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The Orbiting Frog Otolith (OFO) was a NASA space program which resulted in the successful launch in 1970 of the Orbiting Frog Otolith spacecraft (OFO-A mission), sending two bullfrogs into orbit for the study of weightlessness. The name, derived through common use, was a functional description of the biological experiment carried by the satellite. ''Otolith'' referred to the frog's inner-ear balance mechanism. The Orbiting Frog Otolith Program was a part of the research program of NASA's Office of Advanced Research and Technology (OART). One of the goals of the OART was to study vestibular organ function in space and on the Earth. The OFO experiment was designed to allow researchers to collect neurophysiological data on the response of the otolith to prolonged periods of weightlessness. The otolith is a part of the inner ear that is associated with equilibrium control: acceleration with respect to gravity as its primary sensory input. The Frog Otolith Experiment (FOE) was developed by Dr. Torquato Gualtierotti of the University of Milan, Italy, when he was assigned to the Ames Research Center as a resident Research Associate sponsored by the National Academy of Sciences. The experiment was designed to study the adaptability of the otolith to sustained weightlessness, to provide information for manned space flight. Originally planned in 1966 to be included on an early Apollo mission, the experiment was deferred when that mission was canceled. In late 1967 authorization was given to orbit the FOE when a supporting spacecraft could be designed. The project, part of NASA's Human Factor Systems program, was officially designated "OFO" in 1968. After a series of delays, OFO was orbited 9 November 1970. After the successful OFO-A mission in 1970, interest in the research continued. A project called Vestibular Function Research was initiated in 1975 to fly a vestibular experiment in an Earth-orbiting spacecraft. This flight project was eventually discontinued, but a number of ground studies were conducted. The research has given rise to several very useful offshoots, including the ground-based Vestibular Research Facility located at ARC. OFO should not to be confused with similar acronyms describing the Orbiting Observatory series of spacecraft, such as Orbiting Geophysical Observatory (OGO), Orbiting Solar Observatory (OSO), and Orbiting Astronomical Observatory (OAO). ==The OFO spacecraft== The OFO experiment was originally designed for flight within the Apollo Applications Program, which was established to make optimum use of hardware used in Apollo lunar missions. However, because the low acceleration levels needed for the experiment could not easily be maintained in a manned Apollo spacecraft, an unmanned satellite was later chosen as a more suitable vehicle. The satellite's design eliminated exposures to acceleration levels above 10−3''g'' (10 mm/s²). This meant that the experimental specimens could experience an almost weightless state. The spacecraft had a diameter of approximately 30 in (760 mm) and a length of 47 in (1,190 mm) The octagonal lower section of the spacecraft housed the electronic apparatus. The upper section, which contained the experiment package, was shaped like a truncated cone. A heat shield covering this upper section protected the experiment during re-entry into the Earth's atmosphere. A yo-yo de-spin assembly was located around the girth of the spacecraft. Four booms, folded against the side of the spacecraft, were located radially around the satellite. After the spacecraft separated from the launch vehicle, the yo-yo despin subsystem slowed spacecraft rotation. The four booms were then released to extend from the side of the spacecraft. The extension of the booms increased the moment of inertia of the spacecraft, permitting the acceleration level to remain below 10−3g. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Orbiting Frog Otolith」の詳細全文を読む スポンサード リンク
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