When I spoke with Kano Capcom, over Nigeria, on that first pass, I was able to relay a lot of valuable orbital information as well as data on the control and capsule systems. I also checked out the radios and, as ordered by the flight surgeon, telemetered my blood pressure reading. While preparing to take the M.I.T. pictures of the “flattened sun” halfway through that pass, I saw I was getting behind in the flight plan and reported that I wouldn’t be able to complete the pictures on that pass. Just as I was making that report, I figured out the problem, managed to install the film, and was able to take the pictures after all.
Before I lost voice contact with Kano Capcom, I was able to get horizon pictures with the M.I.T. film. The first picture was at f8 and 1/125 taken to the south directly into the sun. The second picture was taken directly down my flight path, and the third was 15 degrees north of west at “capsule elapsed time” (elapsed time since launch) of 00 30 17.1 was very busy.
Tom Wolfe wrote in The Right Stuff that I was having “a picnic” during my flight and “had a grand time” with the capsule maneuvers and experiments. He kindly noted that my pulse rate before liftoff, during the launch and in orbit, was even lower than Glenn’s admirably calm readings. The second part, about my pulse rate, may be true, perhaps because nature wired me that way (and Wally, too, for that matter, if you look at his telemetered readouts). But Wally and I were also following in John’s historic steps, had been fully briefed, and knew pretty much what to expect. Knowledge and training create confidence.
MA-7 was no picnic. I had trained a long time, first as John’s backup, and then for my own surprise assignment to the follow-on flight. To the extent that training creates certain comfort levels with high-performance duties like spaceflight, then, yes, I was prepared for, and at times may even have enjoyed, some of my duties aboard Aurora 7. But I was deadly earnest about the success of the mission, intent on observing as much as humanly possible, and committed to conducting all the experiments entrusted to me. I made strenuous efforts to adhere to a very crowded flight plan.
The cabin became noticeably hot during the first orbit, when I was over the Mozambique channel, forty-five minutes into the flight. I wasn’t the first astronaut to be bothered by a hot cabin, and all of us were prepared for varying degrees of discomfort, and even pain, while we trained for and went through actual space flight. During the selection process, we ran the treadmill at 100 percent humidity and 115 degrees Fahrenheit – and gladly – just to be chosen.
So the term “tolerable temperature,” something the NASA medics determined was endurable with little loss in performance, is relative. You need to know how long the discomfort will likely last, how hard you have to work during that time, and how badly you need to withstand it. It also helps to have an idea of when you believe relief will come. So after giving the Indian Ocean capcom all the normal voice reports, I explained for the record what I was doing inside to bring the high cabin temperatures down.
During all this time, I was also getting some readings with O’Keefe’s airglow filter. All of a sudden my periscope went dark. It really surprised me.
Carpenter reported: “What in the world happened to the periscope? Oh. It’s dark. That’s what happened. It’s facing a dark earth.”
A simple and elegant explanation: day had become night. I was still getting accustomed to moving 17,500 miles per hour.
My flight plan at this point consisted mostly of photography. I had crossed the terminator, which is the dividing line between the dark and sunlit sides of the earth, which caused the light levels to change very rapidly. It was exceedingly important that I photograph the changing light levels. To myself, I read off a lot of camera F-stop and exposure values and was thinking aloud about my next capcom.
Carpenter reported: “It’s getting darker. Let me see. Muchea contact sometime – Oh, look at that sun! F11.”
No one was listening, so I reported to the tape: “It’s quite dark. I didn’t begin to get time to dark adapt . . . cabin lights are going to red at this time. Oh, man, a beautiful, beautiful red, like in John’s pictures. Going to fly by wire.”
A mysterious red light had cascaded through the window just as I went into a new control mode, as specified in the flight plan. It reminded me of the pictures John had taken through his red filter. But mine was only the reflection of the red cabin lights. “That’s too bad.” I was disappointed.
But then I was visited by Venus.
