Flight: Mercury-Redstone 4
Name: LIBERTY BELL 7
Launch: July 21, 1961
Pilot: Virgil I. Grissom
Back-up: John H. Glenn
Duration: 15 minutes, 37 seconds
Remarks: Also suborbital; successful flight but the spacecraft sank shortly after splashdown.
Here is the complete transcript of Gus Grissoms flight:
00:01 Stony: Liftoff.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "As the blockhouse capsule communicator (astronaut Donald K. ‘Deke’ Slayton) called ignition, I felt the launch vehicle start to vibrate and could hear the engines start. Just seconds after this, the elapsed time clock started and the Mercury Control Center capcom (astronaut Alan B. Shepard) confirmed liftoff. At that time, I punched the Time Zero Override, started the stopwatch function on the spacecraft clock, and reported that the elapsed time clock had started."]
00:03 Grissom: Ah, roger. This is Liberty Bell 7. The clock is operating.
00:08 Capcom: Loud and clear, Jose, don’t cry too much.
[Pfannerstill: This is another Al Shepard reference to Bill Dana’s "Jose Jimenez" record. On the recording, the interviewer/straight man asks Astronaut Jose how he plans to pass the time during all of the long, lonely, solitary hours he will spend in space. Jose deadpans, "Well, I plan to cry a lot."]
00:11 Grissom: Oke-doke.
00:18 Grissom: Okay, it’s a nice ride up to now.
00:20 Capcom: Loud and clear.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "Communications throughout the powered flight were satisfactory. The VOX (voice-operated relay) was used for pilot transmissions instead of the push-to-talk button. The noise level was never high enough at any time to key the transmitter. Each standard report was made on-time and there was never any requirement for myself or the capcom to repeat any transmissions."]
00:21 Grissom: Roger.
00:28 Grissom: Okay. The fuel is go; about 1 and a half g’s; cabin pressure is just coming off the peg; the O2 is go; we have 26 amps.
00:36 Capcom: Roger. Pitch 88 (degrees), the trajectory is good.
00:39 Grissom: Roger, looks good here.
00:54 Grissom: Okay there, we’re starting to pick up a little bit of noise and vibration; not bad, though, at all. Fifty seconds, more vibration.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The powered flight portion of the mission was in general very smooth. A low-order vibration started at approximately T-plus 50 seconds, but it did not develop above a low level and was undetectable after about T-plus 70 seconds. The vibration was in no way disturbing and it did not cause interference in either communication or vision. The magnitude of the accelerations corresponds well to the launch simulations in the centrifuge, but the onset was much smoother."]
[Grissom, from "We Seven," Simon and Schuster, Inc., 1962: "There was nothing violent about (the vibration). It was nice and easy, just as Al (Shepard) had predicted. I looked for a little buffeting as I climbed to 36,000 (feet) and moved through Mach 1, the speed of sound. Al (Shepard, during his MR-3 flight on May 5, 1961) had experienced some difficulty here; his vehicle shook quite a lot and his vision was slightly blurred by the vibrations. But we had made some good fixes. We had improved the aerodynamic fairings between the capsule and the Redstone, and had put some extra padding around my head. I had no trouble at all, and I could see the instruments very clearly."]
01:01 Grissom: Okay, the fuel is go; 1 and a half g’s; cabin is 8 (psi); the O2 is go; 27 amps.
01:08 Grissom: And... (rest of transmission not received).
01:09 Capcom: Pitch is... (rest of transmission not received).
01:10 Grissom: Four (g’s), five (g’s)... (rest of transmission not received).
01:11 Capcom: Pitch is 77 (degrees); trajectory is go.
01:13 Grissom: Roger. Cabin pressure is still about 6 (psi) and dropping slightly. Looks like she’s going to hold about 5.5 (psi).
01:23 Grissom: Eh... (rest of transmission not received).
01:24 Capcom: Cabin... (rest of transmission not received).
01:24 Grissom: Believe me, O2 is go.
01:26 Capcom: Cabin pressure holding 5.5 (psi).
01:29 Grissom: Roger, roger.
01:31 Grissom: This is Liberty Bell 7. Fuel is go; 2 and a half g’s; cabin pressure 5.5 (psi); O2 is go; main (bus) 25 (volts), isolated -- ah, isolated (bus) is 28 (volts). We are go.
