in the female base 16 these elements 1 15 may be interchanged the surrounding metal of the base 1 and female base 16 is preferably of a nonmagnetic material such as aluminum in fig3 four male coupling members 17 are positioned on the surface 18 of an orbital replacement unit 19 34 oru 34 intended to be coupled to another object not shown in fig3 these four members 17 are preferably placed in opposed sets set orthogonally to each other with the contained surfaces 21 of each opposed set positioned to face each other towards or away from each as well the ridges 6 of opposed male members are aligned with each other in fig3 the surfaces 21 face towards each other the central 34 directors 34 20 extending from the centers of such contained surfaces 21 preferably lie in a single plane such directors 20 when extended intersecting at an intersection point 22 preferable located above the surface 18 electrical connectors 23 23a may be present at the interface and a micro fixture 24 may be attached to the oru 19 to facilitate its handling in fig4 an electrical box oru 19a is suspended above a docking location on a plate 26 both the oru 19a and plate 26 carry coupling members 17 27 which provide complementary soft docking interfaces these are preferably orthogonally deployed at maximum spacing for optimum stability of engagement a corresponding docking interface to that on the plate 26 may be incorporated in the lift off vehicle not shown to support the oru 19a through its docking interface 27 a floating nut 28 on the plate 26 is engaged by a bolt not shown passing.