  We have constructed a comprehensive grid of 690 metal line-blanketed, NLTE,
plane-parallel, hydrostatic model atmospheres for the basic parameters
appropriate to O-type stars. The OSTAR2002 grid considers 12 values of
effective temperatures, 27500K < Teff < 55000K with 2500K steps, 8 surface
gravities, 3.0 < log g< 4.75 with 0.25 dex steps, and 10 chemical compositions,
from metal-rich relative to the Sun to metal-free. The lower limit of log g for
a given effective temperature is set by an approximate location of the
Eddington limit. The selected chemical compositions have been chosen to cover a
number of typical environments of massive stars: the galactic center, the
Magellanic Clouds, Blue Compact Dwarf galaxies like I Zw 18, and galaxies at
high redshifts. The paper contains a description of the OSTAR2002 grid and some
illustrative examples and comparisons. The complete OSTAR2002 grid is available
at our website at http://tlusty.gsfc.nasa.gov.
