The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small NASA mission launched on 13th June 2012 into a low Earth orbit. It observes in the 3-79 keV range.
It has two focal plane detectors of 13’ x 13’, with spectral resolution of 0.4 keV and angular resolution of 18’’ FWHM. They are is sensitive down to ~1 x 10⁻¹⁴ erg cm⁻² s⁻¹ (10-30 keV) in 1 Ms and have 2 microsecond temporal resolution.
The catalogue contains 1274 sources.
For more information see https://nustar.caltech.edu/