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CubeSats provide a cost effective means to perform scientific and technological studies in space. Due to their affordability, CubeSat technologies have been diversely studied and developed by educational institutions, companies and space organizations all over the world. The CubeSat technology that is surveyed in this paper is the propulsion system. A propulsion system is the primary mobility device of a spacecraft and helps with orbit modifications and attitude control. This paper provides an overview of micro-propulsion technologies that have been developed or are currently being developed for CubeSats. Some of the micro-propulsion technologies listed have also flown as secondary propulsion systems on larger spacecraft. Operating principles and key design considerations for each class of propulsion system are outlined. Finally, the performance factors of micro-propulsion systems have been summarized in terms of: first, a comparison of thrust and specific impulse for all propulsion systems; second, a comparison of power and specific impulse, as also thrust-to-power ratio and specific impulse for electric propulsion systems.

Over 2500 active satellites are in orbit as of October 2020, with an increase of ~1000 smallsats in the past two years. Since 2012, over 1700 smallsats have been launched into orbit. It is projected that by 2025, there will be 1000 smallsats launched per year. Currently, these satellites do not have sufficient delta v capabilities for missions beyond Earth orbit. They are confined to their pre-selected orbit and in most cases, they cannot avoid collisions. Propulsion systems on smallsats provide orbital manoeuvring, station keeping, collision avoidance and safer de-orbit strategies. In return, this enables longer duration, higher functionality missions beyond Earth orbit. This article has reviewed electrostatic, electrothermal and electromagnetic propulsion methods based on state of the art research and the current knowledge base. Performance metrics by which these space propulsion systems can be evaluated are presented. The article outlines some of the existing limitations and shortcomings of current electric propulsion thruster systems and technologies. Moreover, the discussion contributes to the discourse by identifying potential research avenues to improve and advance electric propulsion systems for smallsats. The article has placed emphasis on space propulsion systems that are electric and enable interplanetary missions, while alternative approaches to propulsion have also received attention in the text, including light sails and nuclear electric propulsion amongst others.

High performance is always desired for the propulsion system and the assortment of a better combustion type is also a vital part of the propulsion system. The analysis of different designs of combustion chambers and comparison of their combustion characteristics. In this paper, the assessment of Can-type and Annular-type combustion chambers and the design developed with SOLIDWORKS software and analysis done with ANSYS FLUENT. The systematic and translucent method approaches reduce the design complexity and time. The combustion with turbulence interface was examined to analyze with precision results, and the analysis specified that the nowadays experiment depends on the behavior of gas exit pressure, temperature, and velocity. Parametric analysis is used to acquire the sizing of the combustion chamber.

This paper explores the wide-ranging topography of micro-propulsion systems that have been flown in different small satellite missions. CubeSats, known for their compact size and affordability, have gained popularity in the realm of space exploration. However, their limited propulsion capabilities have often been a constraint in achieving certain mission objectives. In response to this challenge, space propulsion experts have developed a wide spectrum of miniaturized propulsion systems tailored to CubeSats, each offering distinct advantages. This literature review provides a comprehensive analysis of these micro-propulsion systems, categorizing them into distinct families based on their primary energy sources. The review provides informative graphs illustrating propulsion performance metrics, serving as beneficial resources for mission planners and satellite designers when selecting the most suitable propulsion system for a particular mission requirement.

The novel technology of the liquid Ammonium Dinitramide(ADN) propulsion is researched for its higher working performance and safer characteristics. Based on the safe performance, the design of ADN propulsion system for satellites is also presented in this paper. At the same time, the research on ADN propulsion system module is presented in this paper, including the developing processes method, the interface analysis, and the assemblage in satellites. Two examples are described here besides an ADN propulsion module applied in orbit. From the research we can know that ADN propulsion technology is fit for satellites, and the modularization of ADN propulsion system is a better developing mode for small satellites, which can simplify the developing process of propulsion system and crafts. In the end, the further application object and further work of ADN propulsion module for satellites is stated.

