"It is symbolic because all the means of transportation have always tried to cross the Atlantic, the first steamboats, the first aeroplane, the first balloons, the first airships and, today, it is the first solar-powered aeroplane," Piccard told the Guardian.

While the Solar Impulse team's main goal is to cross the world, it has set multiple marks on the way. On top of the record Atlantic crossing, pilot André Borschberg set a record for the longest solo flight ever at 117 hours, besting the previous mark by a prodigious 41 hours. The team has also set night flying records, ironically, thanks to the one-ton lithium battery charged by 17,000 solar panels.

The 236-foot-wide plane can theoretically stay aloft forever, weather and pilot endurance permitting. The lengthy flights aren't exactly dull, though; Piccard said it's a roller coaster of tension and work, mixed with awe from the sights like islands, whales and icebergs. "Every minute is a minute of suspense, a minute of challenge, and the fact I can stay [aloft] without fuel or pollution for four days and four nights is something so new."

The team has now made 90 percent of its trip, and will finish in Abu Dhabi, where it started. It has just a few flights left, and will stay in Saville for a few more days before lifting off toward either Egypt or Greece.