Because graphite composites are hygroscopic, there was a risk that water vapor absorbed by the truss while in Lockheed's clean room would later be expressed in the vacuum of space; the telescope's instruments would be covered in ice.. 
The mission replaced all six ìgbòkègbodòscopes, replaced a fine guidance Sensor and the computer, Installed a Voltage/temperature improvement Kit (vik) to prevent Battery Overcharging, and replaced thermal insulation Blanìkọ̀sẹ̀.. 