Two years ago, we reported on a solar plane that touched down in St. Louis on its way across the United States.
Now it's successor is on its way around the world.
Piloted by the Swiss team of Bertrand Piccard and André Borschberg, the first plane — known as Solar Impulse 1 — successfully flew from San Francisco to New York without using a drop of fuel. Twelve-thousand solar cells powered it by day and charged the batteries that allowed it to keep flying at night.
On Monday its successor, Solar Impulse 2, took off from Abu Dhabi to attempt the first solar-powered round-the-world journey. The plan is for the zero-fuel plane to travel more than 21,700 miles in 25 days — including stops, the entire trip is expected to take about five months to complete.
Who knows, maybe they'll stop here again on this trip!
Follow Véronique LaCapra on Twitter: @KWMUScience