Solar Impulse, the world's first single passenger solar-powered airplane has come a long way since its first flight in 2009, when it rose a mere 3 feet above the ground and flew for just 1,150 feet in the 30 seconds it was in air. In 2012, the elegant green flying machine successfully completed an intercontinental trip from Europe to Africa and on July 6th, 2013, added another feather or should we say 'wing' to its cap, with a flight across the United States of America.

The first leg of the solar plane's 'Across America' journey began on May 3rd from San Francisco, California. Taking off from NASA's Moffett Field with Bertrand Piccard at the helm, it took the airplane that sports a 207-foot wingspan, 19 hours at a top speed of 45km/h, to complete the initial leg to Phoenix, Arizona.

Following a two-week stay during which over 2,200 local residents had the opportunity to admire the sleek airplane up close, it took off again on May 22nd - This time around, the 936-mile journey to Dallas, Texas, the longest ever completed by a manned solar-powered airplane was completed by Captain Andre Borschberg.

On June 2nd, the airplane began its third leg to St. Louis, Missouri. The 21 hr 22 min, 630 mile trip proved to be quite eventful. Not only did the Solar Impulse experience its first flight below ice-filled cirrus clouds, but it also, got a chance to test out its own inflatable hanger because a severe thunderstorm had damaged the one that had been slated to house it. Not surprisingly, it worked like a charm!

The excitement did not end there - High winds on the way to its next destination, Washington D.C, forced the organizers to change the route slightly and instead reroute to Cincinnati, Ohio for a few days, before heading to the nation's capital on June 16th, 2013.

The final leg, an 18 hour flight to New York City, began in the wee hours of July 6th, 2013. A planned flyover the Statue of Liberty had to be canceled after a tear appeared on the underside of the airplane's left wing. By the time it landed at John F. Kennedy airport at 11 pm EST, the solar-powered plane had flown a total of 105 hours and 41 minutes at an average speed of 33.14 mph to complete the 3,511-mile, coast-to-coast journey.

While the Solar Impulse HB-SIA, the only solar-powered airplane capable of flying day and night has the same wingspan as the Airbus 380, it weighs only 2 tons as compared to the 400 ton weight of a fully-laden A380. It comprises of 12,000 solar cells fitted onto the airplane's long wingspan, that capture the sun's energy and transfer it to four 10-hp electric motors. The solar cells also help charge the 882 pounds of lithium batteries that power the airplane at night. In order to conserve and store as much captured energy as possible, the airplane is programmed to travel at reduced speeds even during midday hours, when the sun is at its peak.

With this latest 'Across America' mission out of the way, the jubilant Swiss inventors/pilots - Bernard Piccard and Andre Borschberg are now preparing for the ultimate test - A journey around the world. For this epic trip, the duo plan to use the next generation solar plane - HB-SIB, which will be capable of carrying two people. Mr. Piccard who keeps breaking new ground with every flight, is no stranger to fame - In 1999, the adventurer made headlines after completing a non-stop journey around the world in a hot air balloon!

Though solar-powered planes have a long way to go before they can be used for commercial flying, the Solar Impulse certainly brings them a step closer to reality. To read more about this fascinating aircraft check out solarimpulse.com.