Rovers, drones, and landers will usher in a sustained lunar presence, under the new plan NASA announced this week. The crew of Artemis 2 snapped this image of Earth as it was about to "set" behind the Moon. NASA Two months ago, NASA leadership scrapped their longstanding plans for the lunar Gateway, an international space station designed to orbit the Moon and provide a home base for astronauts en route to the lunar surface. On Tuesday, May 26th, the agency outlined the first steps in its ambitious replacement: the Moon Base missions, complete with rovers, landers, and drones. The agency is putting money where its mouth is, with more than $700 million contracted out amongst top players in the U.S. space industry. (By its completion, the total base is expected to cost $20 billion). But the timelines are ambitious, and some worry the U.S. may be pushing the boundaries of the international treaties it sought to sanction.…