  We report the discovery, tracking and detection circumstances for 85
trans-Neptunian objects (TNOs) from the first 42 deg$^{2}$ of the Outer Solar
System Origins Survey (OSSOS). This ongoing $r$-band Solar System survey uses
the 0.9 deg$^{2}$ field-of-view MegaPrime camera on the 3.6 m
Canada-France-Hawaii Telescope. Our orbital elements for these TNOs are precise
to a fractional semi-major axis uncertainty $<0.1\%$. We achieve this precision
in just two oppositions, as compared to the normal 3-5 oppositions, via a dense
observing cadence and innovative astrometric technique. These discoveries are
free of ephemeris bias, a first for large trans-Neptunian surveys. We also
provide the necessary information to enable models of TNO orbital distributions
to be tested against our TNO sample. We confirm the existence of a cold
"kernel" of objects within the main cold classical Kuiper belt, and infer the
existence of an extension of the "stirred" cold classical Kuiper belt to at
least several AU beyond the 2:1 mean motion resonance with Neptune. We find
that the population model of Petit et al. (2011) remains a plausible
representation of the Kuiper belt. The full survey, to be completed in 2017,
will provide an exquisitely characterized sample of important resonant TNO
populations, ideal for testing models of giant planet migration during the
early history of the Solar System.
