RAMS as a Crucial Contributor Towards Space Sustainability
Creators: name:  S. RADU 
name:   F. COSSON 
name:   C. LAHORGUE 
name:   L. MARCHAND 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: SUSTAINABLE SPACE
LOGISTICS

description: Nowadays space vehicles have a wide range of objectives and scopes aiming at accomplishing critical functions in various fields of aerospace engineering such as science, earth observation, navigation, telecommunication, close proximity operations (CPO), etc. The cost of such space missions can range from millions to billions and most of the spacecraft do not allow access for on-board maintenance, thus planning ahead and targeting high reliability is imperative. This latter aspect, becomes even more essential when building missions that may contribute to space sustainability such as Active Debris Removal (ADR) or In-Orbit Servicing (IOS) where two or multiple objects need to operate in close proximity either in a coordinated or uncoordinated manner. The overall Reliability, Availability, Maintainability and Safety (RAMS) analyses need to be thoroughly developed for such missions, in order to ensure safety and, ensure that at the end, the number of debris in protected regions are decreased. This papers main objective is to highlight the importance of RAMS for unmanned missions that operate in close proximity but also to emphasize on the importance of RAMS in all missions, especially with regards to optimization, cost reduction, schedule, risk and design budgets, while ensuring overall mission success is being maximised. In a space project, the RAMS assurance program comprises of a number of technical activities that consist of an extensive amount of analyses to be performed at various stages. Sometimes, in projects, it is noticed that the purpose of these analyses is slightly neglected or misunderstood and certain outputs from the RAMS analyses are not properly used. The correct and complete use of RAMS becomes even more critical in the CPO types of missions where safety is of paramount importance and the goal is to contribute to the reduction of debris. Similarly, the use of RAMS analyses are crucial also when deciding for life extension of a satellite and guaranteeing that the reliability of disposal is still met, this in turn contributing to space sustainability. The overall performed work aims at clarifying the interaction and intent of the RAMS analyses though the created RAMS map, especially when tailored for complex missions such as ADR or IOS. The paper will first focus on the RAMS analyses and their scope and definition specified in a general manner for space mission. The existing developed RAMS map which aims at showcasing the interaction between RAMS analyses but also their interdependency with other disciplines such as System Engineering and Fault Detection Isolation and Recovery will be disseminated. Furthermore, a thorough and detailed presentation on how these analyses should be performed and used for unmanned satellite missions will be discussed. Finally, the paper will present the tailoring of the RAMS map on specific types of missions operating in close proximity (ADR and IOS), emphasising on the RAMS delta required, in order to ensure in-orbit safety and mission success. Conclusions and recommendations with regards to RAMS for space missions with particular accent on those missions that aim at improving the overall amount of debris currently in orbit will be highlighted.