© HER MAJESTY THE QUEEN IN RIGHT OF CANADA 2014

CANADIAN SPACE AGENCY SPACE EXPLORATION DEVELOPMENT

CANADIAN ON-ORBIT AUTOMATED ROBOTIC SERVICING EXPERIMENT (COARSE) STUDY EXECUTIVE REPORT CSA-EXCO-RPT-0006 INITIAL RELEASE APRIL 28, 2014

LIVELINK NUMBER : 20267112

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2 REVISION HISTORY

Revision Description Issue Date Initials

0 Draft 25-April-2014 YG

1 Initial Release 28-April-2014 YG

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3 TABLE OF CONTENTS 1 PREFACE ............................................................................................................................ III

2 REVISION HISTORY ....................................................................................................... IV

3 TABLE OF CONTENTS .................................................................................................... V

4 LIST OF TABLES .............................................................................................................. VI

5 LIST OF FIGURES .......................................................................................................... VII

1 INTRODUCTION................................................................................................................. 1

2 COARSE MISSION CONCEPT OVERVIEW ................................................................. 2

3 COARSE TOOL CONCEPT OVERVIEW ....................................................................... 3

3.1 PHYSICAL ARCHITECTURE ............................................................................................... 3

3.2 MECHANICAL LAYOUT .................................................................................................... 5

3.2.1 LAR Gripper Tool Tip Overview................................................................................. 9

3.2.2 Actuator Control Software ........................................................................................ 11

4 SCIENCE/TECHNOLOGY .............................................................................................. 12

5 ROADMAP, COST AND IMPLEMENTATION ............................................................ 14

6 BUSINESS POTENTIAL ................................................................................................... 15

7 ACRONYMS ....................................................................................................................... 17

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4 LIST OF TABLES

Table 1: Key Mission Requirements ............................................................................................... 3

Table 2: LAR Capture Sequence .................................................................................................. 10

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5 LIST OF FIGURES Figure 1: Proposed Canadian on-orbit servicing experiment leveraging existing assets on the

International Space Station including Canada’s Dextre and NASA Goddard Space Flight Center’s Robotic Refueling Mission (RRM) payload (Photo inset of RRM courtesy NASA)

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Figure 2: Physical Architecture ...................................................................................................... 4

Figure 3: COARSE Payload Assembly (with Vision-Only Capability) ......................................... 6

Figure 4: COARSE Payload Assembly (with Vision-Only Capability) ......................................... 7

Figure 5: COARSE Payload Assembly (with Capture Capability) ................................................ 8

Figure 6: COARSE Payload Assembly held by SPDM OTCM ..................................................... 9

Figure 7: LAR Gripper Tool Tip .................................................................................................... 9

Figure 8: Concept for LAR Gripper Tool Tip installed in COARSE Payload Assembly ............ 11

Figure 9: Tool Operations Flow .................................................................................................... 12

Figure 10: Roadmap with COARSE enabling future missions requiring autonomous track and capture capability of uncooperative and unprepared targets ................................................. 14

Figure 11: COARSE Mission Technology Advancement ............................................................ 15

Project name

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1 INTRODUCTION This executive report summarizes the work performed in the exploration study for the Phase 0 “Canadian On-Orbit Automated Servicing Experiment” concept study. This study was funded by the Canadian Space Agency (CSA) under the contract 9F052-101461/004/MTB to MacDonald, Dettwiler and Associates Ltd (MDA). The work was performed from October 5th,2011 to April 1st, 2012.

The primary objective of the study was to develop an experimental payload concept for the International Space Station (ISS) to advance Canada’s world-leading position in space robotics and servicing technologies for the next generation of spacecraft servicing opportunities: current unprepared and future lightly-prepared spacecraft.

A prepared spacecraft is one that has been designed with servicing features in mind, such as a grapple fixture that can be captured by a manipulator, while an unprepared space vehicle makes no such accommodations. The large majority of space vehicles in orbit today, and even the large majority of space vehicles that are still on the drawing board or in various stages of preparation for launch, can be classified as unprepared. There are many different agencies and companies developing spaceflight hardware, however, at present, there are few agreed upon robotic servicing standards, and it is expected that this will take years to resolve. A servicing standard imposing only a small set of interface requirements on hardware providers, however, is more likely to be readily adopted. The abundance of unprepared space vehicles and the greater likelihood of achieving acceptance for servicing standards that minimize impacts to spaceflight hardware providers points to an inescapable conclusion: advanced manipulator and servicing technologies that enable the servicing of unprepared (or lightly prepared) space vehicles are critically important for the execution of future servicing missions.

