Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precio...Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.展开更多
The paired approach is a kind of efficiency approach to closely spaced parallel runways(CSPRs),and the point merge system has the powerful interval management function,which is effective to realize the converge of tra...The paired approach is a kind of efficiency approach to closely spaced parallel runways(CSPRs),and the point merge system has the powerful interval management function,which is effective to realize the converge of traffic flows from different approach directions.In order to improve the operation efficiency of the airport terminal area,a model of paired approach sequencing based on point merge is proposed to investigate the problem of increasing the operation capacity of the closely spaced parallel runways.Taking the minimum average flight delay time as the objective,the flight distance on sequencing legs,wake turbulence separation and paired approach safety separation as constraints,the genetic algorithm is used to optimize the paired approach sequencing of arrival flights.Taking the closely parallel runways of Shanghai Hongqiao International Airport run south as an example,the point merge program is designed and the effect of model was analyzed.The results show that after optimization,the average delay time and average landing time are reduced by 40.6%and 51.8%respectively,the capacity of the closely spaced parallel runways are 1.1 times higher than the actual,the flight uptime rate can reach 100%.It is concluded that the proposed model is feasible,which can effectively reduce delay times and alleviate congestion in terminal areas.展开更多
基金supported by the Space Debris and Near-Earth Asteroid Defense Research Project(KJSP2023020303)Youliang Wang is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022146).
文摘Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.
基金supported by the National Key Research and Development Program(No.211221210054)the Fundamental Research Funds for the Central Universities of Chang’an University(No.300102210117)。
文摘The paired approach is a kind of efficiency approach to closely spaced parallel runways(CSPRs),and the point merge system has the powerful interval management function,which is effective to realize the converge of traffic flows from different approach directions.In order to improve the operation efficiency of the airport terminal area,a model of paired approach sequencing based on point merge is proposed to investigate the problem of increasing the operation capacity of the closely spaced parallel runways.Taking the minimum average flight delay time as the objective,the flight distance on sequencing legs,wake turbulence separation and paired approach safety separation as constraints,the genetic algorithm is used to optimize the paired approach sequencing of arrival flights.Taking the closely parallel runways of Shanghai Hongqiao International Airport run south as an example,the point merge program is designed and the effect of model was analyzed.The results show that after optimization,the average delay time and average landing time are reduced by 40.6%and 51.8%respectively,the capacity of the closely spaced parallel runways are 1.1 times higher than the actual,the flight uptime rate can reach 100%.It is concluded that the proposed model is feasible,which can effectively reduce delay times and alleviate congestion in terminal areas.
