| 摘要 |
PURPOSE: To precisely indicate a spacecraft to the earth by providing a three- axis spacecraft attitude control system using an earth sensor and a polar star sensor. CONSTITUTION: A star sensor 18 has a boresight parallel to the spacecraft pitch axis, and produces signals representative of the two-axis location of a selected pole star 22 relative to the boresight. The star sensor signals are processed with the pitch-representative signals and with orbit-location signals to produce roll and yaw signals. The pitch, roll and yaw information controls the torque generation operation of the spacecraft. In a specified embodiment, a horizon sensor 24 device produces a roll signal and the signal is processed with the roll signal from the star sensor 18. |
