NASA Headquarters is offering a federal grant opportunity titled "ROSES 2025: B.3 Heliophysics Theory, Modeling, and Simulations," aimed at advancing research in heliophysics through theory, modeling, and simulations. Proposers must be affiliated with a U.S. institution and are required to submit a Step-1 proposal by September 16, 2025, before proceeding to the Step-2 submission, which is due on November 25, 2025. This grant is part of NASA's broader Research Opportunities in Space and Earth Sciences (ROSES) initiative, which supports a wide range of scientific research and development activities. Interested applicants can find more details and necessary documentation at the provided links, and for inquiries, they may contact Katya Verner at ekaterina.m.verner@nasa.gov or Alex Fletcher at alex.fletcher@nasa.gov.