Inflating A Metal Balloon in Space

Inflating a spacecraft in orbit is not an easy task, but NASA had an solution. Echo-1 and Echo-2 were launched as compact payloads, but once in space, benzoic acid gas was released, inflating the thin shell and expanding into giant reflective balloons. But space isn’t exactly gentle, and the balloons were at risk of micrometeorites puncturing their delicate membranes. The solution for Echo-2 was to build it tougher. Mylar was sandwiched between layers of aluminum foil - a surprisingly simple solution for something floating in orbit, trying not to get shredded by space dust.