Cut-away CAD rendering of CUTE, with transparent top and sides to display the telescope and spectrograph. CUTE has three coarse sun sensors, a star tracker, an S-band transmitter to send data to Earth, and a UHF antenna (not shown) for command uplink.

CUTE just finished a campaign observing several transits of KELT-9b. Prior to that, CUTE captured several transits of WASP-189b.

The Colorado Ultraviolet Transit Experiment (CUTE) is a 4-year, NASA-funded project to design, build, integrate, test, and operate a 6-unit CubeSat (30 cm x 20 cm x 10 cm). CUTE is planned to have a 1-year nominal mission lifetime and will launch in late September 2021. Using  near-ultraviolet (NUV) transmission spectroscopy from 255 to 330 nanometers (nm), CUTE will characterize the composition and mass-loss rates of exoplanet atmospheres by measuring how the NUV light from the host star is changed as the exoplanet transits in front of the star and passes through the planet’s atmosphere. Transit light curves created from CUTE observations will provide constraints on the composition and escape rates of these atmospheres, and may provide the first concrete evidence for magnetic fields on extrasolar planets.

The keys to unlocking the diagnostic potential of these systems are spectral coverage in the appropriate bandpass and the ability to follow the systems for several orbital periods. CUTE is designed to provide exactly that – low resolution spectroscopy of critical atmospheric tracers (Fe II, Mg II, Mg I, OH) that are inaccessible from the ground, and a dedicated mission architecture that enables the survey required to characterize atmospheric structure and variability on these worlds.

CUTE was assembled and tested at the University of Colorado, Boulder and the Laboratory for Atmospheric and Space Physics (LASP). It is operated with LASP’s flight operations facilities. Dr. Kevin France is the Principal Investigator of the CUTE mission at LASP.

Follow CUTE on twitter: @CUTECubeSat