“…Of late, nonlinear adaptive and robust control strategies have been proposed in the literature to solve the regulation problem in a flexible spacecraft. Some of the major attitude control paradigms are based on proportional derivative control (Liu et al, 2012), sliding mode control (Bang et al, 2005; Hu, 2012; Hu et al, 2008; Smaeilzadeh and Golestani, 2019; Tiwari et al, 2018), adaptive control (Chakravarty and Mahanta, 2016; Lu and Xia, 2013; Zhu et al, 2011), robust H ∞ control (Wu et al, 2018), switching control (Amrr et al, 2017), and disturbance observer based control (Li et al, 2016; Yan and Wu, 2017), and so forth. Although the aforementioned methodologies render satisfactory performance, they require continuous information of attitude trajectories in the calculation and update of the control law.…”