This video previews the Neutron star Interior Composition Explorer (NICER). NICER is an Astrophysics Mission of Opportunity within NASA’s Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA’s Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation. NICER is an upcoming International Space Station payload scheduled to launch in June 2017.