This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.bbc.co.uk/news/science-environment-33383521

The article has changed 7 times. There is an RSS feed of changes available.

Version 1 Version 2
Solar Impulse plane closes in on Hawaii landing Solar Impulse plane lands in Hawaii
(about 3 hours later)
Andre Borschberg is into the final hours of his historic solar-powered flight across the Pacific. Solar Impulse, the aeroplane that is powered only by the sun, has landed in Hawaii after making a historic 8,000km flight across the Pacific from Japan.
The Swiss adventurer is due to land at Kalaeloa, Hawaii, around 06:00 local time (1600 GMT; 17:00 BST) after an epic five-day trip from Japan. Pilot Andre Borschberg brought the vehicle gently down onto the runway at Kalaeloa Airport just before 06:00 local time (16:00 GMT; 17:00 BST).
His Solar Impulse aeroplane has covered 8,000km this week, in what was always going to be the toughest leg in the quest to fly around the world. The distance covered and the time spent in the air - 118 hours - are records for manned, solar-powered flight.
Wind conditions will determine the precise moment Mr Borschberg puts down. The duration is also an absolute record for a solo, un-refuelled journey.
His very lightweight vehicle, with its huge, 72m wingspan, needs calm air. Mr Borschberg's time betters that of the American adventurer Steve Fossett who spent 76 hours aloft in a single-seater jet in 2006.
And the pilot will be instructed to circle in front of Kalaeloa airport until meteorologists give him the all clear. Meeting the Swiss pilot in Kalaeloa is his partner on the Solar Impulse project, Bertrand Piccard.
There to meet Mr Borschberg on the ground will be his partner on the Solar Impulse project, Bertrand Piccard. The pair are sharing flying duties in their quest to circumnavigate the globe - an effort they began in Abu Dhabi, UAE, back in March.
The pair have shared the flying duties in the single-seater plane's global effort, which began in Abu Dhabi, UAE, back in March. It is Mr Piccard who will now fly the next leg from Hawaii to Phoenix, Arizona.
It is Mr Piccard who will fly the next leg from Kalaeloa to Phoenix, Arizona. That will not be quite as far as the leg just completed, but it will still likely take four days and nights.
That is not quite as far as the current stint, but it still likely to take four days and nights.
From Phoenix, Solar Impulse will head for New York and an Atlantic crossing that would eventually see the plane return to Abu Dhabi.From Phoenix, Solar Impulse will head for New York and an Atlantic crossing that would eventually see the plane return to Abu Dhabi.
But the Solar Impulse ground crew will need a few days first in Kalaeloa to check over the aircraft, before meteorologists once again take on the tricky task of finding a flight window. But, first, the Solar Impulse ground crew in Kalaeloa will need a few days to check over the aircraft.
Getting from China to Hawaii proved more problematic than anyone could have imagined. During this servicing, meteorologists will once again take on the tricky task of finding a suitable flight window.
The project was stuck in Nanjing for five weeks before the first attempt to cross the ocean was made. Getting Solar Impulse to Hawaii proved more problematic than anyone could have imagined.
This had to be aborted because of a sudden deterioration in the weather, and the plane was diverted to Nagoya. The project was stuck in Nanjing, China, for five weeks before the first attempt to cross the ocean was made.
One further attempt was then abandoned moments from take-off, before Solar Impulse finally got a clear run out of Japan on Monday. Solar Impulse's lightweight and large, 72m wingspan put significant constraints on the type of weather conditions it can handle; and that first sortie was aborted after just one day in the air because of a fast developing cold front ahead of it.
Even so, Mr Borschberg had to cross two cold fronts and endure some uncomfortable turbulence. That bumpiness disrupted his already truncated sleep opportunities. Mr Borschberg diverted to Nagoya, and then had to wait a further month before being given the green light on Monday to take off for Kalealoa.
Over the course of the past week, the pilot has been permitted only 20-minute catnaps. Even so, he has had to cross two weather fronts this week and has endured some uncomfortable turbulence as a consequence.
The journey from Nagoya to Kalaeloa smashes the absolute distance and duration world records for manned solar-powered aeroplanes - records that Solar Impulse itself set on earlier flights. The Swiss team is using the various stopovers on its round-the-world journey to carry a campaigning message to local people on the topic of clean technologies.
In terms of general aviation, the big record broken on this flight is the 2006 mark established by the American adventurer Steve Fossett for the longest duration solo flight in an un-refuelled plane. The Solar Impulse plane is not intended to be a vision of the future of aviation. Rather, it is supposed to be a demonstration of the current capabilities of solar power in general.
Mr Fossett set this record in a jet-powered plane, the Virgin GlobalFlyer. Mr Borschberg bettered it when he went through 76 hours in the air. And if he lands at the expected time of 06:00, he will raise the mark still further to 118 hours.
Borschberg and Piccard have used the various stopovers on their round-the-world journey to carry a campaigning message to local people on the topic of clean technologies.
Their Solar Impulse plane is not intended to be a vision of the future of aviation. Rather, it is supposed to be a demonstration of the current capabilities of solar power in general.
The vehicle is covered in 17,000 photovoltaic cells. These either power the vehicle's electric motors directly, or charge its lithium-ion batteries, which sustain the plane during the night hours.The vehicle is covered in 17,000 photovoltaic cells. These either power the vehicle's electric motors directly, or charge its lithium-ion batteries, which sustain the plane during the night hours.
LEG 1: 9 March. Abu Dhabi (UAE) to Muscat (Oman) - 772km; in 13 hours and 1 minuteLEG 1: 9 March. Abu Dhabi (UAE) to Muscat (Oman) - 772km; in 13 hours and 1 minute
LEG 2: 10 March. Muscat (Oman) to Ahmedabad (India) - 1,593km; in 15 hours and 20 minutesLEG 2: 10 March. Muscat (Oman) to Ahmedabad (India) - 1,593km; in 15 hours and 20 minutes
LEG 3: 18 March. Ahmedabad (India) to Varanasi (India) - 1,170km; in 13 hours and 15 minutesLEG 3: 18 March. Ahmedabad (India) to Varanasi (India) - 1,170km; in 13 hours and 15 minutes
LEG 4: 18 March. Varanasi (India) to Mandalay (Myanmar) - 1,536km; in 13 hours and 29 minutesLEG 4: 18 March. Varanasi (India) to Mandalay (Myanmar) - 1,536km; in 13 hours and 29 minutes
LEG 5: 29 March. Mandalay (Myanmar) to Chongqing (China) - 1,450km; in 20 hours and 29 minutesLEG 5: 29 March. Mandalay (Myanmar) to Chongqing (China) - 1,450km; in 20 hours and 29 minutes
LEG 6: 21 April. Chongqing (China) to Nanjing (China) - 1,241km; in 17 hours and 22 minutesLEG 6: 21 April. Chongqing (China) to Nanjing (China) - 1,241km; in 17 hours and 22 minutes
LEG 7: 30 May. Nanjing (China) to Nagoya (Japan) - 2,852km; in 44 hours and 9 minutesLEG 7: 30 May. Nanjing (China) to Nagoya (Japan) - 2,852km; in 44 hours and 9 minutes
Leg 8: 28 June. Nagoya (Japan) to Kalaeloa, Hawaii (USA) - 8,000km; 118 hours (estimated)Leg 8: 28 June. Nagoya (Japan) to Kalaeloa, Hawaii (USA) - 8,000km; 118 hours (estimated)