A kinematic connector assembly for kinematically coupling two objects is provided. The kinematic connector assembly comprises a receiver defining a cavity and having a plurality of constraint surfaces accessible in the cavity. The kinematic connector assembly further comprises a key having a triplicity of kinematic elements to repeatably position the key in the receiver. The kinematic connector assembly further comprises a preloading mechanism having a load member movable between a clamped position and an unclamped position to secure the key in the receiver, so that the kinematic elements contact the receiver at the plurality of constraint surfaces such that the key is kinematically constrained to the receiver by being constrained by six points of contact with the receiver.