01:46 Capcom: Roger. Pitch is 62 (degrees); trajectory is go.
01:49 Grissom: Roger. It looks good in here.
01:56 Grissom: Everything is good; cabin pressure is holding; suit pressure is okay; two 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.
02:15 Capcom: Roger, we have go here.
02:16 Grissom: And I see a star!
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "Vision out the window was good at all times during launch. As viewed from the pad, the sky was its normal light blue; but as the altitude increased, the sky became a darker and darker blue until approximately 2 minutes after liftoff, which corresponds to an altitude of approximately 100,000 feet, the sky rapidly changed to an absolute black. At this time, I saw what appeared to be one rather faint star in the center of the window. It was about equal in brightness to Polaris. Later it was determined that this was the planet Venus whose brightness is equal to a star of magnitude of -3."]
02:17 Capcom: Stand by for cutoff.
[Pfannerstill: Cutoff of the Redstone booster engine and jettison of the escape tower occurred simultaneously at T-plus 2:23.]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "Launch vehicle engine cutoff was sudden and I could not sense any tail-off of the launch vehicle. I did feel...a very brief tumbling sensation."]
02:23 Grissom: There went the tower.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The firing of the escape tower clamp ring and escape rocket is quite audible and I could see the escape rocket motor and tower thoughout its tail-off burning phase and for what seemed like quite some time after that climbing off to my right. Actually, I think I was still watching the tower at the time the posigrade rockets fired, which occurred 10 seconds after cutoff. The tower was still definable as a long, slender object against the black sky at this time."]
02:24 Chase-1: Roger, there went the tower, affirmative Chase.
02:26 Grissom: Roger, squibs are off.
02:31 Capcom: Roger.
02:33 Grissom: There went the posigrades, capsule has separated. We are at zero-g and turning around and the sun is really bright.
[Capsule separation from the Redstone occurred at T-plus 2:33.]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The posigrade firing is a very audible bang and a definite kick, producing (an acceleration) of approximately 1g. Prior to this time, the spacecraft was quite stable with no apparent motion. As the posigrade rockets separated the spacecraft from the launch vehicle, the spacecraft angular motions and angular accelerations were quite apparent. Spacecraft damping which was to begin immediately after separation was apparently satisfactory, although I cannot really report on the magnitude of any angular rates caused by posigrade firing."]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "As the turnaround started, I could see a bright shaft of light, similar to the sun shining into a blackened room, start to move from my lower left up across my torso. Even though I knew the window reduces light transmissions equivalent to the earth’s atmosphere, I was concerned that it might shine directly into my eyes and blind me. The light moved across my torso and disappeared completely."]
02:42 Capcom: Roger cap. sep. (capsule separation light) is green; turnaround has started, manual handle out.
02:47 Grissom: 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.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The spacecraft turnaround to retrofire attitude is quite a weird maneuver to ride through. At first, I thought the spacecraft might be tumbling out of control. A quick check of the instruments indicated that turnaround was proceeding much as those experienced on the procedures trainer, with the exception of roll attitude which appeared to be very slow and behind the schedule that I was expecting.]
03:01 Capcom: Roger.
03:02 Grissom: I haven’t seen the booster anyplace. Okay, rate command is coming on. I’m in orbit attitude, I’m pitching up. Okay, forty... (rest of transmission not received)... Wait, I’ve lost some roll here someplace.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The spacecraft Automatic Stabilization and Control System (ASCS) had made the turnaround maneuver from the position on the launch vehicle to retrofire attitude. The pitch and yaw axes stabilized with only a moderate amount of overshoot as predicted, but the roll attitude was still being programmed and was off by approximately 15 degrees when I switched from the autopilot to the manual proportional control system. The switchover occurred 10 seconds later than planned to give the ASCS more time to stabilize the spacecraft."]
03:10 Capcom: Roger, rate is command coming on. You’re trying manual pitch.
03:15 Grissom: Okay, I got roll back. Okay, I’m at 24 (degrees) in pitch.
03:20 Capcom: Roger, your IP (impact point) is right on, Gus, right on.
