Nonlinear systems of the form
![\\dot{X}(t)=g[x(t);t]+u(t)](/images/tex/5316.gif)
, where

, and
![g[x(t); t]](/images/tex/5318.gif)
are

vectors, are examined in this paper. It is shown that if

is constant along trajectories of the homogeneous system
![\\dot{X}(t)=g[x(t); t]](/images/tex/5320.gif)
and if the control

is constrained to lie within a sphere of radius

, i.e.,

, for all

, then the control

drives any initial state

to 0 in minimum time and with minimum fuel, where the consumed fuel is measured by

. Moreover, for a given response time

, the control

drives

to 0 and minimizes the energy measured by

. The theory is applied to the problem of reducing the angular velocities of a tumbling asymmetrical space body to zero.