Carpenter reported: “I have Venus now approaching the horizon. It’s about 30 degrees up. It’s just coming into view. Bright and unblinking. I can see some other stars down below Venus. Going back to ASCS at this time. Bright, bright blue horizon band as the sun gets lower and lower – the horizon band still glows. It looks like five times the diameter of the sun.”
The sun completely disappeared at this point in my flight, and I reported the exact time – 00 4734 elapsed – and my total incredulity.
Carpenter reported: “It’s now nearly dark and I can’t believe where I am.”
My wonder gave way to surprise just a minute later, when I saw how much fuel I had already used.
Carpenter reported: “Oh, dear, I’ve used too much fuel.”
“Oh, dear” – a Noxon expression. Over Australia, I would have voice contact with two different capcoms – the first with Deke Slayton at Muchea, the second at Woomera. Over Muchea, Deke and I talked about our Australian friends, John Whettler in particular, who had been a Spitfire pilot during World War II. Then I said “Break, Break,” which is voice communication procedure meaning “change of subject.” We talked about cloud cover, too heavy for me to see the lights in Perth turned on for my encouragement. Deke consulted the flight plan and saw it was time to send some telemetered blood pressure readings. Then some arcane navigational matters – how to determine attitudes, yaw, pitch, and roll – on the dark side.
Carpenter reported: “You’ll be interested to know that I have no moon, now. The horizon is clearly visible from my present position; that’s at 00 54 44 [capsule] elapsed. I believe the horizon on the dark side with no moon is very good for pitch and roll. The stars are adequate for yaw in, maybe, two minutes of tracking. Over.”
In 1962 we didn’t know what was visible on the horizon, on the dark side without moonlight. So Deke and I were discussing how one might establish attitude control under such unfavorable conditions. I relayed what reliable visual references I had out the window or periscope. In the absence of valid attitude instrument readings during retrofire, the pilot can use such external visual references, manually establishing proper retroattitude control with the control stick. Pitch attitude can be established and controlled easily, with reference to the scribe mark etched in the capsule window. Accomplishing the proper yaw attitude, however, is neither easy nor quick.
Attitude changes are also hard to see in the absence of a good daytime horizon. At night, when geographic features are less visible, you can establish a zero yaw attitude by using the star navigation charts, a simplified form of a slide rule. The charts show exactly what star should be in the center of the window at any point in the orbit – by keeping that star at the very center of your window you know you’re maintaining zero yaw. But there are troubles even here, for the pilot requires good “dark adaption” (or a dark-adapted eye) to see the stars, and dark adaption was difficult during the early flights because of the many light leaks in the cabin. The backup measures (“backup” here meaning human) were absolutely critical to have in place at retrofire – in the event of attitude instrument failure.
Deke and I discussed suit temperature, which like the cabin was hotter than I liked. He suggested a different setting, which I tried. Then Woomera capcom hailed me, and I replied: “Hello, Woomera capcom, Aurora 7. Do you read?” while still in voice contact with Deke, at Muchea. “Roger, this is Woomera,” came the capcom’s voice. “Reading you loud and clear. How me?” Deke was confused. He couldn’t hear Woomera and thought to correct me.
Between
Muchea and Woomera, I was trying to see the ground flares, a check for visibility. Deke gave me the attitudes to view the first flare, which involved a whopping, plus-80 degrees yaw maneuver and a pitch attitude of minus 80 degrees. But the cloud cover was too dense. “No joy on your flares,” I told Woomera and then went to drifting flight, where I found that just by rocking my arms back and forth, like attempting a full twist on the trampoline, I could get the capsule to respond in all three axes, pitch, roll, and yaw.
The Cape advised me to keep the suit setting where it was, because the temperature was coming down. I continued in drifting flight, and at capsule elapsed 01 02 41.5, over Canton, we checked attitude readings with telemetry. The Canton Capcom told me my body temperature was registering 102 degrees Fahrenheit, clearly a false reading.
Carpenter reported: “No, I don’t believe that’s correct. My visor was open; it is now closed. I can’t imagine I’m that hot. I’m quite comfortable, but sweating some.”
