  Transient chaos is a characteristic behavior in nonlinear dynamics where
trajectories in a certain region of phase space behave chaotically for a while,
before escaping to an external attractor. In some situations the escapes are
highly undesirable, so that it would be necessary to avoid such a situation. In
this paper we apply a control method known as partial control that allows one
to prevent the escapes of the trajectories to the external attractors, keeping
the trajectories in the chaotic region forever. To illustrate how the method
works, we have chosen the Lorenz system for a choice of parameters where
transient chaos appears, as a paradigmatic example in nonlinear dynamics. We
analyze three quite different ways to implement the method. First, we apply
this method by building a 1D map using the successive maxima of one of the
variables. Next, we implement it by building a 2D map through a Poincar\'{e}
section. Finally, we built a 3D map, which has the advantage of using a fixed
time interval between application of the control, which can be useful for
practical applications.
