  The space ultraviolet (UV) is a critical astronomical observing window, where
a multitude of atomic, ionic, and molecular signatures provide crucial insight
into planetary, interstellar, stellar, intergalactic, and extragalactic
objects. The next generation of large space telescopes require highly
sensitive, moderate-to-high resolution UV spectrograph. However, sensitive
observations in the UV are difficult, as UV optical performance and imaging
efficiencies have lagged behind counterparts in the visible and infrared
regimes. This has historically resulted in simple, low-bounce instruments to
increase sensitivity. In this study, we present the design, fabrication, and
calibration of a simple, high resolution, high throughput far-UV spectrograph -
the Colorado High-resolution Echelle Stellar Spectrograph (CHESS). CHESS is a
sounding rocket payload to demonstrate the instrument design for the
next-generation UV space telescopes. We present tests and results on the
performance of several state-of-the-art diffraction grating and detector
technologies for far-UV astronomical applications that were flown aboard the
first two iterations of CHESS. The CHESS spectrograph was used to study the
atomic-to-molecular transitions within translucent cloud regions in the
interstellar medium (ISM) through absorption spectroscopy. The first two
flights looked at the sightlines towards alpha Virgo and epsilon Persei, and
flight results are presented.
