The Advanced Camera for Surveys (ACS) is a third-generation axial instrument aboard the Hubble Space Telescope (HST). The initial design and scientific capabilities of ACS were defined by a team based at Johns Hopkins University. ACS was assembled and tested extensively at Ball Aerospace & Technologies Corp. and the Goddard Space Flight Center and underwent a final flight-ready verification at the Kennedy Space Center before integration in the cargo bay of the Columbia orbiter. It was launched on March 1, 2002, as part of Servicing Mission 3B (STS-109) and installed in HST on March 7, replacing the Faint Object Camera (FOC), the last original instrument. ACS cost US$86 million at that time. ACS is a highly versatile instrument that became the primary imaging instrument aboard HST. It offered several important advantages over other HST instruments: three independent, high-resolution channels covering the ultraviolet to the near-infrared regions of the spectrum, a large detector area and quantum efficiency, resulting in an increase in HST's discovery efficiency by a factor of ten, a rich complement of filters, and coronagraphic, polarimetric, and grism capabilities. The observations undertaken with ACS provided astronomers with a view of the Universe with uniquely high sensitivity, as exemplified by the Hubble Ultra-Deep Field, and encompass a wide range of astronomical phenomena, from comets and planets in the Solar System to the most distant quasars known. Channels and detectors ACS includes three independent channels (one now disabled), each optimized for specific scientific tasks: Wide Field Channel (WFC) The WFC is the most utilized channel of ACS. Its detector consists of two butted 2048x4096, 15 µm/pixel charge-coupled devices (CCDs) for a total of 16 megapixels manufactured by Scientific Imaging Technologies (SITe). The WFC plate scale is 0.05″ per pixel and it has an effective field-of-view of 202″×202″. The spectral range of the WFC detector is 350–1100 nm. An example of a use of this channel was SWEEPS, which found 16 candidate exoplanets in the Galactic core. High-Resolution Channel (HRC) The HRC, which has been permanently disabled since 2007 due to an electrical fault, provided ultra-sharp views over a smaller field-of-view. The HRC detector was a 1024×1024 SITe CCD which had a smaller field-of-view (26"×29") than the WFC but twice the spatial sampling (0.025" per pixel). This detector was also significantly more sensitive than the WFC at near-ultraviolet wavelengths (<350 nm). The channel used two light suppression options for imaging faint objects