Aerospace Missions Research Articles

Efficient Power Conditioning: Enhancing Electric Supply for Small Satellite Missions

Electric power supply (EPS) is the heart of any aerospace mission and plays an important role in improving the performance and service lifetime of spacecraft. It generates, converts, stores, and distributes power to different voltage levels. The EPS is composed of solar panels, a power conditioning unit (PCU), batteries, and a power distribution unit (PDU). This paper describes the design and analysis of an efficient power conditioning system for a CubeSat standard small satellite. For this purpose, the aim of this paper is to propose a two-input maximum power point tracker (MPPT)-based interleaved boost converter. The design copes with the fact that when a satellite revolves around the Earth, a single panel or at most two panels face solar radiation at different angles. In order to extract maximum power from the panels, the designed converter drives the solar panels at the maximum power point (MPP). A small signal model is drawn for the converter, and the closed-loop gain of the converter is analyzed using a Bode diagram. To improve the phase margin and gain, a PID compensator is designed and added to the closed loop of the converter. Finally, the performance of the proposed converter is validated by the simulation results.

Low‐temperature performance of Na‐ion batteries

AbstractSodium‐ion batteries (NIBs) have become an ideal alternative to lithium‐ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost‐effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep‐sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na+) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na+ in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high‐performance LT NIBs.

Tests and Analysis of Storage Life Extension of Hybrid Microcircuits for Aerospace Applications: A Case Study

Hybrid Microcircuits (HMCs) which bring about miniaturization with better performance and reliability are ideally suited for specific application where low volume requirement needed for aerospace missions. A large number of HMCs for varied applications are used in aerospace industry. HMCs generally use passive components and interconnections in thick film form, and active devices (MOSFETs, Transistor and Diode dice) and monolithic ICs (as bare chips) bonded to a substrate and are employed to carry out multiple functions. The die and other chip components utilized in making HMCs necessitated usage of hermetic sealing. The resulting HMCs consisting of multiple components are used as standalone EEE component. A general guideline of using HMCs for 9 years and re-screening after 3 years result in lot of constraint on resources and not viable in present scenario. The study conducted to find out the criticality and testing methodology for the extension of usable storage period. Comprehensive test plan consisting of variety of HMCs having varied processes, materials, density and various tests conducted as per the plan. This article details the various plans, choice of HMCs, testing results and analysis for the basis of extending the usable storage period of the HMCs for aerospace industry.

Trajectory/propulsion integrated design optimization of the manned lunar lander propelled by hybrid rocket motors using analytical target cascading

Lunar missions are currently experiencing a significant surge in popularity, presenting expansive opportunities for further exploration and development. To thoroughly explore the design margins and potential of lunar landers, and to foster the development of overall designs driven by comprehensive performance objectives, it is crucial to conduct optimization design considering the coupling between key disciplines such as trajectory and propulsion. Considering the significant increase in computational complexity caused by conducting trajectory/propulsion integrated design optimization, the analytical target cascading method is employed to hierarchically decompose and coordinate optimization of the complex systems. This article presents a phased soft-landing strategy on the manned lunar lander propelled by hybrid rocket motors, utilizing powered explicit guidance and Apollo powered descent guidance, and proceeds with the trajectory/propulsion integrated design optimization involving diverse grain shapes and feed systems. This optimization process is separately undertaken utilizing multidisciplinary feasible method and analytical target cascading method. The analysis reveals that integrating trajectory and propulsion considerations into the optimization process facilitates a 5 % reduction in the overall mass relative to optimizations constrained solely by velocity increment and lack comprehensive trajectory design considerations. This highlights the profound impact of trajectory requirements on propulsion system design and the advantages of powered explicit guidance laws in minimizing fuel consumption. Crucially, the use of analytical target cascading achieves the better optimization results, and significantly reduces subsystem evaluation times, enhancing operational efficiency by 48 %, demonstrating the advantage in handling complex, large-scale systems. On another level, with different β values, the Mean Relative Error of the target values for the three schemes obtained by the analytical target cascading method is 0.0016, indicating good stability and strong robustness. The practical exploration in this article provides methods and frameworks for high-performance optimization design of complex aerospace mission profiles in the future.

