Extreme cyclic temperature fluctuations (−200 °C to 200 °C) and inherent clearance nonlinearity in deployment hinges severely threaten the on-orbit deployment accuracy and dynamic stability of large variable-geometry spacecraft antennas for geosynchronous Earth orbit applications. However, current modeling approaches suffer from three critical limitations: single-configuration models requiring manual switching, there are inherent geometric nonlinear errors from conventional floating frame formulations, and incomplete thermo-mechanical coupling neglects the temperature effects on contact stiffness and friction. To address these gaps, we propose a unified high-fidelity dynamic model based on the Absolute Nodal Coordinate Formulation (ANCF). This model eliminates geometric errors and mesh mismatch, enables seamless multi-configuration deployment without switching, and fully incorporates temperature-dependent material properties and nonlinear contact forces. An improved Hilber–Hughes–Taylor-$\alpha$ implicit integration algorithm with second-order accuracy and unconditional stability is adopted to solve the strongly nonlinear differential-algebraic equations. Numerical results demonstrate that the proposed model achieves a calculation error below 3% against experimental data, significantly outperforming the traditional floating frame of reference formulation with an error of 15–22%. Non-uniform temperature fields increase thermally induced vibration amplitudes by 32–45%, and every 0.1 increase in the friction coefficient raises the impact force at the clearance hinge by 15–20%. The proposed unified modeling framework provides a solid theoretical basis for deployment stability prediction and the on-orbit control optimization of large variable-geometry spacecraft antennas.

Space-borne antenna pointing is affected by uncertain disturbances like satellite attitude, structural flexibility, and manufacturing/installation errors. Understanding the effect of these uncertainties is crucial for antenna performance. The main contribution of this paper is the proposal of an uncertainty quantification (UQ) framework for antenna pointing performance that integrates the Global Sensitivity Analysis (GSA) method and Point Estimate Method (PEM), named the GSA-PEM Integrated Framework (GSA-PEM in short). This framework enables systematic analysis of how uncertain parameters (satellite attitude, manufacturing/installation errors, joint rotation, structural deformation, feed displacement, etc.) impact antenna pointing. It establishes a pointing model via coordinate transformation, utilizes the total-effect of the Sobol method to prioritize the key parameters for reliability analysis, and computes pointing performance statistics characteristic via PEM to evaluate pointing reliability. Two case studies are presented to validate the accuracy and efficiency of the proposed framework. Monte Carlo Simulation (MCS) and the Maximum Entropy method using the Fractional-order Moments (ME-FMs) are comparison methods. Results demonstrate that the proposed framework achieves a trade-off between accuracy and efficiency in assessing antenna pointing performance under parameter uncertainty.

Extreme orbital thermal cycling and temperature-dependent clearance nonlinearity make it difficult to predict contact–impact, stick–slip, and bifurcation responses of flexible deployable space structures with sufficient stability, accuracy, and computational efficiency. An Adaptive Dissipation–Precision Coordinated Multi-Scale Implicit Integration Algorithm (ADPC-MSIIA) is proposed. First, an absolute nodal coordinate formulation (ANCF)-based thermo-mechanical clearance-joint model with thermal-viscosity-modified contact and frictional/impact heat feedback is established; second, a dual-time-scale implicit integration scheme with dual-$\alpha$ stability–dissipation control and third-order compensation is developed; finally, numerical validation is performed using a linear single-degree-of-freedom (SDOF) benchmark, a temperature-dependent clearance impact oscillator, finite-element and published benchmark comparisons, and a deployable annular truss antenna case. Simulation results show that ADPC-MSIIA achieves a high-frequency spectral radius of $0.867$, an effective convergence order of $2.98$, a maximum contact force error of $3.1\%$, and a $51.7\%$ reduction in the global cumulative error compared with the generalized-$\alpha$ method. This study contributes to knowledge by linking temperature-driven clearance evolution, frictional heat feedback, and adaptive numerical dissipation within a unified framework for predicting non-smooth thermo-mechanical deployment dynamics of large flexible space structures with clearance joints.

The distant retrograde orbit (DRO) serves as a strategic staging point for future cislunar missions, and geostationary transfer orbit (GTO) provides a practical departure option for rideshare low-thrust cargo missions. However, time-optimal low-thrust GTO-to-DRO transfers remain computationally demanding. Indirect methods are highly sensitive to boundary conditions and prone to divergence, whereas direct methods face dimensionality issues as the number of variables scales with trajectory duration and revolutions. To address this issue, this paper proposes a bidirectional initialization framework for multi-phase indirect shooting. A forward auxiliary solution is constructed for the GTO-raising phase in planar modified equinoctial elements, while a backward auxiliary solution is generated for the DRO-insertion phase in the planar Earth–Moon circular restricted three-body problem. The two subproblems are connected through an intermediate interface and coordinated by an outer-level stationarity iteration, after which lunar phase continuity and lunar perturbations are reintroduced into a fully coupled indirect shooting problem. The numerical results show that the proposed strategy provides a reliable initial guess for the complete optimization and enables robust convergence to a continuous time-optimal GTO-to-DRO transfer. The method improves the tractability of long-duration multi-phase indirect trajectory optimization for low-thrust cislunar mission design.

The minimum fuel transfer problem in low-thrust trajectory optimization remains a major challenge and is typically addressed using bang-bang control. A novel methodology integrating Adaptive Multiresolution Collocation (AMRC) and Sequential Convex Programming (SCP) to solve the minimum-fuel low-thrust trajectory optimization problem is proposed. First, the approach employs the cubic spline wavelet-like transform for mesh refinement, where wavelet coefficients serve as error indicators to dynamically concentrate nodes in regions of rapid state variation. Then, the nonlinear programming problem is convexified via control variable relaxation and small-perturbation linearization, reformulated as a second-order cone programming (SOCP) problem, and efficiently solved using convex optimization tools. Subsequently, progressive selection of the location points ensures rapid and accurate convergence to the optimal trajectory. Finally, numerical simulations of Earth–Mars and Earth–Venus transfer validate the effectiveness and accuracy of the AMRC-based method. Compared with conventional approaches, the proposed method achieves comparable optimality while markedly improving computational efficiency, precisely localizing switching times, and improving numerical precision, requiring only 29.7% of the nodes and 14.7% of the computation time of uniform-grid convex optimization, achieving fuel-optimal deviations within 0.07% of the indirect method and demonstrating accuracy improvements of 2–3 orders of magnitude over GPOPS.