Typical Mission Research Articles

Available Energy Analysis of Electric Unmanned Aerial Vehicle Hybrid Energy System

The issue of energy and power systems is the main challenge faced by electric unmanned aerial vehicles for long endurance. Under the power demand conditions of typical mission profiles of electric drones, this paper establishes an energy balance equation between the hybrid energy system power supply of electric drones and the power demand of drones. Considering the impact of operating temperature of each battery on power generation performance, a heat transfer model for solar cells, fuel cells, and lithium batteries was established. The heat transfer process of hybrid energy systems was analyzed. Based on the heat transfer model of hybrid energy systems, the heat transfer changes of solar cells, fuel cells, and lithium batteries were analyzed, and the heat transfer changes of hybrid energy systems were studied. The heat loss changes of each battery subsystem with operating temperature were given. The results show that the hybrid energy system has the best power generation performance at the reference temperature, and changes in operating temperature will cause thermal losses and reduce power generation.

Counter-Improvised Explosive Devices (C-IED) mission support capabilities

Actions and activities taken against the IED threat comprise complex tasks. In thebeginning, the focus was on the deactivation and destruction of IEDs, as the only wayto fight against them. As time has passed, more existing capabilities were included inthe field of C-IED, which were able to contribute to the mitigation of the effectivenessof an IED attack.Due to the fact that the first type of response to IED-threat was tasked to combatengineers, particularly to EOD personnel, that was rather obvious that C-IED missionsand responsibilities fell to combat engineers. Nowadays, however, capabilities andcapacities in the C-IED can be identified that exceed the competence of engineer unitsand commanders. The C-IED requires a comprehensive approach. In a staff andheadquarters lots of capabilities and capacities should be involved in C-IED activities,which requires coordination and cooperation. The involvement of those capabilitiesdepends on the type of mission, its phases, and the nature of IED threat. Thus amission commander needs to understand which are the C-IED enablers that cancontribute to C-IED tasks, when and how they influence or mitigate IED threats.

Performance seeking control method for minimum pollutant emission mode for turbofan engine

The research shows that the impact of aero-engine pollutant emission on the environment cannot be ignored. In addition to fuel type and combustor structure, aero-engine exhaust pollutants are also related to engine operating conditions and control systems. In this context, taking CO and NOx as the main exhaust pollutants of the engine as the research object, a performance optimization control method of the minimum pollutant emission mode of the engine is proposed. Firstly, the CO and NOx emission characteristics of the engine under different operating conditions at sea level are calculated by CFD numerical simulation method, and the engine component-level model applicable to all flight envelope and all conditions is established according to the characteristic data. Secondly, in order to improve computational efficiency, an airborne model with high accuracy and real-time performance is established through the deep neural network. Compared to the component-level model, the average relative error of each performance parameter is less than 0.5 %, and the real-time performance is improved by about 12 times. Finally, the optimization principle of the minimum pollutant emission mode is discussed. The feasible sequential quadratic programming (FSQP) algorithm is selected, and the fuel quantity and throat area of the tail nozzle are taken as control variables. Numerical simulations are performed in the typical mission envelope. Simulation results show that the CO emission index decreases by 5 % and the NOx emission index decreases by more than 6.5 % through performance optimization control of the minimum pollutant emission mode under the premise of ensuring constant engine thrust and meeting other constraints.

Experimentally backed model of bubbly flow in a CNTP reactor

Centrifugal Nuclear Thermal Propulsion is a second-generation propulsion concept currently being researched to succeed traditional solid core nuclear thermal propulsion. Current efforts across the space industry are focusing on development of technologies for enabling manned flight to Mars and scientific missions to the outer planets. To enable these types of mission's direct injection trajectories are needed to decrease exposure to astronauts and scientific payloads to the harsh environment of space. Current efforts in nuclear thermal propulsion have shown great promise in higher specific impulses ∼900 s, but even these levels of specific impulse fall short for manned Mars missions with durations less than two years or direct injection to orbit of the outer ice giants Uranus and Neptune without the use of gravity assists. High performance nuclear thermal propulsion has been proposed using bubble through nuclear reactors to reach specific impulses as high as 1800 s, however significant challenges exist to prove the feasibility of such a system. One of the major challenges is the fluid mechanics within the core of the engine since little is known about uranium in the liquid phase. An experimental study has been conducted to better understand the fluid dynamics to better inform the thermodynamic and nucleonic models. Using the data from the experiment, high-fidelity simulations have been developed to predict the fluid dynamics of the uranium fuel. This information can then be further fed into thermodynamics models in development to predict core temperatures and system behaviour. The validated models show that small bubbles reach thermal equilibrium, and high centrifugal forces and surface tension assist in confining the molten uranium within the reactor core. Injector methods suggest feasible configurations to encourage bubble flow while minimizing backflow of the propellant, motivating further study of Centrifugal Nuclear Thermal Propulsion based systems.

