Solar Impulse 2 will be taking off this week from China and flying onward to Hawaii, on the seventh leg of its round-the-world journey. The solar-powered aircraft will take around 120 hours (approximately 5 days) to make the journey. This epic, and critical, leg of the journey will be manned by only one pilot. Yikes.

The aircraft took-off on its incredible voyage from Abu Dhabi on March 9, flying to Muscat. Since then the plane has traveled onward to Ahmedabad, India; to Varanasi, India; to Mandalay, Burma; to Chongqing, China; and most recently, to Nanjing, China. Now, the plane is anticipated to launch on its next and longest leg to-date, on May 12, in the evening.

While this isn’t the first solar plane, nor the first around-the-world journey by a plane, it is the first combination of the two. The plane carries no fuel and its 17,000 solar cells are the only source of energy for the four engines. The solar cells charge 633 kilograms of lithium batteries, which allows night-time flying.

Swiss natives Bertrand Piccard and André Borschberg are the founders and the pilots of Solar Impulse. Although both pilots have been flying the aircraft, they alternate between legs. This 120 hour segment will be undertaken by Borschberg alone. His source of sleep will be short 20-minute naps.

Apparently Borschberg will utilize yoga and self-hypnosis, which he says will help him get the maximum rest possible during his short naps. However, sleep deprivation won't be the only challenge he faces as temperatures will vary between the extremes of 30°C and -20°C. Special food has been developed to withstand the conditions while providing the pilot with vital nutrients to remain alert during the long flight.

“We have an aeroplane that is completely sustainable in terms of energy, the question is with only one pilot on the plane, we need to make him sustainable as well,” Borschberg told The National .

We are crossing our fingers and holding our breath to see how this crazy journey pans out. We're certainly not jealous of the conditions Borshberg is about to subject himself to.