Pan-STARRS is a highly cost-effective, modular and scalable approach to wide-field optical/NIR imaging. It uses 1.8m telescopes with very large (7 square degree) field of view and revolutionary1.4 billion pixel CCD cameras with low noise and rapid read-out to provide broad-band imaging from 400-1000nm wavelength. The first single telescope system, PS1, has been deployed on Haleakala on Maui, and has been collecting science quality survey data for approximately six months. PS1 will be joined by a second telescope PS2 in approximately 18 months. A four aperture system is planned to become operational following the end of the PS1 mission. This will be able to scan the entire visible sky to approximately 24th magnitude in less than a week, thereby meeting the goals set out by the NAS 2000 decadal review for a "Large Synoptic Sky Telescope". Here we review the technical design, and give an update on the progress that has been made with the PS1 system.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.