Kinematic accuracy reliability evaluation method of space deployable mechanism based on dynamic model

Space deployable mechanisms are widely used in aerospace missions. The uncertainties in the geometric or physical parameters seriously affect the kinematic accuracy of the mechanism during the deployment process. In this paper, a kinematic accuracy reliability evaluation method of the space deployable mechanism based on dynamic model and adaptive hybrid surrogate models is presented. Firstly, the dynamic model of the space deployable mechanism is established based on the Lagrange method, and the motion error function considering the factors such as the mass, dimension and load is established. In order to improve the efficiency, an adaptive hybrid surrogate model reliability evaluation method based on improved weight measurement method is further proposed. The weight measurement method considers the global errors and local errors of the models. Finally, the Monte Carlo method is used to verify the accuracy of the hybrid surrogate model method. The relative error of the failure probability calculated by the proposed method is within 2.5 %, indicating that the proposed method has high calculation accuracy and efficiency.

Foam with direction: unraveling the anisotropic radiation shielding properties of 2D boron nitride nanoplatelet foams

Neutron radiation exposure is one of the main challenges faced during space missions. There is a critical need for advanced lightweight radiation shielding materials. Two-dimensional (2D) boron nitride nanoplatelets (BNNP) are excellent candidates for polymer matrix nanofillers due to their superior neutron shielding and thermal and mechanical properties. Furthermore, the 2D material anisotropic behavior unlocks the potential for composite property tailoring. This study fabricated ultra-lightweight lamellar BNNP foams (density 0.05 g cm–3 and 97.5% porous) via freeze-drying processing. The neutron shielding effectiveness or mass absorption coefficient of the BNNP foams with walls perpendicular to the direction of the radiation source was 14.47 cm2 g–1, while that of the foam with parallel configuration was only 8.51 cm2 g–1. The orientation-dependent neutron radiation shielding properties were modeled using the Beer-Lambert law for porous composite materials. The BNNP foam in this study has the potential to benefit advanced tailorable radiation shielding technologies for future aerospace missions.

Various Techniques for the Reliability Improvement In Rf Systems and Its Implementation Methodology

The standard transmitter employed for aero-space mission at microwave frequencies need extensive optimization and takes higher turnaround time due to manual tuning and soldering of components. The discrete high power transistor for the output power having varied perform due to batch to batch parameter variations. This makes low throughput due to device limitation and needs extensive tuning approach. Further the weight of the housing and its realization is time consuming process due to standard machining and tuning requirements. In this article, we proposed variety of new approaches to achieve light weight, higher throughput while maintaining reliability without much manual intervention. This article details SMT based approach for RF circuits, CFRP based housing using 3-D printing techniques and GaN device to achieve high output power. Gold plating of the CFRP, realization of circuits on plated CFRP carrier plates, thermal characterization and usage of SMT line for RF circuits are the other areas dwelt in this article. The integration of these techniques may lead to highly reliable RF system while maintaining the stringent specifications for aerospace applications. Structural analysis of CFRP, thermal imaging of high power devices, SMT process steps are further detailed.

Fluid structure interaction of supersonic parachute with material failure

The material damage of parachute may occur in parachutes at high speeds, and the growth of tearing may finally lead to failure of aerospace mission. In order to study the damage mechanism of parachute, a material failure model is proposed to simulate the failure of canopy fabric. The inflation process of supersonic parachute is studied numerically based on Arbitrary Lagrange Euler (ALE) method. The ALE method with material failure can predict the transient parachute shape with damage propagation as well as the flow characteristics in the parachute inflation process, and the simulated dynamic opening load is consistent with the flight test. The damage propagation mechanism of parachute is then investigated, and the effect of parachute velocity on the damage process is discussed. The results show that the canopy tears apart by the fast flow from the initial damaged area and the damaged canopy shape leads to the asymmetric change of the flow structure. With the increase of Mach number, the canopy tearing speed increases, and the tearing directions become uncertain at high Mach numbers. The dynamic load when damage occurs increases with the Mach number, and is proportional to the dynamic pressure above the critical Mach number.

