NASA is seeking capability statements from potential sources for the SPARC contract, a planned Multiple Award IDIQ to develop nuclear systems for space and lunar surface use, with the Lunar Reactor 1 (LR-1) Phase 1 Task Orders expected to be awarded concurrently. The contract may cover technology development, space flight hardware and software, ground support equipment, and related operations, and NASA is looking for companies able to act as developers and prime integrators of space-nuclear systems. NASA is requesting industry feedback on small business subcontracting goals, barriers to small business participation, and strategies to increase participation, including teaming or mentor-protégé approaches. The LR-1 Phase 1 work is expected to take systems from current state to Preliminary Design Review maturity, with non-nuclear hardware demonstrations and deliverables expected within one year of task order award, and NASA currently intends to award to two or more contractors. Interested firms should submit a capability statement addressing their experience in large R&D contracts, spaceflight certification, nuclear regulatory compliance, and relevant technologies at TRL 4 or greater.