Just a few hours remain in the countdown for Artemis II, NASA's mission to return astronauts to lunar orbit for the first time since the Apollo era.The agency's new lunar hopes and dreams are sitting on pad 39B at Florida's Kennedy Space Center in the form of a 322-foot-tall rocket set to launch three Americans and one Canadian on a 10-day flyby of Earth's nearest celestial companion. Why it matters: The mission — a crewed dress rehearsal for a lunar landing, like Apollo 8 and 10 decades ago — w...