SPACE RADIATION-INDUCED BYSTANDER EFFECT IN ESTIMATING THE CARCINOGENIC RISK DUE TO GALACTIC COSMIC RAYS

Space radiobiology is an interdisciplinary science that examines the biological effects of ionizing radiation on humans involved in aerospace missions. The knowledge of the risk assessment of the health hazard related to human space exploration is crucial to reducing damages induced to astronauts from Galactic Cosmic Rays (GCRs) and sun-generated radiation. GCRs have been identified as one of the primary sources of radiation exposure in space. In this context, an accurate characterization of the possible risk of carcinogenesis induced by exposure to GCRs particles is mandatory for safe human space exploration, and one of the most crucial open problems is the contribution to carcinogenesis due to the effects on the cells directly and not directly irradiated, indicated as Target Effects (TEs) and Non-Target Effects (NTEs), respectively. It is accepted that the detrimental effects of ionizing radiation are not restricted only to the irradiated cells but also to non-irradiated distant cells manifesting various biological effects. Tumor Prevalence (TP) is often used to investigate the effects of NTEs in predictions of chronic GCR exposure risk. This paper reports the status of the research on this topic at the INFN Roma Sapienza Alpha Magnetic Spectrometer (AMS) research group, where is in progress an extensive study about the risk evaluation of the NTEs that the GCRs radiation will imply when added to the TE. A theoretical framework is presented for TP-induced NTEs modeling, ready to be used with the data collected from the AMS02 detector. Finally, a possible example of the use of the tool is shown for an accurate estimate of the tumor prevalence function of the exposure period for different typical space protons energies.

Resilient Autonomous Mission Management for Decentralized Multispacecraft Missions

Autonomy will play a crucial role in achieving complex mission goals and reducing the burden for ground operations for upcoming ambitious aerospace missions. Standalone spacecraft can leverage autonomy concepts to optimize data collection and ensure robust operation. Autonomy can additionally provide a feasible method of ensuring coordination for spacecraft clusters through onboard peer-to-peer scheduling. The core of this framework, the schedule manager (SM), manages tasks by associating constraints with each task including time windows, task priority, conflict categories, and resource requirements, which assures that tasks will only run when capable. This increased control over individual tasks also improves the modularity of the overall mission plan and provides a built-in fail-safe in the event of unexpected task failure through the loading of predefined contingency schedules. Various other capabilities were added to the SM, including the SM data server to simplify commanding, distributed coordination, and integration with NASA Goddard Space Flight Center’s core Flight System (cFS) platform. Software validation was achieved with cFS unit tests, functional tests, and code analysis tools. Demonstrations were tested with a cluster of development boards in the loop as representative flight hardware.

Experimental study and numerical analysis of vacuum thermal characteristics of brush DC motor

