NASA astronauts Nick Hague and Suni Williams will replace a rate gyro assembly that helps provide orientation control for the station, install patches to cover damaged areas of light filters for an X-ray telescope called NICER (Neutron star Interior Composition Explorer), and replace a reflector device used for navigational data on one of the international docking adapters. Additionally, the pair will check access areas and connector tools that will be used for future maintenance work on the Alpha Magnetic Spectrometer.