With support from the NSF Divisions of Chemistry, …, the NSF National eXtreme Ultrafast Science facility (NeXUS) is a first-of-its-kind laser user facility that provides broad user access to cutting edge tools for studying ultrafast processes in molecules and materials. Scientific challenges that are being addressed by NeXUS include the ability to produce a molecular “movie” of a chemical reaction, the efficient capture and storage of sunlight to meet demands for renewable energy, and the ability to master information transport on the atomic scale to create new quantum information technologies. As such, NeXUS represents a focal point of interdisciplinary collaboration among researchers spanning chemistry, physics, materials science, biology, and engineering. In the past, the lack of access to ultrafast research infrastructure has not only limited the capabilities of US science, but has presented a major challenge to development of the diverse workforce that is needed to maintain the competitiveness of US research and education. By addressing these challenges, NeXUS fills a key strategic gap in the US research infrastructure.<br/><br/>NeXUS directly responds to the community-identified grand challenges of observing and controlling energy transport on the scale of individual electrons and atoms. To accomplish this, the NeXUS facility allows direct observation of electron motion with attosecond to femtosecond time resolution, angstrom spatial resolution, and element-specific spectral resolution. At the heart of NeXUS is a kW-class ultrafast laser that produces XUV and soft x-ray light by high harmonic generation. The combination of attosecond pulses, soft x-ray photon energies, and high repetition rate enables measurements at NeXUS that can only be made at a handful of places worldwide. Combining this cutting-edge light source with state-of-the-art analysis end stations and a team of professional support staff allows NeXUS to support a dynamic, open-access user program that levels the scientific playing field by providing researchers from all career stages and institutions access to the most advanced characterization tools available worldwide for ultrafast science.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.