and clear. Over. Liberty Bell 7, Liberty Bell 7, this is Atlantic Ship Cap Com. How do you read me? Over.
69 Bell 7 11:12 8 Atlantic Ship Cap Com, this is Liberty Bell 7, I read you loud and clear. How me? Over.
  ATS     Roger, Bell 7, read you loud and clear, your status looks good, your systems look good, we confirm your events. Over.
70 Bell 7 11:28 4 Ah, Roger, and confirm the fuel has dumped. Over.
  ATS     Roger, confirm again, confirm again, has your auto fuel dumped? Over.
71 Bell 7 11:42.5 2.5 Auto fuel and manual fuel has dumped.
  ATS     Roger, roger.
72 Bell 7 11:47.5 3 And I'm in the process of putting the pins back in the door at this time.
73 Bell 7 12:04 5 OK, I'm passing down through 6,000 feet, everything is good, ah.
74 Bell 7 12:15 1.5 I'm going to open my face plate.
75 Bell 7 12:35 16 Hello, I can't get one; I can't get one door pin back in. I've tried and tried and I can't get it back in. And I'm coming, ATS, I'm passing through 5,000 feet and I don't think I have one of the door pins in.
  ATS     Roger, Bell 7, Roger.
76 Bell 7 13:04 2 Do you have any word from the recovery troops?
  Card File 23     Liberty Bell 7, this is Card File 23; we are heading directly toward you.
77 Bell 7 13:18 4 ATS, this is Cap - this is Liberty Bell 7. Do you have any word from the recovery troops?
  ATS     Negative, Bell 7, negative. Do you have any transmission to MCC [Mercury Control Center]? Over.
78 Bell 7 13:33 13 Ah, Roger, you might make a note that there is one small hole in my chute. It looks like it's about 6 inches by 6 inches - it's a sort of a - actually it's a triangular rip, I guess.
  ATS     Ah, roger, roger.
79 Bell 7 13:49 45 I'm passing through 3,000 feet, and all the fuses are in flight conditions; ASCS is normal, auto; we're on rate command; gyros are normal; auto retrojettison is armed; squibs are armed also. Four fuel handles are in; decompress and recompress are in; retro delay is normal; retroheat is off, cabin lights are both. TM [telemeter] is on. Rescue aids is auto; landing bag is auto; retract scope is auto; retroattitude is auto. All the three, five pull rings are in. Going down through some clouds to 2,000 feet. ATS, I'm at 2,000 feet; everything is normal.
  ATS     Roger, Bell 7, what is your rate of descent again? Over.
80 Bell 7 14:39 5 The rate of descent is varying between 28 and 30 feet per second.
  ATS     Ah, roger, roger, and once again verify your fuel has dumped. Over.
  (1)     Seven ahead at bearing 020. Over.
81 Bell 7 14:54 33 OK. My max g was about 10.2; altimeter is 1,000 [feet]; cabin pressure is coming toward 15 [psi].
  (1)     We'll make up.
  Bell 7     Temperature is 90 [oF].
  (1)     We'll make up an eye rep.
  Bell 7     Coolant quantity is 30 [percent]; temperature is 68 [oF]; pressure is 14 [psi]; main O2 is 60 [percent]; normal is, main is 60 [percent]; emergency is 100 [percent]; suit fan is normal; cabin fan is normal. We have 21 amps, and I'm getting ready for impact here.
  Bell 7     Can see the water coming right on up.
  ATS     Liberty Bell 7, Liberty Bell 7, this is Atlantic Cap Com, do you read me? Over.
82 Bell 7   3 OK, does anyone read Liberty Bell 7? Over.
  Hunt Club 1     Liberty Bell 7, Hunt Club 1 is now 2 miles southwest you.
  Card File 9     Liberty Bell 7 this 9 Card File. We have your entry into the water. Will be over you in just about 30 seconds.
83 Bell 7 16:35 2 Roger, my condition is good; OK the capsule is floating, slowly coming vertical, have actuated the rescue aids. The reserve chute has jettisoned, in fact I can see it in the water, and the whip antenna should be up.
