Satellite attitude control mechanism and method

Claim 2

In combination: a. a satellite main body adapted for projection into an orbit around the earth, b. an auxiliary body, c. means for effecting deployment of said auxiliary body in space substantially vertically at a distance from said main body which is more than 10 times the length of any rigid part of said main body, d. a flexible tether adapted for maintaining interconnection of said bodies so deployed and for maintaining said distance by tension therein, e. facilities for storing said tether compactly for launching into orbit, said tether being withdrawable from said facilities during said deployment, f. means for measuring the state of oscillations tilting the tetherline from the local vertical. g. a thruster in said main body positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, said thrust being controllable in response to the output of said means for measuring so as to reduce the amplitude of said oscillations of the tetherline, and h. means for damping rotational oscillations of said main body.

Claim 3

The combination as defined by claim 1 wherein said tether is substantially without bending stiffness, light in weight, and more than 30 times the length of any rigid part of said main body.

Claim 4

The combination as defined by claim 1 wherein one of said bodies comprises a first portion, a second portion, and a damping hinge interconnecting said first and second portions.

Claim 5

The combination as defined by claim 1 wherein said main body includes earth-pointing instrumentation.

Claim 6

The combination as defined by claim 4 wherein said instrumentation comprises a directional antenna.

Claim 7

The combination as defined by claim 1 wherein said last-named means comprises a single-degree-of-freedom gyroscope.

Claim 8

The combination as defined by claim 1 wherein said main body comprises a structure attached to said tether and extensible in orbit, thereby to provide a point of attachment of said tether to said main body relatively distant from the center-of-mass of said main body.

Claim 9

The combination as defined by claim 1 wherein said auxiliary body is releasably attachable to said main body for transport into orbit and said deployment means comprises means for thrusting said auxiliary body away from said main body consequent upon its release therefrom.

Claim 10

The combination as defined by claim 8 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 11

The combination as defined by claim 1 wherein said means for measuring is an earth-horizon sensor.

Claim 12

The combination as defined by claim 12 wherein said last-named means comprises a single-degree-of-freedom gyroscope.

Claim 13

The combination as defined by claim 1 wherein said means for measuring comprises ground-based means for measuring the strength of radio signals received from a directional radio antenna mounted on said main body.

Claim 14

The combination as defined by claim 1 wherein the thrust of said thruster is controllable by radio command from the ground consequent upon grOund-based analysis of the output of said means for measuring.

Claim 15

The combination as defined by claim 2 wherein the length of said tether is more than 100 times the greatest dimension of any rigid part of said main body.

Claim 16

The combination as defined by claim 2 wherein the length of said tether is more then 500 times the greatest dimension of any rigid part of said main body.

Claim 17

The combination as defined by claim 2 wherein one of said bodies comprises a first portion, a second portion, and a damping hinge interconnecting said first and second portions.

Claim 18

The combination as defined by claim 7 wherein said last-named means comprises a single-degree-of-freedom gyroscope.

Claim 19

The combination as defined by claim 8 wherein said last-named damping means comprises a single-degree-of-freedom gyroscope.

Claim 20

The combination as defined by claim 10 wherein said means for damping comprises a single-degree-of-freedom gyroscope.

Claim 21

The combination as defined by claim 11 wherein said last-named damping means comprises a single-degree-of-freedom gyroscope.

Claim 22

The combination as defined by claim 8 wherein said main body comprises a structure attached to said tether and extensible in orbit, thereby to provide a point of attachment of said tether to said main body relatively distant from the center-of-mass of said main body.

Claim 23

The combination as defined by claim 10 wherein said main body comprises a structure attached to said tether and extensible in orbit, thereby to provide a point of attachment of said tether to said main body relatively distant from the center-of-mass of said main body.

Claim 24

The combination as defined by claim 11 wherein said main body comprises a structure attached to said tether and extensible in orbit, thereby to provide a point of attachment of said tether to said main body relatively distant from the center-of-mass of said main body.

Claim 25

The combination as defined by claim 12 wherein said main body comprises a structure attached to said tether and extensible in orbit, thereby to provide a point of attachment of said tether to said main body relatively distant from the center-of-mass of said main body. 25. The combination as defined by claim 12 wherein said auxiliary body is releasably attached to said main body for transport into orbit and said deployment means comprises means for thrusting said auxiliary body away from said main body consequent upon its release therefrom.

Claim 26

The combination as defined by claim 3 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 27

The combination as defined by claim 6 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 28

The combination as defined by claim 7 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 29

The combination as defined by claim 10 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 30

The combination as defined by claim 11 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 31

The combination as defined by claim 12 wherein said auxiliary body is the last stage of the launch vehicle which places said main body into orbit.

Claim 32

The combination as defined by claim 12 wherein said means for measuring is an earth-horizon sensor.