A critical operation for a servicing mission involves either a docking (i.e., direct mating of a servicing vehicle to a client vehicle to be serviced) or a capture and berth operation (i.e., robotic arm capture, handling and berthing of a client vehicle to be serviced to a servicing vehicle). This operation was recently recommended as a high priority technical challenge in the area of robotics in the “NASA Space Technology Roadmaps and Priorities” report released in February 2012 by the Steering Committee for NASA Technology Roadmaps; National Research Council (NRC) of the National Academies. The proposed COARSE mission will demonstrate this critical technology through the autonomous track and capture of a launch adapter ring – the mechanical interface most often used to secure the satellite to its launch vehicle during delivery to orbit.

The experimental payload for COARSE, illustrated below in Figure 1, develops and integrates new hardware and software components essential for unprepared spacecraft capture with existing Mobile Servicing System (MSS) and ISS elements, namely Canada’s Dextre and NASA Goddard Space Flight Center’s Robotic Refueling Mission (RRM) payload, to demonstrate unprepared satellite capture technology aboard ISS. Specifically, a new Dextre-compatible tool equipped with an integrated optical vision system and an interface for interchangeable tool tips, will be launched to the ISS. The new Tool will enable Dextre to demonstrate the autonomous robotic tracking capability required for the capture of unprepared and uncooperative satellites, and should the CSA desire in the future, other selected servicing tasks on unprepared interfaces, simply by equipping the Tool with a suite of new task-specific tool tips.

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FIGURE 1: PROPOSED CANADIAN ON-ORBIT SERVICING EXPERIMENT LEVERAGING EXISTING ASSETS ON THE INTERNATIONAL SPACE STATION INCLUDING CANADA’S

DEXTRE AND NASA GODDARD SPACE FLIGHT CENTER’S ROBOTIC REFUELING MISSION (RRM) PAYLOAD (PHOTO INSET OF RRM COURTESY NASA)

2 COARSE MISSION CONCEPT OVERVIEW To achieve the project objectives, the approach followed during the study mirrored that of system design, from mission requirements, through operations concept, functional decomposition, to sub-system requirements.

The mission requirements were derived by first reviewing the previous accomplishements achieved in flight missions involving the autonomous track and capture of prepared free-flying objects, as well as achievements in targetless vision systems successfully demonstrated on the ground. These benchmarks were applied as the minimum performance goals of the COARSE payload so as to advance the state of flight proven visual servo capability. To select a capture feature to target, international launch adapter manufacturing statistics were reviewed to identify the most common design used historically on satellites. The resultant key driving requirements and the main CSA imposed mission constraints are summarized below in Table 1.

COARSE Payload

RRM Launch Adapter Ring Task board

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TABLE 1: KEY MISSION REQUIREMENTS

Mission Functional Requirements Performance The COARSE mission shall demonstrate the capability to

autonomously track the pose of a launch adapter ring travelling at a relative velocity of <= 2 cm/sec and 0.2 deg/sec Rationale: This will advance the state of flight proven visual servo capability by demonstrating the same tracking rates that were achieved in the Orbital Express Mission but on an unprepared grasp feature.

Capture The COARSE mission will demonstrate the capability to capture a PAS-1194 Launch Adapter Ring section. Rationale: The Launch Adapter Ring, and in particular the PAS-1194, is one of the most commonly used payload-to-launch vehicle interfaces used today on satellites.

Mission Constraints

Technology Readiness The technology proposed for use in the ISS demonstration shall be achievable and support on-orbit demonstration timeframe of no later than 2017

ISS Capabilities The technology demonstration shall take into account the capabilities of the ISS, operating volume, power, and equipment or any other limitations or regulations of the ISS.

Cost The total cost of the COARSE mission shall not exceed a ROM of $10M Canadian including development, qualification, implementation, launch, operations, and disposal

The ability of the proposed COARSE payload to meet its key functional requirements was demonstrated through proof of concept rapid prototyping of the required Dextre-based vision system to determine the pose and orientation of a flight representative version of the RRM task board’s launch adapter ring. With the proof of concept ground demonstration successful, the feasibility of the COARSE mission will be ensured by leveraging the flight proven visual servo arm control algorithms from the Orbital Express mission and extensive vision system development performed previously by MDA on the Hubble Remote Servicing and De-Orbit Mission grapple arm ground demonstration program.

