 Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 124 journals)
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- Analytical configuration uncertainty propagation of geocentric
interferometric detection constellation-
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Abstract: Abstract Long-term configuration stability is essential for an interferometric detection constellation (IDC), which is closely related to initial uncertainty. Therefore, it is vital to evaluate the uncertainty and characterize the configuration stability. In this study, an analytical method was developed for the configuration uncertainty propagation of a geocentric triangular IDC. The angular momentum and the argument latitude were found to be significantly affected by the initial uncertainty and were selected as the core variables. By averaging the perturbation in one revolution, an analytical solution was proposed for propagating the core orbital elements in one revolution. Subsequently, the analytical solution of the orbit elements during the mission period is obtained by multiplying the solutions in iterative revolutions. The relationship between the selected orbital elements and the configuration stability parameters was established using an analytical solution. The effects of the initial uncertainty in different directions on the configuration and stable domains were studied. Simulations show that the developed method is highly efficient and accurate in predicting the configuration stability. The relative error with respect to the Monte Carlo simulations was less than 3% with a time consumption of 0.1%. The proposed method can potentially be useful for constellation design and stability analysis. 
PubDate: 2023-09-01
DOI: 10.1007/s42064-022-0157-x
- Astrometric calibration and source characterisation of the latest
generation neuromorphic event-based cameras for space imaging-
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Abstract: Abstract As an emerging approach to space situational awareness and space imaging, the practical use of an event-based camera (EBC) in space imaging for precise source analysis is still in its infancy. The nature of event-based space imaging and data collection needs to be further explored to develop more effective event-based space imaging systems and advance the capabilities of event-based tracking systems with improved target measurement models. Moreover, for event measurements to be meaningful, a framework must be investigated for EBC calibration to project events from pixel array coordinates in the image plane to coordinates in a target resident space object’s reference frame. In this paper, the traditional techniques of conventional astronomy are reconsidered to properly utilise the EBC for space imaging and space situational awareness. This paper presents the techniques and systems used for calibrating an EBC for reliable and accurate measurement acquisition. These techniques are vital in building event-based space imaging systems capable of real-world space situational awareness tasks. By calibrating sources detected using the EBC, the spatiotemporal characteristics of detected sources or “event sources” can be related to the photometric characteristics of the underlying astrophysical objects. Finally, these characteristics are analysed to establish a foundation for principled processing and observing techniques which appropriately exploit the capabilities of the EBC. 
PubDate: 2023-08-24
- Self-induced collision risk of the Starlink constellation based on
long-term orbital evolution analysis-
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Abstract: Abstract The deployment of mega constellations has had a significant effect on the compounding space debris environment, increasing the number of on-orbit objects in all conditions and damaging the stability of the space debris environment. The increased density of space objects is associated with an increased risk of on-orbit collisions. Collision risk exists not only between a mega constellation and the space debris environment but also inside a mega constellation. In this study, we used the Starlink constellation to investigate the self-induced collision risk caused by malfunctioning satellites. First, we analyzed the conjunction condition between malfunctioning and operative satellites based on long-term orbital evolution characteristics. The collision probability was then calculated based on the conjunction analysis results. The results show that malfunctioning satellites in Phase 1 cause an 86.2% self-induced collision probability based on a malfunctioning rate of 1%, which is close to the collision probability caused by objects larger than 6 cm during five years of service. Therefore, self-induced collisions are another important risk factor for the Starlink constellation. 
PubDate: 2023-08-10
- Safe-event pruning in spacecraft conjunction management
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Abstract: Abstract Spacecraft conjunction management plays a crucial role in the mitigation of space collisions. When a conjunction event occurs, resources and time are spent analyzing, planning, and potentially maneuvering the spacecraft. This work contributes to a subpart of the problem: Confidently identifying events that will not lead to a high collision probability, and therefore do not require further investigation. The method reduces the dimensionality of the data via principal component analysis (PCA) on a subset of features. High-risk regions are then determined by clustering the projected data, and events that do not belong to a high-risk cluster are pruned. A genetic algorithm (GA) is developed to optimize the number of clusters and feature selection of the model. Furthermore, an ensemble learning framework is proposed to combine the suboptimal models for better generalization. The results show that the first set of parameters pruned approximately 50% of the events in the testing set with no false negatives, whereas the second set of parameters pruned 70% of the events and maintained a near-perfect recall. These results could benefit the optimization of operational resources and allow operators to focus better on the events of interest. 
