The coming moon rush: Technology, billionaires, and geopolitics will all help get us back to the moon, but they won't be enough to let us live there indefinitely

Fifty years ago this month, two people walked on the moon. It was by any measure a high point in human history, an achievement so pure and glorious that for a moment, anyway, it seemed to unite the world's fractious, cacophonous communities into a kind of triumphant awe. Over the next three and a half years, 10 more people had the honor of leaving tracks on another world. And then it all came to a halt. • It's time to go back, and this time for a lot more than a series of multibillion-dollar strolls. • After decades of scattered objectives and human missions that literally went nowhere (aboard the International Space Station), the world's space agencies are coming into surprising, if delicate, alignment about returning to the moon and building a settlement there. NASA is leading the charge, with new and aggressive backing from the White House. The U.S. space agency has officially declared its intention to return humans to the moon by 2024—although many observers question whether it can adhere to such an ambitious timetable. • So far, NASA and its partners have drawn up the most detailed plans and spent the most money. But the enthusiasm goes far beyond the United States. This past April, Zhang Kejian, director of the China National Space Administration, said the country planned to build an inhabited research station near the moon's south pole "in about 10 years." China has the world's second-largest space budget behind the United States, and it has already put two landers and two rovers on the moon.