The NICER X-ray telescope pictured on the International Space Station

iss072e371305 (Dec. 17, 2024) --- The NICER (Neutron star Interior Composition Explorer) X-ray telescope is pictured installed on the starboard side of the International Space Station's integrated truss segment. NICER's 56 X-ray concentrators are covered by thermal shields, or filters, that block ultraviolet, infrared, and visible light while allowing X-rays to pass through to the mirrors underneath enabling the observation of neutron stars. Several thermal shields have been damaged allowing unwanted sunlight to "leak" into the astrophysics instrument interfering with X-ray measurements. NASA astronauts Nick Hague and Sun Williams will conduct a spacewalk on Jan. 16 to patch the damaged thermal shields and restore NICER for daytime scientific operations.