Indirect low-thrust trajectory optimization with gridded ion thruster model

2021 ◽  
pp. 095441002110438
Author(s):  
Zhemin Chi ◽  
Yang Wang ◽  
Lin Cheng
Keyword(s):  
Trajectory Optimization ◽  
Electric Propulsion ◽  
Specific Impulse ◽  
Input Power ◽  
Minimum Time ◽  
Mission Design ◽  
Low Thrust ◽  
Ion Thruster ◽  
Solar Electric Propulsion ◽  
Operational Constraints

The work deals with indirect optimization of minimum-time and minimum-fuel interplanetary trajectories when gridded ion thruster models are considered. Using an accurate model of solar electric propulsion is beneficial in preliminary mission design, and allows including operational constraints. The maximum thrust and the specific impulse are expressed as a function of thruster input power, which is achieved by means of point-fitting lines that match the performance capabilities of the thrusters. Minimum-time and minimum-fuel problems are formulated to be solved by indirect optimization. In order to increase the accuracy and robustness of the shooting procedure, analytic Jacobians are derived, and a hybrid switching detection technique is used to improve the integration accuracy for minimum-fuel problems. Two examples of Earth-to-Mars transfer and Near-Earth rendezvous mission using the realistic NASA’s Evolutionary Xenon Thruster (NEXT) are given to substantiate the feasibility and effectiveness of the proposed method.

scholarly journals Design and In-orbit Demonstration of REGULUS, an Iodine electric propulsion system

2021 ◽  
Author(s):  
Nicolas Bellomo ◽  
Mirko Magarotto ◽  
Marco Manente ◽  
Fabio Trezzolani ◽  
Riccardo Mantellato ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Specific Impulse ◽  
Input Power ◽  
Propulsion System ◽  
Electric Propulsion System ◽  
Propulsive Performance ◽  
Plasma Thruster ◽  
Total Impulse ◽  
Acceptance Tests

AbstractREGULUS is an Iodine-based electric propulsion system. It has been designed and manufactured at the Italian company Technology for Propulsion and Innovation SpA (T4i). REGULUS integrates the Magnetically Enhanced Plasma Thruster (MEPT) and its subsystems, namely electronics, fluidic, and thermo-structural in a volume of 1.5 U. The mass envelope is 2.5 kg, including propellant. REGULUS targets CubeSat platforms larger than 6 U and CubeSat carriers. A thrust T = 0.60 mN and a specific impulse Isp = 600 s are achieved with an input power of P = 50 W; the nominal total impulse is Itot = 3000 Ns. REGULUS has been integrated on-board of the UniSat-7 satellite and its In-orbit Demonstration (IoD) is currently ongoing. The principal topics addressed in this work are: (i) design of REGULUS, (ii) comparison of the propulsive performance obtained operating the MEPT with different propellants, namely Xenon and Iodine, (iii) qualification and acceptance tests, (iv) plume analysis, (v) the IoD.

An Analysis of the Efficiency of Electric Propulsion Engines for Maintaining a Low Orbit of Small Spacecraft

2020 ◽  
pp. 65-74
Author(s):  
V.V. Volotsuev ◽  
V.V. Salmin
Keyword(s):  
Electric Propulsion ◽  
Aerodynamic Drag ◽  
Specific Impulse ◽  
Active Movement ◽  
Engine Fuel ◽  
Low Thrust ◽  
Atmospheric Density ◽  
Small Spacecraft ◽  
Drag Forces ◽  
Electric Engine

This paper examines the problem of maintaining the plane parameters of the working orbit of a small spacecraft using an electric propulsion engine. In low working orbits, due to the Earth’s atmosphere, a spacecraft is subjected to aerodynamic drag forces, which results in a decrease in the radius of the orbit and a potential termination of the useful target functioning. The time parameters of the cyclogram for maintaining the working orbit of a small spacecraft with an electric low thrust engine are analyzed taking into account the variability of the atmospheric density. The cyclogram consists of sections of the passive and active movement under the action of the low thrust engine. For the satellite under study, suitable thrust parameters of the electric engine are selected, which allow the correction of the plane parameters of the low orbit. Using the characteristics of the thrust and specific impulse of the electric jet engine, fuel reserves for correction over a long period of time are calculated. The results of the analysis confirm the effectiveness of the electric propulsion engine in terms of fuel consumption for correction.

scholarly journals Minimum-Fuel Planar Earth-to-Mars Low-Thrust Trajectories Using Bang-Bang Control

