Detection of long-lived staus and gravitinos at the ILC

A study is presented illustrating the excellent potential of future International Linear Collider (ILC) experiments to detect metastable staus $\stau$, measure precisely their mass and lifetime, and to determine the mass of the gravitino $\sG$ from the decay $\stau\to\tau\sG$, thus providing direct access to the gravitational coupling, respectively Planck scale.