Don Newcomb was perplexed. It had been five year since he had founded Interplants, Inc., a researchand$-$development firm that developed genetically engineered plants for interplanetary space flight. During that five years, he and his scientists had mad dramatic advances in developing special plants that could be used for food and air$-$purification systems space stations and transports. In fact, he mused, thei scientific success had been far greater than he had ever expected.