The proposed COARSE demonstration on the ISS will enhance MSS software and equip Dextre with a new tool to demonstrate the closed-loop visual servo to a Launch Adapter Ring (LAR) on the Goddard Space Flight Center provided Robotic Refueling Mission (RRM) Payload. The vision system will incorporate camera technology developed on the Next Generation Canadarm (NGC) program, and extend visual servo algorithms developed on past programs and R&D projects. In addition, a new tool tip exchange mechanism developed as part of the NGC program, will enable future demonstration activities through incorporation of new tool tips.

3 COARSE TOOL CONCEPT OVERVIEW

3.1 PHYSICAL ARCHITECTURE The physical architecture of the COARSE payload is illustrated in Figure 2 and composed of the following primary components:

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• Primary tool structure on which all sub-assemblies are attached to

• MSS CLPA wedge interface which provides the robotically compatible ORU interface for external stowage on the MSS Mobile Base System (MBS). This existing ORU interface design includes a micro-fixture, dexterous handling target, and an umbilical connector for electrically interfacing with the MBS when stowed for keep-alive power.

• Cameras

• Illumination Sources (including Light Emitting Diode (LED) lights and pattern projectors)

• Tool avionics which includes all electronics (with the exception of those contained within the cameras) required for the COARSE payload

If the COARSE payload includes the capture capability then the following additional components complete the physical architecture;

• Tool tip interface which consists of a collet mechanism and motor based off of the Next Generation Canadarm (NGC) program developed Multi-Function Tool (MFT)

• A LAR capture tool tip which can be installed/removed by Inter-vehicular Activity (IVA).

FIGURE 2: PHYSICAL ARCHITECTURE

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3.2 MECHANICAL LAYOUT The proposed mechanical layout of the COARSE payload is illustrated in the following figures. The primary features include;

• An ORU Tie-Down interface which is mostly re-used from the MSS L&SE program where it is used on the MSS Camera Light and Tilt Unit Assembly as well as the new MT Relay Assembly (MTRA). This tie-down mechanism includes a micro-fixture and dexterous handling target as well as the “Wedge” interface which mechanically and electrically interfaces with the MTRA when the COARSE payload is not in use. This existing mechanical design is the only mechanical interface to MSS equipment (both the MTRA and the Special Purpose Dexterous Manipulator (SPDM) ORU Tool Change-out Mechanism (OTCM)). Note that the MSS ORU Tie-Down Wedge is slightly modified by clocking the target 180 degrees so as to permit the addition of an OTCM umbilical connector receptacle on the avionics enclosure

• The avionics enclosure which houses all the avionics required for the COARSE payload (see section Error! Reference source not found. for further details on the avionics). Mounted on the avionics box, immediately adjacent to the microfixture is the umbilical receptacle into which the SPDM OTCM plugs in to during COARSE payload operations.

• Two fixed vision system cameras mounted in a stereo pair configuration. Cameras are baselined off of the NGC Cameras developed by MDA.

• A set of “optical triggers” are mounted across the ready-for-capture zone of the tool. These detect when the COARSE payload has been successfully positioned within the capture envelope of the LAR gripper.

• A situational awareness camera to allow the robotics operator to view the tool tip operation during proximity operations. Because of the confining geometry at the tool tip, the situational awareness is currently proposed to be mounted on a protruding mount that permits more optimal camera views.

The primary externally visible differences between the Vision-Only version of COARSE, payload and the version with capture capability are;

• The optical triggers (required for detecting when the COARSE payload has been successfully positioned within the capture envelope of the LAR) are mounted directly to the COARSE payload primary structure in the vision only version of the payload. In the situation where full capture capability is included, the optical triggers are integrated into the LAR tool tip as shown in Figure 7.

• The presence of the collet mechanism for IVA mechanical attachment of tool tips (see Figure 5). The collet mechanism is derived from the Multi-Function Tool developed by MDA as part of the NGC program and works the same as a quick disconnect on air hoses. This interface provides a simple means to mechanically attach and detach tool tips to the payload assembly.

• The presence of a connector on the avionics enclosure to permit the electrical signals from the tool tip (optical triggers and microswitches) to be routed to the avionics. Note that, like the attachment of tool tips to the collet mechanism, connection of the tool tip umbilical is an IVA function.

