Why Did NASA Launch Giant Metal Spheres Into Space?

In the 1960s, NASA launched massive, 100-foot inflatable metallic spheres into orbit. But why? These "big metal balls" were actually part of Project Echo—a pioneering mission to bounce radio signals across the globe using giant orbiting mirrors. In this video, we explore how engineers packed a massive spacecraft into a tiny payload, used sublimating gas to inflate it in the vacuum of space, and proved that thin Mylar and aluminum foil could survive low-Earth orbit. We also touch on the modern "metal balls" (rocket pressure vessels) that occasionally crash back to Earth as space debris!