  The Cosmic Evolution Survey (COSMOS) was initiated with an extensive
allocation
  (590 orbits in Cycles 12-13) using the Hubble Space Telescope (HST) for high
resolution imaging. Here we review the characteristics of the HST imaging with
the Advanced Camera for Surveys
  (ACS) and parallel observations with NICMOS and WFPC2. A square field
(1.8$\sq$\deg) has been imaged with single-orbit ACS I-F814W exposures with 50%
completeness for sources 0.5\arcsec in diameter at I$_{AB} $ = 26.0 mag. The
ACS imaging is a key part of the COSMOS survey, providing very high sensitivity
and high resolution (0.09\arcsec FWHM, 0.05\arcsec pixels) imaging and
detecting 1.2 million objects to a limiting magnitude of 26.5 (AB). These
images yield resolved morphologies for several hundred thousand galaxies. The
small HST PSF also provides greatly enhanced sensitivity for weak lensing
investigations of the dark matter distribution.