Brush direct current (DC) motors have several qualities that make them very attractive for space flight applications. Considering the high reliability requirements of aerospace missions, the thermal characteristics and thermal failure of the brush DC motor in the space environment were studied. Using a motor thermal resistance network model, a special thermal test method was determined and combined with a thermal conductivity analysis model, the thermal parameters were obtained via item-by-item stripping, and the motor temperature field was constructed. By introducing the arc discharge factor to evaluate the electric-corrosion heat consumption, the numerical analysis results were in good agreement with the test results under the conditions of stalled rotor, normal rotation, single brush, and multiple brushes. The analysis and test results show that continuous operation for 110 s will lead to melting of the brush solder joints, and electrical corrosion heat consumption is one of the main factors that cannot be ignored. The reliability model of vacuum applications should be established in the normal working mode of at least two brushes in both the positive and negative electrodes. To improve the reliability, a sealed air-filled structure of the motor was proposed, a heat-flow co-simulation model of a continuous medium flow with a large curvature and constant without a gravity field was established, and the temperature and velocity fields under different sealed pressures were obtained. The results show that the temperature of the single brush reduced to below 140 °C from 204.5 °C in vacuum, which can meet the long-term continuous working requirement of high reliability of brush motors in space missions. In addition, it was found that with the decrease in pressure, the effect of convective heat transfer gradually weakens, the temperature gradually increases and converges to the unique heat conduction process of the gas, while the effect of convection is negligible. As the pressure continues to decrease, the sealed gas evolves from continuous medium flow to transitional and free molecular flow, and the heat conduction effect of the gas weakens again until it approaches the singleness solid conduction process.

Non-Cooperative Spacecraft Pose Measurement with Binocular Camera and TOF Camera Collaboration

Non-cooperative spacecraft pose acquisition is a challenge in on-orbit service (OOS), especially for targets with unknown structures. A method for the pose measurement of non-cooperative spacecrafts based on the collaboration of binocular and time-of-flight (TOF) cameras is proposed in this study. The joint calibration is carried out to obtain the transformation matrix from the left camera coordinate system to the TOF camera system. The initial pose acquisition is mainly divided into feature point association and relative motion estimation. The initial value and key point information generated in stereo vision are yielded to refine iterative closest point (ICP) frame-to-frame registration. The final pose of the non-cooperative spacecraft is determined through eliminating the cumulative error based on the keyframes in the point cloud process. The experimental results demonstrate that the proposed method is able to track the target spacecraft during aerospace missions, which may provide a certain reference value for navigation systems.

413 CARDIOVASCULAR CHANGES MICROGRAVITY-RELEATED: SYSTEMATIC REVIEW OF THE LITERATURE

Abstract Introduction Microgravity-relevant space is characterized by different environmental conditions than terrestrial space, including microgravity, vacuum/hypovaria, acceleration, extreme temperature, ionizing radiation, and confinement/isolation. The space environment induces biomechanical and cardiovascular stress during both takeoff and landing, exposing astronauts to the development of cardiovascular disease (CVD). This literature review focuses on cardiovascular changes that can be traced to an aerospace mission. (Baran, R., et All. 2021). Materials and Methods A systematic literature review was conducted to assess the cardiovascular changes that occur on the human body in microgravity. The search was performed using PUBMED as the database. The inclusion criteria established, for an article to be used, was the relevance of the topic. The choice of articles that were subsequently included in the study was based on predetermined questions and inclusion and exclusion criteria in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). The quality of the study was assessed by two reviewers and then discussed with a third reviewer using the DIXONWOOD checklist. Results and Discussion Baran, R. et all studied cardiovascular changes during spaceflight in vivo and related molecular changes in vitro that, were outside the scope of pre-flight cardiovascular disease. These changes are related to several factors, including the absence of orthostatic pressure, and reduced blood pressure, which results in a depletion of cardiac workload, sometimes leading to cardiac atrophy, i.e., reduced ventricular size in cosmonauts following a mission. In the face of these, the scientific community is investigating through pre- and post-flight simulation tests the adaptation and prevention of the cardiovascular system. An exposure to microgravity greater than 6 months cascades numerous physiological adaptations. Indeed, there is a shift in body fluids, arrhythmias, and an increase in systolic output (35-46%) and cardiac output (18-41%). Despite these increases, astronauts may enter a hypovolemic state and cardiogenic shock (10-15% decrease in volaemia). (Baran, R., et All. 2021). In addition to this, prolonged stay in Space, exposes, the cosmonaut to syncopal events of cardiogenic origin in the re-entry and post-landing phase. (Meck, J. V., et All. 2001). Conclusions Exposure to microgravity conditions results in significant changes in cardiovascular function. Further clinical studies in larger samples are, however, needed to understand and prevent microgravity exposure-related CVD. For future applications and theoretical-practical investigations, there also emerges the need, in view of increasingly longer and riskier missions̀ health teleconsultations, for the presence of the health care team on board the shuttle or at the bases alreadỳ present in Earth orbit.