ANALYSIS OF SPACEFLIGHT ACTIVITIES’ IMPACT ON SUSTAINABLE DEVELOPMENT IN THE GLOBAL SOUTH

Sustainable development is the current paradigm for development in the global south. Since 1976 nations of the global south have conducted space missions. This work investigates which impact on sustainable development in the global south spaceflight has. The majority of Sustainable Development Goals can be addressed with space activities, e.g. by setting up satellite infrastructures for communication, creating businesses or supporting protection of ecosystems. Short-term effects such as build-up of own industry for own satellites and infrastructure can be seen when analysing satellite numbers and mission types. The reduction in launch costs and miniaturization of satellites in the 2010s have increased satellite numbers, by improving accessibility to space technology. This led to a thriving space industry in global south nations e.g. Argentina. The continuity of the effects cannot yet be determined fully, due to the recency of most activities, even though for some nations, e.g. Brazil or Indonesia, activities have been continuous. Strategic integration of space activities into planned sustainable development could not be detected. Potential benefits were realized mostly via services and there is unused potential for technology application on Earth.

Estimating Cotton Canopy Temperature Artifacts in UAV-Based Thermal Measurements

Thermal sensors mounted on unmanned aerial vehicles (UAVs) have been used for crop evaluation. The assembly of multiple UAV images into a composite orthomosaic image that represents an agricultural field is common. The creation of these composite orthomosaic images is predicated on the assumption that the variable of interest, for example, plant height, does not change in the interval between the first image and the last image. Canopy temperature is continuously variable. Thus, in a composite thermal image, the temperature differences between any two points can include both the temperature differences of the two locations, as well as the temperature change occurring during the time the images were captured. A modeling approach was used to investigate these temporal thermal artifacts in cotton (Gossypium hirsutum L.). The objectives were to analyze the average amount of thermal variation that can occur across a field, identify times of maximum variation, and examine the magnitude of these thermal artifacts across the temporal scale of a typical drone mission. As the time between the first image and last image increased from 15 minutes to an hour, the temporal thermal distortion increased from 0.7 to 1.4 °C for a high-water treatment and from 0.9 to 2.8 °C for a low-water treatment. The simulated flights from 1030 to 1230 h had the largest variation and the 1230 to 1430 h and 1430 to 1630 h flights had less thermal variation. Depending on the application, the thermal distortion could range from negligible to potentially significant.

Overcome the Fear Of Missing Out: Active sensing UAV scanning for precision agriculture

This paper deals with the problem of informative path planning for a UAV deployed for precision agriculture applications. First, we observe that the “fear of missing out” data lead to uniform, conservative scanning policies over the whole agricultural field. Consequently, employing a non-uniform scanning approach can mitigate the expenditure of time in areas with minimal or negligible real value, while ensuring heightened precision in information-dense regions. Turning to the available informative path planning methodologies, we discern that certain methods entail intensive computational requirements, while others necessitate training on an ideal world simulator. To address the aforementioned issues, we propose an active sensing coverage path planning approach, named OverFOMO, that regulates the speed of the UAV in accordance with both the relative quantity of the identified classes, i.e. crops and weeds, and the confidence level of such detections. To identify these instances, a robust Deep Learning segmentation model is deployed. The computational needs of the proposed algorithm are independent of the size of the agricultural field, rendering its applicability on modern UAVs quite straightforward. The proposed algorithm was evaluated with a simu-realistic pipeline, combining data from real UAV missions and the high-fidelity dynamics of AirSim simulator, showcasing its performance improvements over the established state of affairs for this type of missions. An open-source implementation of the algorithm and the evaluation pipeline is also available: https://github.com/emmarapt/OverFOMO.

An Initial Investigation of Students’ Understanding of Space Exploration

The topic of space exploration receives little attention in most introductory astronomy courses. However, students come to such courses with both an interest and ideas informed by popular media–ideas that may or may not be consistent with scientific and engineering outlooks. This study explored what students recall about space exploration ideas after engaging with two short, in-class activities on the possibility of travel to Mars and the use of solar sails for exploration. We asked four open-ended questions for extra credit and coded students’ responses ($N$ = 106 to 150) for themes. Coding demonstrated that students had reasonable, if limited, understanding of factors influencing both crewed and uncrewed mission types as well as risks to crews after completing these activities.

