Solar Sail Research Articles

Preparation and Characterization of Atomic Oxygen-Resistant, Optically Transparent and Dimensionally Stable Copolyimide Films from Fluorinated Monomers and POSS-Substituted Diamine.

Optically transparent polyimide (PI) films with good atomic oxygen (AO) resistance have been paid extensive attention as thermal controls, optical substrates for solar cells or other components for low Earth orbit (LEO) space applications. However, for common PI films, it is usually quite difficult to achieve both high optical transparency and AO resistance and maintain the intrinsic thermal stability of the PI films at the same time. In the current work, we aimed to achieve the target by using the copolymerization methodology using the fluorinated dianhydride 9,9-bis(trifluoromethyl)xanthene-2,3,6,7-tetracarboxylic dianhydride (6FCDA), the fluorinated diamine 2,2-bis [4-(4-aminophenoxy)phenyl]hexafluoropropane (BDAF) and the polyhedral oligomeric silsesquioxane (POSS)-containing diamine N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS) as the starting materials. The fluoro-containing monomers were used to endow the PI films with good optical and thermal properties, while the silicon-containing monomer was used to improve the AO resistance of the afforded PI films. Thus, the 6FCDA-based PI copolymers, including 6FCPI-1, 6FCPI-2 and 6FCPI-3, were prepared using a two-step chemical imidization procedure, respectively. For comparison, the analogous PIs, including 6FPI-1, 6FPI-2 and 6FPI-3, were correspondingly developed according to the same procedure except that 6FCDA was replaced by 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Two referenced PI homopolymers were prepared from BDAF and 6FDA (PI-ref1) and 6FCDA (PI-ref2), respectively. The experimental results indicated that a good balance among thermal stability, optical transparency, and AO resistance was achieved by the 6FCDA-PI films. For example, the 6FCDA-PI films exhibited good thermal stability with glass transition temperatures (Tg) up to 297.3 °C, good optical transparency with an optical transmittance at a wavelength of 450 nm (T450) higher than 62% and good AO resistance with the erosion yield (Ey) as low as 1.7 × 10-25 cm3/atom at an AO irradiation fluence of 5.0 × 1020 atoms/cm2. The developed 6FCDA-PI films might find various applications in aerospace as solar sails, thermal control blankets, optical components and other functional materials.

Low-thrust transfer with Theory of Functional Connections: Application to 243 Ida with a solar sail

A spacecraft needs to perform maneuvers in the neighborhood of the body that it orbits in order to achieve the targets of its mission. These maneuvers are usually performed with propellant based engines. Solar sails, as low-thrust propulsion systems, represent a way to perform them without fuel consumption, but it necessitates to change their orientation in order to generate the desired thrust, which is a complex procedure. In this paper, we propose a new method to perform propellant-free maneuvers with a solar sail using the Theory of Functional Connections. This method is applied to the asteroid Ida in the context of transfers between artificial equilibrium points.

Achieving solar sail orbital maintenance with adjustable ballast masses in the ERTBP

An innovative method for orbital maintenance in the Sun-Earth Elliptic Restricted Three-Body Problem (ERTBP) is introduced. The concept arose from observing that Natural Periodic (NP) orbits in the ERTBP exhibit deviations from their periodic behavior over time. These NP orbits are derived solely from accurately specified initial orbital conditions. Hence, a strategy for orbital maintenance becomes essential for these missions. This approach utilizes NP orbits as the designated reference trajectory to be tracked by the spacecraft. It assumes a solar sail equipped with two ballast masses and suggests a Fully Coupled Orbit-Attitude (FCOA) model. In this comprehensive model, both orbital and attitude states mutually influence each other, enabling orbital adjustments through attitude control. Therefore, the first step involves developing the governing equations for this FCOA model incorporating two ballast masses within the ERTBP. The strategy includes dividing the NP orbit period into τ equal time intervals. During each interval, adjusting the velocity of the ballast mass using a 7-mode electrical motor facilitates precise attitude control, establishing a framework for orbital maintenance. Maintaining constant velocity within each interval simplifies achieving the desired ballast mass positions. The adjustment of ballast mass velocity is proposed to be conducted using a hybrid meta-heuristic Invasive Weed Optimization/Particle Swarm Optimization (IWO/PSO). The analysis examines how increasing the mass of the ballast masses enhances tracking performance, underscoring the critical role of mass in optimizing tracking capabilities. This highlights the significance of meticulous structural design in achieving superior outcomes for orbital maintenance missions.

