초록 ▼

A spacecraft system including a spacecraft assembly or "stack" having an upper stage of a rocket-powered launch vehicle providing a final boost phase during launch. The stack also includes a payload structure rotatably interconnected with the upper stage. The upper stage and the payload structure to

A spacecraft system including a spacecraft assembly or "stack" having an upper stage of a rocket-powered launch vehicle providing a final boost phase during launch. The stack also includes a payload structure rotatably interconnected with the upper stage. The upper stage and the payload structure together define a central axis that is generally coincident with the thrust axis during launch. The stack has an axis of maximum moment of inertia that is not parallel to the central axis. The stack has internal damping such that unstable nutation occurs if the upper stage and the payload structure rotate together about the central axis at the same rotational rate and in the same direction. The system includes a controller that rotates the payload structure relative to the upper stage during the final boost phase to alleviate coning motion of the stack.

대표청구항 ▼

The invention claimed is: 1. A spacecraft system, comprising: a stack including an upper stage of a rocket powered launch vehicle providing a final boost phase during launch; a payload structure rotatably interconnected with said upper stage, said upper stage and said payload structure together def

The invention claimed is: 1. A spacecraft system, comprising: a stack including an upper stage of a rocket powered launch vehicle providing a final boost phase during launch; a payload structure rotatably interconnected with said upper stage, said upper stage and said payload structure together defining a central axis that is generally coincident with the launch axis during launch, said stack defining an axis of maximum moment of inertia that is not parallel to said central axis and having internal damping such that unstable nutation occurs if said upper stage and said payload structure rotate together about said central axis at the same rotational rate and direction; said system including a controller that rotates said payload structure relative to said upper stage during the final boost phase and alleviates coning motion of the stack. 2. The spacecraft system of claim 1, wherein said controller is positioned on the earth and communicates with said stack via a radio signal. 3. The spacecraft system of claim 1, wherein said controller is on-board, and forms a part of said stack. 4. The spacecraft system of claim 1, including a motor providing powered rotation of said payload structure relative to said upper stage during the final boost phase. 5. The spacecraft system of claim 1, including a vibration isolation apparatus between said payload structure and said upper stage, said vibration isolation apparatus including a plurality of dampers and spring members. 6. The spacecraft system of claim 5, including a powered drive assembly rotatably interconnecting said upper stage and said payload structure. 7. The spacecraft system of claim 6, wherein said powered drive assembly is connected to said payload structure and to said vibration isolation apparatus, said vibration isolation apparatus being connected to said upper stage. 8. The spacecraft system of claim 6, wherein said vibration isolation apparatus is connected to said payload structure and to said powered drive assembly, said powered drive assembly being connected to said upper stage. 9. The spacecraft system of claim 1, including at least one powered actuator interconnecting said payload structure with said upper stage; and wherein said controller actively controls said actuator to alleviate nutation of said stack during the final boost phase. 10. The spacecraft system of claim 9, wherein said powered actuator comprises an electrically powered extendable strut. 11. The spacecraft system of claim 1, wherein said payload structure rotates relative to said upper stage at a rate that satisfies the Iorillo criterion during at least a portion of the final boost phase such that said stack is dynamically stable with respect to coning motion. 12. A spin stabilized spacecraft, comprising: a payload structure; a launch vehicle having an upper stage, said launch vehicle rotatably interconnected with said payload structure for rotation relative to said payload structure about a spin axis, said launch vehicle including a motor that powers said launch vehicle during a final boost phase; a powered actuator configured to rotate said launch vehicle relative to said payload structure; a release mechanism that is selectively actuated to separate said payload structure from said launch vehicle; and a controller configured to actuate said powered actuator and rotate said payload structure relative to said upper stage to alleviate coning motion of said upper stage during said final boost phase. 13. The spacecraft of claim 12, including: at least one powered actuator interconnecting said payload structure and said launch vehicle structure and generating a moment between the payload structure and the launch vehicle structure that is normal to said spin axis; and wherein said controller selectively actuates said powered actuator to reduce coning growth during said final boost phase. 14. The spacecraft of claim 13, wherein said spacecraft includes a load isolator apparatus having at least one spring and at least one damper interconnecting said payload structure to said launch vehicle structure and dissipating energy to reduce coning. 15. The spacecraft of claim 14, wherein said load isolator dissipates sufficient energy to ensure nutational stability. 16. A launch vehicle system, comprising: a stack including an upper stage of a rocket powered launch vehicle providing a final boost phase during launch; and a payload structure rotatably interconnected with said upper stage, said upper stage and said payload structure together defining a central axis that is generally coincident with the launch axis during launch, said stack defining an axis of maximum moment of inertia that is not parallel to said central axis and having internal damping such that unstable nutation occurs if said upper stage and said payload structure rotate together about said central axis at the same rotational rate and direction; said payload structure including an attitude control system having a rotating member that stores angular momentum; and a controller operably connected to said attitude control system, said controller configured to rotate said payload structure relative to said upper stage to alleviate coning motion of the stack during the final boost phase. 17. The launch vehicle system of claim 16, wherein said controller is positioned on the earth and communicates with said stack via a radio signal. 18. The launch vehicle system of claim 16, wherein said controller on-board, and forms a part of said stack. 19. The launch vehicle system of claim 16, including a vibration isolation apparatus between said payload structure and said upper stage, said vibration isolation apparatus including a plurality of dampers and spring members. 20. The launch vehicle system of claim 19, including a powered drive assembly rotatably interconnecting said upper stage and said payload structure. 21. The launch vehicle system of claim 20, wherein said powered drive assembly is connected to said payload structure and to said vibration isolation apparatus, said vibration isolation apparatus being connected to said upper stage. 22. The launch vehicle system of claim 20, wherein said vibration isolation apparatus is connected to said payload structure and to said powered drive assembly, said powered drive assembly being connected to said upper stage. 23. The launch vehicle system of claim 16, including at least one powered actuator interconnecting said payload structure with said upper stage; and wherein said controller actively controls said actuator to alleviate nutation of said stack during the final boost phase. 24. The launch vehicle system of claim 23, wherein said powered actuator comprises an electrically powered extendable strut.