Mercury Atlas 6 Mission Log (John Glenn becomes the first American in Orbit)

The Missions

Mercury R-3

Mercury R-4

Mercury A-6

The Collection

"Zero-G and I feel fine."

The Honorable Senator John Glenn autographed this astronaut portrait for me. Photo Credit: NASA

Astronaut John Glenn In Mercury Space Suit

With Grissom's flight on MR-4, the United States had launched two men into space, but they had not yet orbited even one. The Redstone rocket did not have the capacity to put a Mercury spacecraft into orbit.

The R-7 Soviet launch vehicle was much more powerful than the Redstone. On August 6, 1961, Soviet Cosmonaut Gherman Titov became the second person to orbit the Earth. America was still far behind in the race.

The Atlas ballistic missile was chosen as the launch vehicle to put a Mercury spacecraft into orbit. The Atlas was much more powerful and advanced than the Redstone, but it was also notoriously unreliable.

John H. Glenn, Jr. was selected as the man to pilot the first Mercury orbital mission. The mission was designated Mercury Atlas 6. Glenn named his Mercury spacecraft Friendship 7.

On February 20, 1962 an anxious nation watched as Glenn lifted off using the dangerous Atlas rocket. The Capsule Communicator counted down the launch sequence and radioed that to Glenn, "3, 2, 1, 0." After ignition, Glenn reported, "Roger. The clock is operating. We're underway." A short while later Glenn described the ride, "Little bumpy along here."

As the vehicle approached the phase of launch where the maximum aerodynamic pressure was exerted upon the vehicle (max Q) Glenn reported, "Have some vibration coming up here now." CapCom acknowledged, "Roger. Reading you loud and clear." Glenn added, "Roger. Coming into high Q a little bit; and a little contrail went by the window or something there."

At 1 minute and 12 seconds into the flight, Glenn reported, "We're smoothing out now, getting out of the vibration area." CapCom informed Glenn, "Roger. You're through max Q. You're flight path is ..." Glenn acknowledged, "Roger. Feels good through max Q and smoothing out real fine."

At 1 minute and 56 seconds Glenn reported, "Roger. Have had some oscillations, but they seem to be damping out now. Coming up on two minutes and the fuel is 102-101 [percent], oxygen 78-102 [percent]. The g's are building up to 6."

It was now time for staging and booster engine cutoff (BECO). At 2 minutes and 12 seconds, Glenn reported, "Roger. BECO back to 1 and 1/4 g's. The tower fired; could not see the tower go, I saw smoke go by the window." Actually the tower had not yet fired at that point and Glenn would see it fire shortly.

CapCom reported, "Roger. We confirm staging on TM [the mark]." At 2 minutes and 36 seconds, Glenn reported, "The tower went right then. Have the tower in sight way out. Could see the tower go. Jettison tower is green."

At 4 minutes and 25 seconds into the flight Glenn reported his flight status, "Roger. Cape is GO and I am GO. Capsule is in good shape. Fuel 103-102 [percent], oxygen 78-100 [percent], cabin pressure holding steady at 5.8 [psi], amps is 26. All systems are GO."

The time approached for sustainer engine cutoff (SECO). At 4 minutes and 44 seconds, CapCom informed Glenn, "Roger. 20 seconds to SECO." Glenn acknowledged, "Roger. Indicating 6 g's." At 5 minutes and 4 seconds, Glenn reported, "SECO, posigrades fired Okay."

The Atlas performed nominally and Friendship 7 was inserted into orbit. The capsule separated from the spent booster. Astronaut Glenn radioed, "Roger. Zero-G and I feel fine. The capsule is turning around." The first American was in orbit! Glenn then added, "Oh, the view is tremendous."

Everyone was relieved when the dangerous boost phase with the Atlas launcher was over. CapCom radioed Glenn, "Roger Seven. You have a GO, at least 7 orbits." Glenn acknowledged, "Roger. Understand GO for at least 7 orbits."

During the first orbit Astronaut Glenn took several blood pressure readings and made some medical observations about himself. At 55 minutes and 49 seconds into the flight Glenn reported, "This is Friendship Seven. I have had no ill effects at all as yet from any zero-g. It's very pleasant in fact. Visual acuity is excellent. No astigmatic effects. Head movements caused no nausea or discomfort what so ever."

