NASA is again shooting for the moon, but before a manned mission can get off the ground, scientists must solve a vexing technological challenge: dust.

As the Apollo 11 astronauts found out when they walked onto the moon 40 years ago Monday, lunar dust is downright treacherous. To the naked eye, it looks powdery, almost fluffy. But each particle is jagged. Dust scratched the astronauts' visors, ground into the joints of their spacesuits, clogged their equipment, and -- after they inadvertently tracked it into their living quarters...