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FIGURE 3: COARSE PAYLOAD ASSEMBLY (WITH VISION-ONLY CAPABILITY)

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FIGURE 4: COARSE PAYLOAD ASSEMBLY (WITH VISION-ONLY CAPABILITY)

Micro-Fixture

Target

OTCM Umbilical

Receptacle

Pip-Pin for IVA securing of situational camera in deployed

configuration

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FIGURE 5: COARSE PAYLOAD ASSEMBLY (WITH CAPTURE CAPABILITY)

Collet Mechanism from NGC Multi-Function Tool

Connector for tool tip I/O

(IVA connected)

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FIGURE 6: COARSE PAYLOAD ASSEMBLY HELD BY SPDM OTCM

3.2.1 LAR Gripper Tool Tip Overview Figure 7 provides an illustration of a LAR gripper tool tip that is envisioned for the COARSE payload if full capture capability is implemented. The claws of the gripper tool tip are opened and closed by the COARSE payload’s collet mechanism motor. Specifically, the collet mechanism drives a ball spline in the tool tip which in turn winds a screw thread connected to the mechanism operating the claws.

The operational sequence of the LAR gripper tool tip is outlined below in Table 2

FIGURE 7: LAR GRIPPER TOOL TIP

Optical Triggers for “Ready to Capture”

Capture Claws Collect Mechanism

Interface

Tool Tip I/O Connector Housing

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TABLE 2: LAR CAPTURE SEQUENCE

Low Hover

Triggered (Optical Gate Interupted)

Captured

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FIGURE 8: CONCEPT FOR LAR GRIPPER TOOL TIP INSTALLED IN COARSE PAYLOAD

ASSEMBLY

3.2.2 Actuator Control Software The COARSE actuator control software will be derived from the NGC JETS CSCI and will perform the following functions:

1) Receive and respond to high level commands from the MSS Local Bus (via the I/O board)

2) Collect data from and send commands to connected peripherals

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3) Execute Autocode controls module (Motor Control)

4) Health monitoring

5) Providing motor drive telemetry to the I/O board for output in the COARSE payload status message to the ISS

6) Software Update

To control the proposed LAR capture tool tip functions, the tool operations flow shown in Figure 9 is envisioned. Capture begins with the tool tip in the “Set-Up for Capture” configuration whereby the capture claws are in the fully open position. When the optical triggers detect that a LAR has entered the capture envelope of the tool, the tool tip claws are driven to the closed position. If the optical triggers continue to detect the presence of the LAR when the tool claws are in the fully closed position then the capture is deemed to be successful and the tool autonomously proceeds to continue driving the tool tip capture process to rigidize the interface.

If the optical triggers no longer detect the LAR when the claws are in the fully closed position then the capture is considered to have failed (i.e. the LAR escaped the capture envelope) and the capture is autonomously halted, after which the operator can command the claws to re-open in preparation for another attempt.

FIGURE 9: TOOL OPERATIONS FLOW

4 SCIENCE/TECHNOLOGY a) Innovative Technologies

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Upon completion, the COARSE mission will advance the technology readiness of a key enabling technology for the next generation of spacecraft servicing opportunities; the autonomous robotic track and capture of unprepared satellite features.

b) Application Fields COARSE is consistent with the goals and strategy of the CSA and will extend the capability of a signature technology. COARSE leverages prior CSA investments in the MSS and will increase the Technology Readiness Level of key technologies developed by the NGC program. Maintaining Canada’s lead in servicing technologies promises a rich scientific and commercial return, while securing Canada's highly visible and critical participation in the next era of exploration activities.

The specific mission classes that could directly benefit from the manipulator and servicing technology to be demonstrated by COARSE include:

• Satellite servicing, repair, de-orbiting

• Orbital debris mitigation

• Planetary exploration missions (on-planet sampling, sample return)

Figure 10 provides a mission roadmap showing COARSE and its applicability to future missions where the autonomous visual servo to unprepared and uncooperative space objects is identified as a key area requiring further technology demonstration and on-orbit validation.

