Optics: NuSTAR implements a conical approximation to the Wolter-I design which consists of 133 concentric mirror shells coated with Pt/SiC and W/Si multilayers. The optics operate in the energy range 3 - 79 keV.

Detectors: The NuSTAR focal planes are comprised of four hybrid hard X-ray detectors consisting of a CdZnTe sensor manufactured by eV Products bonded to a custom readout chip developed by Caltech. Each of the four hybrids (placed in a 2 x 2 array in the focal plane) is segmented into 32 x 32 pixels, each subtending 12.5" on the sky. The detectors measure the arrival time, energy and position of interaction of each incident X-ray.

Mast: NuSTAR was launched with a lightweight stowed mast, which upon entry into to space, extended to its full length of 10 meters (33 feet).