For kicks, I have been reading the following AIAA/NASA paper on hypothetical space drives: http://www.grc.nasa.gov/WWW/bpp/1997-J_AIAA_SpaceDr.pdf Now, I have to admit that I only have a cursory understanding of general relativity & differential geometry. But assume for a moment the unlikely possibility that one or more of these concepts is feasible and engineer-able. Imagine that such a drive was activated within our solar system, with an extra-solar destination. Given the sharp instantaneous S-T curvature implied by these designs and the instability of the N-Body (N>2) problem, wouldn't such a technology pose a serious threat to an inhabited system? Specifically, wouldn't the artificial curvature induce changes in the Christoffel symbols in S-T; ultimately propagating outward as a gravitational wavefront as S-T returned to it's original shape? If so, would it seem likely that these field gradients might stabilize a gravitational system? Thanks in advance for everyone's time/help/explanations/corrections!