The technical brainstorming for the objective of modularity and flexibility on potential communication satellite standardized modules and derived solutions which allows to save manpower and cost for non-recurring and recurring satellites design and to shorten the AIT process have been investigated starting from the current state-of–the-art on some critical technologies having the possibility to make an actual way to design the new generation satellites in a possible very close future.
The starting point and, at the same time, the approach for the entire activity has been the identification and analysis of the modularity already present in the current way to design and manufacture a complete (platform + payload) TLC satellite, trying also to highlight the critical factors or elements constituting obstacle for a complete modularity and flexibility implementation.
For what concern the platform the question that TLC satellites of today are only partly modular is because each subsystem has an impact on the other one for instance for what concern the satellite platform the thermal control function, at same time already the power distribution can be easily modular because it is possible to tune the power with the addition of some strings to the solar panels and/or by adding rows of cells in the battery.
For the satellite (platform + payload) flexibility three possible concepts have been identified for the modularity and flexibility approach, i.e.:
Classical Flexibility Concept (CFC) is the less innovative and it is meant to render the satellites of today as modular as possible without huge breakthrough by optimizing some features (electric propulsion, reorganization of the volumes, thermal and electrical interfaces etc.).
Central Tube Concept (CTC) is meant to optimize the payload accommodation volume and some features while on orbit thanks to a wise deployment of modules away from the central tube and backbone interface. Fig. 1 depicts t a possible CTC configuration.
Fig.1: Centralised Config
click for larger image
Module Configuration Concept (MCC) is meant to optimize the ROI, i.e. the same modules may be used for a SATCOM in GEO and for a SATCOM in LEO with small adaptations:
- Each module has the ability to work alone in GEO or in LEO as a single satellite and to work attached to another module in order to form a bigger assembly.
- The assembly can evolve once in orbit.
- Each module presents the adequate interface to accommodate antennas (reflectors and sources), batteries, solar arrays, radiators, TTC subsystem, data handling, payload equipment, etc. When the modules are part of an assembly forming a bigger satellite some interfaces will not be used.
Modularity and flexibility concepts are strictly connected with the capability both to adapt during the mission lifetime the payload mission to dynamic requirements updating and the capability, at design stage, to adopt a standardized solution in order to achieve a manufacturing optimization and a cost reduction for the commercial market enjoying the benefits of standard integration and test procedures.
Payload modularity can be achieved acting on each sub-system composing the TLC payload itself, as shown in Fig. 2.
Fig. 2: Main payload concepts for modular design
click for larger image