Showing papers on "Spacecraft propulsion published in 2022"

Rarefied Flow Simulation of Conical Intake and Plasma Thruster for Very Low Earth Orbit Spaceflight

Abstract: Air-breathing electric propulsion has the potential to enable space missions at very low altitudes. This study introduces to a 0D hybrid formulation for describing the coupled intake and thruster physics of an air-breathing electric propulsion prototype. Model derivation is then used to formally derive main system’s key performance indicators and estimate the figure of merit for the design of rarefied flow air intakes. Achievable performance by conical intake shapes are defined and evaluated by Monte Carlo simulations. Influence of inlet flow variation is assessed by dedicated sensitivity analyses. The set of requirements and optimality conditions derived for the downstream plasma thruster suggest concept feasibility within an achievable performance range.

Electric propulsion of spacecraft

Abstract: The electrification of spacecraft could significantly extend the useful life of billion-dollar missions in outer space.

Optical Diagnostics for Solid Rocket Plumes Characterization: A Review

Abstract: In recent decades, solid fuel combustion propulsion of spacecraft has become one of the most popular choices for rocket propulsion systems. The reasons for this success are a wide range of applications, lower production costs, simplicity, and safety. The rocket’s plumes leave the nozzle at high temperatures; hence, the knowledge of produced infrared (IR) emissions is a crucial aspect during the design and tests of the rocket motors. Furthermore, rocket plume composition is given by N2, H2, H2O, CO and CO2, while solid rocket motors (SRM) additionally inject some solid particles, given by metal fuel additives in the propellant grain, i.e., aluminum oxide (Al2O3) particles. The main issue is the detection of the particles remaining in the atmosphere due to the exhaust gas of the solid rocket propulsion system that could have effects on ozone depletion. The experimental characterization of SRM plumes in the presence of alumina particles can be conducted using different optical techniques. The present study aims to review the most promising ones with a description of the optics system and their potential applications for SRM plume measurements. The most common measurement techniques are infrared spectroscopy imaging, IR imaging. UV–VIS measurements, shadowgraph, and Schlieren optical methods. The choice of these techniques among many others is due to the ability to study the plume without influencing the physical conditions existing in and around the study object. This paper presents technical results concerning the study of rocket engines plumes with the above-mentioned methods and reveals the feasibility of the measurement techniques applied.

Performance of MEMS-Based Monopropellant Microthruster With Insulating Effect

Abstract: Excessive heat loss in micro scale has been a long-lasting issue, affecting catalyst reactivity particularly for monopropellant thrusters and causing insufficient propellant decomposition. Various MEMS fabrication substrates and technologies were utilized for micro propulsion, but few studies on MEMS-based propulsion have reported their propulsion performance, due to not only insufficient propellant decomposition, but also difficulties of measuring high temperature and pressure in a micro scale chamber. In this work, a microthruster was fabricated using high insulation material (glass) in an optical lithography process of photosensitive glass to suppress heat loss. Chamber temperature and pressure sensing tips were integrated in a MEMS fabrication process, which were essential to evaluating propulsion performance and gaining an understanding of the insulating effects of the material on micro propulsion performance. Experimental test results showed successful propellant decomposition with 78% temperature efficiency, which is one of the highest temperature efficiencies in MEMS-based micro propulsion studies reported. The use of glass as a MEMS fabrication substrate was evaluated favorably through numerical analysis as well, in terms of suppression of thermal energy loss and superior propulsion performance.[2022-0014]

An electric propulsion memoir

Abstract: Abstract Based on over sixty years of working in electric propulsion research, a personal memoir attempts to observe the progress of electric propulsion from early explorations to the present successes in accomplishing attractive and practical systems. It includes several anecdotal remarks on the difficulties of achieving acceptance of electric propulsion for space missions, and concludes with notions for the future. The perspectives offered may be useful for a new generation of electric propulsion workers who have entered a field that is now successful.

Performance of laser ablation propulsion with a high-repetition rate and high-power laser

Abstract: We investigated the propulsive performance of laser ablation propulsion using a high-power and highly repetitive pulsed laser. We demonstrated 100 shots of burst laser irradiation with an aluminum target using repetition frequencies of 0.017 Hz and 1 kHz. The impulse and plasma exhaust velocities were measured using a pressure sensor and an orifice probe. The momentum-coupling coefficient and the specific impulse were estimated from the aforementioned measurements for every shot. The results showed that the momentum-coupling coefficient increased with highly repetitive laser irradiation. The specific impulse increased with increasing shot number for the case of high-repetition frequency. Therefore, high-repetition operation improves the propulsive performance, especially the specific impulse.

