edgar-mitchell

Into the Vacuum 65
By reprogramming the computer manually with Houston’s instructions,
we could get it to ignore the false signal and not actually initiate an abort
when the engine ignited. But there was a penalty in this. If an abort were
actually required anytime during the landing, we would need to perform
the lengthy series of tasks manually and fly for a time without computer
assistance. In order to continue the mission, we were surrendering the
help of an automatic abort system that could deliver us into a safe upward
trajectory at the push of a single button, were another emergency to occur
during or immediately after landing.
The entire team performed magnificently during the 90 minutes available
before descent. All the required tasks were completed, with a few
seconds to spare, as we rotated Antares into position for descent engine
ignition.
As is often the case, however, errors in a system tend to propagate.
Although no one realized it at that moment, what we had done to fix the
abort switch would cause the computer not to recognize and lock on to
the radar signals bouncing off the lunar surface as we descended and approached
the landing site. Thus, we couldn’t check our altitude with these
updates, nor could we just look out the window, as we were quite literally
on our backs, feet forward during powered descent, the windows displaying
nothing but a striking pattern of stars. What made this particularly
unsettling was that the Fra Mauro region happened to be a rather rugged
area of the moon, filled with hills, valleys, and craters. Even if our landing
approach was perfect, we wouldn’t have the benefit of a computer abort
system in case of trouble with the terrain. But more immediately, our
mission rules forbade us to descend below known mountaintop levels without
the radar—a height we would reach within the next minute or so.
We worked quickly, our eyes sweeping the control panel, hoping to
spot the problem that prevented the radar system from measuring the
surface of that meteor-scarred region into which we were rapidly descending.
I recall the unusual sense of detachment, one I’d known before on
occasion, in which the mind focuses impersonally on the pattern of required
tasks. Feeling and emotion were vanquished, and just a body was
left, automatically performing the job, searching for a solution to a dilemma,
functioning as an extension of the computers at my fingertips.
Then something occurred to me in this trance-like state. Through some
deep recess of memory I realized that the radar might need to be reset
after the abort switch fix, and that there were but two quick possibilities.
But which to try first Just then, as though reading my mind, Houston
came in with the right call. Al recycled a circuit breaker, the radar locked
on, and we could see that the data we were receiving was accurate and the
computer had been guiding us perfectly. The mission had been salvaged
once again with the help of Houston, this time within scant minutes of
landing.