PubDate: 2023-07-15
DOI: 10.1007/s42064-023-0165-5
- Covariance analysis of periodic and quasi-periodic orbits around Phobos
with applications to the Martian Moons eXploration mission-
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Abstract: Abstract Understanding the internal composition of a celestial body is fundamental for formulating theories regarding its origin. Deep knowledge of the distribution of mass under the body’s crust can be achieved by analyzing its moments of inertia and gravity field. In this regard, the two moons of the Martian system have not yet been closely studied and continue to pose questions regarding their origin to the space community; thus, they deserve further characterization. The Martian Moons eXploration mission will be the first of its kind to sample and study Phobos over a prolonged period. This study aims to demonstrate that the adoption of periodic and quasi-periodic retrograde trajectories would be beneficial for the scientific value of the mission. Here, a covariance analysis was implemented to compare the estimation of high-order gravitational field coefficients from different orbital geometries and for different sets of processed observables. It was shown that the adoption of low-altitude non-planar quasi-satellite orbits would help to refine the knowledge of the moon’s libration angle and gravitational field. 
PubDate: 2023-07-05
DOI: 10.1007/s42064-023-0166-4
- Orbital radius keeping of floating partial space elevator in cargo
transposition-
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Abstract: Abstract A floating partial space elevator (PSE) is a PSE with a floating main satellite. This work aims to keep the orbital radius of the main satellite of a floating PSE in cargo transposition without the use of thrusts. A six-degree-of-freedom two-piece dumbbell model was built to analyze the dynamics of a floating PSE. By adjusting the climber’s moving speed and rolling of the end body, the main satellite’s orbital radius can be kept. A novel control strategy using a proportional shrinking horizon model predictive control law containing a self-stability modified law is proposed to stabilize both the orbital and libration states to regulate the speed of only the climber. Simulation results validated the proposed control strategy. The system provides a successful approach to the desired equilibrium by the end of the transposition. 
PubDate: 2023-06-16
DOI: 10.1007/s42064-022-0156-y
- Optimal interplanetary trajectories for Sun-facing ideal diffractive sails
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Abstract: Abstract A diffractive sail is a solar sail whose exposed surface is covered by an advanced diffractive metamaterial film with engineered optical properties. This study examines the optimal performance of a diffractive solar sail with a Sun-facing attitude in a typical orbit-to-orbit heliocentric transfer. A Sun-facing attitude, which can be passively maintained through the suitable design of the sail shape, is obtained when the sail nominal plane is perpendicular to the Sun–spacecraft line. Unlike an ideal reflective sail, a Sun-facing diffractive sail generates a large transverse thrust component that can be effectively exploited to change the orbital angular momentum. Using a recent thrust model, this study determines the optimal control law of a Sun-facing ideal diffractive sail and simulates the minimum transfer times for a set of interplanetary mission scenarios. It also quantifies the performance difference between Sun-facing diffractive sail and reflective sail. A case study presents the results of a potential mission to the asteroid 16 Psyche. 
PubDate: 2023-06-16
DOI: 10.1007/s42064-023-0158-4
- Attitude maneuvers avoiding forbidden directions
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Abstract: Abstract Many space missions require the execution of large-angle attitude slews during which stringent pointing constraints must be satisfied. For example, the pointing direction of a space telescope must be kept away from directions to bright objects, maintaining a prescribed safety margin. In this paper we propose an open-loop attitude control algorithm which determines a rest-to-rest maneuver between prescribed attitudes while ensuring that any of an arbitrary number of body-fixed directions of light-sensitive instruments stays clear of any of an arbitrary number of space-fixed directions. The approach is based on an application of a version of Pontryagin’s Maximum Principle tailor-made for optimal control problems on Lie groups, and the pointing constraints are ensured by a judicious choice of the cost functional. The existence of up to three first integrals of the resulting system equations is established, depending on the number of light-sensitive and forbidden directions. These first integrals can be exploited in the numerical implementation of the attitude control algorithm, as is shown in the case of one light-sensitive and several forbidden directions. The results of the test cases presented confirm the applicability of the proposed algorithm. 
