Design and Evaluation of an Orbital Debris Remediation System

Transcription

1 Design and Evaluation of an Orbital Debris Remediation System Collision Risk Remediation Designs Design Evaluation 1. Object Categorization 2. Network Analysis 3. Utility Analysis Debris Remediation Systems Strategy Recommendations 1

2 Agenda Context Analysis Current Environment Space Debris Risk Remediation Efforts Stakeholder Analysis Problem Statement Concept of Operations Method of Analysis Project Plan 2

3 Background A satellite is an artificial object placed in orbit around the earth Types of orbit: LEO: km, 7.6 km/s MEO: ,780 km, 3.8 km/s GEO: 35,780 km, 3 km/s Source: ESA,

4 Uses and Revenue Operational Satellites by Function and Global Satellite Industry Revenues Source: SIA SSIR,

5 Development and Launch Costs Development costs: from $7,500 (Cubesat) to $2.2 billion (Envisat) Launch costs: Satellite masses range from 1 kg to 18,000 kg (UCS) ~$4,500/kg (NASA Marshall Center) 5

6 Space Debris Risk kg satellite impacted by a 39.2 g projectile at 1.72 km/s 1500 fragments produced Source: NASA, JSC, 2007 E imp = impact energy E imp = M 2 p V imp 39.2 g (1.72 km/s)2 = 2 2 = Joules 6

7 Space Debris Risk Kessler Syndrome: a domino effect that could render space systems unusable due to dangerous flight conditions 7

8 Space Debris Risk State-sponsored active anti-satellite measures Chinese ASAT missile, 2007 Random collisions, explosions, and malfunctions Iridium 33 and Cosmos 2251, 2009 Debris Cloud 3 Hours Post Collision Debris Cloud 27 Months Post Collision Source: T.S. Kelso,

9 History of Remediation Effort 1960 s-80 s 1980 s-2000 s 2010 s-today Future First identified as a problem in the 1960 s United Nations Office of Outer Space Affairs (UNOOSA) published 7 guidelines in 2007 to enforce total lifecycle planning Remediation still needs to take place 9

10 Dynamic System Model O = aco 2 + bl A + cl B dp MD en D fd RS C = gco 2 hg A ig B L A = jl A G A ko G A = ll A G A mc L B = nl B G B oo G B = pl B G B qc 10

11 Active Debris Removal ADR Concept of Operations: 1. Identify the target object 2. Maneuver and rendezvous with target 3. Grapple with target and de-tumble if necessary 4. Remove the object(s) from orbit There are many different implementations of the same idea 11

12 Active Debris Removal ADR Alternatives Concept TRL Cost Robotic arm (with de-orbit kit) Throw Net COBRA IRIDES Three Coordinated Electromagnetic Spacecraft Physically grab the debris object using a robotic arm and perform a maneuver to change the object s orbit. Throw a net towards a debris object and pulls the object along a tether. The net entangles the objects due to masses or a closing mechanism. Use plume impingement from a hydrazine monopropellant propulsion system to impart momentum on a target debris either to change its orbit or its attitude. With the application of inter-spacecraft electromagnetic force, disabled satellite with functional magnetorquer can be removed in a non-contacting manner without propellant expenditure and complicated docking or capture mechanisms. 6-7 High 6-7 Low 5-6 Medium 2-4 High Harpoon Eddy Currents Shoot a tethered harpoon into the object. After the harpoon penetrates the object, the bars at the point are opened to keep itself sticking in the object. Then perform a maneuver to change the object s orbit. It is based on the computation of the Magnetic Tensor which depends on how the conductive mass is distributed throughout the debris object, using the open cylindrical shell and flat plates. No mechanical contact with the target is required since an active de-tumbling phrase is based on eddy currents. The study targets an Ariane H10 upper stage (R/B). 6-7 Medium 3-4 High 12

13 Agenda Context Analysis Stakeholder Analysis Objectives Relationships Tensions Problem Statement Concept of Operations Method of Analysis Project Plan 13

14 ADR Implementation Triggers Phase I : Pre-launch Phase II : Launch Phase III : In-orbit life Increases in debris population Research, collect data and present proposals Approve space policy and provide fundings Determine launch type Monitor progress Decreases in space safety Approve space policy politically Design and build spacecraft Determine launch site Cover launching risk Surveil space, and detect movement Dispose at end-of-life Increases in satellite demand Provide launch services Evaluate spacecraft Insure spacecraft National government Commercial industry Civil organizations 14

