Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
165 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission; rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilization phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axes at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed.
Claim 2
Independent Claim
165 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission; rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilization phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axes at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said change of trajectory is from an elliptical transfer trajectory to a substantially circular trajectory.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein said rotating of said satellite is performed at a constant rate.
Claim 5
Dependent Claim
35 words
The method of claim 1, wherein said spinning stabilization phase is performed in an eccentric orbit about the Earth and a later three-axis stabilization phase is during a geostationary position with respect to the Earth.
Claim 6
Dependent Claim
87 words
The method of claim 1, wherein said mission of said satellite includes a phase wherein said satellite is carried by a final stage of a launch vehicle and wherein the step of activating said momentum wheel occurs prior to separation of said satellite from said final stage and wherein said method includes the step of rotating said launch stage and satellite prior to separation in such a manner that the satellite axis of rotation extends parallel to said momentum wheel axis and perpendicular to a predetermined trajectory.
Claim 7
Dependent Claim
40 words
The method of claim 1, further including the step of determining the position of the satellite spin axis during the spin-stabilized transfer phase by using a direction sensor and correcting the attitude of said satellite in response to said determination.
Claim 8
Dependent Claim
31 words
The method of claim 1, further including the step of adjusting the rotational rate of the satellite during the spin-stabilized transfer phase by controlling the rotational rate of said momentum wheel.
Claim 9
Independent Claim
217 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission; rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilization phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axes at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed; and wherein said satellite includes sun and Earth sensors for three-axis stabilization, and further including the step of shifting the null point of said sun sensor rotating the satellite about an axis so that the impulse for changing the trajectory of the satellite will simultaneously change the inclination of the previous orbit.
Claim 10
Independent Claim
217 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission; rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilization phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axes at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed; and wherein said satellite includes sun and Earth sensors for three-axis stabilization, and further including the step of shifting the null point of said sun sensor rotating the satellite about an axis so that the impulse for changing the trajectory of the satellite will simultaneously change the inclination of the previous orbit.
Claim 11
Independent Claim
184 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission: rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilized phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axis at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed; and including the step of de-spinning said momentum wheel when said satellite has substantially achieved a desired new orbit.
Claim 12
Independent Claim
184 words
A method for attitude control and trajectory change of a satellite having a mission encompassing a transfer phase wherein said satellite is spin-stabilized and a latter phase wherein said satellite is three-axis stabilized, said satellite having a momentum wheel, an attitude control system and propulsion means, said method comprising the steps of: activating said momentum wheel at the latest in the transfer phase of the mission: rotating said satellite about an axis of the satellite which is parallel to the spin axis of the momentum wheel with a smaller angular momentum than that of said momentum wheel during said spin-stabilized phase; substantially changing the trajectory of said satellite from said transfer phase to a substantially different trajectory and stabilizing said satellite along three axis at the moment of said changing of trajectory; and selecting the thrust of said propulsion means to be effective to maintain proper satellite attitude during said changing of trajectory and for a period of three-axis stabilization after said trajectory is changed; and including the step of de-spinning said momentum wheel when said satellite has substantially achieved a desired new orbit.
Claim 13
Dependent Claim
205 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite.
Claim 14
Dependent Claim
205 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite.
Claim 15
Dependent Claim
40 words
The system of claim 10, wherein said liquid fuel propulsion means includes a common fuel storage and distribution system, said propulsion means including a portion for changing the trajectory and a separate portion for correcting the attitude of the satellite.
Claim 16
Dependent Claim
34 words
The system of claim 11, wherein said liquid fuel propulsion means includes two pairs of engines disposed on the satellite for each of the roll, pitch and yaw axes respectively for controlling the attitude.
Claim 17
Dependent Claim
20 words
The system of claim 12, wherein said trajectory changing portion is arranged parallel to one of the pairs of engines.
Claim 18
Dependent Claim
290 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite, wherein said liquid fuel propulsion means includes a common fuel storage and distribution system, said propulsion means including a portion for changing the trajectory and a separate portion for correcting the attitude of the satellite, wherein said liquid fuel propulsion means includes two pairs of engines disposed on the satellite for each of the roll, pitch and yaw axes respectively for controlling the attitude and wherein each pair of said two pairs of engines for each axis are offset with respect to the other pair.
Claim 19
Dependent Claim
290 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite, wherein said liquid fuel propulsion means includes a common fuel storage and distribution system, said propulsion means including a portion for changing the trajectory and a separate portion for correcting the attitude of the satellite, wherein said liquid fuel propulsion means includes two pairs of engines disposed on the satellite for each of the roll, pitch and yaw axes respectively for controlling the attitude and wherein each pair of said two pairs of engines for each axis are offset with respect to the other pair.
Claim 20
Dependent Claim
247 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and wherein said satellite includes telemetry means for receiving a ground control signal, said satellite including means responsive to said ground control signal for activating said propulsion means to effect change of trajectory from said transfer phase to said three-axis stabilized phase.
Claim 21
Dependent Claim
247 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and wherein said satellite includes telemetry means for receiving a ground control signal, said satellite including means responsive to said ground control signal for activating said propulsion means to effect change of trajectory from said transfer phase to said three-axis stabilized phase.
Claim 22
Dependent Claim
220 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and including means for controlling the rotational speed of said satellite during said spin-stabilized phase.
Claim 23
Dependent Claim
220 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent three-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and including means for controlling the rotational speed of said satellite during said spin-stabilized phase.
Claim 24
Dependent Claim
242 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent thee-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and including sensor means for monitoring the Earth and sun positions in said three-axis phase, said Earth sensor means also for providing a signal for controlling the rotational speed of the satellite during said spin-stabilized phase.
Claim 25
Dependent Claim
242 words
In a satellite with a mission including a spin-stabilized transfer phase and a subsequent three-axis stabilized phase, a satellite attitude control and trajectory changing system for controlling the attitude of said satellite during said spin-stabilized transfer phase and for effecting substantial change of trajectory and controlling the attitude of said satellite during said subsequent thee-axis stabilized phase, comprising: a momentum wheel, said wheel having a spin axis arranged to be parallel with the spin axis of said satellite during said spin-stabilized transfer phase of said satellite, said momentum wheel spin axis also being aligned with the pitch axis of said satellite in said subsequent three-axis stabilized phase; means for causing said momentum wheel to spin at a rate wherein the angular momentum of said spinning satellite during the transfer phase is less than that of the momentum wheel; means for providing signals for controlling the attitude of said satellite in said spinning and three-axis stabilized phases; and liquid fuel propulsion means responsive to said attitude control signals having a plurality of engines associated therewith, said engines being disposed on said satellite for providing appropriate thrust for substantially changing the trajectory of the satellite when leaving the transfer phase and for stabilizing the attitude of the satellite; and including sensor means for monitoring the Earth and sun positions in said three-axis phase, said Earth sensor means also for providing a signal for controlling the rotational speed of the satellite during said spin-stabilized phase.