  The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall) is a
mission designed to observe faint emission from the circumgalactic medium of
moderate redshift (z~0.7) galaxies for the first time. FIREBall observes a
component of galaxies that plays a key role in how galaxies form and evolve,
likely contains a significant amount of baryons, and has only recently been
observed at higher redshifts in the visible. Here we report on the 2018 flight
of the FIREBall-2 Balloon telescope, which occurred on September 22nd, 2018
from Fort Sumner, New Mexico. The flight was the culmination of a complete
redesign of the spectrograph from the original FIREBall fiber-fed IFU to a
wide-field multi-object spectrograph. The flight was terminated early due to a
hole in the balloon, and our original science objectives were not achieved. The
overall sensitivity of the instrument and telescope was 90,000 LU, due
primarily to increased noise from stray light. We discuss the design of the
FIREBall-2 spectrograph, modifications from the original FIREBall payload, and
provide an overview of the performance of all systems. We were able to
successfully flight test a new pointing control system, a UV-optimized,
delta-doped and coated EMCCD, and an aspheric grating. The FIREBall-2 team is
rebuilding the payload for another flight attempt in the Fall of 2021, delayed
from 2020 due to COVID-19.
