Through an examination of NASA functions and space program areas and their interrelationship, it is shown that the objectives of MSA earth orbital programs are: to develop space systems that will contribute to the solution of basic national problems by exploiting space for human welfare and knowledge, to exploit space for the advancement of science and technology, and to develop space capabilities precursor to planetary exploration. The role of a space station in the earth orbital program is that of a manned orbital research facility capable of exploiting the unique features of the space environment in combination with the capabilities of man as an onboard investigator to accomplish a broad spectrum of research and development in all areas of interest. Man's role in the orbiting research facility is similar to his role in a research laboratory on earth. His ability to observe and act upon unforeseen phenomena and events when coupled with the earth overview, the space environment, and the scientific instrumentation and equipment which can be available aboard an orbiting laboratory offers a unique opportunity. A manned orbiting research facility, however, should not be utilized to perform functions or programs which can be done economically and reliably by automated spacecraft.