National Aeronautics and Space Administration Goddard Space Flight Center On-Orbit Satellite Servicing Study Project Report October 2010 National Aeronautics and Space Administration Goddard Space Flight Center On-Orbit Satellite Servicing Study Project Report October 2010 “Energy and persistence conquer all things.” Benjamin Franklin Contents Figures and Tables iv Executive Summary 1 Chapter 1: Introduction 5 Study Mandate 6 What Will This Study Contribute? 7 Study Methodology 8 Assumptions 9 Why Is Satellite Servicing Important? 11 What Has Been Done Before? 14 The Dawn of Satellite Servicing Skylab Solar Maximum Mission Repair Palapa B2 and Westar 6 Satellite Servicing Gets Its Challenge Hubble Space Telescope International Space Station, The “Killer App” Technology Demonstrators NASDA: Engineering Test Satellite VII U.S. Air Force: Experimental Spacecraft System Demonstration of Autonomous Rendezvous Technology DARPA: Orbital Express New International Initiatives Historical Activities The Evolution of Tools and Techniques Myths about Servicing 27 “There Is Nothing To Service” “Servicing is Costly” “Satellites Cannot Be Serviced Unless They Were Designed To Be Serviced” What Are Appropriate Human and Robotic Servicing Paradigms? 32 Chapter 2: Satellite Servicing: The Vision 35 Refurbishment/Refueling of Satellites in Near-Earth Environments 36 Construction of Large Structures 37 Orbital Detritus Management 38 Contents | i Chapter 3: Satellite Servicing: The Benefits 40 Commercial Benefits 41 Scientific and Technological Benefits 43 Strategic Benefits 45 Outreach Benefits 46 Chapter 4: Satellite Servicing: The Implementation 48 The Map of Servicing Capabilities 49 The Notional Missions 52 Notional Mission Characteristics Mission Design Methodology and Cost Estimation Autonomous Rendezvous and Capture Technology Robotic Technology Astrodynamics The L1 Orbit Trajectory Used for Servicing (LOTUS) Mission Sequence 64 Technology Gap Assessment 67 Servicer Spacecraft Bus Rendezvous and Berthing/Capture/Docking Manipulation Refueling Autonomy Satellite Servicing Integration into Mission Design ISS Demonstration Activities 72 The Recommended Actions 75 Optimize Engineering Design and Trade Studies Invest in Key Enabling Technologies Assess a Range of Customers for Satellite Servicing Create Design Recommendations for Future Spacecraft Establish Customer/Provider Working Groups Integrate the Satellite Servicing Infrastructure with NASA Program Architectures and Priorities Execute the Mission Sequence ii | On-Orbit Satellite Servicing Study Project Report | October 2010 Chapter 5: Satellite Servicing: The Challenges 78 Technological Challenges 79 Economic Challenges 80 Making Future Missions More Serviceable 82 Getting Close Enough Mode of Servicing Serviceability Design Commonality Chapter 6: Conclusion 86 References 89 Related Historical Materials 92 Acronyms 93 Appendixes 96 Appendix A – Congressional Legislation and Reports Bearing 97 on Science with the New Space Transportation Architecture Appendix B – RFI Responses Summary 99 Appendix C – International Workshop on On-Orbit Satellite Servicing 104 Appendix D – Functional Decomposition of the Activities Required 119 for Satellite Servicing Appendix E – Results of the Integrated Design Center (IDC) Instrument 141 Design Laboratory (IDL) Study on Autonomous Rendezvous and (Berthing, Capture, Docking) Sensor Package, and Robots 1 through 3 Appendix F – Notional Mission Studies 153 Contents | iii Figures and Tables Figures 1.1 The Pillars of On-Orbit Servicing vi 1.2 The Gemini Rendezvous and Docking Experiments 5 1.3 Classes of Satellites for Servicing 12 1.4 The Repaired Skylab 14 1.5 Solar Maximum Mission in the Space Shuttle Bay 15 1.6 Palapa B2 Recovery 16 1.7 HST First Servicing Mission: COSTAR Installation 17 1.8 HST Servicing Sophistication Progression 19 1.9 ISS SSRMS Installing Cupola 20 1.10 ISS Solar Array Repair 21 1.11 Robonaut 2 22 1.12 EVA Power Tool Progression 25 1.13 Unique, Purpose-Built, On-Orbit Repair Tools 26 1.14 Astronaut Training Refines the Tools and Improves On-Orbit 26 Performance of the Human-Machine Interface 1.15 AERCam Sprint 33 1.16 Robotic Assistants 33 2.1 Refueling Depot in Use 35 2.2 Refueling Depot Assembly 37 2.3 Orbital Modification 38 3.1 HST SM4 Release 40 3.2 Refueling an Orbiting Communications Satellite 42 3.3 On-Orbit Assembly 44 3.4 Removal of Undesirable Spacecraft 45 3.5 HubbleSite Visits during HST SM4 47 4.1 The Flight Hardware for the Notional Missions 48 iv | On-Orbit Satellite Servicing Study Project Report | October 2010 4.2 Seminal Mission Coverage of the Servicing Study Trade Space 50 4.3 Servicing Study Trade Space Regions Covered by Historical Missions 51 4.4 Notional Mission Suite Coverage of the Servicing