(space X-ray mission specifically to view neutron stars)
NICER (for Neutron Star Interior Composition Explorer)
is an X-raytelescope deployed in 2017 on the International Space Station (ISS)
to observe X-rays from neutron stars.
Its one scientific instrument is XTI ("X-ray timing instrument").
XTI consists of fifty six X-ray sensors that are sensitive (through
grazing incidence optics) to a small portion of the sky. It does
not image, i.e., it is intended to view a point source,
but the sensors record photon energy (spectroscopic information)
and precise time of reception. The goal is to record the X-ray
light curve of pulses from X-ray pulsars.