15 Stakeholder Relationships National Governments Civil Organizations Russian China Political issue United States Europe Financial issue Approve space policy, and provide funding Research, collect data and provide overall guidance NASA RFSA IADC ESA CNSA Build, design and support rockets, spacecrafts and satellites. Also, provides spacecraft launch services. Contracts System Manufacturers Lockheed Martin Boeing Airbus Commercial industry Transport Companies SpaceX ULA Orbital Sciences Insurance Companies XL CATLIN STARR Contracts Tensions Build, design and support rockets, spacecrafts and satellites. Also, provides spacecraft launch services. Objectives 15

16 Agenda Context Analysis Stakeholder Analysis Problem Statement Gap Analysis Problem Statement Need Statement Concept of Operations Method of Analysis Project Plan 16

17 Gap Analysis We don t know how successful individual ADR design alternatives may be or how best to compare them to each other. 17

18 Problem Statement There is currently no consensus on the best strategy for orbital debris remediation. 18

19 Need Statement There is a need for a rigorous, comprehensive analysis of design alternatives. 19

20 Agenda Context Analysis Stakeholder Analysis Problem Statement Concept of Operations Mission Requirements Functional Requirements Simulation Requirements Method of Analysis Project Plan 20

21 Mission Requirements MR.1 The DRS shall de-orbit at least 5 highrisk debris objects per year. MR.2 The DRS shall select high-risk objects as a function of mass and collision probability. MR.3 The DRS shall focus remediation efforts in LEO (below 2000 km). 21

22 Mission Requirements MR.4 The DRS shall not be intentionally destroyed while in orbit. MR.5 The DRS shall release no more objects or vehicles than it recovers. MR.6 The DRS shall allow end-of-life passivation within 2 months. 22

23 Functional Requirements FR.1 The DRS shall be able to identify debris objects larger than 10 cm in diameter. FR.2 The DRS shall be able to maneuver throughout LEO (up to 2000 km). FR.3 The DRS shall be able to engage with debris up to 8900 kg (dry mass of SL-16). FR.4 The DRS shall be able to remove debris objects from orbit. 23

24 Simulation Requirements SR.1 The simulation shall output optimal network paths for given parameters. SR.2 The simulation shall modify the optimal network for different designs. SR.3 The simulation shall account for multiple possible launch sites. SR.4 The simulation shall account for combinations of ADR designs. SR.5 The simulation shall target objects with the highest scores. 24

25 Context Analysis Stakeholder Analysis Problem Statement Concept of Operations Method of Analysis Object Categorization Network Analysis Utility Analysis Design of Experiment Project Plan Agenda 25

26 Project Objective Determine recommendations for best strategies for the remediation of orbital debris in terms of cost, risk, effectiveness, and schedule. 26

27 Method of Analysis 27

28 Method of Analysis 1. Object categorization: effectiveness distributions of ADR designs for types of debris 2. Network analysis: shortest-path network analysis for access and maneuvering to debris 3. Utility analysis: quality (political viability, path length, etc.) vs total life-cycle costs 28

29 1. Object Categorization 29

30 1. Object Categorization Object Types: Operational satellites Defunct satellites Rocket bodies Fragments Metrics: Mass Velocity Rotation Linear Decreasing: V(X) = 1 Max X Max Min Exponential Decreasing: V(X) = e λx 30

31 1. Object Categorization 31

32 1. Object Categorization Operational Satellites Mass Velocity Rotation ADR Design Min Max Mean (1/λ) Mean (1/λ) Net Harpoon PacMan Robotic Arm Coordinated EM COBRA IRIDES Object ID Mass Velocity Rotation Net Score Harpoon Score

33 2. Network Analysis 33

34 2. Network Analysis Objective Function: Max Score = n m i ( j ObjectScore j LaunchCost i VCost i ) Variables: x ij t = arc from node i to j at time t Constraints: n i n i n i ObjectsReached i 5 high risk objects ObjectsReached i Max Payload of Design ObjectScore i 0.7 maxobjectscore 34

35 2. Network Analysis 35

36 X t = 2. Network Analysis 0 x 12 (t) x x 21 (t) 0 1n (t) x m1 (t) 0 x ij t = V cost between objects i and j These matrices vary over time depending on where the objects are in space 36

37 3. Utility Analysis 37

38 3. Utility Analysis 38

39 3. Utility Analysis Object Score Path Length Risk TRL Political Viability U(t) LCC Weights Alt Alt Alt

40 Design of Experiment Network Constraints Utility Function Weights Min Object Min Object Path Experiment Safety Reliability TRL Agreeability Verifiability Score Reached Score Length E1 0.7 of max E of max E3 0.6 of max E of max

41 Agenda Context Analysis Stakeholder Analysis Problem Statement Concept of Operations Method of Analysis Project Plan WBS Budget Earned Value Management Critical Path Project Risks 41