Laser ablation induced impulse study for removal of space debris mission using small satellite

Abstract: Abstract In recent years, many plans have arisen for building constellations in low Earth orbit, some of which have already provided commercial services. The number of satellites that form these constellations will exceed $$10^4$$ 10 4 , and a number of these could become space debris due to accidental failure, leading to serious problems for human activities in space. Laser ablation-induced propulsion achieved by remote irradiation from the service spacecraft has been proposed as one effective method to remove such space debris and it involves effectively generating a propulsion impulse from a laser. Because most of the high-power lasers currently utilized in space applications are Nd:YAG lasers, in this study, we evaluate the characteristics of second harmonic generation (SHG), which can be generated using nonlinear crystals. The momentum coupling coefficient may be dependent on the irradiated laser wave length which has a significant difference in the ablation process such as plasma generation and heating. These effects have been investigated using an impulse measurement instrumental setup with a KD*P nonlinear crystal. As an efficient impulse generation method, the irradiation of the fundamental and SHG beams of the Nd:YAG laser at the same point was found to be more effective than the fundamental beam with the same total energy. SHG does not require additional power-consuming equipment such as additional exciters or amplifiers, but requite temperature-controlled nonlinear crystals, and impulses can be increased with minimal additional power. It turned out to be advantageous for space applications, which will require minimum power operation . Additionally, we found an additional nonlinear laser-induced impulses through the interaction of the beams.

Vacuum Arc Plasma Coating for Polymer Surface Protection— A Plasma Enhanced In-Orbit Additive Manufacturing Concept

Abstract: In-orbit additive manufacturing (AM) is a promising approach for fabrication of large structures. It allows to expand and accelerate human space exploration possibilities. Extrusion-based AM was demonstrated in zero gravity, while the realization of such a process in orbit-like vacuum conditions is currently under exploration. Still, a solution for protection of the UV and IR radiation sensitive polymers is needed in order to prevent their early mechanical failure under space conditions. Vacuum arc plasma based process is widely applied on earth for thin protective coating deposition. Its major advantage is its scalability — from tiny size used in electric propulsion to large scale coating devices. The usability of the vacuum arc process in space conditions was shown in electric propulsion applications in nano-satellites. In this work we discuss and demonstrate the integration of vacuum arc process as a post processing step after Fused Filament Fabrication (FFF) for additive manufacturing and functionalization of long polymer structures. Here we address the concept for technical realization, which integrates the vacuum arc into additive manufacturing process chain. More over we present a laboratory prototype, which implements this concept together with a use case, where a previously printed PEEK structure is coated with aluminum based coating suitable for UV radiation protection.

Preliminary Screening of Multimode Spacecraft Propulsion Systems for Interplanetary Missions

Abstract: Multimode spacecraft propulsion combines two or more propulsive modes into a single system and has been shown to be beneficial for geocentric missions and for specific interplanetary missions. This study develops an analytical method for preliminarily screening all-chemical, all-electric, hybrid, and multimode propulsion systems for small spacecraft (100 kg class) completing interplanetary missions. Key parameters of comparison include payload mass delivered, transfer time, transfer rate, and excess propulsion capability for a given required payload mass. It is shown that present term multimode propulsion systems with a chemical mode specific impulse of 170 seconds and 16% electric mode efficiency provide lower transfer rates than all-electric and hybrid architectures for multiple concepts of operations for Earth-Mars missions. Increasing the multimode chemical specific impulse to 230 seconds and electric mode efficiency to 30% results in transfer rates greater than any other architecture considered can provide. It is also shown that multimode electric mode specific impulse values between 1,000 and 1,500 seconds produce the greatest multimode transfer rates across the scenarios considered. For a fixed payload mass of 40 kg, it is shown that multimode and hybrid systems have the potential for significant propulsive capability at the target planet. Although all-electric, hybrid, and multimode architectures can complete the considered transfers, multimode propulsion provides mission designers increased operational flexibility that may be compelling for some applications with present technology despite lower transfer rates. Future improvements in multimode performance and system dry mass reductions will provide transfer rates greater than all-electric or hybrid architectures in addition to flexibility.

