  We present a novel X-ray assembly of functionally related instrument blocks
intended to measure solar flare and active region (AR) spectra from within the
Russian instrument complex KORTES, to be mounted aboard the International Space
Station (ISS). SolpeX consists of three blocks: fast-rotating multiple flat
crystal Bragg spectrometer, pin-hole X-ray spectral imager and Bragg
polarimeter. This combination of measuring blocks will offer an opportunity to
detect/measure possible X-ray polarization in soft X-ray emission
lines/continuum and record spectra of solar flares, in particular during their
impulsive phases. Polarized Bremsstrahlung and line emission may arise from
presence of directed particle beams colliding with denser regions of flares. As
a result of evaporation, the X-ray spectral-components are expected to be
Doppler shifted, which will also be measured.
  In this paper, we present details of the construction of three SolpeX blocks
and discuss their functionality. Delivery of KORTES with SolpeX to ISS is
expected in 2020/2021.
