Advances in Astronautics Science and Technology最新文献

Aiming at the main constraint of high cost of round-trip transportation between Earth and space in the large-scale space application of space station and manned deep space exploration program, in the development of new-generation manned spaceships in China, to reduce the operation cost and enhance the economic benefit, the relevant design is carried out in accordance with the reusable capability. First, the concept of reusable mode of new-generation manned spacecraft is put forward, the technical difficulties of reusable spacecraft are analyzed, and the technical ways to solve the problems are given in four dimensions, design of reusable conditions, design of reusable performance, design of reusable maintenance security, and design of autonomous health detection and diagnosis, so as to form the technical system of reusable new-generation manned spacecraft. This study has clarified the reusable technology route and realization direction of the new generation of manned spacecraft, which can be used to guide the development of future reusable spacecraft and lay the foundation for large-scale space development.

To cope with the potential thrust-drop malfunction of the manned lunar exploration launch vehicle, a parking orbit replanning method is proposed based on the evaluation of the residual carrying capacity of the launcher. By analyzing the constraints of the whole flight profile and the characteristics of the Earth–Moon transfer orbit systematically, the offline trajectory planning algorithm exhibits improved convergence performance, and thus can be used to evaluate the residual carrying capacity as thrust-drop happens. For the situations that the launcher is not capable of injecting the transfer orbit, a sequential orbit/trajectory replanning method is designed to guarantee the safety of the astronauts. On the premise of ensuring the altitude of the parking orbit, the elements about the orbital plane are further optimized to provide a favorable initial state for the subsequent rescue action. Meanwhile, the nonlinearity of the terminal constraints is alleviated by the injection point forecast, and the initial reference is generated by convex optimization method with well convergence; thus, the solving efficiency of the sequential replanning algorithm can be improved. Simulation results show the proposed method can generate the trajectory that transport the spacecraft to the optimal parking orbit under the thrust-drop malfunction situation. This is an English translated version of “Residual Carrying Capacity Evaluation and Parking Orbit Re-planning for Lunar Exploration Launch Vehicle”.

China's lunar exploration efforts have been focused on developments in space that are sustainable. To this end, the country plans to construct a manned lunar scientific research station after successfully landing on the Moon, with the aim of ensuring long-term human survival on the lunar surface and developing and utilizing lunar resources. To achieve this goal, extensive research has been conducted on the development plans and current situation of manned lunar exploration. Based on the development law of human deep-space exploration, a goal of verifying human long-term, extraterrestrial survival technology and addressing challenges, while carrying out in-depth scientific research on the Moon and exploring its resources, is proposed. After analyzing the difficulties and development trends of the station's construction, possible incremental development plans and paths for the future are discussed. Considering the four major elements of strategy, science, engineering, and economics, and focusing on the safety requirements of manned spaceflight, a preliminary idea for selecting the station location is proposed. Finally, six key technologies and challenges are analyzed with the development plan. Overall, China's commitment to lunar exploration reflects its dedication to advancing scientific knowledge and technological capabilities, while also contributing to the long-term sustainability of human presence in space.

Aiming at the requirements of top-level mission planning for manned lunar exploration, an integrated mission planning and design method is proposed for China’s manned lunar exploration. By decomposing the whole flight profile, an integrated method based on the circumlunar perturbation is proposed. Then, the three key constraints of sunlight condition, lunar orbit and return landing sites are identified and analyzed. According to the analysis results and the different time scale constraints, the mission monthly window, daily window and hourly window are gradually selected to meet the engineering requirements. In the end, the method has been verified by the co-simulation of manned lunar exploration on the integration platform. It has been proved that the proposed method can solve the comprehensive window design problem for standard and delayed mission, and also provides an effective pathway for rapid planning in a large time scale. This is an English translated version of “Research on Integrated Mission Planning and Design Method for China’s Manned Lunar Exploration” originally published in Journal of Astronautics.

