Four astronauts are now inexorably bound for the Moon

Most Americans, indeed about three-quarters of the population around the world, have not witnessed humans leaving low-Earth orbit in their lifetimes. The last time this occurred was 1972, with the final Apollo Moon mission.

The "translunar injection" burn of Orion's main engine occurred about one day after the successful launch of the mission on NASA's Space Launch System rocket from Kennedy Space Center on Wednesday. This burn was the last major firing of Orion's main engine, and sets the crew on a course to fly around the Moon on Monday, slingshot back toward Earth under lunar gravity, and splash down in the Pacific Ocean on Friday, April 10.

"Things are going really well right now," said Lori Glaze, NASA's senior official over exploration, during a news conference on Thursday evening. "I don't think we could be more pleased.