A laser tracker calibration system comprising: a support system ; a support beam rotatably coupled to the support system; a first kinematic mount coupled to a first end of the support beam; a second kinematic mount coupled to a second end of the support beam; and an artifact coupled to said first and second kinematic mounts so as to cause said artifact to be supported by said support system, wherein the laser tracker is calibrated by measuring the length of the artifact, wherein said support system is configured to hold said artifact relative to a laser tracker during calibration of the laser tracker, the laser tracker calibration system further comprising: said support system comprising a positioner , wherein said positioner of said support system is configured such that said artifact can be moved between a horizontal configuration, an angled configuration, and a vertical configuration by rotating said support beam relative to said positioner while said support beam is coupled to said positioner ; said positioner being configured to selectively restrain said artifact in the horizontal, angled, and vertical configurations; and said first and second kinematic mounts being configured such that the artifact is constrained in six degrees of freedom relative to the support beam so as to minimize or eliminate adverse effects associated with over-constraining the artifact. a support system ; a support beam rotatably coupled to the support system; a first kinematic mount coupled to a first end of the support beam; a second kinematic mount coupled to a second end of the support beam; and an artifact coupled to said first and second kinematic mounts so as to cause said artifact to be supported by said support system, wherein the laser tracker is calibrated by measuring the length of the artifact, wherein said support system is configured to hold said artifact relative to a laser tracker during calibration of the laser tracker, the laser tracker calibration system further comprising: said support system comprising a positioner , wherein said positioner of said support system is configured such that said artifact can be moved between a horizontal configuration, an angled configuration, and a vertical configuration by rotating said support beam relative to said positioner while said support beam is coupled to said positioner ; said positioner being configured to selectively restrain said artifact in the horizontal, angled, and vertical configurations; and said first and second kinematic mounts being configured such that the artifact is constrained in six degrees of freedom relative to the support beam so as to minimize or eliminate adverse effects associated with over-constraining the artifact. said support system comprising a positioner , wherein said positioner of said support system is configured such that said artifact can be moved between a horizontal configuration, an angled configuration, and a vertical configuration by rotating said support beam relative to said positioner while said support beam is coupled to said positioner ; said positioner being configured to selectively restrain said artifact in the horizontal, angled, and vertical configurations; and said first and second kinematic mounts being configured such that the artifact is constrained in six degrees of freedom relative to the support beam so as to minimize or eliminate adverse effects associated with over-constraining the artifact. <EOS>