Optical design of the Orbiting Astronomical Satellite for Investigating Stellar Systems

The Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS) is a proposed space telescope with a 14-m inflatable primary reflector that will perform high spectral resolution observations at terahertz frequencies with heterodyne receivers. The telescope consists of an inflatable metallized polymer membrane that serves as the primary antenna, followed by aberration correction optics, and a scanner that enables a 0.1-deg field of regards while achieving diffraction-limited performance over wavelength range from 63 to 660 μm. Here, the parametric solution space of the OASIS inflatable telescope design is systematically investigated by establishing analytical relations among figure of merits including first-order geometrical photon collection area and the size of correction optics. The first-order solution was further optimized by ray-trace code by incorporating numerically calculated mirror shape with preformed membrane gores. Design study shows that a space-based telescope with an effective photon collection area of over 90 m² can be achieved by utilizing a 14-m inflatable aperture.