3.5-meter Segmented-Mirror Robotic Space Telescope Mission White Paper I. Overall Architecture and Scientific Mission

Abstract

A 3.5-meter segmented-mirror robotic space telescope is under study as a space-based observatory for precision astrophysical observations and rapid-response transient astronomy in the 0.2-1.5 micron wavelength range. The telescope adopts a Cassegrain optical configuration optimized to deliver diffraction-limited performance across a wide, flat focal plane, achieving a Strehl ratio greater than 0.8 at 633 nm. The proposed scientific payload includes a Wide-field Camera (WC), a spectroscopic instrument, and an optional Exoplanet Imaging Coronagraph. The Wide-field Camera (WC) provides multi-wavelength imaging and high-cadence time-series photometry over a field of view ranging from 10'X10' to 30'X30'. The spectroscopic configuration and resolving power remain under study to accommodate the requirements of the principal science programs. An optional Exoplanet Imaging Coronagraph is being investigated for high-contrast imaging of nearby planetary systems, with performance goals extending toward raw contrasts of approximately 10^(-8) and improved post-processed performance. Candidate orbital configurations, including Earth orbit and the Sun-Earth L2 region, are currently being evaluated. Planned investigations include gravitational-wave counterparts, rapidly evolving transients, Type Ia supernova cosmology, direct imaging of exoplanets, and exoplanet atmospheric spectroscopy. Although driven by these core scientific objectives, the observatory is conceived as a general-purpose facility providing open-access observing time to the international scientific community. This paper presents the preliminary architecture, performance goals, and scientific mission of the proposed 3.5-meter space telescope.