The sun-powered Solar Impulse plane is gradually working up to a trip around the globe, with the most recent benchmark being its first international flight in 2011. Now Bertrand Piccard and Andre Borschberg are taking the jumbo jet-size plane on its first transcontinental journey. The Solar Impulse set off for Morocco today, and its pilots will stop in Madrid along the way. The goal is to complete the 1,554-mile trip by next week, and the big challenge will be crossing cloudy regions like the Pyrenees mountains separating France and Spain. In a 2010 test flight, the Impulse’s 12,000 solar cells soaked up enough rays to keep the plane going through the night, but in case something goes wrong this time, the pilots are prepared with parachutes. If all goes well on this trial run, Piccard and Borschberg will be just one step away from their goal of circumnavigating the world in 2014.