Two pathfinding odysseys are circling the globe in unconventional carriers.
Explorer Fedor Konyukhov is rugged up in a basket dangling beneath a giant helium balloon, floating in the jet stream. The 65-year-old wants to be back in Western Australia, where he left on Tuesday, by the end of next week.
His goal is to break Steve Fossett's solo hot air round-the-world balloon flight of 13 days, set back in 2002. The Russian orthodox priest, propelled by 165km/h winds, is living in a pod not much bigger than himself. Yesterday he was soaring over the Tasman, 7491m above sea-level. The outside temperature was -5C, but the bearded flier was off the pace. To beat Fossett's record, Konyukhov needs to cover about 2500km a day. In three days, he had crossed about 4500km of the globe. Still, he remains aloft, and while he is up there he has a chance.
Solar Impulse 2, an ungainly aircraft powered by the sun, is lapping up the rays in Cairo before its last leg to Abu Dhabi. It has taken the pilots who share the controls months to nurse the slow machine around the planet, a journey hampered by battery problems and weather diversions.
Such are the challenges of pioneering pursuits.
The beauty of these missions is their uncertainty, and their great promise. The solar plane could usher in a new energy era. The solo balloonist is firmly in the tradition of the best adventurers - pushing the envelope of human endeavour. We can admire all of them even if they don't succeed.