A blueprint for a simultaneous test of quantum mechanics and general   relativity in a space-based quantum optics experiment
  In this paper we propose an experiment designed to observe a general-relativistic effect on single photon interference. The experiment consists of a folded Mach-Zehnder interferometer, with the arms distributed between a single Earth orbiter and a ground station. By compensating for other degrees of freedom and the motion of the orbiter, this setup aims to detect the influence of general relativistic time dilation on a spatially superposed single photon. The proposal details a payload to measure the required effect, along with an extensive feasibility analysis given current technological capabilities. 
Sam Pallister, Simon Coop, Valerio Formichella, Nicolas Gampierakis,   Virginia Notaro, Paul Knott, Rui Azevedo, Nikolaus Bu...
astro-ph.IM quant-ph