Concurrent Space Systems Engineering
- Paper number
IAC-07-D1.3.03
- Author
Prof. Geilson Loureiro, Instituto Nacional de Pesquisas Espaciais (INPE), Brazil
- Year
2007
- Abstract
This paper aims to present and demonstrate a systems engineering approach for mission and safety requirements capture that takes into account the whole system life cycle from the outset of the space system development process. Traditionally, mission and safety requirements documents cover the operational phases of space systems, the traditional CONOPS (concept of operations) approach. Moreover, with time, systems engineering documents such as mission requirements document, systems requirements document and safety requirements document have been developed only as a formality, using previous space systems documents as templates. This led to the view of systems engineering as a document producing and passing approach, with no added value. The approach proposed in the paper extends the concept of mission beyond the traditional launch and operations processes. It defines the mission from the time a system exists as a product, just after the space system is integrated, verified, qualified and accepted. From then on the product must be disassembled, handled, stored, transported, prepared for launch, launched, operated, maintained (if possible), reentered in the Earth atmosphere, rescued, analyzed, refurbished (if applicable), reused (if applicable) and discarded (if applicable). The scope of mission as defined in the paper encompasses all these life cycle processes. Once these processes are identified and detailed, a mission architecture is derived as a system of systems, including not only launcher, launch support systems and payload, but also, integration and testing supporting systems, integrated logistics systems, data acquisition systems, command, control and communication systems. Detailed processes derive mission requirements. Processes are detailed using functional flow block or behavior diagram in order to model activities along a timeline. Processes are also modeled using the IDEF0 approach, focusing on identifying the inputs, outputs, controls and mechanisms for each activity. Controls from these IDEF0 models derive the mission assurance topic of the mission requirements document. Mechanisms from these IDEF0 models derive the mission organization topic of the mission requirements document. Life cycle processes mechanisms in the system environment and the system are presented on a context diagram from where the system requirements document is derived. Life cycle processes mechanisms in the environment and the system interfaces with them derive what is called a passport diagram that provides the initial step for hazard identification from where the safety requirements will be derived. The approach is demonstrated via two examples, one is a sub-orbital launcher and the other is a reusable micro-gravity experimentation capsule. The paper promotes a revival of the systems engineering activity logic. Conclusions are that this approach allows a project to be organized from the outset to deliver not only operational requirements but also full life cycle support, carrying out concurrent engineering for systems (once concurrent engineering is well developed for components), shortening project life cycle, reducing change cycles and improving overall project productivity.
- Abstract document
- Manuscript document
IAC-07-D1.3.03.pdf (🔒 authorized access only).
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