Space mission design software spans the entire lifecycle of space missions and is regarded as the cornerstone of the aerospace industrial software system. Leveraging nearly three decades of technical expertise in the field of manned spaceflight, the research team from the National University of Defense Technology initiated the development of the independent industrial software ATK（aerospace tool kit） in 2020. By the end of 2024, the ATK 3.0 version was officially released, encompassing 5 major categories and 21 functional modules, including standard platform, visibility and coverage analysis, mission analysis, orbital design, and secondary development. The development of ATK has been deeply and continuously supported by China Manned Space Engineering exploring a collaborative research and development model characterized by "engineering-driven demand+centralized academic development". This software has had a significant impact in aerospace engineering, space security, and academic education, marking a solid first step toward replacing STK. The development history of ATK was reviewed, and the functional features was elaborated on. Focuses on analyzing its core technologies breakthroughs of ATK, such as large-scale software architecture design, computational kernel development, and orbital maneuver planning were selective analysed. While ATK faces challenges in enhancing its functionality and building its application ecosystem, its future development roadmap and strategic objectives were outlined.