A Test Platform to Assess the Impact of Miniaturized Propulsion Systems

Miniaturized propulsion systems can enable many future CubeSats missions. The advancement of the Technology Readiness Level of this technology passes through the integration in a CubeSat platform and the assessment of the impact and the interactions of the propulsion systems on the actual CubeSat technology and vice versa. The request of power, the thermal environmental, and the electromagnetic emissions generated inside the platform require careful analyses. This paper presents the upgraded design and the validation of a CubeSat test platform (CTP) that can interface a wide range of new miniaturized propulsion systems and gather unprecedented information for these analyses, which can be fused with the commonly used ground support equipment. The CTP features are reported, and the main achievements of the tests are shown, demonstrating the effective capabilities of the platform and how it allows for the investigation of the mutual interactions at system level between propulsion systems and the CubeSat technology

Orthogonal-Array based Design Methodology for Complex, Coupled Space Systems

The process of designing a complex system, formed by many elements and sub-elements interacting between each other, is usually completed at a system level and in the preliminary phases in two major steps: design-space exploration and optimization. In a classical approach, especially in a company environment, the two steps are usually performed together, by experts of the field inferring on major phenomena, making assumptions and doing some trial-and-error runs on the available mathematical models. To support designers and decision makers during the design phases of this kind of complex systems, and to enable early discovery of emergent behaviours arising from interactions between the various elements being designed, the authors implemented a parametric methodology for the design-space exploration and optimization. The parametric technique is based on the utilization of a particular type of matrix design of experiments, the orthogonal arrays. Through successive design iterations with orthogonal arrays, the optimal solution is reached with a reduced effort if compared to more computationally-intense techniques, providing sensitivity and robustness information. The paper describes the design methodology in detail providing an application example that is the design of a human mission to support a lunar base

Preliminary Sub-Systems Design Integrated in a Multidisciplinary Design Optimization Framework

The aircraft design is a complex subject since several and completely different design disciplines are involved in the project. Many efforts are made to harmonize and optimize the design trying to combine all disciplines together at the same level of detail. Within the ongoing AGILE (Horizon 2020) research, an aircraft MDO (Multidisciplinary Design Optimization) process is setting up connecting several design tools and competences together. Each tool covers a different design discipline such as aerodynamics, structure, propulsion and systems. This paper focuses on the integration of the sub-system design discipline with the others in order to obtain a complete and optimized aircraft preliminary design. All design parameters used to integrate the sub-system branch with the others are discussed as for their redefinition within the different detail level of the design

ENTRY, DESCENT AND IMPACT SYSTEM DESIGN AND ANALYSIS OF A SMALL PLATFORM IN MARTIAN ENVIRONMENT

Thanks to the latest Mars missions, planetary exploration has made enormous strides over the past ten years increasing the interest of the scientific community and beyond. These missions must fulfil many complex operations which are of paramount importance to mission success. Among these, a special mention goes to the Entry, Descent and Landing (EDL) functions which require a dedicated system to overcome all the obstacles of these critical phases. The goal of this study is to describe in detail the design methodology for EDL system during the preliminary phase of the design. The design is supported by a simulation tool integrating the entry trajectory algorithm. The trajectory data computed are used to size the EDL system and strategy in order to have a low aerodynamic acceleration, low dynamic pressure and low convective heat flux incoming to the spacecraft. The reference mission has the goal to find bioevidence and biohazards on Martian subsurface in order to prepare future manned missions. The mission is based on Space Penetrator Systems (SPS) that can descend on Mars surface following a ballistic fall and penetrate the ground after the impact with the surface (around 50 and 300 cm depth). The SPS contains all the instrumentation required to sample and make the required analyses. As results, an Entry Descent and Impact (EDI) system based on inflatable structure is designed, respecting the low-cost and low-mass constraints. For this mission, a solution, like the one of Finnish Meteorological Institute in the Mars Met-Net mission, is chosen, using an inflatable Thermal Protection System (TPS) called Inflatable Braking Unit (IBU) and an additional inflatable decelerator. Consequently, there are three configurations during the EDI phases: at an altitude of 125 km, the IBU is inflated at speed 5.5 km/s; at an altitude of 16 km, the IBU is jettisoned and an Additional Inflatable Braking Unit (AIBU) is inflated; at last, at about 13 km, the SPS is ejected from AIBU and it impacts on the Martian surface. In this paper, the results obtained by the application of this design methodology are presented and, the obtained system and descent strategy satisfy the requirements of the mission

Software Reference Architecture for CubeSats – A Direct Approach

Ever since the first CubeSat mission was launched, the concept and complexity of CubeSat missions has evolved at a pace that current operational system/doctrine cannot match. In an increasingly dynamic space economy, where small businesses have become the norm, innovative solutions that abstract away complexity and increase autonomy are fundamental to reduce operational costs. It is within this frame that the current study is presented. To address the need for a standardized software architecture of NewSpace companies, we first assess the European small satellite market needs through a survey with key players in the space sector. From this survey, we derive the high-level requirements, functionalities, and interfaces of a software architecture for CubeSats, the preferred platform due to its lower cost when compared with traditional platforms. Finally, we report the implementation results of a set of these components and show how they reflect design drivers

Development and Validation of on-board systems control laws

Purpose - The purpose of this paper is to describe the tool and procedure developed in order to design the control laws of several UAV (Unmanned Aerial Vehicle) sub-systems. The authors designed and developed the logics governing: landing gear, nose wheel steering, wheel braking, and fuel system. Design/methodology/approach - This procedure is based on a general purpose, object-oriented, simulation tool. The development method used is based on three-steps. The main structure of the control laws is defined through flow charts; then the logics are ported to ANSI-C programming language; finally the code is implemented inside the status model. The status model is a Matlab-Simulink model, which uses an embedded Matlab-function to model the FCC (Flight Control Computer). The core block is linked with the components, but cannot access their internal model. Interfaces between FCCs and system components in the model reflect real system ones. Findings - The user verifies systems' reactions in real time, through the status model. Using block-oriented approach, development of the control laws and integration of several systems is faster. Practical implications - The tool aims to test and validate the control laws dynamically, helping specialists to find out odd logics or undesired responses, during the pre-design. Originality/value - The development team can test and verify the control laws in various failure scenarios. This tool allows more reliable and effective logics to be produced, which can be directly used on the system

Docking Manoeuvre Control for CubeSats

Rendezvous and Docking missions of small satellites are opening new scenarios to accomplish unprecedented in-obit operations. These missions impose to win the new technical challenges that enable the possibility to successfully perform complex and safety-critical manoeuvres. The disturbance forces and torques due to the hostile space environment, the uncertainties introduced by the onboard technologies and the safety constraints and reliability requirements lead to select advanced control systems. The paper proposes a control strategy based on Model Predictive Control for trajectory control and Sliding Mode Control for attitude control of the chaser in last meters before the docking. The control performances are verified in a dedicated simulation environment in which a non-linear six Degrees of Freedom and coupled dynamics, uncertainties on sensors and actuators responses are included. A set of 300 Monte Carlo Simulation with this Non-Linear system are carried out, demonstrating the capabilities of the proposed control system to achieve the final docking point with the required accuracy