Late on the night of 7 October, 15 men will clear every last stick and stone from a runway in the New Mexico desert as 10 more men wearing cotton gloves and protective suits unfurl and inflate the world's largest helium balloon.
The job will take about eight hours, which seems like a long time until you realize the balloon weighs almost two tons and is taller than the Statue of Liberty. Simply filling it will take 45 minutes to an hour, which doesn't seem long at all when you realize the balloon has a volume of 849,505 cubic metres. This is no ordinary balloon. But then, this is no ordinary mission.
