October 1993 NF202
The legacy of NASA's-and the worlds-first passive communications satellite is a booming metallization industry with scores of applications.
Launched August 12, 1960, Echo I captured the world's imagination, and was the debutante of the year-bigger, brighter and more brilliant than almost any star in the firmament.
The process of coating plastics with a mist of metal to create a foil-like effect-metallization transformed a 1950s small scale manufacturing operation producing decorative metallized plastics into a flourishing industry-thanks to NASA's efforts to share their successful adaptations of an existing technology. The results range from food packaging and aircraft covers to clothing and survival equipment.
NASA first dealt with this type of metallization when developing its Echo I satellite in the 1950s. Developed at the NASA Langley Research Center, Hampton, Virginia, the world's first passive communications satellite was simply a very large balloon, its diameter close to the height of a 10-story building. It served as a space relay station for reflecting communication signals from one point on Earth to another.
When developing Echo I, NASA needed a special material for the balloon's skin. For "bouncing" signals, the material had to be highly reflective. It also had to be lightweight and exceptionally thin so that it could be folded into a beach-ball-size canister for delivery to orbit, where the balloon would automatically inflate. The material selected was mylar polyester coated with a reflective layer of tiny aluminum particles so fine that Echo's skin had a thickness about half that of the cellophane on a cigarette package.
Metallization was not an exotic space-age development. It originated in the 19th century, but the technology and its applications developed slowly. By the late 1950s, when Echo was in design status, the metallization industry barely existed. The market was slim and production was very limited. Metallicized plastics were being produced mostly for decorative purposes.
MORE SPACE APPLICATIONS
Echo requirements triggered extensive research and development (R&D) of metallization techniques by NASA that led to further space applications, mostly for thermal radiation insulation. NASA used metallized film on virtually every U.S. spacecraft, from early satellites of Echo's vintage through the manned Apollo and Skylab programs. NASA also used the material as a reflective insulator to protect astronauts from solar radiation and to protect sensitive spacecraft instruments.
The growing field of applications spurred R&D by manufacturers to improve vacuum metallizing techniques, that resulted in development of a broad, still-growing line of commercializedmetallized products. Today, there are many diverse commercial products, including insulated garments, life rafts, reflective blankets, wall coverings, window shades, food packaging, candy wrappings and photographic reflectors.
A super-reflective, nonporous, waterproof and rot-proof laminate known as TXG was developed from metallization technolology for production of a survival raft that provides maximum protection from heat, cold, wind and rain. The laminate was once used by NASA as a reflective canopy far visual and radar detection of the rafts that returning Apollo astronauts used while waiting to be picked up by ships or helicopters after splash down.
A reflective kite of gold TXG was produced to serve as a highly effective distress indicator in an emergency. The SOS Signal Kite can be flown as high as 200 feet to enhance radar and visual detectability. It provides campers, hikers, mountain climbers and boaters with a lightweight, easily portable emergency signaling device. Made of metallized nylon, the kite spans six feet but weighs only six ounces.
Other products include protective fabrics that retain up to 80 percent of the user's body heat, helping to keep a person warm for hours in cold weather or to prevent post-accident shock. All are remarkably compact. The Space Emergency Bag, for instance, opens into a three-by-seven-foot personal tent-blanket and then folds into a three ounce package the size of a deck of playing cards.
The TXG laminate has also been used to develop heat shields, custom tailored reflective curtains that cover the windshield and windows of parked aircraft to protect electronic equipment from heat buildup and ultraviolet radiation. A multi-layered automatic shade system for large windows has also been adapted.
Alure, a metallized plastic material developed and manufactured by the St. Regis Paper Company, has been developed to meet a multiple packaging material need: good eye appeal, product protection for long periods of time, and the ability to be used successfully on a wide variety of food packaging equipment. When the cost of aluminum foil skyrocketed, packagers sought substitute metallized materials but experiments with a number of them uncovered problems. Some were too expensive, some did not adequately protect the product, some were difficult for the machinery to handle. Alure offered a solution.
Alure effectively blocks out light, moisture and oxygen and, therefore, gives packaged foods a long shelf life. It also runs faster on machines than materials used in the past, and decreases product waste. The net is increased production.
One of the most popular metallized products is a lightweight jacket fabricated by several companies from NASA's super-insulation. The 10-ounce reversible jacket absorbs warmth from the sun, and with the silver-colored side next to your body, it retains a large portion of body heat. In warm weather, you wear the silver side out to reflect the sun's rays.
In a similar model, a gold metallized polyester film is bonded to a tear resistant fabric to allow radar reflection, as well as higher visibility under all light conditions.
Like other jackets, the materials protect against heat or cold and do not absorb moisture.
Other products marketed include a three-ounce Thermos Emergency Blanket, that reflects and retains up to 80 percent of the user's body heat, thus helping to prevent post-accident shock. It will keep a person warm for hours under emergency cold weather conditions, and has been used by participants in the Boston Marathon as a post-race measure to prevent loss of body temperature.
The metallization story is an excellent example of the aerospace spinoff process. This instance involves a technology that existed before the NASA application, but space use prompted far greater commercial applicability. It is a great example, where an adaption of existing technology for an aerospace requirement resulted in expanded markets for the technology to the benefit of the U.S. economy. More often, spinoffs stem from technology specifically developed for the aerospace purposes and are later adapted to Earth needs and conveiniences.
Echo the "Star"
The world's first passive reflector communications satellite, Echo I came down from its nearly circular orbit 800 miles above the Earth May 23, 1968. The 100-foot globe of aluminum-coated mylar plastic, in orbit for more than sevenand-one-half years, was battered by space dust and meteoroids so that its skin was wrinkled like a prune.
During its travels, it was probably seen by more people than any other man-made object in space. It was visible to the unaided eye over most of the Earth. Echo fan clubs sprang up in schools; newspapers and radio stations reported daily predictions where it would pass. Boy and Girl Scout troops waited for her...as did many thousands of others in big and little communities. In slightly more than seven-and-a-half years since launch, Echo I flew around the Earth more than 35,600 times, in excess of one billion miles. It was familiar to millions of people throughout the world as a fast moving star in the sky.
Proposed uses were: