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.
Carpenter reported: “I’m going – I’ll open the visor a minute, that’ll cool – it seems cooler with the visor open.”
The Capcom persisted. Mercury Control needed me to reconfirm that I had used the fly-by-wire control system to check out all the thrusters.
Capcom replied: “Aurora 7, confirm you’ve checked fly-by-wire, and all thrusters are okay.”
Carpenter replied: “Roger. Fly-by-wire is checked, all thrusters are okay.”
But the information coming from the horizon scanner was faulty. During the orbital phase of spaceflight, a malfunctioning automated navigational system is tolerable – for my flight this was especially so because the ASCS was so rarely used. But during an ASCS-controlled retrofire – that critical exit off the orbital highway – an accurate horizon scanner is crucial. For retrofire, the spacecraft must be aligned exactly in two axes – pitch and yaw. Pitch attitude, or angle, must be 34 degrees, nose down. Yaw, the left-right attitude, must be steady at 0 degrees, or pointing directly back along the flight path. The ASCS performs this maneuver automatically, and better than any pilot, when the on-board navigational instruments are working properly.
If the gyros are broken, all is not lost: a pilot can do two things to bring yaw attitude to zero. The first is to point the nose in a direction he thinks is a zero-degree yaw angle and then watch the terrain pass beneath the vehicle. This is nearly impossible to do over featureless ocean or terrain. Far better to have a certain geographical feature or cloud pattern to watch. Because the pilot is traveling backward, the geographical features he is trying to track must begin at the bottom of the window and flow in a straight line from there to the top. When this happens, the pilot knows he is in a zero-degree attitude. This can be done through the periscope too, but it takes a little longer and is less accurate.
My travails with a hot cabin and a humid spacesuit continued over Australia. Deke, the Muchea Capcom, assumed ground communications. It was his unhappy job to tell me that my cabin temperatures had climbed to 107 degrees Fahrenheit (they would peak, during the third orbit, at 108 degrees). Dehydration under such conditions is a worry, and for these and other reasons NASA medics had lobbied for some of the capcom posts, to no avail. By the time I had completed another solid-food experiment, by eating some Pillsbury-made morsels, I was within voice range of the next Australian capcom, at Woomera, and still fussing with my suit temperature controls. The capcom there asked me for suit temperature and humidity readings. They were at 74 degrees Fahrenheit, with the “steam exhaust” registering a miserable 71 degrees of humidity inside my suit. Still, the numbers had come down since Australia, so the Woomera Capcom asked rather hopefully:
“Are you feeling more comfortable at this time?”
A noncommittal “I don’t know” was the best I could manage. I was frustrated with the suit controls and realized with exasperation that for all the exhaustive testing of the suits prior to this and other early launches, no one thought to test its cooling capacity with the face-plate open! And so many in-flight activities required me to keep my visor up.
Carpenter reported: “I’m still warm and still perspiring. I would like to – I would like to nail this temperature problem down. It – for all practical purposes, it’s uncontrollable as far as I can see.”
Capcom asked: “How about water?”
Carpenter replied: “That would be a no.”
Carpenter reported: “I had taken four swallows at approximately this time last orbit. As soon as I get the suit temperature pegged a little bit, I’ll open the visor and have some more water. Over.”
At this point in the flight, over Canton, I was scheduled to take a xylose pill (which is a biomedically traceable sugar pill for later analysis in my collected urine). I could feel the melted Pillsbury mess in the plastic bag and said, “I hate to do this,” more to myself than to the Canton Capcom. Then, surprise, when I opened it: “It didn’t melt!” I found the xylose pill, but all my cookies had crumbled. Chocolate morsels escaped their confines to float, weightless, around my tiny workspace. The rest of the stuff in the bag was a mess. The Nestle concoction, more fruit and nougat than heat-sensitive chocolate, held up far better.
I was approaching Hawaii, and my second sunrise in space. Referring to the flight plan, the Canton Capcom prompted me, before LOS, for an update on the balloon experiment: “Which of the five colors was most visible?”
Carpenter reported: “I would say that the day-glow orange is best.”
Capcom replied: “Roger. For your information, the second sunrise should be expected in approximately 3 to 4 minutes.”
“The Surgeon is after me here,” he added, for another blood pressure check. “Is this convenient?” My in- flight duties at sunrise called for vigorous physical activity, so I waved him off:
“Negative. I won’t be able to hold still for it now. I’ve got the sunrise to worry about.”
He let me alone.
Sunrises and sunsets were extremely busy time-blocks during Mercury flights. There were important measurements to make of the airglow and other celestial phenomena and innumerable photographs to take.
John O’Keefe had some solid hypotheses about the “fireflies” John had seen during his flight. But they remained unexplained. Whatever the critters were, they were particularly active, or at least visible, at dawn, adding to the scientist-pilot’s burden. At 02 49 00 I reported the arrival of a beautiful dawn in space: “I’ll record it,” I told the Canton Capcom, “so you can see it.” As a patrol plane pilot, I had trained to serve as the U.S. Navy’s eyes and ears – a militarily indispensable role. In space, as a Mercury astronaut, I was now the eyes and ears for an entire nation. I felt an obligation to record what few would ever have a chance to see.
I was just beginning to go through my crowded schedule of sunrise-related work when Hawaii took over from Canton, announcing, “Hawaii Com Tech. How do you read me?” prompting me for a short report. The Navy has a one-through-five scale for grading the volume and clarity of voice transmissions. An old Navy quip came to mind, “I read you two by two” – a voice-report short-hand for “too loud and too often.” But I reserved the smart answer and said only, “Stand by one. My status is good. My capsule status is good. I want to get some pictures of the sunrise. Over.”
Capcom asked for a fuel consumption report. Carpenter reported that his fuel supplies were 45–62.
The 45–62 figures were the percentages of Aurora 7’s fuel supply. I had less than half my manual fuel supply left; my automatic fuel supplies stood at 62 percent. Not alarmingly low yet, but low enough. Still Kraft, directing the flight from the Cape, later reported that he wasn’t worried: “except for some overexpenditure of hydrogen peroxide fuel,” he wrote in his own postflight analysis of MA-7, “everything had gone perfectly.” I still had 40 percent of my manual fuel, which, “according to the mission rules,” Kraft figured, “ought to be quite enough hydrogen peroxide… to thrust the capsule into the retrofire attitude, hold it, and then to reenter the atmosphere using either the automatic or the manual control system.”
