| 1 | Mission Design of an Aperture-Synthetic Interferometer System for Space-Based Exoplanet Exploration显示文摘In recent years,exoplanet detection has become the technological frontier in the field of astronomy,because it provides evidence of the origin of life and the future human habitable exoplanet.Deploying several satellites to form an aperture-synthetic interferometer system in space may help discover“another Earth”via interferometry and midinfrared broadband spectroscopy.This paper analyzes a space-based exoplanet exploration mission in terms of the scientific background,mission profile,trajectory design,and orbital maintenance.First,the system architecture and working principle of the interferometer system are briefly introduced.Secondly,the mission orbit and corresponding transfer trajectories are discussed.The halo orbit near the Sun-Earth L2(SEL2)orbit is chosen as the candidate mission orbit.The low-energy transfer via stable invariant manifold with multiple perigees is designed,and the proper launch windows are presented.A speed increment less than 10 m/s is imposed for each transfer to achieve the insertion of the halo orbit.Finally,the tangent targeting method(TTM)is applied for high-precision formation maintenance with the whole velocity increments of less than 5×10^(−4)m/s for each spacecraft when the error bound is 0.1 m.The overall fuel budget during the mission period is evaluated and compared.The design in this paper will provide technical support and reliable reference for future exoplanet exploration missions. | Feida Jia Xiangyu Li Zhuoxi Huo Dong Qiao | 2022 | Space(Science & Technology)2022，，1： | 1 |
| 2 | Efficient optimization method for variable-specific-impulse low-thrust trajectories with shutdown constraint显示文摘This paper develops a sequential convex programming(SCP)-based method to solve the minimum-fuel variable-specific-impulse low-thrust transfer problem considering shutdown constraint,with emphasize on improving the computational efficiency.The variable parameter engine is more applicable for many low-thrust scenarios,therefore,both a continuously variable model and a ladder variable model are adopted.First,the original problem is convexified by processing the constraint feasible domain,which is composed of the nonlinear dynamic equations and second-order equality constraint,into convex sets.Then,the approximation is generated to close the optimal solution of the low-thrust problem by iteratively solving the convexified subproblem.Moreover,the switching self-detection and adaptive node refinement methods are presented,which can improve the accuracy of the solution and accelerate the convergence during the approximation process and is especially necessary and effective in the scenarios with shutdown constraint.In numerical simulations,the comparison with the homotopic approach shows that the proposed method only needs 4%computational time as that of the homotopic approach,and two variable-specificimpulse examples further demonstrate the effectiveness and efficiency of the proposed method. | JIA FeiDa QIAO Dong HAN HongWei LI XiangYu | 2022 | Science China(Technological Sciences)2022，65，3： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员