Named after NASA’s first chief astronomer, the ‘mother of the Hubble Space Telescope,’ the Nancy Grace Roman Space Telescope will have a field of view at least 100 times larger than Hubble's, potentially measuring light from a billion galaxies in its lifetime. This observatory will also be able to block starlight to directly see exoplanets and planet-forming disks, complete a statistical census of planetary systems in our galaxy, and settle essential questions in the areas of dark energy, exoplanets, and infrared astrophysics.