Project spearhead Bertrand Piccard laughs as I ask if pilot Borschberg is thirsty, tired or anything else that we can relate to on the ground.
Borschberg was in high spirits, though he had complained of back pain. His cockpit is a little smaller than the size of an economy-class seat on a commercial airliner. He is thirsty, and could not drink because his liquids froze when he approached 28,000 feet. Some of his answers were cut off due to a safety on his microphone–after a certain time the mic will shut off to preserve energy. This was installed as a precaution against inadvertantly leaving the mic on, and potentially draining the batteries.
Every drop of energy will be needed to maintain flight through the morning. As of now (2:08 in the morning) things are looking positive to make the goal. This is an historic event, but each member of the crew is treading softly. They know this fragile plane still has a long way to go.