The NASA Landolt Mission

The NASA Landolt mission is an astrophysics PIONEERS program small satellite that will provide significant improvement in the accuracy of photometric measurements of absolute stellar fluxes. This will be accomplished with a NIST-calibrated suite of single-mode fiber-fed laser beacons. The satellite will be placed in a near-geosynchronous orbit with a one-year primary mission with launch no earlier than October 2028.  After commissioning, Landolt will point to scheduled ground-based observatories including designated ground stations and a guest observer program for calibration observations. Landolt has a level 1 mission requirement to improve the photometric accuracy to 60 target stars. Such measurements can only be achieved by a space-based orbiting artificial "star", where the emitted physical photon flux is accurately known. Accuracy of absolute flux zero points is now the leading error budget term in the characterization of stars, be they standard stars or exoplanet hosts. Landolt will enable the refinement of dark energy parameters, improve our ability to assess the properties of terrestrial worlds, and advance fundamental constraints on stellar astrophysics and evolution.