Magnetic Attitude Control of the Tiros Satellites

A Magnetic Attitude Control System for an Axisymmetric Spinning Spacecraft

“…The first operational magnetically controlled spinning spacecraft, the TIROS satellites, were discussed by Hecht and Manger. 6 This paper combines and extends these results to a system with limited attitude determination capability operating in an eccentric orbit. Figure 1 illustrates the local reference frame of the spacecraft which has unit vector xi oriented outward along the radius vector from the geocenter.…”

“…For explanatory simplicity, the disturbance torque v and the measurement noise w are treated here as uncorrelated white noise with covariances (6) E{wiW k } = where Ri is a positive definite matrix and Ri is a positive number. Let us define 12 (t) as the covariance matrix of the error (xx e ), where x e is the estimate of state x.…”

“…Estimation accuracy and system performance also depend upon the deviation of the actual disturbance torque and measurement noise characteristics from the white noise assumptions of Eq. (6).…”