The core features of the payload have been stable for more than a decade: the interferometric measurement system, the telescope, the gravitational reference sensor. Their design has evolved and reached maturity. Many of the design features and concepts of LISA, e.g., the optical bench, have been demonstrated on LISA Pathfinder (LPF).
LISA is designed to measure gravitational radiation over a broad band at low frequencies, from about 0.1 mHz to 1 Hz, a band where the Universe is richly populated by strong sources of gravitational waves.
LISA can achieve 10-20 strain resolution by measuring displacements of the order of a picometer. Its observations in the quiet environment of space will not be disturbed by seismic and gravity-gradient noise. Thus, LISA’s unparalleled sensitivity will allow studying sources within the Galaxy and out to the edge of the visible Universe.