© 2024 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.The capacity to keep a desired topology with a requested accuracy plays a significant role in every spacecraft formation-flying operation. These missions can be terminated in case of an unexpected spacecraft fault, preventing the system from returning to its nominal configuration. This paper presents and tests a new recovery solution, called Reconfigurable Guidance Strategy (RGS), for the spacecraft formation-flying control problem subject to a look-inplace permanent thruster fault. The proposed method relies on autonomously and in real-time reconfiguring the guidance function to compensate for the loss of the spacecraft actuation system. The performance and cost of the RGS have been tested in a high-fidelity simulation scenario, the 42 spacecraft simulator developed by NASA Goddard Space Flight Center, taking into account orbital and rotational nonlinear coupled dynamics, high-order perturbation models, and actuator and sensor models. The numerical simulation results have demonstrated the proposed recovery strategy’s effectiveness, feasibility, and robustness.

© 2024 by the authors.This research unveils a cutting-edge navigation system for deep space missions that utilizes cosmic microwave background (CMB) sensor readings to enhance spacecraft positioning and velocity estimation accuracy significantly. By exploiting the Doppler-shifted CMB spectrum and integrating it with optical measurements for celestial navigation, this approach employs advanced data processing through the Unscented Kalman Filter (UKF), enabling precise navigation amid the complexities of space travel. The simulation results confirm the system’s exceptional precision and resilience in deep space missions, marking a significant advancement in astronautics and paving the way for future space exploration endeavors.

© 2022, The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering.The use of CubeSats is increasing to a wide range of areas in science and technology with some of them requiring an accurate Attitude Determination and Control System (ADCS) and deployable structures such as booms. However, small satellites commonly do not have latching systems to lock their booms, which introduce vibrations and oscillations and might degrade the ADCS performance. Also, some applications propose missions with CubeSats operating in close proximity and coordination, requiring thrusters to perform orbit maneuvers such as the planned ITASAT-2 spacecraft formation flying mission, which will have non-latching booms and a thruster. These thrusters can excite the satellite’s non-latching flexible booms, intensifying their impact on the ADCS. Additionally, on-off thrusters are usually controlled using a Pulse-Width Modulation (PWM), introducing more effects in the system’s dynamic. Hence, motivated by the ITASAT-2 mission, this work aims to understand the impact of a thruster’s PWM parameters in the non-latching flexible booms dynamics. Also, this work presents a framework to obtain the influence of PWM parameters on a satellite, which can be applied to other small spacecraft. The results show that booms’ deformation decreases when the thruster provides a continuous force, compared to a modulated force. Peaks in deformation and rotation were identified near frequencies of the non-latching flexible booms’ system. Further, it was verified that resonances might occur in latched booms at distinct PWM periods. Moreover, the influence of the non-latching mechanism and PWM parameters was observed in the system forming regions of larger deformation.

© 2022 Society of Photo-Optical Instrumentation Engineers (SPIE).Silicon nanophotonics is contributing to the development of devices with small dimensions and low energy consumption. In optical systems for space applications, whether in large or small satellites, such as CubeSat, the demand for photonic devices has been a necessity, mainly in the communication subsystem, due to limitations in the conventional optical beam pointing subsystems. Silicon nanophotonics can be a solution in this case as it allows for the construction of an optical beam pointing system without moving parts, such as optical phased array antennas, in which the component responsible for the pointing functionality is the optical phase modulator. With this objective, we propose an efficient non-resonant all-optical modulator based on an Archimedean spiral waveguide topology by means of the indirect thermo-optical effect. Computational results are presented and discussed.

© 2022 IEEE.The earlier phases of any product development greatly influence its life cycle, especially in the aerospace field. Therefore, precise requirements are critical for good acquisition/development contract execution. Firstly, this study has made use of OPM (Object Process Methodology) to model the current Brazilian Air Force Policy for aerospace products' life cycle and a robust hazard analysis technique (STPA-System-Theoretic Accident Model and Processes) to investigate the causal factors which lead to negative impacts on the contract elaboration process for military aerospace products in Brazil. STPA uses System Theory to model any process as a feedback control structure. Focusing on the minimization of losses, the method considers the hazards, safety constraints, unsafe control actions, and causal factors. Based on that, it proposes requirements (which can be understood as recommendations), showing a path throughout the earlier phases of the Brazilian military aerospace products life cycle to improve the contract elaboration process.

