Abstract
The goal of the laser interferometer gravitational-wave observatory (LIGO) project is to detect and study gravitational waves from astrophysical sources. Currently, three interferometers with arm lengths of several kilometres and a design strain sensitivity of order 2 × 10−23 Hz−1/2 are being commissioned at two independent sites in Hanford (WA) and Livingston (LA). This paper describes the current work towards achieving LIGO's final sensitivity.