Since Glenn was the first American to experience weightlessness for an extended duration there were many medical and physiological questions to be answered.

At 1 hour and 12 minutes Glenn would become the first American to attempt eat food in zero-g. Glenn informed the ground, "This is Friendship Seven. Opening visor, going to eat. Over." CapCom acknowledged, "Roger, Friendship Seven." Glenn continued, "This is Friendship Seven. Have no trouble at all eating, very good. In the periscope, I can see the brilliant blue horizon coming up after me; approaching sun rise. Over."

CapCom responded, "Roger, Friendship Seven. You are very lucky." Glenn finished off his tube of food and reported, "This is Friendship Seven. Have eaten one tube of food, shutting the visor. I've had no problem at all eating. Oh the sun is coming up behind me in the periscope, a brilliant brilliant red. Over."

Glenn then made an unexpected observation outside of his spacecraft. He reported, "This is Friendship Seven. I'll try to describe what I'm in here. I am in a big mass of some very small particles, that are brilliantly lit up like they're luminescent. I never saw anything like it. They round a little; they're coming by the capsule and they look like tiny stars. A whole shower of them coming by. They swirl around the capsule and go in front of the window and they're all brilliantly lighted. They probably average maybe 7 or 8 feet apart, but I can see them all down below me also."

CapCom listened to Glenn's report and responded, "Roger, Friendship Seven. Can you hear any impact with the capsule? Over." Glenn answered, "Negative, negative. They're very slow; they're not going away from me more than maybe 3 or 4 miles per hour. They are going at the same speed I am approximately. They're only very slightly under my speed. Over. They do, they do have a different motion, though, from me because they swirl around the capsule and then depart back the way I am looking."

The discussion about the particles continued on for some time. CapCom instructed Glenn, "Cape asks you to correlate the actions of the particles surrounding the vehicle with the reaction of one of your control jets. Do you understand? Over." Glenn replied, "This is Friendship Seven. I do not think they were from my control jets, negative. Over."

An apparent problem began showing up in the telemetry from the spacecraft during the second orbit. At 2 hours, 19 minutes, and 12 seconds into the flight, CapCom instructed Glenn, "We have a message from MCC to keep your landing bag switch in the off position. Over." Glenn acknowledged the call, "Roger. This is Friendship Seven." The landing bag was a cushion that was supposed to be deployed after the heatshield separated from the spacecraft just before splashdown to soften the impact with the water.

At 2 hours, 26 minutes, and 40 seconds CapCom again asked Glenn about his landing bag switch, "Will you confirm the landing bag switch is in the off position? Over." Glenn answered, "That is affirmative. The landing bag switch is in the off position." CapCom then asked Glenn, "You haven't heard any banging noises or anything of this type during the higher rates?" Glenn responded, "Negative." CapCom replied, "They wanted this answer."

Ground control had not informed Astronaut Glenn yet, but they had an indication that his heatshield had come loose and the landing bag deployed. The heat shield was essential for the spacecraft and the astronaut to be able to survive reentry. If it had come loose the results during reentry would be catastrophic.

At 2 hours, 47 minutes, and 14 seconds, CapCom radioed to Glenn, "Friendship Seven, this is Canton. We also have no indication that your landing bag might be deployed. Over." A concerned Glenn asked, "Roger. Did someone report that the landing bag could be down? Over." CapCom answered, "Negative, we had a request to monitor this and to ask you if you heard any flapping when you had high capsule rates..." Glenn replied, "Negative."

During Glenn's 3rd orbit of the Earth, at 4 hours, 22 minutes, and 38 seconds into the flight, CapCom relayed a message to Glenn about the landing bag. CapCom informed Glenn, "Friendship Seven, we have been reading an indication on the ground of segment 51, which is Landing Bag Deploy. We suspect this is an erroneous signal. However, Cape would like you to check this by putting the landing bag switch in auto position, and see if you get a light. Do you concur with this? Over." Glenn replied, "Okay. If that's what they recommend, we'll go ahead and try it. Are you ready for it now?" CapCom gave Glenn the go ahead, "Yes, when you're ready."

Glenn flipped the switch and reported, "Roger. Negative in automatic position, did not get a light and I'm back in the off position now. Over." CapCom acknowledged Glenn's observation, "Roger, that's fine. In this case we'll go ahead, and the reentry sequence will be normal."

