The Colorado Ultraviolet Transit Experiment (CUTE) 6U CubeSat: On-orbit instrument performance and early science results

The Colorado Ultraviolet Transit Experiment (CUTE) is a recently launched space mission dedicated to characterizing the upper atmospheres of short-period exoplanets using mid-resolution, near-ultraviolet (~2500 – 3300 A) transmission spectroscopy. The CUTE science instrument comprises a Cassegrain telescope, spectrograph, and CCD detector, and is housed in a 6U CubeSat bus. CUTE was developed in four years at the Laboratory for Atmospheric and Space Physics before it launched into a polar Low Earth Orbit (altitude ~560km) on September 27^th, 2021. Spacecraft commissioning and instrument performance qualification took place during the first several weeks in orbit, and normal science operations commenced shortly after. This presentation will highlight the instrument’s on-orbit characteristics by summarizing the spectrograph performance (including the final bandpass, resolution, wavelength calibration, and instrument throughput), measured instrument systematics (thermal cycles and pointing stability), and the mission’s general observing strategy. We will present early science results and discuss CUTE’s expected contribution to the realm of exoplanetary transit observations during its 8 month primary mission.