NASA is fueling its new moon rocket in one final make-or-break test before sending astronauts on a lunar fly-around. The launch team began loading the 322-foot rocket with super-cold hydrogen and oxygen on Monday. More than 700,000 gallons have to flow into the tanks and remain on board for several hours. The all-day operation will determine when four astronauts can blast off on NASA's first lunar voyage in more than half a century. The only thing missing from the action is the crew. The three Americans and one Canadian remain in quarantine in Houston. They could launch as soon as this coming weekend.