THE ATTEMPTS TO CLOSED LIFE SUPPORT SYSTEM DEVELOPMENT, THE EARLY CONTEXT OF MELISSA PROJECT

For more than 50 years, space actors are considering quitting the Earth orbit, and to elaborate a human mission to Mars. This type of mission, estimated to be longer than 1000 days, requires only to support human metabolism a high mass of resources not compatible of the launchers. Although, nowadays, the possibility of heavy mass launcher is proposed, a more elegant approach based on a high recycling is proposed. Many projects have been started with this objective. So far almost all had to stop after some years. In this publication the authors are trying to understand some of the reasons, which could be later-on recommendations for project developments and key decisions.

Development and evaluation of a light-weight flexure-based lockable joint for morphing wings

Single degree of freedom (single-DOF) morphing wings have the advantages of light-weight and multiple morphing shapes, which can enable aircraft to adapt to uncertain flight environments and various mission types. A single-DOF morphing wing with four morphing shapes designed based on the reconfigurable mechanism is introduced firstly in this paper. Then, a light-weight compliant locking mechanism (CLM) based on flexure hinges is proposed for lockable joints in the reconfigurable mechanism. The CLM has two types depending on the locking method, namely the “plug-in” compliant locking mechanism (PCLM) and the “friction” compliant locking mechanism (FCLM). The working principles of the two CLMs are described. The mathematical models are established to assess the static and dynamic characteristics of the proposed CLM, which are also verified by the finite element simulation. The influence of the flexure hinge dimensions on the working performance of the CLM is analyzed, and its dimensions are optimized considering both the locking performance and the maximum stress. Finally, a PCLM and a FCLM actuated by SMA wires are fabricated based on the optimized dimensions. The experiment is conducted to assess the locking torque of the CLM and the feasibility of the proposed CLM used for morphing wings is confirmed.

Peace at Home, Conflict Abroad: Government Ideology, Mission Type, and Parliamentary Support for Military Interventions

Abstract International relations scholarship has long overlooked the role of parliament in shaping states’ decision to go to war. In contrast, recent studies explored variations in parliamentary war powers across time and countries and their impact on troop deployments abroad. However, a systematic analysis of the determinants of support for military interventions in parliament is still missing. This article fills this literature gap by examining votes on 119 missions in twenty-one democracies between 1990 and 2019. Our findings suggest that parliamentary contestation is fundamentally driven by government ideology and the type of mission. Parliamentary support for military intervention is significantly higher when a left-wing government is in power. Moreover, “inclusive” missions with a robust humanitarian dimension draw a considerably lower level of contestation than “strategic” missions aimed at contrasting a security threat. Through such findings, the article contributes to the debates on the relevance of domestic political institutions in foreign policy and the party politics of military interventions.

A tale of two cities: mission-oriented innovation policy in China’s green industries

ABSTRACT Mission-oriented innovation policy (MOIP) has become an important means of fostering green transition in many countries. However, few studies have focused on how the various challenges unique to developing and emerging economies affect the design and implementation of MOIPs. Through a longitudinal comparative analysis of China’s two green industries, our study contributes to understanding MOIP instrument mixes within the context of developing countries and industrial differences. First, we identify a four-dimensional framework of MOIP instruments aligned with the existing literature, while also highlighting China’s policymaking features under authoritarian yet adaptive governance. An in-depth analysis of the implementation of MOIP instrument mixes throughout niche development uncovered dynamic mechanisms, industry differences, and complex local government responses. Our work suggests that, with an adaptive instrument mixes that focuses on both types of missions and the local institutional context, MOIP can potentially promote green transition in developing countries.

Community Citizen Science Inquiry: The Case of nQuire

Community citizen science inquiry is a combination of two ideas: first, citizen science inquiry (mass participation citizen science and learning to be a scientist through scientific inquiry, (Herodotou et al, 2017), and a concern to involve participation by the members of a community for community purposes. We describe the work we have done on this topic developing from our initial experiments in supporting inquiry learning with school children using technology and describing how this work has developed through conducting a number of studies involving students in a university technical college, and distance education students, then widened into investigation of the ideas with members of the public conducting citizen inquiries. These experiences have been supported by the development of the web platform nQuire (http://www.nquire.org.uk) which is now the basis of our work. 
 Our approach to citizen inquiry is driven by a concern for the nature of the participation from which members of the public can benefit and goes beyond involving people solely as volunteer data collectors. We report here on our experiences of the different types of inquiries or missions which have run on the platform since 2018, and the views of some participants on their involvement. We also discuss the issues in developing our vision of community citizen science inquiry and a potential centre for democratising research.