Study Trade Space 51 4.5 Front-end Robotics Enabling Near-term Demonstration (FREND) System 57 4.6 Ranger Telerobotic Shuttle Experiment 58 4.7 Safety Ellipse 60 4.8 The LOTUS 61 4.9 The Recommended Mission Sequence 64 4.10 Tools for Closing the Technology Gap 67 4.11 Robotic Refueling Mission (RRM) 72 4.12 Dextre Pointing Package (DPP) 73 4.13 Astronaut in Action 75 5.1 Earthrise from the Moon 78 6.1 Returning from Mars 86 Tables 1.1 Table of Recommended Actions 4 4.1 Notional Mission Summary Table 53 4.2 Servicer Costs for Each Notional Mission 55 4.3 Table of Recommended Actions 76 Figures and Tables | v Executive Summary In the past two decades, some of the most extraordinary successes in space exploration have emphasized the growing importance of on-orbit servicing. As space explorers, our challenges have moved beyond simply launching complex spacecraft and systems. We are faced with the need to more fully exploit the flight systems already launched, to construct large structures in situ to enable new scientific ventures, and to provide systems that reliably and cost-effectively support the next steps in space exploration. A more refined consciousness of the need to reduce, reuse, and recycle here on Earth drives towards a similar awareness of these needs beyond our planet. The proliferation of abandoned satellites poses known hazards to newer members of the constellation, and may occupy unique and economically valuable orbital real estate that could be recycled for other uses. With the successful completion of a series of Hubble Space Telescope repairs, as well as the assembly of the International Space Station, we can look forward with confidence to plan such a future. Satellite servicing is a tool—a tool that can serve as the “master enabler” to create the architectures needed to conquer the next frontiers in space. Figure 1.1 – The Pillars of On-Orbit Servicing – This graphic highlights the three pillars of satellite servicing to date: the space shuttle (lower left), the Hubble Space Telescope (right), and the International Space Station (upper left). The NASA On-Orbit Satellite Servicing Study, (HEFT) that is charged with developing the new mandated by Congress and supported by the space exploration plans. The comprehensive HEFT NASA Advisory Council (NAC), investigates what study is in keeping with the will of the Congress our future may hold. This document, an internal and the Administration as expressed in the recently report by the Space Servicing Capabilities Project signed multiyear 2010 NASA Authorization Bill. at the NASA Goddard Space Flight Center that It will include a study of the development of an performed the study, captures the work performed in-space servicing capability and identify those areas under this Congressional mandate. Its conclusion where human participation in servicing is required or is unequivocal. Viable plans can be put into place beneficial. to develop a meaningful on-orbit satellite servicing Our introduction dissects some common myths capability, allowing us to achieve our key ambitions in about satellite servicing. The main points fall into space using today’s technology and with current and two general categories: “There is nothing to service” projected launch systems. These plans would advance and “It is too costly to service.” Superficially, these our presence in space by enabling more effective use statements appear plausible. However, by studying of assets at near-Earth locations and by supporting the end-to-end life cycle costs of a wide variety of future ventures to more distant destinations. This missions, it becomes apparent that these myths are report discusses such an initiative. incorrect except for limited or unlikely situations. This study incorporates the results from the There are constellations of satellites that would following major activities: 1) conduct an industry- benefit from refueling and/or orbit modifications. wide Request For Information (RFI) to notify the These were not designed to be serviceable, although satellite servicing community of an opportunity for current technology could enable such servicing. discussion, 2) conduct the International Workshop Moreover, the business cases are sound for those on On-Orbit Satellite Servicing in March 2010 to applications that have a commercial component, thus engage the community, 3) examine notional missions refuting the statement that servicing is too costly. to bracket the trades involved for possible servicing Even for those applications that do not have a customers, 4) examine near-term in-space hardware commercial business case, the systems engineering demonstrations to provide relevant and immediate rigor of designing a serviceable system improves the results, and 5) develop and validate