Plume Performance of Electrodeless Plasmoid Electromagnetic Propulsion

Abstract: Electrodeless plasmoid electromagnetic propulsion was recently proposed for robotic and crewed space missions. This electrodeless construction has the potential to solve the existing limitations, such as duration and low efficiency. The rotating magnetic field (RMF) excitation and Lorentz Force acceleration mechanism of the plasmoid has the advantage of producing a highly variable thrust and a discrete impulse. In this article, the plume performance of the proposed propulsion primer was presented for the first time and evaluated by varying the RMF input power, bias magnetic field, and flow rate, while the power of the preionization source and discharge propellant are held constant. The RMF excitation and Lorentz Force acceleration mechanism of the plasmoid were confirmed by the plume performance and discharge characteristics. The stable discharge in Ar, N ₂ , and Xe demonstrated the potential application of this electrodeless technology in future multipropellant high-power propulsion applications. The phase angle of 90° in the RMF coil was essential for the higher performance of the plasma plume. The propulsion thrust and specific impulse were estimated to be 16.1 mN and 1600 N $\cdot $ s, respectively, at 1.2 kW from the initial test conducted using the Langmuir probe, assuming a complete penetration of RMF in the plasma.

Experimental investigation of electric propulsion systems using C12A7 electride hollow cathodes

Abstract: Abstract The development and experimental investigation of two low-power electric propulsion concepts using compact heaterless C12A7 electride (C12A7:e-) hollow cathodes is presented. The first concept represents an electrothermal thruster, in which a cathode discharge is used to heat a gas that is subsequently accelerated in a nozzle-shaped anode. The second propulsion system is an attempt to develop a sub-500 W magnetoplasmadynamic thruster (MPDT) that uses a rectangular discharge channel that allows to increase the applied magnetic field and thus lower the necessary discharge current. Extensive parameter studies with both concepts were conducted, and the thrust and discharge properties of different geometric and operational configurations were determined. This work is a follow-up publication of a previous paper (Gondol and Tajmar in CEAS Space J 14:65–77, 2021).

Marshall Enriched Storable Oxidizer for Cislunar Liquid Propulsion Applications

Abstract: One of the most significant future needs for in-space missions is for on-demand, “multi-mode” propulsion systems for missions (manned and unmanned) which can be operational with short notice (i.e. rapid response), and also with lengthy mission and variable “time to orbit” needs. These requirements place a premium on development of storable, non-cryogenic, minimized-toxicity storable propellants which also meet the high-performance requirements. Based on the previous work for DARPA and working with NASA MSFC, it was discovered liquid nitrous oxide can be dissolved (not just mixed) into liquid nitrogen tetroxide, resulting in a stable, non-cryogenic, storable, self-pressurizing liquid oxidizer with performance characteristics approaching liquid oxygen and with minimized toxicity and minimized detonation attributes over nitrous oxide alone. Since nitrous oxide is the predominant gas over this liquid, called MESO, it can also be used to generate electricity in a fuel cell when combined with a fuel. This liquid propulsion oxidizer innovation is especially beneficial for cislunar space — the areas beyond geosynchronous orbit — where electrical propulsion and chemical propulsion can synergistically work in tandem for mission success.

The View of Micropropulsion Technology for China’s Advanced Small Platforms in Deep Space

Abstract: In this paper, micropropulsion systems are analyzed in conjunction with the various mission requirements of China’s deep space exploration. As a great challenge facing the world, deep space exploration can be enabled only in a few countries with a success rate of around 50%. With the advancement of spacecraft and scientific instruments, it is now feasible to build small and low-cost spacecraft for a variety of deep space missions. As spacecraft become smaller, there is a need for proper micropropulsion systems. Examples of propulsion system selections for deep space exploration are discussed with a focus on products developed by Beijing Institute of Control Engineering (BICE). The requirements for propulsion systems are different in lunar/interplanetary exploration and gravitational wave detection. Chemical propulsion is selected for fast orbit transfer and electric propulsion for increasing scientific payloads. Cold gas propulsion and microelectric propulsion are good choices for space-based gravitational wave detection due to the capability of variable thrust output at the micro-Newton level. The paper also introduces the sub-1-U micropropulsion modules developed by BICE with satisfactory performance in flight tests, which are promising propulsion systems for small deep space platforms. A small probe with an electric sail propulsion system has been proposed for the future solar system boundary exploration of China. The electric sail serves as not only a propellant-free thruster but also a detector probing the properties of the space medium.