03:24 Grissom: Okay. I’m having a little trouble with rate, ah, with the manual control.
03:28 Capcom: Roger.
03:31 Grissom: If I can get her stabilized here, all axes are working all right.
03:36 Capcom: Roger. Understand manual control is good.
03:40 Grissom: Roger, it’s -- it’s sort of sluggish, more than I expected.
03:45 Grissom: Okay, I’m yawing.
03:47 Capcom: Roger, yaw.
03:50 Grissom: Left, ah.
03:51 Grissom: Okay, coming back in yaw. I’m a little bit late there.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "I realized I would have to hurry my programmed pitch, yaw and roll maneuvers. I tried to hurry the pitch-up maneuver; I controlled the roll attitude back within limits, but the view out the window distracted me, resulting in an overshoot in pitch. This put me behind in my schedule even more. I hit the planned yaw rate but overshot in yaw attitude again."]
03:57 Capcom: Roger. Reading you loud and clear, Gus.
03:59 Grissom: Lot of stuff -- there’s a lot of stuff floating around up here.
04:02 Grissom: Okay, 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 yet.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "I realized that my time for control maneuvers was up and I decided at this point to skip the planned roll maneuver, since the roll axis had been exercised during the two previous maneuvers, and go immediately to the next task."]
04:15 Capcom: Roger, you’re on the window. Are you trying a yaw maneuver?
04:18 Grissom: 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.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "This was the part of the flight to which I had been looking forward. There was a full minute that was programmed for observing the earth. The view through the window became quite spectacular as the horizon came into view. The sight was truly breathtaking. The earth was very bright, the sky was black, and the curvature of the earth was quite prominent. Between the earth and the sky, there was a border which started at the earth as a light blue and became increasingly darker with altitude. There was a transition region between the dark blue and the black sky that is best described as a fuzzy gray area. This is a very narrow band, but there is no sharp transition from blue to black. The whole border appeared to be uniform in height over the approximately 1,000 miles of horizon that was visible to me."]
04:25 Capcom: I understand.
04:29 Grissom: You sh, ah, really. There I see the coast, I see.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The earth itself was very bright. The only landmark I was able to identify during the first portion of the weightlessness period was the Gulf of Mexico coastline between Apalachicola, Florida and Mobile, Alabama. The cloud coverage was quite extensive and the curvature of this portion of the coast was very difficult to distinguish. The water and land masses were both a hazy blue, with the land being somewhat darker. There was a frontal system south of this area that was clearly defined."]
04:30 Capcom: Four plus thirty (elapsed time since launch), Gus.
04:37 Grissom: I can see the coast, but I can’t identify anything.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "One other section of the Florida coast came into view during the left yaw maneuver, but it was a small section of beach with no identifiable landmarks."]
04:42 Capcom: Roger, four plus thirty (elapsed time since launch), Gus.
04:44 Grissom: Okay, let me get back here to retro attitude, retro sequence has started.
[Pfannerstill: The retro sequence was initiated by a timer at T-plus 4:46.]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The retro sequence started automatically and at the time it started, I was slightly behind schedule. At this point, I was working quite hard to get into a good retrofire attitude so that I could fire the retrorockets manually."]
04:48 Capcom: Roger, retro sequence has started. Go to retro attitude.
04:52 Grissom: Right, we’ll see if I’m in bad, not in very good shape here.
04:57 Capcom: Got 15 seconds, plenty of time, I’ll give you a mark at 5:10 (elapsed time since launch).
05:01 Grissom: Okay, retro attitude (light) is still green.
05:05 Capcom: Retros on my mark, 3, 2, 1, mark.
05:11 Grissom: Okay, there’s one firing, there’s one firing.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "I received the countdown to fire from Mercury Control Center Cap Com and fired the retrorockets manually. The retrorockets, like the escape rocket and posigrades, could be heard quite clearly. The thrust buildup was rapid and smooth. As the first retrorocket fired, I was looking out the window and could see a definite yaw to the right was starting. I had planned to control the spacecraft attitude during retrofire by using the horizon as a reference; but as soon as the right yaw started, I switched my reference to the flight instruments. I had been using instruments during my retrofire practice for the two weeks prior to the launch in the Cape Canaveral procedures trainer since the activity at the Cape prevented the use of the ALFA trainer located at Langley. This probably explains the instinctive switch to the flight instruments. The retrofire difficulty was about equal to the more severe cases that have been presented on the procedures trainer."]
