Alignment, calibration, and the first flight of the Rockets for Extended Source X-ray Spectroscopy

The Rockets for Extended-source X-ray Spectroscopy (tREXS) spectrograph is designed to detect diffuse soft-X-ray emission from astrophysical sources by utilizing a relatively large (~10 sq. deg.) field of view and moderate (R~50) spectral resolving power. The payload houses two coaligned optics channels that use passive, mechanical beam shapers, modules of reflection gratings, and an extended focal plane based around Teledyne CIS 113 CMOS sensors. The first flight of tREXS launched from White Sands Missile Range and targeted the Cygnus Loop supernova remnant. We present an overview of the component- and instrument-level alignment, calibration, and results from the first flight.