Using Model-Based Systems Engineering For Space Mission Analysis And Design

Space mission analysis and design is a process of complex systems engineering involving multi-disciplinary fields, muti-objectives and muti-constraints, associated with severely system coupling, lots of participants and inundated design information. Document-centric paradigm of traditional systems engineering highlights some difficulties and we have an urgent need to explore new systems engineering methods. In this paper, model-based systems engineering is the main object of studies, and issues related to its applications in space mission and analysis are discussed.MBSE provides rich means of system design to system engineers. This paper studies the fundamental knowledges of MBSE and general contents of MBSE methodologies and basic knowledges of Sys ML.System model is the major artifact of MBSE, and it unites all the design information. This paper presents a method for modeling the Fire SAT mission. Through analyzing Fire SAT investors, users and other stakeholders, we construct requirement models and use case scenarios of Fire SAT mission. Logical architecture models are derived from requirement models and use case scenarios, and as a basis for building a physical reference architecture model. These models are cohesive and form the system model of Fire SAT mission, which provide a support for cost estimates and parameter analysis and physical architecture selections.The lifecycle cost(LCC) estimates of space mission is an important aspect of the space mission design. LCC includes costs of all stages of the mission life and various constituent elements, and therefore the LCC estimates need comprehensive mission information. The system model just provides such an information platform. This paper presents a model-based cost estimating method of the Fire SAT mission. It builds a Excel cost model and a Sys ML cost analysis model based on the Fire SAT system model, defines a reference relationship between the analysis model and the architecture model, and then achieves LCC estimates through the integration between these two models. The estimates are compared with the Fire SAT Ⅱ mission cost estimates in the SME reference books, and it proves the effectiveness of this estimates. The estimating process is compared with the process of traditional methods, which shows that this process can improve the work efficiency and avoid errors caused by manual input.System parameters design and physical architecture trade-offs are also important aspects to be considered in space mission design. The system model provides an authoritative source of information for them. In this paper, Fire SAT’s orbit analysis model, payload analysis model and power analysis model are built using Fire SAT’s overall parametric constraint relationships, and multi-subsystem system parameters are solved. The results show that the method is an effective means of parametric modeling and analysis. We proposed a method for generating alternative physical architectures from the physical reference architecture model and selecting a preferred solution, and then we complete the physical architecture selection of the power subsystem. The application results show that it is a clear, definite and efficient process, and that MBSE can ensure design information intuitive and reusable, and MBSE is an efficient method for space mission analysis and design.