42 WBS 42

43 Budget We estimate 1275 hours of work on this project from beginning to end. At $30 per hour, this gives us a working budget of $38,250. Using an overhead and profit multiplier of 2.0, we come to an overall project budget for $76,

44 CPI/SPI 44

45 EV 45

46 Critical Path 46

47 Project Risks Quantitative requirements elicitation Risk Description Mitigation Strategy Stakeholders are not Develop requirements forthcoming with independently and later ask requirements for verification Political feasibility metrics and calculations Acquiring datasets Modeling (coding) Verification of accuracy Determining a solid, quantifiable metric for political feasibility is not simple Datasets can be unreliable, using differing definitions, or sometimes wholly contradictory Modeling complex orbital networks may prove technically difficult The time scale for our project is too long for any immediate verification of results Make contact with political insurance underwriters to gain further knowledge Prepare for a large amount of data cleaning before use Further research into feasibility, previous similar work, and discussion with experienced SEOR faculty Be honest with this weakness in our presentation of data, and include generous error bounds where appropriate 47

48 Future Work Data collection on ADR designs for effectiveness distributions Collect latest information on orbital population Object Categorization metrics Object trajectories Data collection on X(t) matrices (time-sensitive arc lengths) Explore expansion of parameters for DoE Implement model designs in code 48

49 BACKUP SLIDES 49

50 Debris Risk Risk = Probability x Severity Space Debris Risk = Collision Probability x Mass Mass has an effect on damage caused and creation of debris Large number of small objects vs small number of large objects Source: D. Bensoussan, WSRF,

51 Current and Proposed Systems 51

52 Stakeholders National Governments Commercial Industry Civil Organization USA Transport companies NASA Russia System manufacturers RFSA Europe Insurance companies ESA China CNSA IADC 52

53 Stakeholders objectives Process Objective Stakeholder 1 Research, collect data, and overall guidance Civil organizations Pre-launch 2 Approve space policy, and provide fundings National governments 3 Agreement, verification National governments 4 Design and build spacecraft Commercial industry 53

54 Stakeholders objectives Process Objective Stakeholder Prelaunch 5 Assessment of spacecraft design, and covering launch risk Commercial industry Launch In-orbit life 6 Determine launch type Civil organizations 7 provide launch services Commercial industry 8 Monitor progress Civil organizations 9 Space surveillance, and detection of movement of objects in space Commercial industry 54

55 Stakeholders Tensions Type Stakeholders Tension Political Political Political/Technical Russia, U.S, EU Russia, China international concern Russia has most debris, and doesn t want anybody to remove it Some methods have dual use, some countries would suspect Inaccuracy of falling objects in some methods Commercial Insurance, commercial industry costs of risk management and commercial companies Commercial Insurance Competitiveness 55

56 Stakeholders Tensions Type Stakeholders Tension Financial Civil organizations Nature and probability of collisions Space agencies and governments IADC All Fundings Regulations about re-entry controlled plan Space agencies concerned, while others want to make profit in present time 56

57 Stakeholder Tensions Type Stakeholders Problem Political Russia, U.S, EU Russia s debris Political Political/Technical Commercial Russia, China International concern Insurance, commercial industry Some methods have dual use, some countries would suspect Inaccuracy of falling objects in some methods Costs of risk management by insurance companies, while commercial companies manage to reduce costs 57

58 Gap Analysis Without remediation, the number of objects and collisions will continue to climb, even without additional launches. Source: J. C. Liou, 2011 Source: AAS,

59 Gap Analysis Source: J. C. Liou, % Post Mission Disposal (PMD) does not halt growth of population 90% PMD along with 2 high-risk objects removed per year slows but does not halt growth 90% PMD coupled with 5 high-risk objects removed per year leads to a stable environment 59

60 Factors ADR Techniques Robotic Arm Robotic Arm with Deorbit Kit Throw Net COBRA IRIDES Three Coordinated Electromagnetic Spacecraft Size/Maneuverability Deployed length: 3.7m 80 kg 314 kg Total area of 3,600 m 2 connected to a tether with a length of 70 m Number of Debris Payload Single Single Single Single Single Mass of Debris Payload Up to 6,000 kg Up to 7,000 kg Up to 10,000 kg Risk cannot offer a safe removal of debris target via controlled entry the limited time available between final burn and entry for activities like debris release, arm retrieval and closing of aft hatch complex and heavy ADR payload design failure of shooting a net Power Generation An estimated peak power demand of 360W Star-20 engine from Alliant Techsystem Inc. (ATK) and total impulse of 722 kns 60

61 Constraints Object locations X(t) matrices Network Analysis Effectiveness Distributions Object Scores Utility Analysis 61

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