Method and system for unloading the inertia wheels of a spacecraft
AssigneeThales
InventorFrancois Guyot
Life of this patent
Estimating the term…
Abstract
The method for unloading the inertia wheels of a spacecraft comprising three references axes X, Y, Z, the axis Z corresponding to a pointing direction, consists in inverting the direction of accumulation of the angular momentum in the wheels by automatic rotational flipping of the spacecraft about the axis Z, the pointing direction remaining fixed. The method has application to the field of satellites or of interplanetary probes.
Claims9
A method for unloading inertia wheels of a spacecraft, the spacecraft comprising three reference axes X, Y, Z, the Z axis corresponding to a pointing direction and the spacecraft having a capacity to accumulate an onboard angular momentum in the inertia wheels up to a maximum loading value corresponding to a maximum angular speed, said method comprising, for unloading the inertia wheels of the spacecraft along the three axes X, Y, Z comprising:
- choosing a threshold value Hs for the onboard angular momentum in the inertia wheels, said threshold value being less than the maximum loading value, and,
- flipping the spacecraft only about the Z axis, while a pointing direction remains fixed, when the onboard angular momentum in the inertia wheels reaches or exceeds said threshold value, the flipping inverting the direction of accumulation of the angular momentum in the inertia wheels.
A system for a spacecraft comprising at least one inertia wheel, the spacecraft having a capacity to accumulate an onboard angular momentum in the at least one inertia wheel up to a maximum loading value, said system for unloading the at least one inertia wheel, said system comprising:
- at least one onboard computer for storing a threshold value Hs for the onboard angular momentum in the at least one inertia wheel, said threshold value being less than a maximum loading value, and,
- the at least one onboard computer triggering an automatic manoeuvre for rotational flipping of the spacecraft by a predetermined angle only about a Z axis corresponding to a pointing direction, the pointing direction remaining fixed, when the onboard angular momentum in the at least one wheel reaches or exceeds said threshold value, the angle being chosen so as to invert the direction of accumulation of the angular momentum in the at least one inertia wheel.
Dependencies are inferred from the claim text.