© 2021 Elsevier Masson SASThe Scintillation Prediction Observations Research Task (SPORT) nanosatellite is being developed in partnership with the National Aeronautics and Space Administration agency and the Brazilian Space Agency, with its launch planned for 2022. Its goal is to collect data to improve our understanding of plasma bubbles and the condition that lead to their formation, helping to predict and mitigate their interference in navigation and communication systems. Therefore, to reach this goal, the satellite has several scientific instruments to perform in-situ measurements, with five of them positioned on four booms. These booms do not have a latching system to lock their position; instead, torsional springs are employed to keep them in the deployed state, holding them against their mechanism's structure. This configuration of torsional spring and collision may lead to vibration with the potential to degrade the Attitude Determination and Control System performance, impacting the whole mission. Motivated by the lack of literature covering the non-latching booms dynamics in satellites, this work proposes a framework based on multibody dynamics to simulate satellites with such booms. It also presents a practical method to acquire experimental data and identify the parameters of the booms' deployment mechanism. Later, this work applies the proposed framework and investigates the impact of non-latching booms on the satellite control system to verify if SPORT is able to complete the maneuver. Therefore, experiments were conducted to calibrate both spring and collision models. The multibody model of the satellite was developed and later validated using commercial software. The method for capturing booms' data and determining the mechanisms' parameters shows a satisfactory performance near the booms' deployment position. The proposed framework to simulate satellites with non-latching booms is applied to the SPORT satellite. Simulations in closed-loop indicate that the booms' influence on the SPORT's control system is negligible and the satellite meets its requirements.

© 2021 IEEE.Silicon nanophotonics is contributing to develop devices with small dimensions and low energy consumption. In space systems, whether in large or small satellites, such as CubeSat the demand for photonic devices has been growing, especially in the communication subsystem. For CubeSat the need to develop optical communication devices with reduced dimensions, low energy consumption and a precision aiming system, with no movable parts, is a challenge. In order to meet these requirements, this article presents a theoretical study on the use of a silicon nanophotonic device, in the form of Archimedean spiral waveguide, for phase modulation in Optical Phased Array antennas.

© 2020, Univelt Inc. All rights reserved.In this work, an attitude determination algorithm was developed for the 6U CubeSat satellite model of the Scintillation Prediction Observation Research Task (SPORT) mission. The project is a cooperation among the US Space Agency (NASA), American universities, the National Institute for Space Research (INPE) and the Aeronautics Institute of Technology (ITA). The work includes obtaining data from star, solar, magnetometer and gyro sensors and, with them to carry out, the attitude estimation. One of the requirements of the mission is the accuracy of attitude determination, which is only satisfied by the star sensor. However, there are periods in which the star sensor does not have valid measures, therefore, there is a need to study methods to improve the attitude given by the solar sensor and magnetometer. Thus, the TRIAD algorithm, in addition to the Kalman Filter, were analyzed to achieve the most accurate result within the established requirement. It was concluded that when the star sensor does not present valid measures, the analyzed case that fulfilled the requirements was the Kalman Filter with the TRIAD algorithm.

© The Author(s) 2018.Nowadays, it is practically impossible to develop a complex project without the assistance of a comprehensive set of modeling and simulation tools. In space engineering, they are used throughout the product design cycle, from component up to the system level. In conceptual, pre-phase A studies of a space mission, these tools are essential to explore more broadly the design space, in the search for suitable candidate system solutions for the mission. They are also of prime importance in helping to reduce the design time in integrated concurrent design environments. Here, a multidisciplinary tool for concept of operation simulation, developed to be used in that kind of environments, is presented. FOrPlan has the main purpose of performing functional simulations of the satellite and associated ground segments, providing a dynamic verification of the mission designed operational concept. Through the use of suitable graphical interfaces, key parameters of the mission functional scenarios can be presented to the design team and other mission stakeholders, allowing them also a better understanding of the mission operational concept. The simulator presents high flexibility such that it can be quickly customized to different mission scenarios. It has been used successfully at the Space Missions Integrated Design Center (CPRIME) of the Brazilian National Institute for Space Research. In this article, the structure of FOrPlan is presented, and its main features highlighted through results of concept of operation simulations performed for a scientific space mission study that was carried out recently at CPRIME.

© 2017, Springer Science+Business Media B.V., part of Springer Nature.The strongly perturbed environment of a small body, such as an asteroid, can complicate the prediction of orbits used for close proximity operations. Inaccurate predictions may make the spacecraft collide with the asteroid or escape to the deep space. The main forces acting in the dynamics come from the solar radiation pressure and from the body’s weak gravity field. This paper investigates the feasibility of using bi-impulsive maneuvers to avoid the aforementioned non-desired phenomena (collisions and escapes) by connecting orbits around the triple system asteroid 2001SN263, which is the target of a proposed Brazilian space mission. In terms of a mathematical formulation, a recently presented rotating dipole model is considered with oblateness in both primaries. In addition, a “two-point boundary value problem” is solved to find a proper transfer trajectory. The results presented here give support to identifying the best strategy to find orbits for close proximity operations, in terms of long orbital lifetimes and low delta-V consumptions. Numerical results have also demonstrated the significant influence of the spacecraft orbital elements (semi-major axis and eccentricity), angular position of the Sun and spacecraft area-to-mass ratio, in the performance of the bi-impulsive maneuver.