1. The location of the secondary saddle-type equilibrium and the associated stable eigendirection, and therefore, the basin of attraction in a frozen-V error plane, depend on Dr and T as well as V. (There is also a dependence on l, but it is not considered here.) Fig. 5a for V = 4 km/s and Dr = 9 m/s2 and Fig. 5b for V = 10 km/s and Dr = 4 m/s2 show the basin boundaries for several values of the control law parameter T.The Shuttle operates with T in the range 90-200 s. In this range, the domain of attraction includes all of S for V = 4 km/s and all but the lower left corner for V = 10kds. Stability with Bounded Control
2. This research was supported by the NASA Langley Research Center under Grant NAG1-907.