Description
Priority 2: A request for initiation has been received for this Priority 2 activity.
Objective:
Development of design and manufacturing technology of ultralight and stable CFRP tubes.
Targeted Improvements:
Mass and MAIT time reduction of tubular structures, such as S/C central tubes and booms for payloads.
Description:
All current telecom satellites are based on a central tube concept which usually is manufactured as a CFRP sandwich structure. Such structures require significant reinforcement for any access holes, piping or harness holes, and the locations to put these holes are restricted. The manufacturing process for CFRP sandwich tubes is complex and time consuming. CFRP grid structures are highly efficient load bearing structures that can be manufactured using automatic techniques such as fibre placement or filament winding. For some launcher applications (Proton) CFRP grid structures have been demonstrated to be superior to monolithic CFRP or sandwich structures. Therefore it is of interest to investigate CFRP grid structure concept for central tubes. Gridded structures are known to have been used before in space. As remarkable example the central tubes of some Russian telecom spacecraft are built in an iso-grid architecture, with significant mass advantage. Europe does not yet have such capability.
The challenge is twofold for central tubes: in addition to the concept it is necessary to develop the interfaces for significant load transfer, and also the manufacturing, employing automated processes. In the case of payload structures, this type of tubes offer not only a significant mass reduction but also a very stable architecture due to the homogeniesation of temperatures, internal loads and low thermal expansion coefficients. Applications for payloads range from booms to tubular structures such as pallets for antenna farms, towers for feed elements and payload modules.
This activity is devoted to the identification of benchmark structures, the development of the grid concept architecture, the development of the automated manufacturing process, and the design of different types of mechanical interfaces to other structures and elements (a.o. to a ring interface, and for inserts). Sample and component testing shall be included as necessary to verify the main properties.
Two breadboards shall be produced and tested for their applications: a central tube for a spacecraft, and a boom for deployable antennas. The characterisation tests shall include mechanical loading, vibration and thermal stability. Results shall be compared to conventional solutions – in terms of mechanical performance, mass, cost, and manufacturing and integration time.