In recent years, offshore service vessels have increasingly used hybrid propulsion systems with generators mounted coaxially with the main engine. These latest state-of-the-art shaft generators enable ship operators and builders to benefit from efficiency, performance, and reliability. By reducing a ship’s CO2 emissions, it also helps ships meet the International Maritime Organization’s (IMO) EEDI (Energy Efficiency Design Index) measure targeting new ship designs and construction to ensure energy-efficient standards and EEXI (Existing Ship Energy Efficiency Index) measure addressing existing ships and promotes retrofits and optimizations. The paper presents the vibration analysis of Power Take Off generators (PTO) driven by engine-driven reduction gear. This analysis relates measurements of vibration carried out at 90% and 100% rated generator speed with unloaded generator and ship service speed under steady state operation. First, the study introduced experimental measurement on the same type of PTO generator installed on different ships with the same or different main engines. Second, based on this experimental measurement, the vibration analyses are evaluated and compared to relevant criteria and standards. The research results of the vibration analysis and the comparison with the criteria required on these in-shaft generators driven from the main engine were used as results of the quality assessment of the installation of hybrid propulsion systems for recent new building ships in Vietnam. This was verified by the results of vibration measurement, analysis and evaluation on shaft generators installed on three recent new-building ships.

The new turboelectric aircraft with aft propulsion fuselage concept (APFC) utilizes an electrically driven fan powered by main engines that ingest the fuselage boundary layer for increased propulsive efficiency. However, with the high integration of the fuselage and the aft propulsion system, the APFC produces the coupling problem of the internal/external flow field. In this paper, an integration model using computational fluid dynamics (CFD)-based aerodynamic shape optimization is performed to study the power savings of the APFC to a reference traditional podded configuration. The results show that the power savings of APFC have a better performance compared to a traditional propulsion system.

This article investigates the impact of modular propulsion system design on the performance and cost of a three-stage hybrid rocket. Furthermore, it conducts a multi-objective optimization of unit payload cost, take-off mass, and payload mass ratio, considering factors such as the number of motors and layout considerations. The optimization design scheme for the three-stage hybrid rocket is divided into four cases. In the first case, each stage is equipped with a fixed single motor, and each stage is independently optimized without modular design. The second case considers the use of multiple motors in the first and second stages, still without modular design. The third case also involves multiple motors in the first and second stages, but all motors in each stage have identical parameters except for the nozzle expansion ratio, implementing a modular design. In the fourth case, the number and layout of the motor design method are the same as those in the third case, with independent optimization in the third stage using partial modular design. The results indicate that the unit payload cost of the multi-motor non-modular design case can be reduced by 13.12% compared to the single-motor non-modular design case. Within the modular case, the full modular design case is slightly inferior to the partial modular design case. Based on the above data, it can be concluded that the first and second stages of modular rockets offer the best performance and the lowest cost.

With the increasing pace of commercialization, the proton exchange membrane fuel cell (PEMFC) system‐powered fuel cell electric vehicles/vessels (FCEVs) present a highly efficient, zero tailpipe emission propulsion solution. A battery energy storage system (BESS) is normally integrated with the PEMFC system to improve its performance, energy efficiency and operational life. However, both the PEMFC system and the BESS suffer from relatively short operation life and high replacement costs. Optimal energy management strategies (EMSs) become essential to improve their working conditions, thus extending their working life based on their distinct performance degradation behaviours and achieving the minimum lifecycle costs (LCCs). Extending from the present static modelling approach, this research introduces three new methods for dynamically updating the performance and degradation models of lithium‐ion (Li‐ion) batteries and PEMFCs using real‐time operation data of a fuel cell–battery hybrid electric propulsion system. The combined methods more accurately capture the performance and capability of each specific fuel cell hybrid propulsion system’s BESS and PEMFC system. This enables precise performance tracking, degradation assessment and optimal energy management. A new integrated approach to the hybrid electric propulsion system’s component sizing design optimization and optimal energy management is introduced using these new modelling schemes, minimizing the LCC by balancing the propulsion system performance, fuel economy and the BESS and PEMFC system degradations. These modelling and optimization methods are applied to a medium‐sized vehicle and passenger ferry to produce the optimal fuel cell–battery hybrid propulsion system design and EMS to strike the best balance between fuel efficiency and the PEMFC and BESS operation life.

In continuation of the studies related to the performances of electric vehicles and their optimization solutions, in this work a simulation model will be created in accordance with all the demands that appear on the vehicle during driving and the model will be adapted for urban driving conditions on a certain length of time, so that the performance of the electric propulsion system can be determined, such as: the state of charge of the battery, the consumption of electricity, the characteristics of the electric motor, as well as the variation of the autonomy of the vehicle. The simulation model made will later be correlated with a series of experimental data determined in real driving conditions so that the accuracy of the made model can be checked and validated so that it can be used on different types of electric vehicles with different performances and destinations.