Claim 33

The combination as defined by claim 12 wherein said means for measuring comprises ground-based means for measuring the strength of radio signals received from a directional radio antenna mounted on said main body.

Claim 34

In combination: a. a satellite main body adapted for projection into an orbit around the earth, b. an auxiliary body, c. a flexible tether, d. facilities fOr containing said tether compactly for launching, e. means for effecting deployment of said auxiliary body in space substantially vertically at a distance from said main body which is more than 10 times the length of any rigid part of said main body, for withdrawing said tether from said facilities during said deployment, and for maintaining said distance by tension in said tether, f. means for measuring the state of oscillations tilting the tetherline from the local vertical, g. a thruster in said main body positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, said thrust being controllable in response to the output of said means for measuring so as to reduce the amplitude of said oscillations of the tetherline, and h. means for damping rotational oscillations of said main body.

Claim 35

In combination: a. a satellite main body adapted for projection into an orbit around the earth, b. an auxiliary body, c. a flexible tether, d. facilities fOr containing said tether compactly for launching, e. means for effecting deployment of said auxiliary body in space substantially vertically at a distance from said main body which is more than 10 times the length of any rigid part of said main body, for withdrawing said tether from said facilities during said deployment, and for maintaining said distance by tension in said tether, f. means for measuring the state of oscillations tilting the tetherline from the local vertical, g. a thruster in said main body positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, said thrust being controllable in response to the output of said means for measuring so as to reduce the amplitude of said oscillations of the tetherline, and h. means for damping rotational oscillations of said main body.

Claim 36

In combination: a. a satellite main body adapted for projection into an orbit around the earth, b. an auxiliary body, c. a flexible tether adapted for maintaining taut interconnection of said bodies substantially along the local vertical, the length of said tether being at least 10 times the greatest dimension of any rigid part of said main body, d. means for effecting deployment of said auxiliary body to the required position relative to said main body after orbital injection, e. facilities for storing said tether completely for launching into orbit, said tether being withdrawable from said facilities during said deployment, f. means for measuring the state of oscillations tilting the tetherline from the local vertical, g. a thruster in said main body positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, said thrust being controllable in response to the output of said means for measuring so as to reduce the amplitude of said oscillations of the tetherline, and h. means for damping rotational oscillations of said main body.

Claim 37

In combination: a. a satellite main body adapted for projection into an orbit around the earth, b. an auxiliary body, c. a flexible tether adapted for maintaining taut interconnection of said bodies substantially along the local vertical, the length of said tether being at least 10 times the greatest dimension of any rigid part of said main body, d. means for effecting deployment of said auxiliary body to the required position relative to said main body after orbital injection, e. facilities for storing said tether completely for launching into orbit, said tether being withdrawable from said facilities during said deployment, f. means for measuring the state of oscillations tilting the tetherline from the local vertical, g. a thruster in said main body positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, said thrust being controllable in response to the output of said means for measuring so as to reduce the amplitude of said oscillations of the tetherline, and h. means for damping rotational oscillations of said main body.

Claim 38

For use with a satellite main body adapted for projection into an orbit around the earth, a system for maintaining said body in a preferred earth orientation comprising; a. an auxiliary body, b. a tether, c. facilities for containing said tether for launching, d. means for deploying said auxiliary body in space at a distance from said main body which is more than 20 times the length of any rigid part of said main body, connected to said main body by said tether, and for maintaining said distance by tension in said tether, e. reaction means, part of said main body, positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, f. means for measuring the state of dumbbell oscillations of said tetherline, g. means for controlling said thrust responsive to the state of said dumbbell oscillations, and h. means for damping rotational oscillations of said main body.

Claim 39

For use with a satellite main body adapted for projection into an orbit around the earth, a system for maintaining said body in a preferred earth orientation comprising; a. an auxiliary body, b. a tether, c. facilities for containing said tether for launching, d. means for deploying said auxiliary body in space at a distance from said main body which is more than 20 times the length of any rigid part of said main body, connected to said main body by said tether, and for maintaining said distance by tension in said tether, e. reaction means, part of said main body, positioned to provide thrust directed substantially horizontally and through the center of mass of said main body, f. means for measuring the state of dumbbell oscillations of said tetherline, g. means for controlling said thrust responsive to the state of said dumbbell oscillations, and h. means for damping rotational oscillations of said main body.

Claim 40

The combination as defined by claim 36 wherein said main body contains for yaw stabilization, a rotor constrained with its spin axis oriented so as to produce a substantial quantity of angular momentum directed substantially in that plane of the main body that is to be stabilized vertically and perpendicular to the orbital plane.

Claim 41

The combination as defined by claim 37 wherein said rotor is the rotor element of a gyroscope and said gyroscope comprises viscous damping means applied to its gimbal axis motion.