We propose a four year suborbital-class research program to develop, launch, and operate a cubesat mission to study the atmospheric properties of planets orbiting other STARS. Exoplanets in…

The Regents of the University of Colorado, through its Office of Contracts and Grants Division, was awarded a $3,794,546.09 grant from the National Aeronautics and Space Administration (NASA) to develop, launch, and operate a CubeSat mission called the Colorado Ultraviolet Transit Experiment (CUTE). The objective is to study the atmospheric properties of exoplanets orbiting other stars, particularly focusing on phenomena such as atmospheric mass-loss, interaction with the host star, and potential planetary magnetism. The CUTE instrument, a compact low-resolution spectrograph operating in the ultraviolet range, will enable spectral observations of key atmospheric tracers that are inaccessible from the ground. This four-year suborbital-class research program will provide a dedicated mission architecture to characterize the atmospheric structure of these exoplanet systems over multiple orbital periods. The award was not associated with a set-aside designation. As a leading public research university, the University of Colorado has a history of conducting fundamental space science research and providing training for future NASA leaders under past federal contract and grant awards.

We propose a four year suborbital-class research program to develop, launch, and operate a cubesat mission to study the atmospheric properties of planets orbiting other STARS. Exoplanets in short-period orbits (prot = 1 5 days) provide a unique opportunity to observe phenomena critical to the development and evolution of our own solar system writ large, including atmospheric mass-loss, interaction with the host star, and possibly even planetary magnetism. Hot jupiters and hot neptunes are laboratories for studying the physics of atmospheric escape. Owing to their large sizes and short-periods, the physics of atmospheric mass-loss can be studied at with a dedicated small instrument. Observations of short-period planets have found them to be greatly inflated, extended to several planetary radii in some cases. Systems with light curves showing late-egress relative to their optical transit have been modeled as comet-like tails that form as the planet s extended atmosphere extends beyond the roche lobe and escapes into interplanetary space. Early-ingress observations may also indicate rapid mass-loss, but have been alternatively interpreted as evidence for a magnetically supported BOW shock ahead of the planet s orbital motion. These processes cannot be observed in broad-band optical light curves (e.g., with kepler). The colorado ultraviolet transit experiment (cute) is designed to spectrally isolate diagnostic atomic and molecular transitions arising within these atmospheres to study the physics of atmospheric mass-loss and possibly detect the presence of magnetic fields on exoplanets. 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 necessary factor-of-twenty increase in survey time (relative to large treasury projects with the hubble space telescope) required to characterize the atmospheric structure of these worlds. The cute instrument is comprised of a cassegrain telescope (190MM 85MM, f/2.5, primary) feeding a compact, low resolution (r = 2000) spectrograph operating from 2500 3500 . The spectrogram is recorded on a UV-optimized E2V CCD. Onboard data reduction is performed and data products are relayed to an existing ground station at the university of colorado. This station currently serves as the ground segment for several cubesat payloads built and operated by students and researchers on campus. The science instrument is incorporated into a 6U form factor with a bus provided by blue canyon technologies. The blue canyon bus provides power, command and data handling, attitude control, and communications. Blue canyon and the instrument team at colorado are located within 3 miles of each other, facilitating collaboration during the fabrication and integration of the cute payload. Calibration and testing will occur in the existing ultraviolet space-instrument characterization facilities at colorado. Cute will be developed in the framework of a university-led program where undergraduate, graduate, and postdoctoral training is paramount. The university of colorado has a long history of training NASA s future leaders in space sciences, and the cute program will extend that heritage to a new generation of investigators with access to small satellite opportunities.