Photograph depicting Nancy Wendler demonstrating zero gravity shoes for their developer, John F. Heard. The soles of the shoes are covered with minute nylon hooks that engage with a carpeted surface to create the fastening effect. The holding power of the material is great enough to suspend the weight of an average size person even with the earth's gravity pulling. In space, relatively small amounts of the hook material would be required to keep an astronaut walking properly. Dated 20th century