NASA counts down for first crewed lunar mission in half a century

NASA is set to launch four astronauts as soon as Wednesday evening on a 10-day flight around the moon, marking the most ambitious U.S. space mission in decades and a major step toward returning humans to the lunar surface before China's first crewed landing. NASA mission managers on Monday polled "go" to launch the Artemis II mission's towering, 322-foot (98 m) Space Launch System rocket topped with the astronauts' Orion crew capsule as early as 6:24 p.m. EDT (2224 GMT) on Wednesday. It will launch from NASA's Kennedy Space Center in Florida just one pad away from where the last moon-bound astronauts of the U.S. Apollo program lifted off more than half a century ago. The Artemis II crew includes NASA astronauts Christina Koch, Victor Glover and Reid Wiseman and Canadian astronaut Jeremy Hansen, who arrived in Florida from Houston on Friday. They awoke about nine hours before launch, for breakfast, a weather briefing and pre-mission preparations ahead of their 2 p.m. drive to the launchpad. They have been in a two-week quarantine leading up to liftoff and spent time with their families over the weekend at the Kennedy Space Center's beach house, a spot where astronauts rest before blasting off into space. NASA on Wednesday morning started filling the SLS core stage with 733,000 gallons of super-cooled propellant that powers the rocket's four RS-25 engines. The pickup truck-sized engines, built by Aerojet Rocketdyne, had powered NASA's Space Shuttle for decades. "Everything is going very well right now," assistant launch director Jeremy Graeber said of the SLS core stage fueling process. Weather conditions appeared favorable for an on-time liftoff, with only a 20% chance of souring within the agency's two-hour launch window on Wednesday. If the weather worsens and triggers a scrub, NASA could try again to launch as soon as Friday and until April 6, after which it would wait until April 30 for its next opportunity. "Certainly all indications are right now, we are in exc...