  The 2175 {\AA} bump shows considerable variations in its strength, width, and
central wavelength when observed along different sightlines in the Milky Way
and other galaxies. These variations offer valuable insights into the
composition, size distribution, and processing of interstellar dust grains
along different sightlines. This paper introduces a mission concept called
UVESS (Ultraviolet Extinction Sky Survey) aimed at exploring the composition of
the interstellar medium (ISM) within both the Milky Way and nearby Local Group
Galaxies by mapping the variation of UV extinction curve slopes and the 2175
{\AA} feature across a majority of the sky to gain insights into the makeup of
the ISM. Recent advancements in UV instrumentation and technologies pave the
way for the development of high-throughput instruments in compact form factors.
In this paper, we outline mission science goals and instrument concept tailored
for a small satellite-based platform dedicated to the study of UV extinction.
