Fig. 7From: Tiangong-1’s accelerated self-spin before reentryRelation between the change rate of \(\psi _H\) and the equivalent rotation speed \(H/I_z\). The relation example is estimated from Fig. 2 where the orbit altitude is approximately 280 km. A series of parameter sets of rotational motion, which are not sensitive to H, are obtained using Eq. (3). We use each set of parameters as initial values to extrapolate the rotation and extract the change rate of \(\psi _H\). Then, we can establish a mapping from \(H/I_z\) to \(\omega _{\psi _H}\). Once the change in \(\psi _H\) from two passes is determined, the exact \(H/I_z\) can be reversedBack to article page