PubDate: 2023-06-16
DOI: 10.1007/s42064-023-0163-7
- Midcourse correction of Earth–Moon distant retrograde orbit transfer
trajectories based on high-order state transition tensors-
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Abstract: Abstract Midcourse correction design is key to space transfers in the cislunar space. Autonomous guidance has garnered significant attention for its promise to decrease the dependence on ground control systems. This study addresses the problem of midcourse corrections for Earth–Moon transfer orbits based on high-order state transition tensors (STTs). The scenarios considered are direct Earth–Moon transfers and low-energy transfers to lunar distant retrograde orbits (DROs), where the latter involve weak stability boundary (WSB) and lunar gravity assist (LGA) techniques. Semi-analytical formulas are provided for computing the trajectory correction maneuvers (TCMs) using high-order STTs derived using the differential algebraic method. Monte Carlo simulations are performed to evaluate the effectiveness of the proposed approach. Compared with existing explicit guidance algorithms, the STT-based approach is much cheaper computationally and features fewer final position errors. These results are promising for fast and efficient orbital autonomous correction guidance approaches in the cislunar space. 
PubDate: 2023-06-15
DOI: 10.1007/s42064-023-0162-8
- Feasibility analysis of angles-only navigation algorithm with multisensor
data fusion for spacecraft noncooperative rendezvous-
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Abstract: Abstract Relative navigation is crucial for spacecraft noncooperative rendezvous, and angles-only navigation using visible and infrared cameras provides a feasible solution. Herein, an angles-only navigation algorithm with multisensor data fusion is proposed to derive the relative motion states between two noncooperative spacecraft. First, the design model of the proposed algorithm is introduced, including the derivation of the state propagation and measurement equations. Subsequently, models for the sensor and actuator are introduced, and the effects of various factors on the sensors and actuators are considered. The square-root unscented Kalman filter is used to design the angles-only navigation filtering scheme. Additionally, the Clohessy—Wiltshire terminal guidance algorithm is introduced to obtain the theoretical relative motion trajectories during the rendezvous operations of two noncooperative spacecraft. Finally, the effectiveness of the proposed angles-only navigation algorithm is verified using a semi-physical simulation platform. The results prove that an optical navigation camera combined with average accelerometers and occasional orbital maneuvers is feasible for spacecraft noncooperative rendezvous using angles-only navigation. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0148-y
- Application of homotopy perturbation method to the radial thrust problem
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Abstract: Abstract The dynamics of a spacecraft propelled by a continuous radial thrust resembles that of a nonlinear oscillator. This is analyzed in this work with a novel method that combines the definition of a suitable homotopy with a classical perturbation approach, in which the low thrust is assumed to be a perturbation of the nominal Keplerian motion. The homotopy perturbation method provides the analytical (approximate) solution of the dynamical equations in polar form to estimate the corresponding spacecraft propelled trajectory with a short computational time. The accuracy of the analytical results was tested in an orbital-targeting mission scenario. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0150-4
- Closed-loop deep neural network optimal control algorithm and error
analysis for powered landing under uncertainties-
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Abstract: Abstract Real-time guidance is critical for the vertical recovery of rockets. However, traditional sequential convex optimization algorithms suffer from shortcomings in terms of their poor real-time performance. This work focuses on applying the deep learning-based closed-loop guidance algorithm and error propagation analysis for powered landing, thereby significantly improving the real-time performance. First, a controller consisting of two deep neural networks is constructed to map the thrust direction and magnitude of the rocket according to the state variables. Thereafter, the analytical transition relationships between different uncertainty sources and the state propagation error in a single guidance period are analyzed by adopting linear covariance analysis. Finally, the accuracy of the proposed methods is verified via a comparison with the indirect method and Monte Carlo simulations. Compared with the traditional sequential convex optimization algorithm, our method reduces the computation time from 75 ms to less than 1 ms. Therefore, it shows potential for online applications. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0153-1
- A review of dynamic analysis on space solar power station
