  The Colorado Ultraviolet Transit Experiment (CUTE) is a near-UV (2550 - 3300
Angstrom) 6U cubesat mission designed to monitor transiting hot Jupiters to
quantify their atmospheric mass loss and magnetic fields. CUTE will probe both
atomic (Mg and Fe) and molecular (OH) lines for evidence of enhanced transit
absorption, and to search for evidence of early ingress due to bow shocks ahead
of the planet's orbital motion. As a dedicated mission, CUTE will observe more
than 100 spectroscopic transits of hot Jupiters over a nominal seven month
mission. This represents the equivalent of more than 700 orbits of the only
other instrument capable of these measurements, the Hubble Space Telescope.
CUTE efficiently utilizes the available cubesat volume by means of an
innovative optical design to achieve a projected effective area of 28 sq. cm,
low instrumental background, and a spectral resolving power of 3000 over the
primary science bandpass. These performance characteristics enable CUTE to
discern transit depths between 0.1 - 1% in individual spectral absorption
lines. We present the CUTE optical and mechanical design, a summary of the
science motivation and expected results, and an overview of the projected
fabrication, calibration and launch timeline.
