Mission Design from Cradle to Grave: Applying Concurrent Engineering from Mission Feasibility Analysis through to End of Life Operations

摘要

Concurrent Engineering is a specialised work methodology based on the parallelization of tasks. The complete design team, composed of the various technical domain specialists, work on the different aspects of the project at the beginning of the design process. The methodology relies on identifying and parameterising dependencies between team members. Rapid gain of design consistency and overall project convergence is obtained with constant direct communication and data interchange. Results are achieved in a dramatically shorter time compared with a classical design approaches. This technique has been put to very good effect in Europe to assess the technical and financial feasibility of future space missions and new spacecraft concepts, space system trade-offs and options evaluation, new technology validation at system & mission level, requirements definition and consolidation. For example, the ESA Concurrent Design Facility (CDF) is routinely used for Phase 0 (pre-phase A studies); Large system integrators (LSI) also have established similar infrastructure for their own mission engineering tasks. Concurrent Design may be conducted as a manual process, which can be aided by the use of simple tools and techniques such linked spreadsheets. But it is most effective and efficient when supported by modern tools, such as J-CDS Concurrent Design Platform (CDP) and ESA's Open Concurrent Design Server (OCDS, under development), which not only support the process but are increasingly integrated with other external tools such as simulation frameworks, requirements management tools, and other system modelling environments. At this point, the artefacts of a concurrent design session become a design model; a set of integrated data products which can be reused in later phases of the project. These artefacts will eventually specify or influence the design of the mission components, spacecraft, payload and ground segment, which traditionally follow parallel (but independent) traditional development lifecycles. Concurrent design sessions at facilities such as CDF feature the strong interactions of a physically collocated team. The ESA CDF organises the studies in bi-weekly half day sessions with the participation of all disciplines needed. For a typical ESA study the ESA CDF holds between 6 to 10 sessions (i.e. 3 to 6 weeks). This paper explores the potential use of Concurrent Engineering techniques and tools throughout the whole lifecycle, supporting physically distributed teams. Phase 0 to B could effectively be classed as a single "design phase", which continues from initial concept to the finished design using the same specialists, tools and communication techniques. There is still a need for reviews and acceptance at different phases of the design which can be achieved by taking "snapshots" of the ongoing process and measuring the maturity of the desired products/The concurrent design tools are increasingly connected with system models for supporting the satellite, payload and simulator designs, which themselves manifest themselves in the operational data products, such as TM/TC database, operational procedures, operational simulators, used for system validation and operator training prior to launch and maintained throughout the operational lifetime. This natural flow of information has been recognised in literature such as ECSS-E-TM-10-20A: Space Engineering Product Data Exchange. Using a consistent methodology (concurrent engineering) and toolset from the cradle (mission concept) to grave (end of life of operations) will liberate the natural benefits of the methodology (agility, reduced timescale, increased communications, flexibility ) compared with traditional rigid approaches and allow a complete, traceable, auditable flow of mission design information. What's more, it presents an opportunity for operational aspects to have greater influence on the mission design than might currently be the case. The paper will describe how this vision