05:13 Capcom: Roger, retro 1.
[Pfannerstill: The spacecraft reached it’s apogee, or it's maximum altitude of 102.8 nautical miles above the earth, at T-plus 5:16.]
05:19 Grissom: There’s two firing, nice little boost. There went three.
05:21 Capcom: Roger, three, all retros are fired.
05:23 Grissom: Roger, roger.
05:25 Grissom: Okay, yeah, they’re fired out right there.
05:29 Capcom: Roger, retro jettison armed.
05:33 Grissom: Retro jettison is armed, retro jettison is armed, going to rate command.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The control mode was switched from manual proportional to rate command immediately after retrofire. The procedures trainer simulation in this system seems to be slightly more difficult than the actual case. I found attitudes were easy to maintain and rates were no problem. The rate command system was much easier to fly than the manual proportional system. The reverse is normally true on the trainer. The sluggish roll system was probably complicating the control task during the manual proportional control phase of the flight, while roll accelerations appeared to be normal on the rate command system."]
05:36 Grissom: Okay, I’m going to switch.
05:38 Capcom: Roger. Understand manual fuel handle is in.
05:41 Grissom: Manual fuel handle is in, mark, going to HF.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "This one attempt to communicate on HF (high frequency) was unsuccessful. At approximately peak altitude, the HF transmitter was turned on and the UHF (ultra-high frequency) transmitter was turned off. All three receivers -- UHF, HF and emergency voice -- were on continuously. Immediately after I reported switching to HF, the Mercury Control Center started transmitting to me on HF only. I did not receive any transmission during this period."]
05:44 Capcom: Roger, HF.
05:52 Capcom: Liberty Bell 7, this is capcom on HF, 1, 2, 3, 4, 5. How do you read, Seven?
06:00 Grissom: I got you.
06:05 Capcom: This is capcom on HF, 1, 2, 3, 4, 5. How do you read, Seven?
[Pfannerstill: The retro rocket package was jettisoned at T-plus 6:07.]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "After allowing the HF transmitter approximately 10 seconds to warm up, I transmitted but received no acknowledgement that I was being received. Actually the Atlantic Ship telemetry vessel located in the landing area and the Grand Bahama Island did receive my HF transmissions. Prior to the flight, both stations had been instructed not to transmit on the assigned frequencies unless they were called by the pilot."]
06:08 Grissom: ...here, do you read me, do you read me on HF? ... Going back to U (UHF)... Boy, is that... Retro, I’m back on UHF and, ah, the jett -- the retros have jettisoned. Now I can see the Cape and, oh boy, that’s some sight. I can’t see too much.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "Immediately after retrofire, Cape Canaveral came into view. It was quite easy to identify. The Banana and Indian Rivers were easy to distinguish and the white beach all along the coast was quite prominent. The colors that were the most prominent were the blue of the ocean, the brownish-green of the interior, and the white in between, which was obviously the beach and surf. I could see the building area on Cape Canaveral. I do not recall being able to distinguish individual buildings, but it was obvious that it was an area where buildings and structures had been erected."]
06:34 Grissom: Roger, I am on UHF high, do you read me?
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "After switching back to the UHF transmitter, I received a call on the emergency voice that was loud and clear. UHF communications were satisfactory throughout the flight. I was in continuous contact with some facility at all times, with the exception of a brief period on HF."]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "Even though all communications equipment operated properly, I felt that I was hurrying all transmissions too much. All of the sights, sounds and events were of such importance that I felt compelled to talk of everything at once. It was a difficult choice to decide what was the most important to report at any one time. I wanted as much as possible recorded so that I would not have to rely on my memory so much for later reporting."]
06:38 Capcom: Roger, reading you loud and clear UHF high, can you confirm retro jettison?
06:41 Grissom: Okay, periscope is retracting, going to reentry attitude.
06:47 Capcom: Roger, retros have jettisoned, scope has retracted, you’re going to reentry attitude.
06:51 Grissom: Affirmative.
