Speaker
Description
Through its Clean Space (CS) initiative and to fully benefit from the removal of constraints linked to on-ground manufacturing and launcher requirements, ESA has set up the OMAR (On-orbit Manufacture, Assembly & Recycle) initiative. It is a system approach aiming to give an overview of the most interesting applications, to map the state-of-the-art and to derive a roadmap for the critical technologies development. The On-orbit Manufactured Large Antenna Reflector Preliminary Design study is part of it, alongside On-orbit Servicing Satellite design study, Mission Architectures and On-orbit Manufactured Spacecraft. These studies aim at understanding the possible strategies, system level impacts and potential benefits, while exploring the trade-space.
The starting point is a state-of-the-art looking at antenna designs focused on assessing the currently used technologies against the specific requirements for on-orbit manufacturing. Despite the enormous range of design variation for an antenna reflector, there are some key features of the key components of the antenna which are consistently the design drivers. In parallel, main requirements are surface accuracy (as-built, thermo-elastic, dynamic), pointing stability, mass, and stiffness.
Many of the current on ground manufacturing processes and reflector designs are not compatible with an on-orbit manufacturing. Different conceptual designs have been proposed with different manufacturing and assembly philosophy including parts size and proportions of manufacturing occurring on-orbit. The conceptual have been ranked on the following criteria:
• Maturity/Risks
• Robotical Needs
• Mechanical Performance
• Radiofrequency Performance
• Versatility
• Pollution
• Lead Time
• Stowability
Similarly, a wide range of materials, manufacturing and joining processes have been studied and ranked according to relevant criteria such as:
• Mechanical Performance
• Resistance to space environment
• Cleanliness
• Reliability
Taking into account all these criteria, the combination of conceptual design, materials and process converge on designs for the two use cases identified.
Further than reflector conceptual design itself, the “Space Factory” that will perform on-orbit manufacturing, testing and integration steps of large antenna reflector has also been preliminary designed. Preliminary mass, power and time budget have been estimated.
Finally, a technology roadmap has been achieved highlighting a clear distinction between:
• On-orbit manufacturing technologies (materials, processes, operations) which are still in their infancy.
• Client satellite that will require large evolutions to manage such very large reflectors.
The high cost of the overall development corresponding to the standard conservative space approach suggests the need to consider a new space approach to reduce the cost and make competitive products in terms of price and performances.
