Solar Impulse is the first ever airplane of perpetual endurance, able to fly day and night on solar power, without a drop of fuel. And now the solar plane is flying around the world becoming the first ever airplane to do so on the power of the sun only.

Solar impulse, the solar plane hoovering in the air

Solar impulse, the solar plane hoovering gracefully in the air

It all started with the construction of the revolutionary Solar Impulse 1 (also called HB-SIA). Its huge wingspan of 64m, equal to that of an Airbus A340, combined with its tiny weight of 1600 kg – equal to an average car – the solar impulse 1 was able to break seven solar aviation world records due to its  innovative aerodynamic features. Most notably it flew across the USA from Los Angeles to New York in 2013.

All the lessons learned from this Solar Impulse 1 formed the basis for the construction of the Solar Impulse 2, the Round-The-World Solar Airplane.

After the Solar Taxi – which drove a 54,000km full loop around the world powered by solar power only in 2007 – solar impulse 2 is hoping to achieve the second purely solar powered circumnavigation of Earth ever.

Solar Plane’s First Leg: Abu Dhabi to Muscat

Solar impulse 2, the take off in Abu Dhabi of the record breaking solar plane

Solar impulse 2, the take off in Abu Dhabi of the record breaking solar plane

On monday March 9, 2015 businessman and pilot Andre Borschbeg, together with Swiss adventurer Bertrand Piccard took off for the first leg of the historic rtw solar flying journey. Their journey started in Abu Dhabi (United Arab Emirates) without a single drop of fuel on board of their Solar Impulse 2.

Abu Dhabi to Muscat, flight plan

Pilot André Borschberg needed 13 hours and 1 minute to fly the 400 kilometers to Muscat in Oman.  reaching a maximum altitude of 5,791 m, 19,000 ft.

The solar plane touching down in Muscat

The solar plane touching down in Muscat

Onwards towards the East

In the next five months the Solar Impulse 2 will fly further East with the ultimate goal of landing back in Abu Dhabi in mid summer 2015. Their planned stops includeIndia, Myanmar, China, the United States and the Mediterranean.

route map for the solar plane's RTW and record breaking journey

route map for the solar plane’s RTW and record breaking journey

They will be crossing both the Pacific and Atlantic oceans in the process, their biggest obstacles. Borschberg said the following about crossing those two big bodies of water:

“I am confident we have a very special aeroplane, and it will have to be to get us across the big oceans. We may have to fly for five days and five nights to do that, and it will be a challenge. But we have the next two months, as we fly the legs to China, to train and prepare ourselves.”

The Pilots: André Borschberg & Bertrand Piccard

Solar Impulse 2: Borschberg and Piccard the initiators of the solar plane expedition

Borschberg and Piccard the initiators of the solar plane expedition

Of the two protagonists, Andre Borschberg is the lesser known. A trained engineer and former air-force pilot, he has built a career as an entrepreneur in internet technologies.

Piccard, on the other hand,  is a famous explorer’s name as both his father Jacques Piccard and grand father Auguste Piccard broke records by exploring the far corners of the world. Jacques was the first to reach the deepest place in the Ocean in 1960 and Auguste was the first to take a balloon in the stratosphere in 1931.

Bertrand inherited the flying and ballooning bug from his granddad and in 1999 he became a record breaker himself by completing the first non-stop, circumnavigation of the world in a hot air balloon, using the Breitling Orbiter 3 balloon, together with Brian Jones.

Now they form the team that is flying the biggest solar plane ever across the globe

Biggest Wingspan ever

The first solar flying round-the-world venture is altogether more dramatic and daunting than just a crossing of the USA and has required the construction of an even bigger plane than its very successful predecessor, the Solar Impulse-1.

The impulse 2 has a wingspan of 72m, which is wider than a 747 jumbo jet. And yet, it weighs only 2.3 tonnes.

This revolutionary single-seater aircraft made of carbon fiber has a 72 meter wingspan (larger than that of the Boeing 747-8I) for a weight of just 2,300 Kg, which was imperative for the venture to stand a chance.

Solar impulse 2 fact sheet

Solar impulse 2 fact sheet

The 17,000 solar cells built into the wing supply four electric motors (17.5 CV each). During the day, the solar cells recharge lithium batteries weighing 633 Kg (2077 lbs.) which allow the aircraft to fly at night and therefore to have virtually unlimited autonomy

Flying at Night

Operating through darkness will be particularly important when the men have to cross the Pacific and the Atlantic. The slow speed of their prop-driven plane means these legs will take several days and nights of non-stop flying to complete.

Piccard and Borschberg – whoever is at the controls – will have to stay alert for nearly all of the time they are airborne. They will be permitted only powernaps of up to 20 mins – in the same way a single-handed, round-the-world sailor would catch small periods of sleep as to not crash his ship into whales or oil tankers.

They will also have to endure the physical discomfort of being locked up in a cockpit that measures just 3.8 cubic metres in volume – not a lot bigger than a public telephone box (which by the way other kickass adventurers tied on their car’s roof and drove to Mongolia)

Flight simulators have helped the pilots to prepare, and each man has developed his own regimen to cope.

Borschberg will use yoga to try to stay fresh up amongst the clouds while Piccard is using self-hypnosis techniques
But it is also their pure passion for flying and breaking a record that keeps Piccard going:

“I had this dream 16 years ago of flying around the world without fuel, just on solar power. Now, we’re about to do it. The passion is there and I look forward so much to being in the cockpit.”

Ground Support & Weather Conditions

The support team is well drilled. While the mission will be run out of a control room in Monaco, a group of engineers will follow the plane around the globe. They have a mobile hangar to house the plane when it is not in the air.

It is not at all certain Solar Impulse will succeed as they are highly dependable on weather conditions.  Computer modelling suggests the ocean crossings are feasible, given the right weather conditions. In case of unfavourable circumstances therefore it is very well possible the team simply has to sit tight on the ground for weeks before a fair window opens.

Raymond Clerc, mission director explained:

“Last year, we had a very good exercise. We went around the world virtually, but with actual conditions. For the Pacific crossing, it was an easy decision. We had a very good window on 2 May. But when we were on the East Coast of the USA, we had to look to cross the Atlantic and we had to wait 30 days to find a good window. And then it was easy – 3.5 days and we were in Seville, [Spain]”

Let’s just hope the weather gods are with them so they can cruise their way around the globe……