As a spin-off to our drop tower experiments, we have come to apply optical frequency references such as optical high finesse cavities or a frequency comb in these experiments. In our atom interferometry projects these are applied as a highly stable frequency reference for the beam splitter lasers. Beyond this application, we are interested in the technological development and qualification of these instruments towards future space application. We are also investigating further scientific applications of these instruments in other space based experiments, such as precision tests of the theory special relativity.