Solar Impulse 2: Swiss pilot Andre Borschberg well on course to Hawaii

After a whole day and night of flying solo over the Pacific, Swiss pilot Andre Borschberg has completed almost 34 hours of the total 120 hours from Nagoya to Hawaii in the sun-powered Solar Impulse 2 craft.

At 6.15 am UTC he had covered 2,362 km of the total 6,495 km since taking off from Nagoya early on Sunday (28 June). The flight to Hawaii will be the longest duration flight, as well as the longest clean fuel solo flight.

Cruising at 29,000 feet with the batteries charged almost to the full and outside temperature -20 deg C, the craft is doing well despite some turbulence.

The pilot is in constant touch with the Swiss mission control centre and receives real time support through an array of electronic systems.

Data on temperature of the motors, position of craft, etc is relayed by a transmission system on board which weighs 5 kgs and consumes 50 watts.

A stabilisation system monitors the craft, pilot and auto-pilot and alerts the pilot through a device on his arms. An electrocardiogram constantly checks for anomalies.

The pilot takes brief 20-minute naps when the batteries are recharged, with self-hypnosis and meditation keeping him alert.

The total trip around the world was expected to span approximately 25 flight days broken up into 12 legs at speeds between 30 to 60 mph.

The present leg of the journey is the most challenging with no breaks in between the 120 hours.

Bertrand Piccard, chairman and co-founder of Solar Impulse, will fly the next leg from Hawaii to the US mainland after which the craft will continue across North America, before attempting to fly over the Atlantic.

Piccard became the first person to circumnavigate the globe in a hot air balloon in 1999.

The light weight craft weighing a bit over two tonnes travels at a maximum speed of 140km/h.

The Solar Impulse epic journey began on 8 March in Abu Dhabi with the craft touching down in Oman, India, Myanmar, China and Japan so far.

The founders hope to demonstrate capabilities of clean energy technologies. The craft bears the words "Future is clean" on its body.

You can watch live transmission of the epic journey here.