Spacecraft are subject to strict requirements in terms of angular position and actuation limits so good control performances combined to small inputs must be achieved. The robustness properties of both sliding-mode controllers (SMC) and Linear Parameter Varying controllers (LPV) make them suitable for many real situations corroborated by their solid mathematical bases. On the other hand, real SMC exhibit high-frequency oscillations in the plant output, called chattering, which lead to excitement of unmodeled dynamics. This issue can be mitigated both by exploiting an higher order sliding mode controller and by substituting the classical sliding mode control law with an approximated smoother function.