Touch down! After nearly five days of flying non-stop over the Pacific Ocean, the experimental solar-powered airplane Solar Impulse 2 landed in Honolulu, Hawai'i, today, having made it through the most treacherous portion of its journey around the world and, in the process, having crushed the record for the longest duration solo flight without refueling (118 hours). Congrats Solar Impulse team! And Happy Fourth! Read more here at PopSci.