A food experiment had left crumbs floating in the cabin. I remarked on them, and reported the dutiful downing of “four swallows” of water. At his prompting, however, I could not confirm that the flight plan was on schedule. But I reported what I could: “At sunset I was unable to see a separate haze layer – the same height above the horizon that John reported. I’ll watch closely at sunrise and see if I can pick it up.”
Canton Capcom wished me “good luck,” and then LOS – loss of signal.
Everyone on the ground had had an eye on the fuel levels since the end of the first orbit. Gordo Cooper, capcom at Guaymas, had told me to conserve fuel, which was then at 69 percent capacity for the manual supplies, and 69 percent for the automatic. By the time I returned for my second pass over Kano, they had dropped to 51 and 69, respectively.
Carpenter reported: “The only thing to report is that fuel levels are lower than expected. My control mode now is ASCS.”
I explained to the Kano Capcom: “I expended my extra fuel in trying to orient after the night side. I think this is due to conflicting requirements of the flight plan.”
Live and learn. I spoke to the flight recorder, although Kano Capcom still had voice contact.
I should have taken time to orient and then work with other items. I think that by remaining in automatic I can keep – stop this excessive fuel consumption.
When I went to fly-by-wire aboard Aurora 7, very slight movements of the control stick in any axis activated one-pound thrusters and changed the attitude very slowly. Larger stick movements would activate the twenty-four-pound thrusters, which would change the attitude much more quickly but use twenty-four times as much fuel. If the manual proportional control mode were chosen, the change capsule attitude would be proportional to stick movement, just as an airplane. (Move the stick a little, get a little bit of thrust; move it halfway, get half thrust; move it all the way, get full thrust.) Each increment of movement had attendant increases in fuel expenditure. If, however, both control modes were chosen concurrently – and this happened twice during MA-7 as a result of pilot error – then control authority is excessive and fuel expenditure exorbitant.
For my flight the twenty-four-pound thrusters came on with just a wrist flick, that I then corrected with a wrist flick in the other direction. This countermovement often activated the twenty-four-pound thrusters yet again, all for maneuvering power not required during orbital flight. The high thrusters weren’t needed, really, until retrofire, when the powerful retrorockets might jockey the capsule out of alignment. The design problem with the three-axis control stick as of May 1962 meant the pilot had no way of disabling, or locking out, these high-power thrusters. Because of my difficulties and consequent postflight recommendations, follow-on-Mercury flights had an on-off switch that would do just that, allowing Wally Schirra and Gordo Cooper to disable the twenty-four-pound thrusters. Gemini astronauts had a totally different reaction control system.
But I understood the problem and resolved to limit my use of fuel. Consulting my index cards, I saw that I still had voice reports to make on several experiments – the behavior of the balloon, still tethered to the spacecraft; a night-adaption experiment; and the ingestion of some more solid food. Holding the bag, however, I could feel the crumbled food. If I opened it, food bits would be floating through my work space. I made a mental note: “Future flights will have transparent food bags.” See-through bags would make crumb strategy easier during these zero-G food deployments. I was beginning to regret my lack of training time.
Before loss of signal, Kano Capcom asked me to repeat my fuel-consumption critique.
Capcom asked: “Would you repeat in a few words why you thought the fuel usage was great? Over.”
Carpenter replied: “I expended it on – by manual and flyby – wire thruster operation on the dark side, and just approaching sunrise. I think that I can cut down on fuel consumption considerably during the second and third orbits. Over.”
The Zanzibar Capcom took over ground communication. Consulting the same flight plan I had, he reminded me I was supposed to be on fly-by-wire. I thought better of it and said so:
“That is negative. I think that the fact that I’m low on fuel dictates that I stay on auto as long as the fuel consumption on automatic is not excessive. Over.”
The irony is that even the ASCS control mode, ostensibly thrifty with fuel, was now guzzling fuel because of the malfunctioning pitch horizon scanner. “Roger, Aurora 7,” replied Zanzibar Capcom and then congratulated me on my trip so far. “I’m glad everything has gone-” but the rest of this message dropped out. “Thank you very much,” I said, hoping he could still hear me.