Intelligent Optimization Method of Human–Computer Interaction Interface for UAV Cluster Attack Mission

In modern warfare, it is often necessary for the operator to control the UAV cluster from a ground control station to perform an attack task. However, the absence of an effective method for optimizing the human–computer interface in ground control stations for UAV clusters leads to usability difficulties and heightens the probability of human errors. Hence, we propose an optimization framework for human–computer interaction interfaces within UAV ground control stations, rooted in interface-essential elements. Specifically, the interface evaluation model was formulated by combining the Salient, Effort, Expectancy, and Value (SEEV) framework with the essential factor mutation cost of the quantified interface. We employed the SEEV–ant colony algorithm to address the challenge of optimizing the interface design within this context. For a typical UAV cluster attack mission, we optimized the human–computer interaction interfaces of the three mission stages based on the proposed SEEV-AC model. We conducted extensive simulation experiments in these optimized interfaces, and used eye-movement indicators to evaluate the effectiveness of the interface optimization model. Based on the experimental results, divergence is reduced by 11.59%, and the fitness of the optimized interface is increased from 1.34 to 3.42. The results show that the proposed intelligent interface optimization method can effectively improve the interface design and reduce the operator’s workload.

Impact of a ground intermediate transport from the helicopter landing site at a hospital on transport duration and patient safety

BackgroundHelicopter emergency medical service provides timely care and rapid transport of severely injured or critically ill patients. Due to constructional or regulatory provisions at some hospitals, a remote helicopter landing site necessitates an intermediate ground transport to the emergency department by ambulance which might lengthen patient transport time and comprises the risk of disconnection or loss of vascular access lines, breathing tubes or impairment of other relevant equipment during the loading processes. The aim of this study was to evaluate if a ground intermediate transport at the hospital site prolonged patient transport times and operating times or increases complication rates.MethodsA retrospective analysis of all missions of a German air rescue service between 2012 and 2020 was conducted. Need of a ground transport at the accepting hospital, transfer time from the helipad to the hospital, overall patient transport time from the emergency location or the referring hospital to the accepting hospital and duration of the mission were analyzed. Several possible confounders such as type of mission, mechanical ventilation of the patient, use of syringe infusion pumps (SIPs), day- or nighttime were considered.ResultsOf a total of 179,003 missions (92,773 (51,8%) primary rescue missions, 10,001 (5,6%) polytrauma patients) 86,230 (48,2%) secondary transfers) an intermediate transport by ambulance occurred in 40,459 (22,6%) cases. While transfer times were prolonged from 6.3 to 8.8 min for primary rescue cases (p < 0.001) and from 9.2 to 13.5 min for interhospital retrieval missions (p < 0.001), the overall patient transport time was 14.8 versus 15.8 min (p < 0.001) in primary rescue and 23.5 versus 26.8 min (p < 0.001) in interhospital transfer. Linear regression analysis revealed a mean time difference of 3.91 min for mechanical ventilation of a patient (p < 0.001), 7.06 min for the use of SIPs (p < 0.001) and 2.73 min for an intermediate ambulance transfer (p < 0.001). There was no relevant difference of complication rates seen.ConclusionsAn intermediate ground transport from a remote helicopter landing site to the emergency department by ambulance at the receiving hospital had a minor impact on transportation times and complication rates.

Space Target Tracking with the HRRP Characteristic-Aided Filter via Space-Based Radar

Approaching space target tracking is a typical and challenging mission in the space situational awareness (SSA) field. As the space-based radar is able to monitor the space targets of interest full-weather all-time, the space-based radar system is utilized in this paper. However, most multi-target tracking (MTT) filters in target tracking studies merely utilize the location or narrow measurements, and many potentially valuable electromagnetic scattering characteristics are missed, which leads to space target false tracking problems. The space-based radar transmits a wide-band signal, and the measured high-resolution range profile (HRRP) information is an effective characteristic for different target discrimination. Therefore, the HRRP characteristics of space targets are implemented into the update recursion of the MTT filter, which can be utilized to improve the tracking performance. Then, to predict the target HRRP sequence, the geometrical theory of diffraction (GTD) model is utilized. Additionally, a modified spatial spectrum method with a novel covariance matrix is designed to improve the scattering parameter estimation accuracy. Finally, an adapting threshold is devised for merging the Gaussian mixture (GM) components weights. The proposed threshold is on the basis of the proposed HRRP characteristic-aided probability hypothesis density (PHD) filter, and it can tackle the problem of space target discrimination. Simulation results validate the effectiveness and robustness of the proposed probability hypothesis density (HGI-PHD) filter aided by HRRP information and improved with GM weights.

