Abstract: A method for controlling a spacecraft comprising the steps of providing a first spacecraft in a known first predetermined orbit, and a second spacecraft in a second predetermined orbit. The distance between the first and second spacecraft is measured. The measured distance and data describing the known first predetermined orbit are used for determining an orbital error bias of the second spacecraft relative to the second predetermined orbit. The second spacecraft is maneuvered to compensate for the orbital error bias, and to maintain the second spacecraft in the second predetermined orbit.

Abstract: A method for controlling a spacecraft comprising the steps of providing a first spacecraft in a known first predetermined orbit, and a second spacecraft in a second predetermined orbit. The distance between the first and second spacecraft is measured. The measured distance and data describing the known first predetermined orbit are used for determining an orbital error bias of the second spacecraft relative to the second predetermined orbit. The second spacecraft is maneuvered to compensate for the orbital error bias, and to maintain the second spacecraft in the second predetermined orbit.

Abstract: A space platform assembly designed to be attached to the outer surface of a space station structure for deployment of a tethered space platform into isolation orbit alongside the space station. The space platform is designed to carry payloads such as for research experimentation in the microgravity environment of space. The tether comprises a loose power/data umbilical for the deployed space platform while it orbits free of the vibration and g-jitter problems of the space station.

Abstract: A system is described for determining motion of an object that is acoustically positioned in a standing wave field in a chamber. Sonic energy in the chamber is sensed, and variation in the amplitude of the sonic energy is detected, which is caused by linear motion, rotational motion, or drop shape oscillation of the object. Apparatus for detecting object motion can include a microphone (24) coupled to the chamber and a low pass filter (40) connected to the output of the microphone, which passes only frequencies below the frequency of sound produced by a transducer (18) that maintains the acoustic standing wave field. Knowledge about object motion can be useful by itself, can be useful to determine surface tension, viscosity, and other information about the object, and can be useful to determine the pressure and other characteristics of the acoustic field.

Abstract: Apparatus for detecting and computing the location of a baseball as it is pitched over a plate is disclosed. Infrared receivers are disposed at corner locations on opposite sides of a target zone which is aligned with the plate. First and second arrays of infrared emitters are mounted on opposite sides of the target zone for transmitting infrared light pulses to the opposite corner receivers. The infrared emitters are sequentially energized and transmit infrared pulse signals having relatively short durations in a scan cycle. Digital data words representative of the reception and nonreception by the receivers of the optical pulse signals are generated during each pulse interval of the scan cycle. Computer circuitry calculates the coordinates of the baseball within the target zone as a function of predetermined angular data retrieved computer memory.