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Abstract: Abstract The concept of a space solar power station (SSPS) was proposed in 1968 as a potential approach for solving the energy crisis. In the past 50 years, several structural concepts have been proposed, but none have been sent into orbit. One of the main challenges of the SSPS is dynamic behavior prediction, which can supply the necessary information for control strategy design. The ultra-large size of the SSPS causes difficulties in its dynamic analysis, such as the ultra-low vibration frequency and large flexibility. In this paper, four approaches for the numerical analysis of the dynamic problems associated with the SSPS are reviewed: the finite element, absolute nodal coordinate, floating frame formulation, and structure-preserving methods. Both the merits and shortcomings of the above four approaches are introduced when they are employed in dynamic problems associated with the SSPS. Synthesizing the merits of the aforementioned four approaches, we believe that embedding the structure-preserving method into finite element software may be an effective way to perform a numerical analysis of the dynamic problems associated with the SSPS. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0144-2
- Adaptive connected hierarchical optimization algorithm for minimum energy
spacecraft attitude maneuver path planning-
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Abstract: Abstract Space object observation requirements and the avoidance of specific attitudes produce pointing constraints that increase the complexity of the attitude maneuver path-planning problem. To deal with this issue, a feasible attitude trajectory generation method is proposed that utilizes a multiresolution technique and local attitude node adjustment to obtain sufficient time and quaternion nodes to satisfy the pointing constraints. These nodes are further used to calculate the continuous attitude trajectory based on quaternion polynomial interpolation and the inverse dynamics method. Then, the characteristic parameters of these nodes are extracted to transform the path-planning problem into a parameter optimization problem aimed at minimizing energy consumption. This problem is solved by an improved hierarchical optimization algorithm, in which an adaptive parameter-tuning mechanism is introduced to improve the performance of the original algorithm. A numerical simulation is performed, and the results confirm the feasibility and effectiveness of the proposed method. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0149-x
- Natural coupled orbit—attitude periodic motions in the perturbed-CRTBP
including radiated primary and oblate secondary-
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Abstract: Abstract This study investigated periodic coupled orbit—attitude motions within the perturbed circular restricted three-body problem (P-CRTBP) concerning the perturbations of a radiated massive primary and an oblate secondary. The radiated massive primary was the Sun, and each planet in the solar system could be considered an oblate secondary. Because the problem has no closed-form solution, numerical methods were employed. Nevertheless, the general response of the problem could be non-periodic or periodic, which is significantly depended on the initial conditions of the orbit-attitude states. Therefore, the simultaneous orbit and attitude initial states correction (SOAISC) algorithm was introduced to achieve precise initial conditions. On the other side, the conventional initial guess vector was essential as the input of the correction algorithm and increased the probability of reaching more precise initial conditions. Thus, a new practical approach was developed in the form of an orbital correction algorithm to obtain the initial conditions for the periodic orbit of the P-CRTBP. This new proposed algorithm may be distinguished from previously presented orbital correction algorithms by its ability to propagate the P-CRTBP family orbits around the Lagrangian points using only one of the periodic orbits of the unperturbed CRTBP (U-CRTBP). In addition, the Poincaré map and Floquet theory search methods were used to recognize the various initial guesses for attitude parameters. Each of these search methods was able to identify different initial guesses for attitude states. Moreover, as a new innovation, these search methods were applied as a powerful tool to select the appropriate inertia ratio for a satellite to deliver periodic responses from the coupled model. Adding the mentioned perturbations to the U-CRTBP could lead to the more accurate modeling of the examination environment and a better understanding of a spacecraft’s natural motion. A comparison between the orbit-attitude natural motions in the unperturbed and perturbed models was also conducted to show this claim. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0154-0
- Review of space relative navigation based on angles-only measurements
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Abstract: Abstract Relative navigation is a key enabling technology for space missions such as on-orbit servicing and space situational awareness. Given that there are several special advantages of space relative navigation using angles-only measurements from passive optical sensors, angles-only relative navigation is considered as one of the best potential approaches in the field of space relative navigation. However, angles-only relative navigation is well-known for its range observability problem. To overcome this observability problem, many studies have been conducted over the past decades. In this study, we present a comprehensive review of state-of-the-art space relative navigation based on angles-only measurements. The emphasis is on the observability problem and solutions to angles-only relative navigation, where the review of the solutions is categorized into four classes based on the intrinsic principle: complicated dynamics approach, multi-line of sight (multi-LOS) approach, sensor offset center-of-mass approach, and orbit maneuver approach. Then, the flight demonstration results of angles-only relative navigation in the two projects are briefly reviewed. Finally, conclusions of this study and recommendations for further research are presented. 
