System and method for sensing attitude of a spacecraft with equilized star tracker errors along three orthogonal axes
AssigneeHughes Aircraft Company
InventorRene Abreu
Life of this patent
Estimating the term…
Abstract
A star tracker 10 of an attitude control system 8 on board a spacecraft 9 is positioned so that the tracker's line-of-sight vector 12 intersects the origin of the reference axis but is askew from any reference axis of the spacecraft. The attitude control system transforms the dam from a star tracker reference coordinate system to a spacecraft reference coordinate system so as to allow control of the attitude of the spacecraft without modification of existing equipment.
Claims11
A tracker for an attitude control system of an object having a set of reference axes that define the reference coordinate system of the object, said tracker comprising:
- a planar light detecting array having a line-of-sight vector normal to said array and a data output for outputting data;
- means for positioning said light detecting array on said object, such that said line-of-sight vector intersects the origin of the reference axes and is askew from each reference axis of said object.
A system for controlling the attitude of an object, said object having a set of reference axes which define the reference coordinate system of the object, said system comprising:
- a planar light detecting array having a line-of-sight vector normal to said array and a data output for outputting data,
- means for positioning said light detecting army on said object, such that said line-of-sight vector intersects the origin of the reference axes and is askew from each reference axis of said object;
- and
- means connected to the data output of said tracker for responsively controlling the attitude of said object with respect to said reference axes.
A system on-board a spacecraft for controlling the attitude of a spacecraft, said spacecraft having a set of reference axes which define the reference coordinate system of the spacecraft, said system comprising:
- a star tracker including a planar light detecting array having a line-of-sight vector normal to said array and a data output for outputting tracking data;
- means for positioning said tracker on said spacecraft, such that said line-of-sight vector intersects the origin of the reference axes and is askew from each reference axis of said spacecraft;
- and
- means connected to the data output of said tracker for responsively controlling the attitude of said spacecraft with respect to said reference axes.
A method for controlling the attitude of a spacecraft in space, said method comprising:
- acquiring data about a field of view of a star tracker having a light detecting planar array with a line-of-sight vector normal to said array and askew from any axis of a set of axes defining reference axes for said spacecraft, and a data output for outputting tracking data;
- transforming said data from a tracker reference coordinate system orthogonal to said line-of-sight vector to a reference coordinate system defined by said spacecraft reference axes;
- outputting said transformed data to a means for adjusting the attitude of said spacecraft;
- and
- adjusting the attitude of said spacecraft.
Dependencies are inferred from the claim text.