An Orbital-attitude Coupled Control Framework for a Full-scale Flexible Electric Solar Wind Sail Spacecraft in Orbital Transformation Missions

In this work, a novel orbital-attitude coupled control framework is developed for the electric solar wind sail (E-sail) spacecraft, aiming to handle the orbital transformation and attitude maneuver simultaneously. In the framework, the desired attitude parameters and the slow-varying voltage component are provided by the orbital control strategy, while the current attitude parameters and the fast-varying voltage component are manipulated by the attitude control strategy to approach their desired values. The orbital-attitude coupled characteristics of the E-sail spacecraft, including the flexibility-induced coupling effect, are fully described by the referenced nodal coordinate formulation. Considering the input saturation conditions, the governing equation for the orbital control strategy is then derived, in which the in-plane and out-of-plane displacement and velocity errors are prescribed as the state variables to be eliminated. An integral sliding mode control (ISMC) scheme is proposed to improve the robustness against the unmeasurable disturbance term. A model predictive control (MPC) scheme is introduced to enhance the convergence efficiency, where a quadratic optimization is performed to plan the desired attitude parameters and voltage components within the prediction horizon. To evaluate the control performance in the orbital transformation and attitude maneuver missions on the displaced non-Keplerian orbit, a series of scenarios with complex initial conditions are simulated under different control schemes, including the ISMC-MPC compound scheme. The results show that the control strategy designed under the rigid-body assumptions may not be feasible for the flexible E-sail spacecraft, while the investigated control strategy realizes the accurate and efficient convergence of the orbital and attitude variables on both the rigid and flexible E-sail spacecraft with the tether deformation stabilized.

Thrust Model and Trajectory Design of an Interplanetary CubeSat with a Hybrid Propulsion System

This paper analyzes the performance of an interplanetary CubeSat equipped with a hybrid propulsion system (HPS), which combines two different types of thrusters in the same deep space vehicle, in a heliocentric transfer between two assigned (Keplerian) orbits. More precisely, the propulsion system of the CubeSat considered in this work consists of a combination of a (low-performance) photonic solar sail and a more conventional solar electric thruster. In particular, the characteristics of the solar electric thruster are modeled using a recent mathematical approach that describes the performance of the miniaturized engine that will be installed on board the proposed ESA’s M-ARGO CubeSat. The latter will hopefully be the first interplanetary CubeSat to complete a heliocentric transfer towards a near-Earth asteroid using its own propulsion system. In order to simplify the design of the CubeSat attitude control subsystem, we assume that the orientation of the photonic solar sail is kept Sun-facing, i.e., the sail reference plane is perpendicular to the Sun-CubeSat line. That specific condition can be obtained, passively, by using an appropriate design of the shape of the sail reflective surface. The performance of an HPS-based CubeSat is analyzed by optimizing the transfer trajectory in a three-dimensional heliocentric transfer between two closed orbits of given characteristics. In particular, the CubeSat transfer towards the near-Earth asteroid 99942 Apophis is studied in detail.

Evaluation of the Hand Grip and Sheet Rope Pulling Strength in Laser Sailing Athletes by Using Hiking Bench

Evaluation of the Hand Grip and Sheet Rope Pulling Strength in Laser Sailing Athletes by Using Hiking Bench

Preliminary Trajectory Design for Mitigating Debris Utilizing Solar Sailing and Conventional Propulsion

AbstractIn this study, preliminary trajectory design for debris removal in low Earth orbit using solar sails is explored. Emphasis is placed on regions below 1000 km altitude, where the debris population is rapidly growing. The aim is to propose a mission concept capable of repetitively executing removal processes. The trajectory is intricately crafted, segmented into rendezvous, proximity operations, and deorbiting phases. Safety is prioritized by leveraging walking safety ellipses during proximity operations, ensuring efficient capture of targeted debris. Additionally, the feasibility and limitations of the mission concept are assessed through numerical simulations based on characteristic acceleration, a pivotal performance index of solar sails.

Solar sail orbital motion at the non-autonomous oblate earth-moon system: family of periodic orbits

Solar sail orbital motion at the non-autonomous oblate earth-moon system: family of periodic orbits

Smart tubular hinge with multi-environment adaptability for rapid elastic and gentle shape memory deployment

Smart deployable structures are a crucial solution for reducing spacecraft weight and enhancing rocket space utilization. Traditional deployable structures based on composite materials can only achieve either elastic deployment or shape memory deployment, failing to meet multi-condition, high-intelligence requirements. In this work, we developed a tubular hinge with dual-deformation deployability. For rapid deployment needs, the hinge can be deformed at room temperature and achieve quick elastic deployment within 0.3 s at room or low temperatures. For autonomous fixation and slow deployment, the hinge can be fixed at high temperatures and achieve a gentle shape memory deployment within 100 s. More significantly, the hinge exhibits excellent environmental stability, maintaining superior deployable characteristics even after exposure to high and low-temperature environments and long-term folding. This hinge has been used to the deployment of solar panels and solar sails.

