BFORE: The B-mode Foreground Experiment
  The B-mode Foreground Experiment (BFORE) is a proposed NASA balloon project
designed to make optimal use of the sub-orbital platform by concentrating on
three dust foreground bands (270, 350, and 600 GHz) that complement
ground-based cosmic microwave background (CMB) programs. BFORE will survey ~1/4
of the sky with 1.7 - 3.7 arcminute resolution, enabling precise
characterization of the Galactic dust that now limits constraints on inflation
from CMB B-mode polarization measurements. In addition, BFORE's combination of
frequency coverage, large survey area, and angular resolution enables science
far beyond the critical goal of measuring foregrounds. BFORE will constrain the
velocities of thousands of galaxy clusters, provide a new window on the cosmic
infrared background, and probe magnetic fields in the interstellar medium. We
review the BFORE science case, timeline, and instrument design, which is based
on a compact off-axis telescope coupled to >10,000 superconducting detectors.
