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Context. The protoMIRAX hard X-ray imaging telescope is a balloon-borne experiment developed as a pathfinder for the MIRAX satellite mission. The experiment consists essentially in a coded-aperture hard X-ray (30-200 keV) imager with a square array (13 × 13) of 2 mm-thick planar CZT detectors with a total area of 169 cm 2 . The total, fully-coded field-of-view is 21 • × 21 • and the angular resolution is 1 • 43 . Aims. The main objective of protoMIRAX is to carry out imaging spectroscopy of selected bright sources to demonstrate the performance of a prototype of the MIRAX hard X-ray imager. In this paper we describe the protoMIRAX instrument and all the subsystems of its balloon gondola, and we show simulated results of the instrument performance. Methods. Detailed background and imaging simulations were performed for protoMIRAX balloon flights. The 3σ sensitivity for the 30-200 keV range is ∼1.9 × 10 −5 photons cm −2 s −1 for an integration time of 8 h at an atmospheric depth of 2.7 g cm −2 and an average zenith angle of 30 • . We developed an attitude-control system for the balloon gondola and new data handling and ground systems that also include prototypes for the MIRAX satellite.Results. We present the results of Monte Carlo simulations of the camera response at balloon altitudes, showing the expected background level and the detailed sensitivity of protoMIRAX. We also present the results of imaging simulations of the Crab region. Conclusions. The results show that protoMIRAX is capable of making spectral and imaging observations of bright hard X-ray source fields. Furthermore, the balloon observations will carry out very important tests and demonstrations of MIRAX hardware and software in a near space environment.

Software for space applications requires significant testing. This paper presents an evaluation of the CoFI testing methodology as applied to actual space software, where deterministic fault cases derived from state-based models were executed using the software-implemented fault injection technique. Different models were used to represent the behavior of embedded software in a real satellite computer under the presence of both normal inputs and external faults in communication, processor, and memory. CoFI methodology was used for model construction, the Condado tool for test derivation, and the QSEE-TAS tool for test execution. In total, 8,620% of 471 fault cases detected errors in the software; this is a very large number, and more so considering that the software had already been tested by the company which developed it before being subject the CoFI methodology.

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ABSTRACT.  The INPE-UFSM’s NANOSATC-BR, CubeSats Development Program started in 2008. Currently, the Program counts with two CubeSats: the NANOSATC-BR1 (1U) launched in 2014 and still in operation & the NANOSATC-BR2 (2U), under development, which is expected to be launched in the last quarter of 2019. In this article, the scientific and technological results of the NANOSATC-BR1 and the finalization of NANOSATC-BR2 are presented. Considering the Capacity Building, the major target of the Program, the paper emphasizes the involvement of Universidade Federal de Santa Maria - UFSM undergraduate/graduate students in the conception, development and operation of NANOSATC-BR1, as well as the participation of the Instituto Nacional de Pesquisas Espaciais - INPE graduate students in the onboard data handling (OBDH) software subsystem development, verification and validation for the NANOSATC-BR2. In addition, the collaborations of other Space Science, Engineering and Computer Science institutions involved in Brazil and abroad are discussed. The Program has received financial support from the Brazilian Space Agency (AEB) and the Ministry of Science, Technology, Innovation and Communications (MCTIC). Keywords: cubesats, nanosatellites, capacity building. RESUMO. O programa NANOSATC-BR, Desenvolvimento de CubeSats, parceria INPE – UFSM, teve início em 2008. Atualmente, o Programa conta com dois CubeSats: o NANOSATC-BR1 (1U), lançado em 2014 e ainda em operação, e o NANOSATC-BR2 (2U), que está em desenvolvimento e tem expectativa de lançamento no último trimestre de 2019. Nesse artigo, a finalização do desenvolvimento do NANOSATC-BR2 e os resultados científicos e tecnológicos do NANOSATC-BR1 são apresentados. Considerando a Capacitação Profissional, o maior objetivo do Programa, o artigo dá ênfase ao envolvimento dos alunos de graduação na concepção, desenvolvimento e operação do NANOSATC-BR1, ao mesmo tempo em que enfatiza a participação dos alunos de pós-graduação do INPE no desenvolvimento, verificação e validação do Subsistema de Computador de Bordo para o NANOSATC-BR2. Além disso, colaborações de outras instituições de Ciência Espacial, Engenharia e Institutos de computação aplicada do Brasil e Exterior, são igualmente discutidas. O Programa recebeu suporte financeiro da Agência Espacial Brasileira (AEB) e do Ministério da Ciência, Tecnologia, Inovações e Comunicações (MCTIC). Palavras-chave: cubesats, nanosatélites, formação de recursos humanos.

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Different arguments were being presented in the last decade about CubeSats and their applications. Some of them address wireless communication (5G and 6G technologies) trying to achieve better characteristics as coverage and connectivity.Some arrived with terms as IoST (Internet of Space Things), Internet of Satellites (IoSat), DSS (Distributed Space Systems), and FSS (Federated Satellite Systems).All of them aim to use Small/NanoSatellites as constellations/swarms is to provide specific services, share unused resources, and evolve the concept of satellites-as-a-service (SaS).This paper aims to emophasize performance attributes of such cyber-physical systems, model their inherent operational constraints and at the very end, evaluate the quality of service in terms of figures of merit for the entering/leaving of new heterogeneous constituent systems, a.k.a satellites, to the constellation. This "whitepaper"-styled work focuses on presenting the definitions of this heterogeneous constellation problem, aims at its main capabilities and constraints, and proposes modeling approaches for this system representation and evaluation.

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