Nano-graphite field-emission cathode for space electric propulsion systems

Abstract: Improving the thruster efficiency is a crucial challenge for the development of space electric propulsion systems, especially advanced air-breathing thrusters utilizing the surrounding rarefied atmosphere as fuel. A significant reduction in thruster power consumption can be achieved by using field emission (FE) cathodes that do not require heating and have the highest energy efficiency. In this work, we study FE from nano-graphite thin films, consisting of carbon nanostructures with a high aspect ratio, and demonstrate their suitability for use in the space electric propulsion systems. The films shown appropriate FE characteristics in a wide range of gas pressures at high current loads in constant and pulsed operation modes. Based on the obtained experimental results, nano-graphite cathodes were employed for the design of an electron gun with increased reliability and minimized energy losses associated with electron extraction. The possibility of using such a gun in a specific air-breathing satellite operating in low Earth orbits is demonstrated.

Swing-By Applications and Estimation of the Van Allen Belts’ Radiation Exposure for a Spacecraft in a Low Thrust Transfer to the Moon

Abstract: This paper presents a handful of the underlying properties of a spacecraft’s transfer from a low Earth orbit (LEO) to the moon’s orbit using an electric propulsion (low-thrust) system. The use of analytical and numerical-analytical modeling in complex natural and technical processes is a key factor in this issue of Symmetry, which has been thoroughly explored in this paper. First, an optimization problem was considered to find the locations and lengths of the thrust arcs that maximizes the final mass of the spacecraft for a number of transfer orbits, thereby limiting the scope of trajectories to the most fuel-efficient ones. In addition to this, the Van Allen belts were modelled according to the density of electrons and protons in each point of space, in order to measure the total radiation absorbed by the spacecraft through an integration of the density of particles over the corresponding time. The simulations were then able to predict the relationship between the fluence of the particles and several initial parameters, such as the initial orbit’s eccentricity and the propulsion system’s characteristics. Then, a multi-linear regression and an artificial neural network were fitted to the data through a regression that related the fluence of protons and electrons as a function of the following parameters: mission time, specific impulse, thrust, final mass (i.e., propellant consumption) and the initial height of the perigee, eccentricity and inclination. This analysis was proven to be powerful due to the expressive values from statistical tests, showing underlying positive correlations between thrust, mission time and final spacecraft mass with the fluence of particles, and negative correlations between specific impulse, initial orbit eccentricity, inclination and the height of the perigee with the fluence of particles. Finally, an analysis of a swing-by maneuver was also carried out, together with the radiation incidence, revealing hidden dependencies of the increments in energy and velocity with respect to the fuel consumption, radiation absorption, propulsion system and initial orbit parameters.

Thrust generation by ion propulsion technology

Abstract: Electric propulsion system proven to be a suitable and efficient alternative for conventional propulsion systems .Ion thrusters is one of the electric propulsion systems. It has very high specific impulse generation (Isp) and consumes very low amount of fuel. Ion thrusters can easily compete with chemical rockets propulsion, even if the thrust produce is very low compares to chemical propulsion. Ion propulsion system can be used for various space missions like orbit station keeping for geostationary satellite, orbit and altitude controlling, multi-goal missions. Ion thrusters are more compatible for deep space missions as they are tested for endurance test where as chemical proportion is highly unsuitable for deep space mission.

Comparison of Four Space Propulsion Methods for Reducing Transfer Times of Crewed Mars Missions

Abstract: We assess the possibility of reducing the travel time of a crewed mission to Mars by examining four different propulsion methods and keeping the mass at departure under 2500 tonne, for a fixed architecture. We evaluated representative systems of three different state of the art technologies (chemical, nuclear thermal and electric) and one advance technology, the ``Pure Electro-Magnetic Thrust'' (PEMT) concept (proposed by Rubbia). A mission architecture mostly based on the Design Reference Architecture 5.0 is assumed in order to estimate the mass budget, that influences the performance of the propulsion system. Pareto curves of the duration of the mission and time of flight versus mass of mission are drawn. We conclude that the ion engine technology, combined with the classical chemical engine, yields the shortest mission times for this architecture with the lowest mass and that chemical propulsion alone is the best to minimise travel time. The results obtained using the PEMT suggest that it could be a more suitable solution for farther destinations than Mars.