Manned lunar exploration missions require thousands of tons of launch vehicles to deliver astronauts and a small number of payloads to the lunar surface. To improve the system performance of manned lunar exploration missions, an analysis is conducted at the system level, including the design concepts, design methods, model optimization, and data correction. The proposed technologies include probability-based systems design, integrated design of spacecraft and launch vehicle, optimization design based on digital models, and system performance improvement based on measured data correction. Based on the practice of the systems design of manned lunar exploration missions, the application effects of these technologies are summarized, and the direction for future research is pointed out. These technologies play an important role in improving the system performance of manned lunar exploration and maximizing the efficiency.

The purpose of this study is to report the numerical investigation on the aerodynamic performance of tangent ogive wedge of varying fineness ratio from 2 to 4 when fully submerged in an incoming supersonic airflow having a velocity of Mach 2.5 and at zero degrees angle of attack. Numerical simulations have been carried out for flow over tangent ogive wedge using ANSYS CFD. A computation domain was created with appropriate geometrical constraints and was meshed into elements of optimum size. The supersonic airflow was simulated to observe and analyze the effects of change in fineness ratio of tangent ogive wedge on various aerodynamic parameters of interest under given boundary conditions and flow physics. It was observed that tangent ogive wedge with increasing fineness ratio experienced decreasing pressure drag force. The nature of shock generated for various tangent ogive wedge has been compared to understand airflow/shock interactions. The presented study revealed the dependency of different aerodynamic parameters on the fineness ratio of tangent ogive wedge, which may be efficiently utilized in missiles, rockets, and bullet design. The reported findings would contribute towards optimizing tangent ogive wedge shapes for supersonic missiles, rockets, and bullets, delivering optimum aerodynamic performance under given operating conditions.

To prolong the service life of satellites, space crawling robots are used for in-orbit services such as inspection and repair. However, the complex structure of the satellite surface requires path planning. Most current path planning algorithms are only applicable to the planar and 3D unconstrained case, and cannot be applied to CubeSat surface with abrupt changes in normal vectors. In this paper, we design a cube unfolding method to reduce the cube surface path planning problem to a planar path planning problem. This is accomplished by obtaining obstacle point cloud data through laser radar and converting the point cloud data into a grid map using the Gmapping algorithm. And considering the limitation of arithmetic power for operations on satellites, this paper uses PSO to solve this planar path planning problem. The experimental results show that the method can be applied to the surface of the CubeSat.

In view of ESA’s horizon goal of establishing a human presence on the Moon by 2040, the Earth’s moon is increasingly coming into the focus of research and industry. Lunar exploration can benefit from systems developed for low-Earth orbit, as the environmental conditions are overlapping. The development of the CubeSat industry in recent decades has led to a revolution in access to near-Earth space. The goal of Neurospace and its partners is to explore the similarities of both environments for a direct application of existing CubeSat technologies for lunar exploration. Using an open standard and a tiered approach for the development of lunar rovers will allow future missions to focus more on the actual use case rather than the individual development, qualification, and certification of required components. This paper introduces the HiveR rover and provides a classification of the future importance of robotic systems for lunar exploration. It also discusses, in review of past lunar missions, how such rovers differ from previous lunar rovers, and how important they can be in supporting increasingly complex missions. The similarities and differences between the low-Earth orbit and the lunar surface are outlined. Based on this, the new challenges in adapting existing CubeSat technologies for robotics on the lunar surface will be discussed and initial solutions presented. As examples of potential payloads, various experiments are presented, such as a robot arm that was developed to fit in a 1 U volume. It can be used for docking operations between individual systems or various tool handling operations.

Cyclically asymmetrically distributed charges introduced to explain a cause of gravity produce significant directed forces for useful safe energy generation, as harnessed by the Electric Kinetic Pulse generator, an experiment to illustrate cyclically asymmetrically distributed charges. This is established by analysing solutions to the equations of motion and energy of 4 charges in the Electric Kinetic Pulse generator, as they alternately move close to and from electric field singularities using repulsion in each of the 4 cylinders; with extensions to several charges. The system is shown to be robust against transverse vibrations. The theoretical validity of the generator and the principles underlying cyclically asymmetrical charge distributions is established. The theoretical verification proposes an iterative process for solving first order differential equations which requires continuity but no separation of variables. Ample useful nuclear energy independent of heat phenomena or the atmosphere can be generated with no harmful radiation or radioactive waste.