Part of the departure and arrival back into the atmosphere, there exists a requirement to withstand certain gravitational forces on your body, better known as g-force. It reminds me of the times when I was a child when my father would drive over the crest of a hill. As we went over the crest and proceeded down the other side, it felt as if my stomach was floating. I loved that feeling as much as that ‘sinking into your seat’ feeling when you took-off in a passenger jet. All of this typically ranged between 0.8 and 1.3 G’s, where 1 G is the normal gravitational loading you’re feeling right now as you read this (unless you’re in space!).
The requirement we were being tested for was to withstand up to 3.5 times the force of gravity for up to one minute. This would demonstrate that we were able to withstand the typical gravitational loading that we would experience when going into, and coming back from, space. This is tested via a centrifuge, where you sit in a pod at one end of a mechanical arm with the other end on a pivot point. The arm speeds up going around the pivot point, spinning the person in the pod round and round, faster and faster, so that you feel those g-forces. Most people not trained for higher g-forces will typically pass out approaching 4 G’s of vertical gravitational pressure as the blood drains from your head and pools in your feet.
The requirement of this test was to not pass-out, not be sick, and to remember coordinates that you were given by the testing judge before you strapped into the pod. Without much fanfare, I was lined up with a few other candidates and told by the testing judge, “Remember these coordinates and don’t be sick”. Then he raised a tablet in front of me for a few seconds that contained random coordinates, basically a series of numbers that I had to memorise and recite to him after I got out of the centrifuge. Just as I committed the last few digits to memory, he lowered the tablet and beckoned toward the pod with a quick “Good luck!”
I moved up to the pod, which was no bigger than a telephone box, sat in the metal seat and strapped in. As the assistant proceeded to shut the pod door, she leant forward and gestured toward a red button that I could push should I wish to abort the test. This would have resulted in a fail and so I removed that button from my mind and focussed on the screen ahead. Click, click, thud! The centrifuge came to life and I started to feel heavier and heavier in my seat as the whirl of the air outside the pod became more noticeable.
In an earlier post, I touched on the 7 P’s of preparation that I stuck to during the lead-up training to this selection course. Focussing on the specific fitness required to withstand excessive gravitational loading was paying off as I felt no discomfort. So excited by what was happening, I caught myself smiling and ‘wooo-ing’ as the centrifuge slowed to a stop. I was elated that the centrifuge was not only a lot of fun; it was much easier than expected. We were summoned back into line and asked to repeat the coordinates back to the testing judge. Some candidates unfortunately forgot the coordinates, either from sheer excitement or, as I witnessed in one case, from being pre-occupied with being ill. Rolling the coordinates off my tongue, I needed to keep my confidence in check as this was just the beginning of the selection course.
“Help yourself to some fruit and water. This may help if you’re feeling sick” said one of the assistants, gesturing to a table of snacks in the corner of the waiting area. With excitement running through my veins from getting a taste of what fighter pilots and astronauts would normally go through, there was only one way I could respond; “So, can I do that again?”