After Zanzibar was the Indian Ocean Capcom, stationed aboard a United States picket ship called Coastal Sentry, permanently anchored at the mouth of the Mozambique channel. After the usual preliminaries (“How do you read?” ‘Loud and clear. How me?’), he reminded me to conserve fuel and then inquired: ‘Do you have any comments for the Indian Ocean?’ I replied, but not with a greeting. I was having that old ASCS difficulty:
“That is Roger. I believe we may have some automatic mode difficulty. Let me check fly-by-wire a minute.”
Going to fly-by-wire is the best way to diagnose any problem with the thrusters, the small hydrogen peroxide-spewing jets that control spacecraft attitudes. I checked them again. The thrusters were fine. We didn’t know it at the time, but the thrusters were receiving faulty information, through the autopilot, from the pitch horizon scanner. Worse, the error from the automated navigational tool was intermittent and thus hard to identify. I reported that the gyros, my onboard navigational tools, were not “indicating properly.” This sort of problem requires patient investigation. I told the Indian Ocean Capcom to wait.
Carpenter reported: “The gyros are . . . okay, but on ASCS standby [the off position]. It may be an orientation problem. I’ll orient visually and see if that will help out the ASCS problem.”
I went off autopilot to fly-by-wire, oriented the capsule visually, and then returned to ASCS autopilot, to see what would happen. My hope was to catch the autopilot misbehaving. It was an angel. Imagine that you own a high-performance car that develops a quirky habit, when on autopilot, of veering off the interstate as you’re speeding along at 80 miles per hour. You take it to the dealer, describe the trouble, and the mechanics can’t duplicate the malfunction when they take it out to the freeway the next day. Imagine this happening in space, with your space car, and you have only two circumnavigations left on the orbital hightway. Imagine further that your precisely timed exit off the orbital highway will be performed using this intermittently malfunctioning autopilot. This is what I was facing, but didn’t know it. No one did.
Technicians, pilots among them, often make erroneous assumptions when troubleshooting a problem. An erroneous assumption early on can invalidate all subsequent efforts to find a solution. Nobody realized that the problem lay in the pitch attitude indicator. From the pilot’s viewpoint, the problem with the ASCS was an anomaly
, and the intermittent failure meant little. When your navigational tools disagree with the view out your window and this persists in any great disparity, the instruments are malfunctioning. When the instruments are malfunctioning, you have no recourse but to navigate visually with reliable reference points – the horizon, the position of a known star, geographical landmarks. This is what I did.
The Indian Ocean Capcom waited patiently. Nearly a minute passed while I tried diagnosing the problem. We were working off a tight flight plan, so he reminded me I was “supposed to, if possible, give a blood pressure.” This was a simple matter of pressing a semi-automatic device on my suit, which I did, and felt the blood pressure cuff inflate. “Roger,” I said, “I’ve put blood pressure up on the air already. Over.”
Mercury Control had in the meantime picked up on my earlier transmission about the thrusters. During MA-6, a thruster malfunction had forced John to assume manual control for his final two orbits. Rightly concerned about a repeat of the old problem, Mercury Control pressed the capcom to get me to submit a complete report on the thrusters.
Capcom ordered: “Report to Cape you have checked fly-by-wire, and all thrusters are okay. Is there anything else?”
“Negative,” I said. Mercury Control was working on an erroneous assumption about the thrusters malfunctioning and needed to be sure I had checked them thoroughly. Having satisfied my own questions about the thrusters, and done the best I could with the ASCS, I had moved on to grappling with my spacesuit’s coolant and steam-vent settings and said so: “Except for this problem with steam-vent temperature.” It wasn’t the heat now, but the humidity, in this case inside my suit: I knew that the cabin temperatures were high, at about 103 degrees. The dry air would at least provide some evaporative relief from the sweat now pouring down my forehead, plowing through my eyebrows, and stinging my eyes with salt.
The Mammoth Book of Space Exploration and Disaster Page 14
