Presentation #628.06 in the session Future Missions and Instrumentation.
With a renewed emphasis in cis-lunar and lunar-based observing platforms and an abundance of exciting exoplanet science yet to be done, we are developing a UV/optical-sensitive telescope to be mounted on an upcoming NASA-sponsored robotic lander. This mission is named the LUnar-based Survey for Time-domain Research on Exoplanets and Solar System Objects (LUSTRESSO). With this mission we will complete exoplanet and near Earth asteroid centered science programs. The telescope design is currently a ~20-cm aperture, wide-field telescope with a UV (200-300nm) and V band (500-600nm) detectors. The exoplanet science program focuses on transmission spectro-photometry of transiting hot Jupiters around bright host stars including classics like HD 209458 b and newer systems including WASP-189 b. The photometry collected by this instrument will improve the impact of optical and infrared transmission spectra by constraining the Rayleigh scattering slope of the bluest portion of the spectrum. This is essential for characterizing the properties of clouds, hazes, and metallicity which then influence models of the spectral features at longer wavelengths. The UV and optical photometry will help break the degeneracy of atmospheric models which are dependent on the assumed composition and the temperature-pressure profile. Collecting this photometry in two channels simultaneously will mitigate the impact of stellar variability on the observed spectral properties. Observing from the lunar surface has important benefits over terrestrial telescopes and smallsats in low-Earth orbit. These include access to the UV wavelengths, precision photometry enabled by the vacuum environment, a high-stability platform, and a long-duration, continuous observing window of up to two weeks at a time (one lunar day). Dust mitigation protocols and lunar night survival are incorporated into the telescope design. The current mission goal is to place the telescope and instrument onto a lunar-lander scheduled for launch in 2027.