Automatic approach procedure of a flying vehicle on a mobile platform using backstepping controller

This paper presents the automatic approach procedure of a flying vehicle, attached to an ABB 7600 robot, and a mobile platform, attached to a Stewart platform. Due to a nonlinear dynamic behavior, it is necessary to implement complex control, stabilization and guidance schemes. The proposed solution for this system includes the development of an algorithm based on a backstepping control method, the controller design methodology being based on Lyapunov's stability theory. The proposed command law requires that the states are known, but it is also necessary to introduce a series of state estimators. Tracking a mobile platform is critical in surveillance, reconnaissance and tracking missions, with the control methodology defining a clear distinction between translational and rotational dynamics. The proposed algorithm is developed by separating two types of states involving an inverse kinematics, known as algebraic kinematics, in which the dynamic movements of the two pieces of equipment are used. The dynamics of the ABB 7600 robot involves a movement with seven degrees of freedom, while the Stewart platform can be used with a movement of six degrees of freedom. The proposed algorithm is implemented in both Matlab software and experimental testing. This paper provides results in terms of generating dynamics for both devices that can be used for simulating different scenarios of aerospace missions.

Stability of Cernox® temperature sensors stored at room temperature over a 29-year period

Many cryogenic applications critically depend upon accurate temperature measurement for success. In certain applications, including aerospace missions, temperature sensor components are procured years in advance of the mission’s launch date in order to accommodate installation and ground-based testing. Once installed there is little opportunity for recalibration, so the stability of the sensor stored at room temperature over extended time periods becomes vitally important. One of the most common cryogenic temperature sensor types used in aerospace applications is the Cernox Resistance Temperature Sensor manufactured by Lake Shore Cryotronics, Inc., and has been commercially available since 1993. For 29 years a set of 35 sensors manufactured from two of the initial production wafers has been stored at room temperature in ambient atmosphere. These sensors have been periodically recalibrated over the 1.4 K to 325 K or 4 K to 325 K temperature range as appropriate to provide an estimate of the long-term stability of these sensors when stored at room temperature. Data for each temperature sensor were analyzed in terms of equivalent temperature shift between each subsequent calibration and its initial calibration in 1992. The data show that the overall 29-year average stability for devices from these two Cernox wafers roughly follows a stability of ±10 mK for temperatures below 10 K and 0.07% of temperature for temperatures above 10 K. Data for an additional nine Cernox devices from an actual JWST production build lot showed they all exhibited stabilities better than ±8 mK for T < 10 K and (ΔT/T) < ±0.075% for T > 10 K.

Deep-Learning-Based Satellite Relative Pose Estimation Using Monocular Optical Images and 3D Structural Information

Relative pose estimation of a satellite is an essential task for aerospace missions, such as on-orbit servicing and close proximity formation flying. However, the changeable situation makes precise relative pose estimation difficult. This paper introduces a deep-learning-based satellite relative pose estimation method for monocular optical images. The method is geared towards uncooperative target satellites with known 3D models. This paper proposes a novel convolutional neural network combined with 3D prior knowledge expressed by the 3D model in the form of the point cloud. The method utilizes point cloud convolution to extract features from the point cloud. To make the result more precise, a loss function that is more suitable for satellite pose estimation tasks is designed. For training and testing the proposed method, large amounts of data are required. This paper constructs a satellite pose estimation dataset BUAA-SID-POSE 1.0 by simulation. The proposed method is applied to the dataset and shows desirable performance on the pose estimation task. The proposed technique can be used to accomplish monocular vision-based relative pose estimation tasks in space-borne applications.