Are smallsats taking over bigsats for land Earth observation?

In this work the evolution of the utilization of small satellites for land Earth observation missions is addressed. Scatter and “bubble” plots, supplemented by the calculation of correlation coefficients for pairs of selected variables, are used to identify, qualify and quantify trends. Optical and Synthetic Aperture RADAR (SAR) missions are considered separately. Systems are discriminated as single or constellation, and commercial or government owned. Trends coupling satellite mass to ground sample distance, and number of spectral bands, for optical satellites, and spatial resolution and microwave band for SARs, are also analyzed. The present analysis indicates that smallsats seems to be getting increasingly competitive, that is, they have become an alternative to bigger satellites, for most types of optical missions. On the other hand, the SAR arena still seems to pose a big challenge to satellite miniaturization, in spite of recent remarkable advances obtained on the fielding of smallsat X-band SAR constellations.

A Novel Digital Twin Framework for Aeroengine Performance Diagnosis

Aeroengine performance diagnosis technology is essential for ensuring flight safety and reliability. The complexity of engine performance and the strong coupling of fault characteristics make it challenging to develop accurate and efficient gas path diagnosis methods. To address these issues, this study proposes a novel digital twin framework for aeroengines that achieves the digitalization of physical systems. The mechanism model is constructed at the component level. The data-driven model is built using a particle swarm optimization–extreme gradient boosting algorithm (PSO-XGBoost). These two models are fused using the low-rank multimodal fusion method (LWF) and combined with the sparse stacked autoencoder (SSAE) to form a digital twin framework of the engine for performance diagnosis. Compared to methods that are solely based on mechanism or data, the proposed digital twin framework can effectively use mechanism and data information to improve the accuracy and reliability. The research results show that the proposed digital twin framework has an error rate of 0.125% in predicting gas path parameters and has a gas path fault diagnosis accuracy of 98.6%. Considering that the degradation cost of a typical flight mission for only one aircraft engine after 3000 flight cycles is approximately USD 209.5, the proposed method has good economic efficiency. This framework can be used to improve engine reliability, availability, and efficiency, and has significant value in engineering applications.

Experimental Validation of a Numerical Coupling Environment Applying FEM and CFD

Experimental results for the transient heat transfer characteristics over a flat plate and over a plate with V-shaped ribs were compared to numerical results from a coupling environment applying FEM and CFD. In order to simulate transient effects in the cooling process of engine components during typical flight missions, the temperature and the velocity at the inlet of the channel were varied over time. The transient temperature distribution at the plate was measured using infrared thermography. Five different plate materials (perspex, PEEK, quartz, aluminum, and steel) were considered to investigate the influence of thermal conduction on the heat transfer between solid and fluid depending on the Biot number. The experimental results represent a reference database for a Python-based coupling environment applying CalculiX (FEM) and ANSYS CFX (CFD). The results were additionally compared to numerical results simulating the complete transient conjugated heat transfer with CFD. A good agreement between the numerical and the experimental results was achieved using different coupling sizes at different Biot numbers for the flat plate and the plate with V-shaped ribs.

Off-Design Performance Analysis of a Parallel Hybrid Electric Regional Turboprop Aircraft

Hybrid electric propulsion is one of the alternative solutions for reducing fuel burn and lower emissions while keeping a reasonable battery mass for regional turboprop aircraft operating on short routes. Most studies reporting fuel burn reductions evaluate the aircraft on the design mission, although regional transport aircraft rarely operate under these conditions. Therefore, considering its off-design performance is essential for providing a more complete understanding of aircraft capabilities under various operating conditions. Under these flight conditions, the multi-energy management aspect of hybrid propulsion and the fixed size of the batteries could have a significant impact on the system robustness in off-design operation. In this study, the off-design performance of an existing regional turboprop aircraft retrofitted with a parallel hybrid electric powertrain is assessed. Fuel burn benefits are evaluated on the payload–range diagram for an initial hybrid design and compared to the baseline aircraft. Then, using a novel sizing approach, considering a typical mission operation, this study shows an average improvement of percentage point on fuel burn benefits relative to the initial hybrid aircraft, creating a more robust design.