en.wikipedia.org/wiki/Jacques_Piccard

Bertrand Piccard’s own official Solar Impulse history says 2009 was the year of the aircraft’s first test flights, not a round-the-world flight. The same official page says the around-the-world mission began on March 9, 2015 and that Piccard concluded the flight on July 26, 2016 after returning to Abu Dhabi.

A contemporaneous TIME report from March 9, 2015 likewise describes that date as the start of "the world's first round-the-world trip on a solar-powered plane," which confirms the circumnavigation had not already happened in 2009.

So the article’s statement incorrectly places the solar-powered around-the-world flight in December 2009. That year corresponds to early test flights, not the completed global circumnavigation.