Space-Based Searches for Lorentz and CPT Violation
  In this proceedings, a summary is presented of recent research investigating ways in which high-precision atomic clocks on the International Space Station could search for violations of Lorentz and CPT symmetry. Space-based searches offer certain experimental advantages over Earth-based experiments investigating these symmetries. The results are based on work published in Physical Review Letters, volume 82, article 090801, 2002. 
Neil Russell