The Mammoth Book of Space Exploration and Disasters

With Aurora 7 nearing reentry, Kraft learned with as much dismay as the pilot himself that the spacecraft’s ASCS was not, in the best traditions of astronaut understatement, “operating properly.”

Scott had in fact noticed the symptoms, now and then, of a malfunctioning pitch horizon scanner, and was puzzled, at times, by some instrument readings. He reported them as the anomalies they were. But the intermittent nature of these instrument failures made repeated checking of little value. The view out the window was a very good backup, and it was impervious to failure.

It was clear at Mercury Control that day that Kraft’s indignation, simmering since the second-orbit incident over Hawaii, was now compounded by the man’s genuine anxiety. Speaking of MA-7 Kranz explains: “A major component of the ground team’s responsibility is to provide a check on the crew.” And the ground, Kranz says, “waited too long in addressing the fuel status and should have been more forceful in getting on with the checklists.” A thoroughgoing attitude check during the first orbit would probably have helped to diagnose the persistent, intermittent, and constantly varying malfunction of the pitch horizon scanner. By the third orbit it was all too late. MA-7’s fuel problems dictated drifting flight. A third-orbit attitude check, particularly in yaw, would have used prodigious amounts of fuel – at reentry, an astronaut’s lifeblood.

Scott, meanwhile, was busy aviating and navigating. The California Capcom, Al Shepard, took over voice communications for the retrofire sequence, one minute away:

“Seven, this is Cap Com. Are you in retroattitude?”

Carpenter replied: “Yes. I don’t have agreement with ASCS in the window, Al. I think I’m going to have to go fly-by-wire and use the window and the [peri]scope. ASCS is bad. I’m on fly-by-wire and manual.”

Capcom responded: “Roger. We concur.”

But in going to fly-by-wire, Scott forgot to shut off the manual system that he’d activated during the pre-retro checklist over Hawaii as backup for the automatic system. So his efforts to control attitude during retrofire were accomplished on both fly-by-wire and manual control modes, spewing out fuel from both tanks. Halfway through his fifteen-minute flight the year before, Al himself had committed the identical error. Retrosequence was coming up.

Capcom radioed: “About ten seconds on my mark… 6, 5, 4, 3, 2, 1.”

Carpenter reported: “Retrosequence is green.”

Green is good. Green means that everything is set right for automatic retrofire. But not in this case, because the automatic system was locked out and the gyros were caged. Scott would have to fire the retros manually, throwing switches upon Al’s count, coming up fast. Suddenly a critical intervention from Al. If Scott’s gyros were caged, Al reported, he would have to “use attitude bypass.” His gyros were off, Scott answered, and Al repeated his remark:

“But you’ll have to use attitude bypass and manual override.”

Carpenter reported: “Roger.”

Then two seconds. Al counted down, “4, 3, 2, 1, 0.”

Before, during, and after the retrofire firing, Al offered Scott two crucial observations. Because of the instrument failures, the cockpit was in a configuration never before envisioned, and Al perceived the effect it would have on the required cockpit procedure. His contribution to Scott’s safe reentry was a resounding endorsement of the decision made a few years before to place astronauts in the communication loop, as knowledgeable buffers between the ground-control people and the man doing the flying. Al’s insight at a crucial moment probably kept Scott’s landing from being even farther off target than it was.

Carpenter continued:

The last thirty minutes of my flight, in retrospect, were a dicey time. At the time I didn’t see it that way. First, I was trained to avoid any active intellectual comprehension of disaster – dwelling on a potential danger, or imagining what might happen. I was also too busy with the tasks at hand. Men and women who enter high-risk professions are trained to suppress, or set aside, their emotions while carrying out their duties. After the job, and after the danger has passed, is the time for emotions.

Without the ability to detach oneself from the peril in a situation, one has no chance of surviving it. What perils did I face? They were the same perils faced by Al, Gus, and John – and later by Wally and Gordo. The retros might not fire. They might explode or not burn properly. The heat shield might not work. The drogue or the main chute might not deploy or reef properly. Thinking about all the things that could go wrong, no one would ever climb into a spacecraft. A pilot counts on all those things going right, not because he needs to believe in a fairy tale, but because he has confidence in the hardware, in the systems, in the men and women on the ground. In himself.