Mechanical technician, Thomas Huber, tightens bolts on the Ocean Color Instrument (OCI) is installed onto the Ground Support Equipment Application for Tilt or Rotation (GAToR) made by Newton Engineering. GAToR will allow engineers to tilt and rotate OCI in different orientations for further testing prior to integration onto the PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) spacecraft. OCI is a highly advanced optical spectrometer that will be used to measure properties of light over portions of the electromagnetic spectrum. It will enable continuous measurement of light at finer wavelength resolution than previous NASA satellite sensors, extending key system ocean color data records for climate studies. OCI is PACE's (Plankton, Aerosol, Cloud, ocean Ecosystem) primary sensor built at Goddard Space Flight Center in Greenbelt, MD.