• Author: Bruni Giuseppe
  • Description:

    The small satellites like the ARAMIS platforms [1] are solutions growing low cost and small size, to realize several kind of satellite applications. The ARAMIS is a new approach to the CubeSat designing. It is characterized by the particular designing of the side faces of a CubeSat. These implement PCB boards that realize all the basic features of a satellite platform as reaction wheels, magnetorquer, power management systems and so on. Thus, the PCBs represent also the physical tiles of the lateral faces of the CubeSat. In this way the inner space of the CubeSat will be completely employed all to accommodate a payload. The ARAMIS systems are based on a completely modular approach. All tiles are designed to be easy assembled with interfaces of interconnections realised in standard way. An ARAMIS structure can also be implemented using different format of CubeSat as 1U, 2U, 3U [1], or other more complex formats as the 2x2x2U [1]. They are able to bring on board, payloads like small telescopes or cameras, antennas, remote sensing instruments, small radios telescopes and so on. Many of these payload applications are characterized by a high working power consumption. Just think a remote sensing application that uses ecodoppler techniques to trace the altimetry profile of the earth surface or atmospheric moisture and ionization ones. These instruments usually require high power transmitters and receivers equipment, in order to send and receive the eco signal. So, for these particular high power instruments the only outer tile surfaces of a 1U ARAMIS CubeSat, cannot be large enough to mount a number of solar panels able to provide enough power to the payloads and the satellite subsystems. Furthermore there are situations where the radiation efficiency of the sun is low. It is the case of a space mission much farther from the sun.
    So, in all these situations where a large surface of solar arrays needs, they are very useful the arrays of solar panels mounted on deployable mechanicals structures that at launch, for reasons of space, are closed filling a small space. Once in orbit, the structure is deployed increasing the total satellite surface exposed to the sun. In this way, more surface of solar panels can produce more power to supply high power consumption applications.
    The main application of the deployable structures if for use in space. Launch vehicles are limited in space and every other kilogram of weight added represents a problem for the launch, mainly in terms of costs. Since a space application is characterised by the not possibility to repair a system, the high cost of a failure leads the space industry to be conservative in the use of its applications or devices, including deployable mechanical structures. In this way, for each for each structure of new concept, the space industry is prevented to the immediate qualification or validation the new systems.
    For the market of the nanosatellites nowadays we have been realizing a large amount of deployable structures of solar panels. These structures are deployed in different ways. Generally an elastic mechanical element is used to charge a structure that is suddenly opened when sealing element is released. This is the case of the system developed for example by the Clyde Space company [2].
    The designing of a deployable mechanical structure of solar panels compatible for ARAMIS platforms is the target of my work. The thesis discusses in details the mechanical and electrical design, the compatibility of the shape for ARAMIS, its simulations and tests. In addition are explained in details: how the problems of spaces are solved, the electromechanical deployment system and the choice of the employed materials. Are further provided an analysis of opening for a structure of three elements, its thermal analysis and its orbital spin analysis.
    The thesis covers also the designing of a board of test for the management of the opening control for a deployable solar panels structure. A specific board is designed. The control circuit of the opening phase is designed on the outer plate element of a reaction wheel tile. In this way, this element will implements on
    board also part of the mechanical system of opening of the deployable solar panels structure. The outer plate element is chosen because it is a worst case for the realization of a support tile for the deployable solar panel structure, since it has only one side that can be covered by components and it presents several holes that reduce the space for the circuits. Finally the outer plate board represents a reference model to implement the compatibility interface of the 1B111E, on others different types of ARAMIS tiles. About opening system, particular attention is done to a system of electrical thermal fusers used to detach the fixing wire that maintains the tails of the deployable structure folded during the launch and before the in orbit deployment. The last part of the discussion deals the management software of the outer plate board.
    The UML is use to describe the main operation and the design phases. All main blocks are introduced with the corresponded UML class. All these classes are related to the 1B111E and the Bk1B213A1 sections of the ARAMIS project [1] of Polytechnic of Turin.

  • Year: 2016
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