  SuperBIT was a 0.5-meter near-ultraviolet to near-infrared wide-field
telescope that launched on a NASA superpressure balloon into the stratosphere
from New Zealand for a 45-night flight. SuperBIT acquired multi-band images of
galaxy clusters to study the properties of dark matter using weak gravitational
lensing. We provide an overview of the instrument and its various subsystems.
We then present the instrument performance from the flight, including the
telescope and image stabilization system, the optical system, the power system,
and the thermal system. SuperBIT successfully met the instrument's technical
requirements, achieving a telescope pointing stability of 0.34 +/- 0.10
arcseconds, a focal plane image stability of 0.055 +/- 0.027 arcseconds, and a
PSF FWHM of ~ 0.35 arcseconds over 5-minute exposures throughout the 45-night
flight. The telescope achieved a near-diffraction limited point-spread function
in all three science bands (u, b, and g). SuperBIT served as a pathfinder to
the GigaBIT observatory, which will be a 1.34-meter near-ultraviolet to
near-infrared balloon-borne telescope.