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FIGURE 10: ROADMAP WITH COARSE ENABLING FUTURE MISSIONS REQUIRING AUTONOMOUS TRACK AND CAPTURE CAPABILITY OF UNCOOPERATIVE AND

UNPREPARED TARGETS

5 ROADMAP, COST AND IMPLEMENTATION COARSE specifically addresses this existing technology gap by advancing the technology readiness level of the building block of this critical capability from TRL 3/4 to TRL 7 as illustrated in Figure 11. Furthermore, COARSE will advance the technology readiness levels of servicing technology building blocks prototyped in CSA’s Next Generation Canadarm (NGC) program including; high resolution micro-cameras, minaturized motor controlers, and a mechanism for rapid replacment of mechanical tool tips.

This advancement in technology readiness can be accomplished by a full COARSE mission on the International Space Station by 2015 for a payload cost of $10M - $20M, with an option for a reduced scope payload that fully advances the vision system TRL. After the on-orbit demonstration, the COARSE infrastructure (hardware, enhanced MSS software and operational techniques) will remain available for use by Canada and its international partners for the testing of international mission components and next generation robotic servicing tools. As such, it represents an available asset for Canada to use in international collaboration discussions and as a function that Canada could provide as part of an overall mission contribution.

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FIGURE 11: COARSE MISSION TECHNOLOGY ADVANCEMENT

6 BUSINESS POTENTIAL COARSE is consistent with the goals and strategy of the CSA and will extend the capability of a signature technology: the provision and operation of fully capable, end to end space robotic systems. COARSE leverages prior CSA investments in the MSS and will increase the Technology Readiness Level of the technologies developed by the Next Generation Canadarm (NGC) program. Maintaining Canada’s lead in servicing technologies promises a rich scientific and commercial return, while securing Canada's highly visible and critical participation in the next era of exploration activities.

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This capability will contribute to business opportunities for:

• The repair and refueling of the existing fleets of satellites

• Removal of space debris from crowded orbital slots

• The tracking and capture of sample return capsules

• Assembly of observatory satellites and outposts

COARSE enables these opportunities by eliminating the need for dedicated ‘robotic’ capture interfaces on future spacecraft. Mission planners and designers will be able to reduce the equipment overhead required for routine servicing and create new mission opportunities for unprepared spacecraft.

The next generation of satellite servicing missions are under consideration by organizations including NASA. The CSA, ESA, CNES, ASI, NASA, MDA, the U.S. military and other groups are studying solutions for orbital debris mitigation. The active removal of large space debris from high value orbits is internationally recognized as being necessary to prevent an eventual catastrophic chain reaction of on-orbit collisions (often referred to as the “Kessler syndrome”). Unprepared capture is required to removal satellites and spent rocket bodies from the high-traffic, high-risk orbital slots.

Advances in on-orbit servicing technologies may lead to advances in robotics for planetary exploration including sample return missions. A critical requirement is to track and capture sample capsules in a Mars or Lunar orbit. Vision systems, visual servoing software, joints, end-effectors, materials, autonomous operations algorithms and other components developed for servicing are directly applicable to planetary exploration, including:

• Robotic arms

• Sample handling and transfer devices

• On-orbit sample transfer for return to Earth

The key advances resulting from COARSE can also be applied to terrestrial markets as well. The ability to find and track an object using the object’s own natural features, across a variety of lighting conditions has applications in the following markets / uses:

• Military / security market

o Tracking vehicles or objects suspected of containing explosives

o Using robots to inspect suspicious packages

• Entertainment

o Imbeded software in remote control cars / helicopters to enable “convoying”

• Search & rescue

o Autonomously direct helicopter ladders/harnesses to stranded people

• Intelligent highway systems

o Use targetless tracking system for convoying applications

• Nuclear robotics

o Maintain or inspect objects /areas that have not been prepared for servicing

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7 ACRONYMS

CLPA Camera, Light & Pan/Tilt Assembly

COARSE Canadian On-Orbit Automated Robotic Servicing Experiment

CSA Canadian Space Agency

CSCI Computer Software Configuration Item

ISS International Space Station

IVA Intra-vehicular Activity

LAR Launch Adapter Ring

L&SE Logistics and Sustaining Engineering

LED Light Emitting Diode

MDA MacDonald, Dettwiler and Associates Ltd

MBS MSS Mobile Base System

MSS Mobile Servicing System

MT Mobile Transporter

MTRA MT Relay Assembly

NRC National Research Council

NGC Next Generation Canadarm

ORU Orbital Replacement Unit

OTCM ORU Tool Change-out Mechanism

RRM Robotic Refueling Mission

SPDM Special Purpose Dexterous Manipulator