NICER mission preparations. Neutron star Interior Composition Explorer (NICER) engineers preparing the instrument for a final pre-ship check at NASA's Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA. At left is NICER Mechanical Engineer Steven Kenyon, with GPS and Star Tracker Camera Engineer Eric Rogstad at right. The payload was shipped to the Kennedy Space Center in Florida, and was launched and deployed on the International Space Station (ISS) in June 2017. NICER is designed to study neutron stars using an X-ray timing and spectroscopy instrument. Photographed in May 2016.