The center of mass offset could probably be explained by thrust vectoring or powerful gyros but the convenient clamp is a bit suspicious unless the ship was designed with that purpose in mind.
One of the best and more realistic sci-fi movies is 2010 the year we make contact. I even prefer it over 2001. http://www.youtube.com/watch?v=34MXGB83heI&list=FLSiy1IfJmYJmd3BGnmGl5eg