Nominal is a word from aerospace vernacular that has been slowly but surely permeating my vocabulary.
“All as expected.”
“It’s what we anticipated.”
“This is the intention.”
“This is what is supposed to happen.”
“None of this is a surprise, it’s what we were looking for.”
All just more verbose ways of saying the same thing: nominal. The thing that is planned for.
Nominal is fantastic, because it means that the scenario is perfectly within the confines of what we want. Nominal means that we’re running on time, it means the code is working as intended, it means that the rocket is going to the moon and that the muffins came out of the oven fully cooked.
Today in sim, Mars was anything but nominal.
The first sign that we got anything was wrong was during the collection of regolith (read: dirt) from sample site #2. The clouds that had given us the perfect overcast lighting for a few photos while walking to the science location were now turning darker and more ominous. We kept an eye on them during sample #3, but, if anything, they only got darker. We decided to leave the EVA early and, keeping comms open to make sure no one was falling behind, hiked quickly back to the rovers we had left on the main road through the landscape. As we did, the wind grew.
And grew. Before we knew it, it was hard to even hear each other over the comms. When we were talking, it was becoming harder to hear each other over the howling of the wind. As we scrambled up out of the gorge we had climbed into for samples, we felt the air pushing back on us, creating enough resistance to push us off of our feet.
I’m sure everyone remembers the scene from the beginning of the movie, “The Martian.” I would bet money that the growing storm had jogged in each of us the memory of Mars’ dangerous and planet-wide windstorms, and made us wonder just how much time we had left.
Back in the vehicles, we hightailed it back to the Hab. The entire way back, I was flooring it in Perseverance, only stopping to check several times that the Crew Engineer was still following on the ATV.
When the comms crackled back to life, Habcomm was hailing us. An emergency status had been declared, but they’d trusted us to already be coming back – or else they would have broken sim and come to get us.
But they trusted us, and we made the right call, reading the signs of the environment around us. We got back safely. We got back in time.
For a few minutes, we were truly in a choppy situation. But, none of this was a big deal. In the real world, things are rarely nominal. On Mars, things are never nominal.
It’s important to understand that a key part of any research, any adventure, any field science, and any expedition, that if you expect things to be nominal, you’ll be in for a world of surprise. Things rarely go according to plan, and in fact, the plan is more of a guideline that helps us to understand what to expect.
Part of preparing for any challenge is discussing the off-nominal ahead of time, for knowing what to do in case of an emergency, and for being in a headspace to handle the unexpected. Without an alignment of priorities in a mission, handling the off-nominal becomes a lot harder, because a rapid decision on low information is asked for – and well, humans aren’t known at being the best at that.
But, in our case, we had our priorities. Safety, sim, science. Within EVA’s, 1st emergency shelter, soil sampling, second emergency shelter, any extra samples, photos. We managed to get through the first two of those items, and with the essentials to make this a successful EVA, still made a calm decision to return to the Hab immediately at the first rumor of danger.
Plan for the nominal, expect the off-nominal. Lessons for EVA’s and for life.