Comment on ‘Stability and chaos of a damped satellite partially filled with liquid’ [Acta Astronautica 65 (2009) 1628–1638]

In the commented paper the authors consider a model for a damped satellite partially filled with liquid. They claim to prove the existence of Sil'nikov homoclinic and heteroclinic orbits using the undetermined coefficient method. It is enough to read their Theorem 3 to understand that their results are incorrect: according to it, if the equilibria are saddle-foci the existence of Sil'nikov homoclinic and heteroclinic connections is guaranteed. As we show along this comment, their conclusions are erroneous because the form of the function they assume for the global connections is incongruous.