Trade-off study of a high-resolution spectrograph on a CubeSat to study exoplanets

The majority of the 4,000 known exoplanets have been detected via transit photometry. Unambiguous characterization of their atmospheres for biosignatures such as H2O, CH4, O3 and O2 can be unlocked with high-resolution spectroscopy from space. To this end, we investigate the feasibility of a high-resolution (R=50,000) spectrograph on a CubeSat. This work compares optical design elements of traditional Echelle grating and a virtually imaged phased array (VIPA) using exposure time calculations. The limited magnitude when varying the spectral resolution and instrument size is reported. VIPAs on a 6U CubeSat is a cost-effective solution for high-resolution spectroscopy from space.