# US 2013/0153710 A1 · Tool for accessing satellite fill/drain valves during propellant resupply > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153710 A1 - Document ID: US20130153710A1 - Status: Published application - Kind: A1 - Application number: 13/706,126 - Filed: 2012-12-05 - Published: 2013-06-20 - Earliest claimed: 2011-12-05 - Assignees: Macdonald, Dettwiler and Associates Inc. - Inventors: Paul ROBERTS; Gavin HAY; Jason WHITE; Geoffrey SPRAWSON - Web page: https://patentgrep.com/patent/US20130153710A1 ## CPC - B64G 4/00: Tools specially adapted for use in space - B64G 1/402: {Propellant tanks; Feeding propellants} - B64G 1/4021: {Tank construction; Details thereof} - B64G: COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR ## Abstract Herein is disclosed a tool, system and method for refueling on-orbit spacecraft. The tool and system are configured to allow for resupply of spacecraft configured to be propelled by either a bipropellant (oxidizer and fuel) or a monopropellant (typically hydrazine). The refueling tool is particularly suited for resupply of satellites not originally prepared for refueling but the system may also be used for satellites specifically designed for refueling. ## Claims ### Claim 1 A tool mounted on a first satellite for opening a rotationally removable access component of a second satellite, the access component on the second satellite having rotatable and static features coaxially aligned along a first axis, comprising: a housing including a motor mounted in said housing, a gear shifter coupled to said motor, a wrench mechanism mounted in said housing including at least first and second adjustable wrench mechanisms coaxially aligned one on top of the other along a second axis; a differential gearbox mounted in said housing coupled to said first and second adjustable wrench mechanisms, the gearbox being configured to split the torque received by the gear shifter evenly between the first and second adjustable wrench mechanisms; and wherein, when the tool is positioned with the wrench mechanism down over the access component with the second axis coincident with the first axis, the first adjustable wrench mechanism engages the rotatable feature of the rotationally removable access component and the second adjustable wrench mechanism engages the static feature of the access component such that the wrench mechanism applies equal and opposite forces to the rotatable feature and the static feature to apply bi-directional torque to the rotatable feature while reacting the torque on the static feature. ### Claim 2 (depends on 1) The tool according to claim 1 wherein said differential gearbox is coupled to said at least two adjustable wrench mechanisms via at least first and second shafts, the gear shifter being coupled to said gearbox, the gear shifter being configured to transmit torque from said motor to said gearbox, said gearbox being configured to transmit said torque received from said gear shifter to said at least first and second output shafts. ### Claim 3 (depends on 2) The tool according to claim 2 wherein said tool is a tool for exchanging one or more fluids between first and second satellites in orbit, the robotic tool being mounted on said first satellite, the rotationally removable access component on the second satellite including at least one fill/drain valve having the rotatable features and static features, including a fluid exchanger subsystem mounted in said housing and configured to mate with one or more fluid sources on the first satellite and to selectively pass fluid between the first and second satellites, wherein the gear shifter is coupled to said fluid exchanger subsystem. ### Claim 4 (depends on 3) The tool according to claim 3 wherein the at least one fill/drain valve includes a rotationally removable secondary seal fitting with an associated rotatable feature coaxially aligned with the rotatable and static features of the fill/drain valve, wherein said wrench mechanism includes at least a third adjustable wrench mechanism being aligned coaxially with the first and second wrench mechanisms, said differential gear box including a third output shaft, said third output shaft being coupled to said third wrench mechanism, said third wrench mechanism being configured to engage the associated rotatable features of the secondary seal fitting to apply bi-directional torque thereto while the second adjustable wrench mechanism reacts this bi-directional torque on the static features on the fill/drain valve. ### Claim 5 (depends on 4) The tool according to claim 4 wherein said third adjustable wrench mechanism is configured to grasp said secondary seal fitting and to secure it once the applied torque has disengaged it from the fill/drain valve. ### Claim 6 (depends on 4) The tool according to claim 4 wherein said differential gear box is a shifting differential gear box in which an operator can selectively shift between differentially paired output shafts. ### Claim 7 (depends on 4) The tool according to claim 4 wherein said differential gear box is a shifting differential gear box in which an operator can selectively shift between said first and second output shafts and said second and third output shafts. ### Claim 8 (depends on 7) The tool according to claim 7 including an actuator configured to selectively engage said gear shifter for shifting between gear positions in said differential gear box. ### Claim 9 (depends on 8) The tool according to claim 8 wherein said actuator is a linear actuator mounted on said end effector and is configured for remote teleoperator control which, when commanded by an operator, engages said gear shifter to move said gear shifter between selected gears of the gearbox. ### Claim 10 (depends on 8) The tool according to claim 8 wherein said actuator is mounted on said housing and is configured for remote teleoperator control which, when commanded by an operator, engages said gear shifter to move said gear shifter between selected gears of the gearbox. ### Claim 11 (depends on 4) The tool according to claim 4 wherein each adjustable wrench mechanism includes a housing having a rotational axis, a pair of opposed nut cams pivotally mounted each to a toothed cam lock, said nut cams each including a pawl member, said cam locks being translationally mounted to a cam ring, said cam ring coaxially mounted in said housing and being rotationally movable with respect to said housing, a detent spring mounted between said cam ring and said housing to restrict movement of said cam ring, a toothed drive ring having inner and outer toothed surfaces mounted in said housing and being rotatable with respect to said housing, said cam pawls being engaged with said toothed drive ring so that