An autonomous, multi-agent, IoT-empowered space logistics system for mission-critical inventory packing

In recent aerospace missions, space logistics have proven essential in storing, delivering and returning crew and materials between terrestrial facilities and space stations. Unlike classical commercial logistics, space logistics operations are cost-prohibitive and mission-driven, and its replenishment cycle for essential materials is relatively long. Therefore, the complete utilisation of spacecraft payload is of utmost importance. The theory of the inventory packing problem is extended in this study to build autonomous agents that interact with one another within a space logistics decision support system to reinforce the replenishment decision, chunk loading optimisation, and quality inspection. With the long replenishment cycle time, an agent embedded with interval type-2 fuzzy logic is explored to support chaotic time-series demand forecasting to derive re-order quantities in the desired period. Afterwards, the second agent solves the space chunk loading problem using the differential evolution algorithm to utilise payloads and capacities, particularly cylindrical chunks fully. The third agent measures actual item dimensions and quality to deploy the three-dimensional object scanning devices. Feedback is provided to the second agent to derive optimal chunk-loading instructions. Thanks to the autonomous interactions among the above agents, mission-critical decisions for space logistics are supported to achieve operational excellence.

Auxiliary Minimum Covariance Resolution of Infinite-Order Singular Arcs

Singular arcs are a common feature in optimal control problems when the standard necessary conditions fail to reveal a candidate control. In some cases, a singular arc can be proven to be nonoptimal and discarded. In other cases, the solution can be resolved through additional convexity conditions on the Hamiltonian. A less common, but nonetheless interesting, scenario occurs when the singular arc appears with infinite order. This situation becomes apparent when the problem definition lacks sufficient information to identify a unique solution. In this work, we consider conditions under which singular optimal control problems may exhibit indeterminate behavior due to insufficiency of the cost objective and boundary conditions. The resulting problem is shown to be singular, but in a degenerate sense wherein the necessary conditions yield no new information. A relaxation approach is developed to repose the problem with augmented covariance dynamics. The method permits finite-order arcs producing a well-posed problem. The approach has relevance to engineering systems, which are almost always subject to some level of uncertainty in initial states or parameters. Examples are provided based on classical problems in optimal control, as well as aerospace mission design.

Deep Kernel-Based Optimal Control Prediction in Aerospace Missions

Deep Kernel-Based Optimal Control Prediction in Aerospace Missions

Pyroshock Response Prediction of Spacecraft Structure in Wide Frequency Domain Based on Acceleration FRF

The initiating explosive shock environment of an aerospace mission has the characteristics of instantaneity, high amplitude and a wide frequency domain. An improved method based on the acceleration frequency response function (FRF) and virtual mode synthesis method (VMSS) is proposed to predict the pyroshock response of a spacecraft structure in a wide frequency domain. Firstly, the statistical energy analysis (SEA) model of the spacecraft structure was established, and the FRF and modal density of the model were obtained. Then, the paper explains how, due to the small number of modes in the low-frequency band, the calculation results of the SEA method in the low-frequency band were not accurate enough. The FRF of the SEA model in the low-frequency band was modified by an FRF test of the structure. Finally, the shock response spectrum (SRS) was obtained based on the VMSS and the modified FRF. A shock experiment on the spacecraft structure was conducted by using the shock experiment system, which is based on a light-gas gun. The accurate shock force function and acceleration response results were obtained. The numerical results based on the improved method are in line with those in the experiment. This verifies that the novel method can better grasp the response characteristics of the structure in the broadband domain. The novel method effectively improves the response prediction accuracy of the SEA model in the relatively low-frequency band. While ensuring the computational efficiency, more accurate shock response results in a wide frequency domain were obtained. The novel method presented in this paper provides support of numerical analysis for pyroshock response prediction of spacecraft structure in a wide frequency domain.