The goal of the Laser Interferometer Gravitational-Wave Observatory (LIGO) is to detect gravitational radiation and to open the entirely new field of gravitational-wave astrophysics. The R&D in support of the construction of LIGO will be completed in FY 1998, about 80% of the total construction funds have been expended, and the integration of the systems has begun. By the end of 2001, after a period of commissioning and pre-operations, the facility is expected to reach its initial design goal of 10^-21 in strain sensitivity. A scientific run lasting about two years is scheduled to begin in early 2002.
However, the full scope of LIGO science will require that LIGO be equipped with gravitational-wave detectors that are more sensitive than those installed initially. Caltech and MIT will conduct a program of research and development, leading to significant improvements in the sensitivity of the initial LIGO interferometer subsystems. This activity, together with coordinated activities among other participants in the LIGO scientific program, is in preparation for the fabrication of new, more sensitive subsytems to be installed over a period of about five years beginning as early as 2004. With these upgrades the sensitivity of LIGO will be improved by a factor of 10 to 100.
