Manned Spacecraft Programs are the largest research and development tasks ever undertaken by the government or by private industry in the United States. Under the direction of the National Aeronautic and Space Administration (NASA) these programs have advanced from Project Mercury in the early 1960's through Gemini, Apollo, including Moon Landing, and Skylab Programs to the present day Space Shuttle Program. With the development of each new program, there comes a growing awareness of the ever increasing complexity of tasks relating to integrated preflight test and checkout. Data rates have grown from one (1) pulse amplitude modulated/frequency modulated (PAM/FM) link with just over a hundred (100) measurements to multiple pulse code modulated (PCM) links with many thousands of measurements and bit rates up to fifty (50) megabits per second (MBPS). A unique requirement of Manned Spacecraft Programs in the "Man Rating" concept. Man rating requires that every failure and test anomaly be analyzed, understood and/or corrected prior to flight. This further complicates an already complex test and checkout program. Exploitation of the potentials of automation was and is the only recourse for present day and future programs. Such automation should be as automatic as possible but must have a man-in-the-loop capability to assure that the test engineer has positive control at all times. This paper analyzes the progress in automation in round test and checkout from Project Mercury days with a simplified prototype technique for Space Shuttle.