Fig. 6From: Tiangong-1’s accelerated self-spin before reentryProbability distributions of the estimated \(\psi _H\). The three sets of data are estimated from three consecutive passes on January 18, 2018, at UTC 9.5 h, 11.1 h, and 12.6 h. Due to the influence of the gravity gradient torque, \(\psi _H\) will increase or decrease at a certain rate, which can be used to find the correct solution in Fig. 5 and calculate the magnitude of the angular momentum in Fig. 7Back to article page