Symmetric engineered central cross-shaped broadband metamaterial absorber with high absorption and stability for solar sailing and solar energy applications

We propose a theoretical design and analysis of a broadband metamaterial absorber (MMA) with significant potential for solar sailing applications which is a method of spacecraft propulsion that usages the momentum of sunlight to propel a spacecraft through space. The absorber features a metal-dielectric-metal configuration with a tungsten (W) based resonator and ground plane, and a Silicon-dioxide (SiO₂) substrate. Addressing the critical need for materials that can efficiently harness solar radiation for propulsion in space, our design achieves an average absorption of 99.15 % over a broad spectrum from 250 nm to 1200 nm, covering the UV–Visible–NIR regions, with near-unity absorption peaks at 362 nm and 915.8 nm. It maintains high absorptions of 84.9 % and 86 % under transvers electric and transvers magnetic modes respectively, demonstrating excellent wide incident angle stability and polarization insensitivity due to its symmetric design. PCR values close to zero confirm its functionality as an absorber rather than a polarizer. The MMA shows minimal deformation across temperatures from 500 K to 1750 K and remains stable under various mechanical stresses, proving its durability and efficiency in space. Additionally, in solar thermophotovoltaic (STPV) systems, the MMA demonstrates high photothermal conversion efficiency (PTCE) over a wide temperature range (500 °C to 1500 °C) and different concentration factors. This dual functionality highlights its potential for both efficient space exploration and terrestrial solar energy harvesting, making it a versatile tool for future technological applications.

Review of Solar Sail Propulsion Mechanisms and Missions for Space Travel

Since solar sailing employs the speed of sunlight to drive spacecraft, it is an efficient and environmentally friendly alternative to traditional propulsion technologies. The physics of photon compression, the significance of novel materials and systems that enhance sailing performance, and the appropriate testing of solar sailing systems are all covered in this research paper. The main solar sailing projects— LightSail, NEA Scout, and IKAROS—are examined in this paper, and their merits, demerits, and contributions to the field are discussed. Potential solar sailing technology for extended space travel are also covered, along with space sustainability. Consider how crucial it is for space exploration in the future. The goal of this research is to demonstrate the transformative potential of navigation and to spark further developments in the exciting field of space aerospace engineering by effectively integrating mission data and current research in the ever-changing landscape of space exploration. Since solar sailing employs the speed of sunlight to drive spacecraft, it is a practical and environmentally friendly alternative to traditional propulsion technologies. The physics of photon compression, the significance of novel materials and systems that enhance sailing performance, and the appropriate testing of solar sailing systems are all covered in this research paper. The main solar sailing projects—LightSail, NEA Scout, and IKAROS—are examined in this paper, and their merits, demerits, and contributions to the field are discussed. Potential solar sailing technology for extended space travel are also covered, along with space sustainability. Pay attention to how crucial it is for future space exploration. Through the efficient integration of mission data and current research, this project seeks to address the dynamic landscape of space exploration in the industry and encourage future advancements in the exciting field of space aeronautical engineering. Additionally, it aims to illustrate how navigation can have a transforming effect. Keywords: Space Exploration, Propulsion Technology, Interstellar Travel, Spacecraft Navigation, Attitude control, Trajectory optimization, Material Durability, Deep Space Missions, Interplanetary Travel, Solar Radiation Effect, Photon Pressure, Solar sail Deployment, Orbital Mechanics, Continues Thrust.

