  Chemistry along the star- and planet-formation sequence regulates how
prebiotic building blocks -- carriers of the elements CHNOPS -- are
incorporated into nascent planetesimals and planets. Spectral line observations
across the electromagnetic spectrum are needed to fully characterize
interstellar CHNOPS chemistry, yet to date there are only limited astrochemical
constraints at THz frequencies. Here, we highlight advances to the study of
CHNOPS astrochemistry that will be possible with the Orbiting Astronomical
Satellite for Investigating Stellar Systems (OASIS). OASIS is a NASA mission
concept for a space-based observatory that will utilize an inflatable 14-m
reflector along with a heterodyne receiver system to observe at THz frequencies
with unprecedented sensitivity and angular resolution. As part of a survey of
H2O and HD towards ~100 protostellar and protoplanetary disk systems, OASIS
will also obtain statistical constraints on the inventories of light hydrides
including NH3 and H2S towards protoplanetary disks, as well as complex organics
in protostellar hot corinos and envelopes. Line surveys of additional
star-forming regions, including high-mass hot cores, protostellar outflow
shocks, and prestellar cores, will also leverage the unique capabilities of
OASIS to probe high-excitation organics and small hydrides, as is needed to
fully understand the chemistry of these objects.
