SIGNIFICANCE FOR PRACTICAL APPLICATIONS It can be predicted as confidently for space biology as for other space sciences that the economic costs will be amply repaid in the long run by applications of space-oriented biotechnology to other fields of biology and medicine. There are inevitable substantial, though indirect, contributions of NASA’s continuing efforts in space biology. NASA-supported biological research has many practical applications and "spinoffs" which contribute to the fields of health and medicine, food and agriculture, and industry and manufacturing. Some of these are presented to show the range and value of applications which have resulted from basic and applied biological research. In addition to those listed are many others from the biosatellite program, particularly in the fields of bioengineering and miniaturization. Health and Medicine Solar cells, which have powered space systems, are now being used as a power source in studies on brain function. A miniaturized solar cell developed by General Electric provides enough power, under ordinary house lights, to stimulate an animal’s brain and to telemeter respiratory, cardiovascular, and brain-wave data while the animal is allowed to move about freely. Such a system is now used by the National Institute of Mental Health Laboratory at Rethesda, Md. Scientists at the Ames Research Center have devised a new technique for studying organic compounds, whether synthesized in the laboratory or produced by a living system. This technique is based on a property of matter called optical activity. Previous methods of measuring optical activity have been plagued by low sensitivity. The new method is many tunes more sensitive and represents a real contribution to modern analytical instrumentation. Studies on calcium metabolism and bed rest simulating weightlessness are adding knowledge on the prevention of demineralization of the skeleton; treatment of Paget’s disease and osteoporosis prevention of muscular atrophy; the cause and treatment of renal calculi (kidney stones); optimal calcium for the human diet; and the factors influencing calcium absorption, metabolism, and excretion. The results will have great importance in bone healing and repair, care and treatment of fracture cases, treatment of paraplegics, and treatment of polio patients and similar cases. These grant studies at Texas Woman’s University have also proven that the X-ray bone densitometry method can accurately detect changes in the skeleton.