Probing Relativity using Space-Based Experiments
  An overview of space tests searching for small deviations from special relativity arising at the Planck scale is given. Potential high-sensitivity space-based experiments include ones with atomic clocks, masers, and electromagnetic cavities. We show that a significant portion of the coefficient space in the Standard-Model Extension, a framework that covers the full spectrum of possible effects, can be accessed using space tests. Some remarks on Lorentz violation in the gravitational sector are also given. 
Neil Russell