One of our balloons has had quite a journey over the past few weeks. It did a lap around the world in 22 days, and has just clocked the project’s 500,000th kilometer as it begins its second lap. It enjoyed a few loop-de-loops over the Pacific ocean before heading east on the winds toward Chile and Argentina, and then made its way back around near Australia and New Zealand. Along the way, it caught a ride on the Roaring Forties — strong west-to-east winds in the southern hemisphere that act like an autobahn in the sky, where our balloons can quickly zoom over oceans to get to where people actually need them.
Traversing the stratosphere is particularly challenging this time of year because the winds actually change direction as the southern hemisphere moves from warmer to colder weather, resulting in divergent wind paths that are hard to predict. Since last June, we’ve been using the wind data we’ve collected during flights to refine our prediction models and are now able to forecast balloon trajectories twice as far in advance. In addition, the pump that moves air in or out of the balloon has become three times more efficient, making it possible to change altitudes more rapidly to quickly catch winds going in different directions. There were times, for example, when this balloon could have been pulled into the polar vortex – large, powerful wind currents that whip around in a circle near the stratosphere in the polar region – but these improvements enabled us to maneuver around it and stay on course. We can spend hours and hours running computer simulations, but nothing teaches us as much as actually sending the balloons up into the stratosphere during all four seasons of the year.
Take a look through our photo album to see some of the specific improvements that have been made to the balloon technology, thanks to the lessons we’ve learned in flight.