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What are the main characteristics of "memory" alloys?

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In order to implement the lunar antenna plan, a large diameter parabolic antenna must be transported to the moon ball by an aerospace aircraft. However, how can such a large antenna be equipped with a very small space shuttle inside the person? The U.S. Aerospace Administration uses the shape memory alloy technology. This alloy material will undergo significant changes in its physical properties under specific temperature conditions. It is an alloy with a unique shape memory function. After the initial deformation of the alloy, When the pre-deformation shape memory alloy is heated so that the temperature exceeds the phase transition temperature of the alloy, the shape memory alloy material will return to the shape before the deformation. NASA scientists made a parabolic lunar antenna from a shape memory alloy at room temperature, then kneaded it into a small group of less than 5 cm in diameter and launched it into the moon in the capsule of Apollo 11. Heated by sunlight on the moon surface to restore it to its original parabolic shape. This will allow the large antenna to be transported in a space limited space shuttle cabin.