Venus Magnetotail Long-Term Sensing Using Solar Sails

Propellantless propulsion systems, such as the well-known photonic solar sails that provide thrust by exploiting the solar radiation pressure, theoretically allow for extremely complex space missions that require a high value of velocity variation to be carried out. Such challenging space missions typically need the application of continuous thrust for a very long period of time, compared to the classic operational life of a space vehicle equipped with a more conventional propulsion system as, for example, an electric thruster. In this context, an interesting application of this propellantless thruster consists of using the solar sail-induced acceleration to artificially precess the apse line of a planetocentric elliptic orbit. This specific mission application was thoroughly investigated about twenty years ago in the context of the GeoSail Technology Reference Study, which analyzed the potential use of a spacecraft equipped with a small solar sail to perform an in situ study of the Earth’s upper magnetosphere. Taking inspiration from the GeoSail concept, this study analyzes the performance of a solar sail-based spacecraft in (artificially) precessing the apse line of a high elliptic orbit around Venus with the aim of exploring the planet’s induced magnetotail. In particular, during flight, the solar sail orientation is assumed to be Sun-facing, and the required thruster’s performance is evaluated as a function of the elliptic orbit’s characteristics by using both a simplified mathematical model of the spacecraft’s planetocentric dynamics and an approximate analytical approach. Numerical results show that a medium–low-performance sail is able to artificially precess the apse line of a Venus-centered orbit in order to ensure the long-term sensing of the planet’s induced magnetotail.

Trajectory & maneuver design of the NEA Scout solar sail mission

The Near-Earth Asteroid Scout (NEA Scout) mission aimed to deliver a 6U CubeSat to a slow flyby of a Near Earth Asteroid using a solar sail as the primary propulsion system. NEA Scout was launched as a secondary payload aboard Artemis I, on November 16, 2022, but communication with the spacecraft was not achieved. This paper describes the target asteroid selection and the innovative trajectory and maneuver design for the NEA Scout mission, including cold gas maneuvers, multiple lunar flybys, solar sail thrusting, and design margins for solar sailing. The resulting trajectory design tools, solutions, and analyses are potentially applicable to future solar sail missions.

Minimum-time rendezvous for Sun-facing diffractive solar sails with diverse deflection angles

Minimum-time rendezvous for Sun-facing diffractive solar sails with diverse deflection angles

Multi-modal control and position optimization of solar panels

This paper investigates the impact of the position of piezoelectric actuators on the vibration control effect of the membrane plane composed of solar sail materials with a given unit area. Firstly, the nonlinear vibration equation of the membrane structure is perfected based on the system equation established by Yifan Lu et al. Then, the modal coupling effect pointed out by Liu Xiang is considered, and the fourth-order modal displacement generated by the piezoelectric actuator in vibration control is derived. Subsequently, the sliding mode controller used in vibration control is designed based on Lyapunov stability theory, and its effectiveness is verified through Simulink simulation. The sliding mode controller is used to calculate the required excitation signal and apply it to the piezoelectric patches. The reverse force is generated through the inverse piezoelectric effect of the patches to actively suppress the vibration of the solar sail. By changing the position and size of each piezoelectric actuator on the solar sail plane, this paper compares the impact of different layout positions on vibration control, and proposes an optimal layout scheme for the position of the piezoelectric patches in terms of control effectiveness.

Dynamics and control for spacecraft tracking a displaced orbit around an asteroid exploiting solar sail

This study investigates the displaced orbit around a near-Earth asteroid for spacecraft achieved via a realistic solar sail with a performance based on the existing technology in a low distance. Using the realistic solar sail to achieve the displaced orbit with a short displaced distance is more difficult compared with using a traditional thruster under two main limitations: The force limitation and the position limitation. Firstly, the solar radiation pressure (SRP) force generated by the solar sail is limited by the solar sail’s property and the sunlight direction. Therefore, the feasibility of maintaining a displaced orbit at an equilibrium point around the asteroid at a low distance using a solar sail with realistic performance is investigated analytically. The results demonstrate that the equilibrium point of the displaced orbit can be achieved. Secondly, the usage of the solar sail is also limited by the position of the spacecraft. The SRP force cannot be generated in the eclipse region wherein sunlight is absent; specifically, in a displaced orbit with a low displaced distance, the position limitation is more notable. To address this challenge, spacecraft dynamics and control using a solar sail are investigated to achieve the displaced orbit, and a method of orbit transfer outside the eclipse region is proposed. Numerical simulations reveal that the spacecraft can maintain the displaced orbit using the solar sail without entering the eclipse region. Moreover, spacecraft can achieve orbit transfer between two equilibrium points without entering the eclipse region by using the solar sail. The impact of non-spherical shape of the primary asteroid is also investigated. Results show that the proposed method can maintain a displaced orbit with errors from the reference state less than 10 % during a limited time span when the primary asteroid has a non-spherical shape.

