Abstract: In this paper, targeting the solar system boundary exploration mission, the scientific objectives of the mission were formulated by addressing multiple scientific issues such as the formation and evolution of the solar system, heliospheric physics, and interstellar medium properties. Based on these objectives, a requirement analysis was conducted, a preliminary mission concept was proposed, and an overall plan for two exploration missions—the “Nose” (nose-first approach) and “Tail” (trailing approach) missions—was developed. Both missions will be launched using the Long March 5 rocket, with the “Nose” mission following a flight sequence of Earth-Earth-Jupiter and the “Tail” mission following Earth-Jupiter. Based on this framework, focusing on mission challenges, key technical aspects—including detector platform design, nuclear power system design, and scientific payload configuration—were elaborated and a detector design scheme based on a 1 kWe-class space reactor power source was proposed. This study can provide reference for the implementation of China’s solar system boundary exploration projects.