PubDate: 2023-06-01
DOI: 10.1007/s42064-022-0152-2
- Reconstructing the cruise-phase trajectory of deep-space probes in a
general relativistic framework: An application to the Cassini
gravitational wave experiment-
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Abstract: Abstract Einstein’s theory of general relativity is playing an increasingly important role in fields such as interplanetary navigation, astrometry, and metrology. Modern spacecraft and interplanetary probe prediction and estimation platforms employ a perturbed Newtonian framework, supplemented with the Einstein-Infeld-Hoffmann n-body equations of motion. While time in Newtonian mechanics is formally universal, the accuracy of modern radiometric tracking systems necessitate linear corrections via increasingly complex and error-prone post-Newtonian techniques—to account for light deflection due to the solar system bodies. With flagship projects such as the ESA/JAXA BepiColombo mission now operating at unprecedented levels of accuracy, we believe the standard corrected Newtonian paradigm is approaching its limits in terms of complexity. In this paper, we employ a novel prototype software, General Relativistic Accelerometer-based Propagation Environment, to reconstruct the Cassini cruise-phase trajectory during its first gravitational wave experiment in a fully relativistic framework. The results presented herein agree with post-processed trajectory information obtained from NASA’s SPICE kernels at the order of centimetres. 
PubDate: 2023-04-15
DOI: 10.1007/s42064-023-0160-x
- Capacity of Sun-driven lunar swingby sequences and their application in
asteroid retrieval-
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Abstract: Abstract For deep-space mission design, the gravity of the Sun and the Moon can be first considered and utilized. Their gravity can provide the energy change for launching spacecraft and retrieving spacecraft as well as asteroids. Regarding an asteroid retrieval mission, it can lead to the mitigation of asteroid hazards and an easy exploration and exploitation of the asteroid. This paper discusses the application of the Sun-driven lunar swingby sequence for asteroid missions. Characterizing the capacity of this technique is not only interesting in terms of the dynamic insights but also non-trivial for trajectory design. The capacity of a Sun-driven lunar swingby sequence is elucidated in this paper with the help of the “Swingby-Jacobi” graph. The capacity can be represented by a range of the Jacobi integral that encloses around 660 asteroids currently cataloged. To facilitate trajectory design, a database of Sun-perturbed Moon-to-Moon transfers, including multirevolution cases, is generated and employed. Massive trajectory options for spacecraft launch and asteroid capture can then be explored and optimized. Finally, a number of asteroid flyby, rendezvous, sample-return, and retrieval mission options enabled by the proposed technique are obtained. 
PubDate: 2023-04-11
DOI: 10.1007/s42064-023-0161-9
- Message from the Guest Editors of the Special Issue on Asteroid
Exploration-
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PubDate: 2023-03-01
DOI: 10.1007/s42064-022-0155-z
- Stretching directions in cislunar space: Applications for departures and
transfer design-
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Abstract: Abstract Stable or nearly stable orbits do not generally possess well-distinguished manifold structures that assist in designing trajectories for departing from or arriving onto a periodic orbit. For some potential missions, the orbits of interest are selected as nearly stable to reduce the possibility of rapid departure. However, the linearly stable nature of these orbits is also a drawback for their timely insertion into or departure from the orbit. Stable or nearly stable near rectilinear halo orbits (NRHOs), distant retrograde orbits (DROs), and lunar orbits offer potential long-horizon trajectories for exploration missions and demand efficient operations. The current investigation focuses on leveraging stretching directions as a tool for departure and trajectory design applications. The magnitude of the state variations along the maximum stretching direction is expected to grow rapidly and, therefore, offers information for efficient departure from the orbit. Similarly, maximum stretching in reverse time enables arrival with a minimal maneuver magnitude. 
PubDate: 2022-09-29
DOI: 10.1007/s42064-022-0147-z
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