Optimal control of a solar sail

SummaryOptimal control of a solar sail orbiting around a fixed center of mass is considered. The sail is modelled as a plane surface with two sides having similar optical properties. The control is assumed to be the attitude of the sail and is represented as an element of the projective plane. Mapping this plane into the three dimensional ambient space to compute the actual force generated by a given attitude results in a generally non‐convex set of admissible control values. A suitable convex relaxation is introduced to study the optimality system associated with maximising the change of the sail orbital parameters in a given direction along one orbit. Existence for both the relaxed and the original problems are deduced. Building on previous works, a refined analysis of the control structure is given, proving rigorously that it contains only switchings, and a global bound of the number of switchings is obtained. In order to compute effective solutions, a multiple shooting approach is retained that is well suited for systems with a sequence of switchings between various control subarcs. Three issues are addressed: initialization of shooting by means a tailored semi‐definite relaxation that takes advantage of good convergence properties of modern convex optimization algorithms; changes in the control structure that are accommodated by coupling shooting with differential continuation; implicit character of the Hamiltonian maximization when using Pontrjagin maximum principle that is taken care of by incorporating the associated equation for the dynamical feedback into the shooting procedure. The method is illustrated on an example from NASA for which the sail inclination is optimally changed over one orbital period.

Optimal multi-segment trajectory of solar sail with analytical approximation

This paper focuses on the optimization of two-dimensional transfer trajectories for solar sails using analytical approximation and modified analytical approximation methods. Instead of assuming circular orbits [29-31,37], the proposed approach allows for the analysis of solar sails launched from general heliocentric elliptical orbits. By employing linear perturbation theory, analytical propelled trajectories with fixed pitch angles are derived, where the perturbation coefficient serves as the reference lightness coefficient. To obtain the optimal transfer orbit between general heliocentric elliptical orbits, the analytical segments corresponding to different pitch angles are spliced together. A nonlinear optimization algorithm is then utilized to optimize the multi-segment trajectory, aiming to achieve the optimal performance index while satisfying boundary and intermediate constraints. Remarkably, this method requires the optimization of only the pitch angle for each segment, resulting in a small number of optimization variables and significantly improved efficiency in transfer orbit optimization. Additionally, the analytical approximation approach offers substantial time savings compared to numerical integration, particularly when repeated calculations are involved. Furthermore, the modified approximate trajectory exhibits high accuracy, with the optimal analytical transfer trajectory closely approximating the optimal actual trajectory acquired through the shooting method. This paper extensively validates and analyzes the precision of the proposed analytical transfer orbit through numerical verification. Additionally, when contrasted with actual transfer orbit, the suggested analytical approach can significantly decrease the computation time for multi-object challenges by a minimum of 80%. This makes the proposed method highly suitable for rapid design of optimal transfer orbits in multi-target mission scenarios for solar sail-based probes.

Shape memory polymer composite hinges for solar sails

Smart hinges for self-deployable solar sails have been prototyped by using shape memory polymer composites (SMPCs). During hinge lamination, a shape memory (SM) epoxy resin is deposited between carbon fiber reinforced (CFR) plies, and consolidation is obtained by an out-of-autoclave (OOA) process. The smart hinges have been assembled with CFR booms to prototype a small self-deployable square sail. Polymeric supports, made by fused deposition modelling (FDM), have been added for correct assembly and to drive the recovery of the SMPC hinges. Flexible heaters have been used as heating elements for SMPC hinge activation. The sail consisted of a polyimide membrane which was connected with the composite booms by flexible joints. The solar sail prototype size has been limited to 260 × 260 mm2 for on-Earth testing, with 4 hinges at the middle length of the composite booms. Recovery tests have shown the ability of the smart hinges to overcome the sail weight and additional friction forces, and the small sail has been successfully deployed in laboratory. Full recovery has been achieved in less than 3 min under different configurations.

Mechanical Property Analysis of a Boom-Membrane Structure Used for Aerospace Technologies.

Traditional deployable truss space structures previously had upper limits on their key indicators, such as the deployed area, folded ratio and total weight, and hence, the application of new extendable mechanisms with novel deployment types is desired. Foldable extendable tape spring booms made from FRP (fiber-reinforced polymer) laminate composites and their corresponding boom-membrane structures were invented in recent years to satisfy the needs of the large-scale requirements of spacecraft, especially for antennas, solar sails and solar arrays. This paper aimed to analyze the properties of the deployed states of extendable tape spring booms and their boom-membrane structures. By establishing an analytical model of the boom and the structure, the bending stiffness, critical buckling load of the boom and the fundamental frequency of the membrane structure were acquired. To provide more guidance on the boom-membrane structure design, a geometric and material parametric study was carried out. Meanwhile, an experimental study to investigate the deployed properties of the booms and membrane structures was introduced to afford some practical verification.