06:56 Capcom: Bell 7 from capcom, your IP (impact point) is right on.
07:00 Grissom: Roger, I’m in reentry attitude.
07:05 Grissom: Ah.
07:07 Capcom: Roger, how does it look out the window now?
07:09 Grissom: Ah, the sun is coming in and so all I can see really is just, ah, just darkness, the sky is very black.
07:14 Capcom: Roger, you have some more time to look if you like.
07:27 Capcom: Seven from capcom, how do you feel up there?
07:30 Grissom: I feel very good, auto fuel is 90 (per cent), manual is 50 (per cent).
07:33 Capcom: Roger, 0.05g in ten (seconds).
07:37 Grissom: Okay.
07:50 Grissom: Okay, everything is very good, ah.
07:54 Grissom: I got 0.05g (light) and roll rate has started.
[Pfannerstill: The "0.05g light" is an indicator light on the left side of the spacecraft instrument panel which lights up when the accelerometer detects 5/100 of a "g". The illumination of the 0.05g light signifies that weightlessness is ending and entry of the spacecraft into the atmosphere has begun."]
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The 0.05g telelight illuminated on schedule and shortly thereafter I reported g’s starting to build. I checked the accelerometer and the g-level was something less than 1g at this time. The next time I reported (at T-plus 08:11), I was at 6g and I continued to report and function throughout the high-g portion of the flight."]
07:57 Capcom: Roger.
08:03 Grissom: Got a pitch rate in here, okay, g’s are starting to build.
08:09 Capcom: Reading you loud and clear.
08:11 Grissom: Roger, g’s are building, we’re up to six (g’s).
08:17 Grissom: There’s nine (g’s).
08:19 Grissom: There’s about ten (g’s); the handle is out from under it; here I got a little pitch rate coming back down through seven (g’s).
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The spacecraft rates increased during the reentry, indicating that the spacecraft was oscillating in both yaw and pitch. I made a few control inputs at this time, but I could not see any effects on the rates, so I decided just to ride out the oscillations. The pitch rate needle was oscillating full scale at a rapid rate of about 6 degrees per second during this time and the yaw rate began oscillating full scale slightly later than pitch. At no time were these oscillations noticeable inside the spacecraft."]
08:32 Capcom: Roger, still sound good.
08:34 Grissom: Okay, the altimeter is active at 65 (thousand feet). There’s 60 (thousand feet).
08:38 Capcom: Roger, 65,000 (feet).
08:42 Grissom: Okay, I’m getting some contrails, evidentally shock wave, 50,000 feet; I’m feeling good. I’m very good, everything is fine.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "During this phase of reentry and until main parachute deployment, there is a noticeable roar and a mild buffeting of the spacecraft. This is probably the noise of a blunt object moving rapidly through the atmosphere and the buffeting is not distracting nor does it interfere with pilot function."]
08:49 Capcom: Roger, 50,000 (feet).
08:52 Grissom: Forty-five thousand (feet), do you still read?
08:54 Capcom: Affirmative. Still reading you. You sound good.
09:00 Grissom: Okay, 45,000 feet, do you read?
09:07 Grissom: Thirty-five thousand feet, if you read me.
09:19 Grissom: Thirty thousand feet, everything is good, everything is good.
09:24 Capcom: Bell 7, this is capcom. How.... (rest of communcation not received).
09:28 Grissom: Twenty-five thousand feet.
09:36 Grissom: Approaching drogue chute altitude.
[Pfannerstill: Drogue chute deployment occurred at T-plus 9:41.]
09:41 Grissom: There’s the drogue chute. The periscope has extended.
[Grissom, from 1961 MR-4 Pilot’s Flight Report: "The drogue parachute deployment is quite visible from inside the spacecraft and the firing of (the) drogue parachute mortar is clearly audible. The opening shock of the drogue parachute is mild; there is a mild pulsation or breathing of the drogue parachute which can be felt inside the spacecraft."]
09:45 Capcom: This is... we have a green drogue (light) here, Seven, how do you read?
09:49 Grissom: Okay, we’re down to 15,000 feet, if anyone reads. We’re on emergency flow rate, can see out the periscope okay. The drogue chute is good.
10:03 Capcom: Roger, understand drogue is good, the periscope is out.
