  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 degrees Field of Regards
while achieving diffraction limited performance over wavelength range from 63
to 660 {\mu}m. Here the parametric solution space of the OASIS inflatable
telescope design is systematically investigated by establishing analytical
relations among figure of merits including 1st order geometrical photon
collection area and the size of correction optics. The 1st order solution was
further optimized by ray-trace code by incorporating numerically calculated
mirror shape with pre-formed membrane gores. Design study shows that a
space-based telescope with an effective photon collection area of over 90m2 can
be achieved utilizing a 14m inflatable aperture.
