From the next room, through a thick granite wall, comes a chug-a-chuga- chug-a, like an old steam train closing in. Rounding the corner, I see the source of the racket: a table, shaking. The long, metal slab jerks quickly back and forth. On it, in two neat rows, are a half-dozen rectangular prisms packed with sensors measuring pressure and motion. Each one holds a titanium-alloy bolt the size of a grown man’s forearm and weighing about 10 pounds. As the elaborate assemblage might hint, these bolts are special.

Eventually, this remarkable hardware will go to space. The bolts, or ones like them, will hold together sections of the Orion spacecraft, a new vehicle that, sometime in the next decade, will carry humans out of low-Earth orbit for the first time since 1972—initially to the moon and later on trips to Mars. But before that, the fasteners must survive a mock version of their journey. Only worse.