An Orbital Replaceable Unit is a modular component of spacecraft that can be replaced upon failure by a robot or by an Extra-Vehicular Activity. The Hubble Space Telescope was designed with 70 such parts.[1] The electrical system of the International Space Station also has such subsystems that provide power generation, power distribution and energy storage.[2]


  1. ^ "HST Orbital Replacement Units". Retrieved 2013-03-27. 
  2. ^ "Glenn Leads Sustaining Engineering of Power System Hardware". 2008-02-14. Retrieved 2013-03-27.