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Santoni F.,University of Rome La Sapienza | Piergentili F.,University of Rome La Sapienza | Candini G.,Institute Astrofisica Of Andalucia | Perelli M.,IMT Srl | And 2 more authors.
Proceedings of the International Astronautical Congress, IAC | Year: 2013

A steerable deployed solar array system for 1-5 kg weight nanospacecraft is described in the paper, enhancing the achievable performance of these typically power-limited systems. The system is based on a deployable solar panel system previously developed in cooperation between Laboratorio di Sistemi Aerospaziali of University of Roma "la Sapienza" and the company IMT (Ingegneria Marketing Tecnologia). The system proposed is a modular one, and suitable in principle for the 1U, 2U and 3U standard Cubesat bus, even if the need for accurate pointing control makes is typically preferred for 3U Cubesats. The size of each solar panel is the size of a lateral Cubesat surface. A single degree of freedom maneuvering capability is added to the deployed solar array in order to follow the apparent motion of the sun as close as possible, given the mission requirements on the spacecraft attitude. A relevant design effort has been devoted to make the system compatible with the Cubesat standard, being mounted outside from the external spacecraft structure, without requiring modifications to the standard. The small available volume is the major constraint, which forces to use miniaturized electric motor technology. The system design tradeoff is discussed, comparing different deployment and motion control concepts and architectures, based on single or double motor implementations. The final selected architecture and the detailed design are illustrated in the paper. The system validation based on numerical simulations and prototype testing is discussed, showing the possible enhancements offered by the system in typical mission scenarios. Copyright © 2013 by the International Astronautical Federation. All rights reserved. Source


Santoni F.,University of Rome La Sapienza | Piergentili F.,University of Rome La Sapienza | Candini G.P.,Institute Astrofisica Of Andalucia Csic | Perelli M.,IMT Srl | And 2 more authors.
Acta Astronautica | Year: 2014

An orientable deployed solar array system for 1-5 kg weight nanospacecraft is described, enhancing the achievable performance of these typically power-limited systems. The system is based on a deployable solar panel system, previously developed with cooperation between Laboratorio di Sistemi Aerospaziali of University of Roma "la Sapienza" and the company IMT (Ingegneria Marketing Tecnologia). The system proposed is a modular one, and suitable in principle for the 1U, 2U and 3U standard Cubesat bus, even if the need for three axis attitude stabilization makes it typically preferred for 3U Cubesats. The size of each solar panel is the size of a lateral Cubesat surface. A single degree of freedom maneuvering capability is given to the deployed solar array, in order to follow the apparent motion of the sun as close as possible, given the mission requirements on the spacecraft attitude. Considerable effort has been devoted to design the system compatible with the Cubesat standard, being mounted outside on the external spacecraft structure, without requiring modifications on the standard prescriptions. The small available volume is the major constraint, which forces to use miniaturized electric motor technology. The system design trade-off is discussed, leading to the selection of an architecture based on two independently steerable solar array wings. © 2014 Elsevier Ltd. All rights reserved. Source


Perelli M.,IMT Srl | Negri A.,IMT Srl | Marino M.,IMT Srl | Pepponi C.,IMT Srl | And 3 more authors.
IEEE-NANO 2015 - 15th International Conference on Nanotechnology | Year: 2015

The aim of our research is to investigate about the respiratory activity (thermodynamics and kinetics) of eukaryotic cells in micro-gravity condition. Cells used for the experiment are saccharomyces cerevisiae cells (common yeast). By now yeast cells, due to their similarity to human cells, are used to detect the presence of pollution, or harmful particles on food or liquids. As well as human beings, yeast cells are sensitive to pollutant, therefore the detection of such substances is based upon a measurement of yeast state of health, in terms of metabolic activity. The most common way to measure yeast metabolic activity is by respirometry: measurement of oxygen concentration change over time in a solution containing yeast, glucose and the investigated substance. Yeast cells, while breathing, produce a decrease of oxygen concentration. The steady state value, reached few minutes after the yeast injection into the glucose solution, is an indicator of the metabolic activity. The purpose of our study is to use a miniaturized device as an environmental sensor for future manned missions. For this aim has been necessary to miniaturize a whole respirometric lab and make it fully stand alone, than compare the behavior of yeast cells in a microgravity medium to the behavior on Earth conditions. The space laboratory is less than 1dm3 (600g) and contains 4 identical experiments based on biosensors. In this paper are described the chemical and engineering processes (included qualification tests) needed for a miniaturization of 600 times less. © 2015 IEEE. Source


Santoni F.,University of Rome La Sapienza | Piergentili F.,University of Rome La Sapienza | Donati S.,University of Rome La Sapienza | Perelli M.,IMT Srl | And 2 more authors.
Acta Astronautica | Year: 2014

One of the main Cubesat bus limitations is the available on-board power. The maximum power obtained using body mounted solar panels and advanced triple junction solar cells on a triple unit Cubesat is typically less than 10 W. The Cubesat performance and the mission scenario opened to these small satellite systems could be greatly enhanced by an increase of the available power. This paper describes the design and realization of a modular deployable solar panel system for Cubesats, consisting of a modular hinge and spring system that can be potentially used on-board single (1U), double(2U), triple (3U) and six units (6U) Cubesats. The size of each solar panels is the size of a lateral Cubesat surface. The system developed is the basis for a SADA (Solar Array Drive Assembly), in which a maneuvering capability is added to the deployed solar array in order to follow the apparent motion of the sun. The system design trade-off is discussed, comparing different deployment concepts and architectures, leading to the final selection for the modular design. A prototype of the system has been realized for a 3U Cubesat, consisting of two deployable solar panel systems, made of three solar panels each, for a total of six deployed solar panels. The deployment system is based on a plastic fiber wire and thermal cutters, guaranteeing a suitable level of reliability. A test-bed for the solar panel deployment testing has been developed, supporting the solar array during deployment reproducing the dynamical situation in orbit. The results of the deployment system testing are discussed, including the design and realization of the test-bed, the mechanical stress given to the solar cells by the deployment accelerations and the overall system performance. The maximum power delivered by the system is about 50.4 W BOL, greatly enhancing the present Cubesat solar array performance. © 2013 IAA. Published by Elsevier Ltd. All rights reserved. Source


Campanella L.,University of Rome La Sapienza | Merola G.,University of Rome La Sapienza | Plattner S.,University of Rome La Sapienza | Negri A.,IMT Srl | And 2 more authors.
Lecture Notes in Electrical Engineering | Year: 2015

The primary aim of the research is to investigate about the respiratory activity (thermodynamics and kinetics) of eukaryotic cells in micro gravity medium. This information can be precious both with reference to human activity in the same conditions and to possible applications to environmental sensing by respirometry. In a space platform, one of the human main activities is surely respiration as strictly related to life conditions. When breathing is not permitted, life expires. What happens to this function in a small satellite system? How do the specific conditions affect the capacity of oxygen uptake and the shape of a respiration curve? In this presentation we describe a research aiming to study the behavior of a well common respirometric system, Saccharomyces Cerevisiae yeast cells when located within a closed system positioned inside a small satellite system. More the consequently needed miniaturization of the Clark electrode to amperometrically determine oxygen brings to a further reason of uncertainness related to the high current density and consequent polarization. Some problems were faced such as the aggregation of the cells able to close the circuit where solution is flowing in the experimental system, the formation of gaseous bubbles going to constitute cause of increasing electric resistance, the rigorous stability of the applied tension, the miniaturization of reactor passed from a mean 20 mL model in normal lab to 1 mL and less model when located in a small satellite system. © Springer International Publishing Switzerland 2015. Source

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