Why landing on the moon is proving more difficult today than 50 years ago

News Snapshot:

It was a flawless launch. In the early hours of Monday morning, the Vulcan Centaur rocket rattled into the darkness over Cape Canaveral, shed its solid rocket boosters and released the Peregrine spacecraft on the perfect trajectory for its landmark mission to the moon. The success prompted a “Yee-haw!” from Tory Bruno, the chief executive of United Launch Alliance, which built the rocket: this was the Vulcan’s maiden flight, after all. But it wasn’t long before the mood shifted. Astrobotic, the company behind Peregrine, found the spacecraft was leaking propellant. And without sufficient fuel, the chances of landing softly on...