Accessing the millihertz gravitational wave symphony with space-based missions

The discovery of gravitational waves by ground-based detectors opened a new window into the dynamic Universe, unveiling a rich population of merging stellar-mass black holes. Most recently, pulsar timing arrays have uncovered evidence for a deep rumble of Galaxy-scale gravitational waves likely produced by the distant population of merging supermassive black holes. In the coming decade, development for space-based gravitational wave detectors will ramp up, utlimately aiming to discover a millihertz frequency symphony punctuated by loud individual mergers of supermassive black holes, extreme-mass-ratio inspirals of stellar mass black holes merging with massive black holes, and the constant hum of nearby stellar origin binaries or cosmologicall sourced gravitational-wave backgrounds. In this talk I will review the current state of development for space-based gravitational wave observatories and discuss the the wide range of sources these new detectors may discover.