The JWST sunshield is about 21 m × 14 m (69 ft × 46 ft), roughly the size of a tennis court, and is too big to fit in any existing rocket. Therefore, it was folded up to fit within the fairing of the launch rocket and was deployed post-launch, unfolding five layers of metal-coated plastic. The first layer is the largest, and each consecutive layer decreases in size.