  (1)     Hunt Club, did you copy?
  (1)     OK, Hunt Club, this is... Don't forget the antenna.
  Hunt Club 1     This is Hunt Club, say again.
84 Bell 7 18:07 4 Hunt Club, this is Liberty Bell 7. My antenna should be up.
  Hunt Club 1     This is Hunt Club 1... your antenna is erected.
85 Bell 7 18:16 1 Ah, roger.
  Bell 7 18:23 3 OK, give me how much longer it'll be before you get here.
  Hunt Club 1     This is Hunt Club 1, we are in orbit now at this time, around the capsule.
86 Bell 7 18:32.5 8.5 Roger, give me about another 5 minutes here, to mark these switch positions here, before I give you a call to come in and hook on. Are you ready to come in and hook on anytime?
  Hunt Club 1     Hunt Club 1, roger we are ready anytime you are.
87 Bell 7 18:44 5 OK, give me about another 3 or 4 minutes here to take these switch positions, then I'll be ready for you.
  Hunt Club 1     1, wilco.
  Card File 9     Hey Hunt Clubs, Card File, Card File 9, I'll stand by to escort you bark as soon as you lift out. I keep other aircraft at at least 2,000 feet.
  Hunt Club 1     Ah, Bell 7 this is Hunt Club 1.
88 Bell 7 20:15 1.5 Go, go ahead Hunt Club 1.
  Hunt Club 1     Roger, this is 1, observe something, possibly the canister in the water along side capsule. Will we be interfering with any TM [telemetry] if we come down and take a look at it?
89 Bell 7 20:26 7.5 Negative, not at all, I'm just going to put the rest of this stuff on tape and then I'll be ready for you, in just about 2 more minutes, I would say.
  Hunt Club 1     1 Roger.
  Cap Com     Liberty Bell 7, Cap Com at the Cape on a test count. Over.
  Cap Com     Liberty Bell 7, Cape Cap Com on a test count. Over.
  Card File 9     Any Hunt Club, this is 9 Card File.
  Hunt Club 1     Station calling Hunt Club, say again.
  Card File 9 24:03 22 This is Niner Cardfile, there's an object on a line in the water, ah, just about 160 degrees. The NASA people suspect it's the dye marker that didn't activate, ah, say it's about, ah, 3/4 of a mile out from the capsule. Ah, after the lift out, will you take a check on it? Over.
  Hunt Club 1     All, this is Hunt Club 1, Roger, will have Hunt Club 3 check at this time, you copy 3.
  Hunt Club 3     Hunt Club 1, believe he said 3/4 of a mile?
  Card File 9     This is 9 Card, that is affirmative.
90 Bell 7 25:19.5 5.5 OK, Hunt Club. This is Liberty Bell 7. Are you ready for the pickup?
  Hunt Club 1     This is Hunt Club 1; this is affirmative.
91 Bell 7 25:30 5 OK, latch on, then give me a call and I'll power down and blow the hatch, OK?
  Hunt Club 1     This is Hunt Club 1, roger, will give you a call when we're ready for you to blow.
92 Bell 7 25:42 3 Roger, I've unplugged my suit so I'm kinda warm now so.
  Hunt Club 1     1, Roger.
93 Bell 7 25:52.5 5 Now - if you tell me to, ah, you're ready for me to blow, I'll have to take my helmet off, power down, and then blow the hatch.
  Hunt Club 1     1, Roger, and when you blow the hatch, the collar will already be down there waiting for you, and we're turning back at this time.
94 Bell 7 26:09 1 Ah, Roger.

1 Communicator unidentified.

No further communications were received as a result of the emergency egress required by the failure of the side hatch.


  1. Slayton, Donald K.: Pilot Training and Preflight Preparation. Proc. Conf. on Results of the First U.S. Manned Suborbital Space Flight, NASA, Nat. Inst. Health, and Nat. Acad. Sci., June 6, 1961, pp. 53-60.

Previous Index Next