By segmenting the body into 14 idealized masses, a mathematical model is developed to approximate the mass distribution, center of mass, moments of inertia, and degrees of freedom of a human being. An analysis of the model reveals that the segment moments of inertia about the mass centers of the hands, feet, and forearms are negligible when compared to the total body moments of inertia, although the torso moment of inertia is not negligible. Some selected problems in thrust misalignment, freebody dynamics, stability of rotation, and torque application are solved analytically to predict man's dynamic response characteristics in space. Preliminary experiments indicate that the torque which weightless man can exert by applying a sudden twist to a fixed handle varies as a halfsine wave, and is approximately 67% of his maximum torque under normal gravity conditions. PUBLICATION REVIEWThis technical documentary report has been reviewed and approved.

The two automatic control modes of the Astronaut Maneuvering Research Vehicle (AMRV) are analyzed: the Control Moment Gyro (CMG) and the Rate Gyro (RG). The AMRV is an autonomous maneuvering unit which translates and rotates the pilot by means of hand-controller input commands. The CMG normal operation, desaturation, and cage/lock dynamics are described in terms of a typical AMRV mass property configuration. No propellant is used for normal operation in the CMG mode, and the maximum rotation rate is 5°/sec about each AMRV axis. The.RG attitude maneuvering and limit cycle submode dynamics are described in terms of the same AMRV mass property configuration. In the RG mode, attitude and attitude rate are maintained within limits of ±4° and ±2°/sec, respectively; the maximum rotation rate is 20°/sec about each AMRV axis. Translational maneuvering is identical in either mode, with linear velocities normally not exceeding 0.5 fps.

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This paper proposes a stop-gap nonoptimum vehicle for transferring astronauts from a tumbling stranded spacecraft to a nearby rescue spacecraft. The design is limited to the use of available or "soon-to-be" available flight-qualified hardware and consists of three major components: the manned maneuvering unit, the personnel rescue enclosure, and the apogee kick motor capture device. The apogee kick motor capture device is modified to serve as the connection between the manned maneuvering unit and the personnel rescue enclosure. The performance of this interim rescue vehicle is analyzed with NASA flight simulation software to test the feasibility of the design. Results show that the control system of the manned maneuvering unit adequately limits uncommanded rotations during all simulated maneuvers in the primary control mode but not during transverse translations in the backup control mode. Impingement of thruster plumes on the personnel rescue enclosure is shown to be of some importance in certain maneuvers. The satellite stabilization mode of the control system is found to have significant rotational-to-translational coupling that has associated adverse affects on flying qualities, making the mode undesirable for the rescue mission.

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