The route for the first ever round the world flight powered only by the sun has been announced by Solar Impulse, the Swiss company headed by pioneering balloonist Bertrand Piccard and pilot André Borschberg.

If successful, the 35,000km flight in solar-powered plane Solar Impulse 2 (Si2), which will cover much of Asia before crossing the US and Europe, will be a historic moment.

Si2, which Factor was recently given rare up-close access to, will demonstrate solar’s capabilities for long-term flight on a scale never previously seen.

The route, which was announced at a globally streamed press conference in Abu Dhabi this morning, will require the plane to fly continuously for days at a time, with stops to enable Piccard and Borschberg to switch roles as the pilot.

During the conference, Piccard stressed the untested nature of the flight, indicating that there was no guarantee it would be a success.

“Nobody has done anything like this in the past – there is no benchmark for what we are trying to do. An aeroplane flying day and night with no fuel travelling around the world is still considered completely impossible so I am not saying we are going to do it,” he said, adding that the team remained optimistic.

The round-the-world trip will start in Abu Dhabi, which the team has selected due to the Emirate’s sustainability credentials, with the first stop being in Muscat, Oman.

The first leg will continue over the Arabian Sea to Ahmedabad, India, and then onto Varanasi, India, where the team will stop for a night to switch pilots.

From there, the team will continue to Manderlay, Myanmar, before heading to the Chinese city of Chongqing which Borschberg said is “not a city that is well known around the world, but one of the biggest”.

The first leg will end in the historic city of Nanjing, China, where the team will spend a month preparing for the next leg and promoting their message of sustainability.

Although each stop on this first leg may seem like a short hop for a regular aeroplane, the solar plane is considerably slower, meaning the team will have spent around 120 hours in the air by the time they reach Nanjing.

“One month in China will be a really important time to spread our message and prepare for the next leg,” added Borschberg.

If the first leg was gruelling, however, this will be nothing compared to what follows, as the team starts the second leg with a flight over the ocean to Hawaii.

“The goal is to reach Hawaii in 5 days and 5 nights,” said Borschberg. This will mean flying continuously, in a tiny space with little ability to switch pilots in mid-air, and could represent the most demanding section of the route.

From here the precise details are a little less set, as the team leave their options open for change nearer their arrival date.

The plane will next go to Phoenix, the US, before heading to an unspecified location in the mid US for a one-night stop to change pilots.

After that the plane will go to New York and land at the famous JFK airport, a fact that Piccard described as “really important”.

He said that in planning the trip the team expected to be told to stay away from the major transit hub, but found those responsible very receptive to the idea.

“They said it’s a historic flight, we want you at JFK,” he added.

After the landing at JFK – which is set to be a historic and widely covered moment if everything goes to plan – the team will embark on a second five day and five night flight over water, bringing them to a yet-to-be-finalised location in Southern Europe or North Africa.

From there, the final journey will take them back to Abu Dhabi, completing the round-the-world journey in around five months.

Borschberg said that the trip should start in just over a month’s time, giving an approximate starting window of 27th February to 1st March, with an expected end date some time in July.

However, considerable preparation still needs to occur to make the trip a reality.

“There is a huge amount of things we still have to do before we can leave Abu Dhabi,” he said.

In particular he stressed the importance of preparing the crew for such a gruelling journey.

“It became clear that the aeroplane needed to be the size of a transport aeroplane – it’s bigger than a 747 – but the maximum weight we could afford was a family car. We have an airplane which is sustainable in terms of energy, but we need to provide an environment that makes the pilot sustainable as well.”

Other factors, such as the safety of flying over certain countries also need to be taken into consideration, which is why the landing point in Europe or Africa remains unconfirmed.

“When I flew around the world in a balloon 16 years ago, it was possible to sneak through many of the countries in North Africa and the middle east, but now it is only possible in Egypt – all the other countries have wars,” said Piccard.

Despite the challenges that lie ahead, Piccard and Borschberg remain incredibly enthusiastic about the project and in particular its ability to promote solar as a sustainable solution.

“We have today already enough clean technologies to divide the energies of the world by two and provide half of them with clean technologies,” said Piccard, adding that flying a plane around the world without fuel would serve to demonstrate solar’s value as a real technological solution, and not just a political concept.

By bringing the plane to so many countries, Piccard hopes that the technology will gain popular support and encourage government action.

“If the governments feel they have popular support, they will act. if they don’t feel this they will wait. That’s why we act,” he explained.

However, for that to happen the journey will need to be a success.

“I hope it will work, I really hope it will work,” he said.

Image courtesy of Solar Impulse | Revillard | Rezo.ch.