2016美赛b题优秀论文.pdf

For office use only T1________________ T2________________ T3________________ T4________________ Team Control Number 52214 Problem Chosen B For office use only F1________________ F2________________ F3________________ F4________________ 2016a MCM/ICM Summary Sheet (Your team's summary should be included as the first page of your electronic submission.) Type a summary of your results on this page. Do not include the name of your school, advisor, or team members on this page. summarysummary Space junk has reached into a unbelievable number these days, as a result of high speed development in aviation industry. Thus, the space debris bring mankind serious obstacles in space exploration. Therefore, clearing the space debris has become a top-task to be dealt with. To begin with, we have studied the time-space distribution pattern of debris, we have predicted the variation of fragments with time. After knowing the distribution feature of fragment’s density in altitude and latitude, we have learned roughly that space junk’s distribution mainly ranges from 800km to 1200km of orbit altitude, on which we are able to calculate flux to illustrate the collision of space fragments. Next step, we analysed the successful launching rate, and by combining two aspects, as a sort of risk parameter, we can assess the risk of different projects. We adopt three normal methods for clearing space debris before making a cost analysis and a profit assessment respectively. .After assessing profit in each method, we draw a conclusion that Large satellites is the most profitable one. These two assessment can be later used as an essential indicator for all projects. Following step is that we use analytic hierarchy approach to assess three projects’ profit, safety, efficiency, applicability, by which we learn what weight coefficient can be when consider four indicators comprehensively and the advantages and disadvantages of each project’s indicator. Using these weight coefficient as a indicator for fuzzy comprehensive evaluation of weight coefficient, we reach three projects’ assessment with weight average principle. The results follows, Space-based water jets is fair, High energy lasers is better and Large satellites between two. Since fragments will change with time, we last step apply Markov model to revise.Then comes our conclusion, that is clearing space junk is worthwhile for private company. contentcontent 1.Introduction1 1.11.1OverviewOverview1 1.2 Assumptions2 1.3 Nomenclature2 2 Model Theory3 2.1 Evolutionary modeling Thought.3 2.1.1The basic sub-models modeling thought3 2.1.2 Debris at a future time in the evolution4 2.2 Space debris density distribution model5 2.2.1 The basic concept of the track5 2.2.2 Spatial density distribution5 2.3 Risk Assessment Model8 2.3.1 Mathematical model of the collision probability8 2.3.2 Launch success rate analysis10 3. Based on the economic evaluation model.11 3.13.1costcost analysisanalysis11 3.2 Benefit Analysis16 3.3 Analytic Hierarchy Model Select weight17 3.4 Fuzzy Comprehensive Evaluation Model20 3.5 Fixed time-based Markov model22 4 Final Remarks23 4.1 Strengths and Weaknesses23 4.2 Future Model Development23 4.3 Conclusions24 The Executive Summary25 Economic-optimizedEconomic-optimized modelmodel forfor spacespace junkjunk 1.Introduction1.Introduction 1.11.1OverviewOverview Space junk is brought by human beings in aerospace activity, which generally refers to the fragments made from any disabled payload, rock body that distribute in spacecraft orbit, and from explosion and collision. Normally, they appear in different size and mass, show various distribution patterns in different altitude. Thereby, the running velocity can be different too. Figure 1Status of space debris Space junk has reached into a unbelievable number these days, as a result of high speed development in aviation industry. Besides, it will have collision with spacecraft in a remarkable speed, bringing safety problem to spacecraft itself. For example, The issue itself became more widely discussed in the news media when the Russian satellite Kosmos-2251 and the USA satellite Iridium-33 collided on 10 February, 2009.Clearing the space junk, therefore, has become a top- task to be dealt with, but at the same time, is also worthwhile for private company. Being a private high-tech company, working out clearing space debris project should make sure the technique could be fully carried out, consider which theoretical project would be adopted and improved. Given understanding how to eliminate the fragments, such as space-based Water jets and high energy lasers and large satellites designed to sweep up the debris, among others, the difference of application scope, operation efficiency and cost, high-tech company is able to combine several projects according to its own demand. In addition, it is also obligated to asses if there is a appealing attraction in terms of economic profit through including cost and profit in economic 。