2021 ◽  
Author(s):  
Daero Lee
Keyword(s):  
Optimal Control ◽  
Boundary Value Problems ◽  
Electric Propulsion ◽  
Direct Method ◽  
Boundary Value ◽  
Specific Impulse ◽  
Direct Methods ◽  
Optimization Methods ◽  
Low Thrust ◽  
Primer Vector Theory

Recent advance in electric propulsion systems have demonstrated that these engines can be used for for long-duration interplanetary voyages. Constant specific impulse engine described as a thrust-limited engine is an example of this type of engine, processing the ability to operate at a constant level of impulse. The determination of minimum-fuel, planar heliocentric Earth-to-Mars low-thrust trajectories of spacecraft using a constant specific impulse is discussed considering the first-order necessary conditions derived from Lawden’s primer vector theory. The minimum-fuel low-thrust Earth-to-Mars optimization problem is then solved in two-dimensional, heliocentric frame using both indirect and direct methods. In the indirect method, two-point-boundary-value problems are derived to solve boundary value problems for ordinary differential equations. In the direct method, a general-purpose optimal control software called GPOPS-II is adopted to solve these optimal control problems. Numerical examples using two different optimization methods are presented to demonstrate the characteristics of minimum-fuel planar low-thrust trajectories with on-off-on thrust sequences at three chosen flight times and available maximum powers. The results are useful for broad trajectory search in the preliminary phase of mission designs.

scholarly journals Increasing the specific impulse of the ion engine by zone engineering of the solid-state field cathode

2021 ◽  
pp. 41-50
Author(s):  
Nikolay Petrov ◽  
◽  
Tamara Antonova ◽  
◽  
Keyword(s):  
Electric Propulsion ◽  
Open Space ◽  
Technology Development ◽  
Rapid Development ◽  
Specific Impulse ◽  
Solid Material ◽  
Space Technology ◽  
Electric Motors ◽  
Low Thrust ◽  
Deep Space

With the rapid development of space technology, the scale of human space exploration is expanding significantly. However, the growing demand for deep space travel cannot be met with conventional chemical engines. Thus, the need for new mechanisms for providing jet thrust, including electric motors, becomes clear. Electric propulsion technology has significant advantages over traditional chemical engines in deep space flight due to its characteristics such as high specific impulse, small size, long service life. A negative feature of electric motors can be called low thrust, however, firstly, in open space this is insignificant and, secondly, the thrust of electric motors can be significantly increased, and for this, there are reserves available at the current level of technology development. Ways to increase the thrust of electric ion thrusters will be detailed and discussed in this work. The increase in the power of ion engines is limited to a large extent by the erosion of the control grids; the ion flow hits the surface of the solid material of the control grid electrode with energetic ions and gradually leads to the failure of this electrode. In this work, the authors will show that the use of field emission as a source of electron beams ionizing the working medium can solve the problem of erosion of control electrodes, due to which it will be possible to significantly increase the strength of the working fields for ion engines, which in turn will increase the specific impulse, efficiency, flow rate and power of the ion engine as a whole.

scholarly journals Hybrid Low Thrust Propulsion Trajectory Design and Optimization Using Virtual Gravity Method

2018 ◽  
Vol 36 (4) ◽  
pp. 618-626 ◽  
Author(s):  
Chong Sun ◽  
Jianping Yuan ◽  
Qun Fang ◽  
Yao Cui ◽  
Mingxiao Wang ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Design Method ◽  
Trajectory Design ◽  
Low Thrust ◽  
Design And Optimization ◽  
Solar Electric Propulsion ◽  
Spacecraft Trajectory ◽  
Rendezvous Problem ◽  
Steering Law ◽  
Thrust System

a novel spacecraft trajectory design method using hybrid low thrust system is proposed in this paper. The hybrid system is constituted with a solar sail propulsion thruster and a solar electric propulsion thruster. In proposed method, the former one provides radical thrust and circumferential thrust to from a virtual gravity, while the later one provides a tangential thrust. In this way, the spacecraft is virtually motioned by constant tangential thrust in a virtual gravity field. Using proposed method, the thrusting trajectory can be parameterized, and a large number of feasible trajectories for circle to circle rendezvous problem can be obtained. To the end the steering law to minimize the fuel cost is found using Matlab optimization tools Fmicon function, and the result is compared with traditional pure solar electric propulsion method in terms of payload mass fraction. The simulation results show that the proposed method can reduced propellant consumption significantly compared with the pure SEP system.

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