Engineers, on the ground, studied the problem as Astronaut Glenn's orbited the Earth. It was decided after much consultation that the retrorocket pack strapped onto the back of the Mercury spacecraft would not be jettisoned after the deorbit burn. It was hoped that these straps might retain the heat shield just long enough for Glenn to survive reentry.

Shortly before the retro fire sequence was to begin, CapCom Wally Schirra, who was stationed in California, informed Glenn, "John, leave your retropack on through your pass over Texas. Do you read?" Glenn acknowledged, "Roger."

At 4 hours, 32 minutes, and 32 seconds, CapCom Schirra counted down the time until Glenn's retrorocket ignition. Schirra radioed Glenn, "5, 4, 3, 2, 1, fire." Glenn activated the retrorocket sequence and reported, "Roger, retros are firing." CapCom Schirra answered, "Sure they be." The noticeable deceleration caused Glenn to remark, "Are they ever. It feels like I'm going back toward Hawaii."

After the retro fire sequence completed, CapCom Schirra again instructed Glenn, "Keep your retro pack on until you pass Texas." Glenn acknowledged, "That's affirmative." Glenn asked Schirra, "Do you have a time for jettison retro? Over." Schirra answered, "Texas will give you that message. Over."

At 4 hours, 38 minutes, and 23 seconds, Glenn was in communication range with Texas and the CapCom stationed in Texas instructed Glenn, "This is Texas CapCom, Friendship Seven. We are recommending that you leave the retropackage on through the entire reentry. This means that you will have to override the 0.5 g switch which is expected to occur at 04 43 53. Also this means that you will have to manually retract the scope. Do you read?"

The change in plan without an explanation worried Glenn. Glenn responded, "This is Friendship Seven. What is the reason for this? Do you have any reason? Over." CapCom answered Glenn, "Not at this time; this is the judgment of Cape Flight." A short while later the Texas CapCom told Glenn, "Friendship Seven, Cape Flight will give you the reasons for this action when you are in view."

At 4 hours, 40 minutes, and 34 seconds, Glenn was in communications range with the CapCom stationed at the Cape. That CapCom was America's first man in space Alan Shepard. CapCom Shepard informed Glenn, "While you're doing that, we are not sure whether or not your Landing Bag has deployed. We feel that it is possible to reenter with your retropackage on. We see no difficulty at this time with that type of reentry. Over." Glenn now had the answer for the change in plans but it did little to reassure him.

The g forces began to build up and the capsule was subject to significant heating due to the friction from reentry. Radio contact with the astronaut is normally lost during reentry. This loss of communication occurs because a sheath of ionized atoms envelopes the spacecraft during reentry. There was no way to know during the inferno whether the first American to orbit the Earth had survived or perished.

At 4 hours, 43 minutes, and 14 seconds Glenn called, "This is Friendship Seven. I think the pack just let go." He then followed that call with, "This is Friendship Seven. A real fireball outside."

A relieved mission control re-established radio contact with Astronaut Glenn after the ionization cloud dissipated. The heat shield was not loose and had not failed! A malfunctioning sensor had caused the false indication.

Glenn attempted repeated calls to the Cape, "Hello Cape. Friendship Seven. Do you receive? Over." Finally the CapCom responded, "How do you read? Over." Glenn answered, "Loud and clear; how me? Over." CapCom answered, "Roger, reading you loud and clear. How are you doing?" Glenn calmly responded, "Oh, pretty good."

Glenn then reported, "Okay, we're through the peak g now." CapCom asked Glenn, "Seven, this is Cape. What's your general condition? Are you feeling pretty well?" Glenn's answer was, "My condition is good, but that was a real fireball boy! I had great chunks of retropack breaking off all the way through."

A short while after the drogue parachute had deployed, the main recovery parachute followed. At 4 hours, 50 minutes and 10 seconds, Glenn reported, "Main chute is on green. Chute is out in reef condition at 10,800 feet and beautiful chute. Chute looks good. On O₂ emergency and the chute looks very good. Rate of descent has gone to about 42 feet per second. The chute looks very good."

Friendship 7 safely splashed down in the Atlantic Ocean 4 hours, 55 minutes, and 23 seconds after it was launched. The primary recovery ship was the USS Noa.