These include the centuries-old custom of "bul", where leaders would call a temporary stop to fishing for key species in order to give fish stocks an opportunity to replenish.

"There are situations, particularly for correcting blood-vessel problems like an aneurysm, where we cool the brain in order to stop circulation to an area to perform our work safely," he says.

All stop-ship scenarios had to run successfully without defects or patches in order to successfully complete an iteration.