when said toothed drive ring is rotated by an output shaft from said differential gear box, said nut cams are rotationally driven until they contact opposing outer surfaces of a faceted rotatable element, at which point said toothed cam locks slide radially outward to engage said toothed inner surface of said drive ring thereby locking the drive ring and the cam ring together to permit torque applied by said output shaft to be transmitted to said faceted surface. ### Claim 12 (depends on 1) The tool according to claim 1 wherein said wrench mechanism is mounted adjacent to a first end of said housing, said first end of said housing being configured to allow engagement of said wrench mechanism with said rotationally removable access component, and including a vision system mounted on said housing disposed, and having a field of view, to observe a region around said first end of said housing to observe the engagement of the wrench mechanism with the rotationally removable access component to allow remote operator control of said wrench mechanism. ### Claim 13 (depends on 3) The tool according to claim 3 wherein the second satellite is configured to receive at least two different fluids and includes at least a first fill/drain valve and a second fill/drain valve each having different fool proof coupling features, and wherein said fluid exchanger subsystem mounted in said housing includes at least two fluid flow pathways having corresponding fool proof coupling features associated with each to mate with the first and second fill/drain valves. ### Claim 14 (depends on 13) The tool according to claim 13 wherein fluid exchanger subsystem is configured to be movable between at least two positions in said housing such that when in a first position a first of the at least two fluid flow pathways is coupled to a first fluid source on the first satellite and the first fill/drain valve then the second of said at least two fluid flow pathways is disengaged from the second fill/drain valve and from a second fluid source on the first satellite, and wherein when in a second position the second fluid flow pathway is coupled to the second fluid source on the first satellite and the second fill/drain valve then the first fluid flow pathway is disengaged from the first fill/drain valve and from the first fluid source on the first satellite, and wherein said fluid exchanger subsystem includes an interface adapted to be engaged by said actuator for moving said fluid exchanger subsystem between said first and second positions. ### Claim 15 (depends on 1) The tool according to claim 1 including features mounted on said housing to allow the tool to be grasped and manipulated by an end effector mounted on a distal end of a robotic arm, said features includes a grapple fixture. ### Claim 16 (depends on 15) The tool according to claim 15 wherein said housing includes at least one power and data connector, at least one fluid coupling connected to at least one fluid flow path from at least one fluid storage tank on said first satellite, and wherein said at least one power and data connector, and said at least one fluid coupling are positioned to mate with corresponding power and data connector and fluid flow coupling on said end effector. ### Claim 17 (depends on 16) The tool according to claim 16 wherein said power and data connector on said housing is connected to said actuator for providing power to said actuator, and for providing power and a data connection to various sensors including a vision system mounted to said housing for transmitting image data from said vision system to a communication system on said first satellite for transmitting the image data to a remote operator and for receiving instructions from said remote operator for commanding said actuator, said vision system disposed, and having a field of view, to observe a region around said first end of said housing to observe the engagement of the wrench mechanism with the rotationally removable access component to allow remote operator control of said wrench mechanism. ### Claim 18 (depends on 17) The tool according to claim 17 wherein said end effector includes at least a first actuator configured such that when the tool is grasped by the end effector and said first actuator is activated, said at least one electrical connector on said end effector is advanced and plugged into said at least one electrical connector on said housing, and including a second actuator configured such that when the tool is grasped by the end effector and said second actuator is activated, said at least one data connector on said end effector is advanced and plugged into said at least one data connector on said housing, and including a third actuator configured such that when the tool is grasped by the end effector and said third actuator is activated said at least one fluid coupling on said end effector is advanced and mated to said fluid exchanger subsystem. ### Claim 19 (depends on 1) The tool according to claim 1 wherein said housing includes thermal insulation and temperature controllers for controlling a temperature of the housing. ### Claim 20 (depends on 1) The tool according to claim 1 including sensing means incorporated into said housing for sensing locations of designated moving parts. ### Claim 21 (depends on 11) The system according to claim 11 wherein said each nut cam includes a cam face, and wherein when said adjustable wrench mechanism is rotated within said housing over a fill/drain valve the cam faces on the two nut cams move towards each other until they contact the features on the fill/drain valve. ### Claim 22 A system mounted on a servicing spacecraft for transferring fluid between one or more selected fluid storage tanks on the servicing spacecraft and a client satellite, the client satellite including one or more fluid storage tanks and a fill/drain valve associated with each of the one or more fluid storage tanks, each fill/drain valve having rotatable features and static features, comprising: a) a positioning mechanism, an end effector mounted on the positioning mechanism, the end effector being coupled to the one or more selected fluid storage tanks; b) a tool including a housing, a fixture mounted on said housing configured to be grasped by said end effector, a fluid selection and coupling mechanism mounted in said housing and configured to be coupled to the end effector for coupling the one or more fluid storage tanks on the client satellite to the one or more selected fluid storage tanks mounted on the servicing spacecraft, a wrench mechanism located in said housing and configured for opening and closing each fill/drain valve on the one or more tanks and mating the fluid selection and coupling mechanism to the at least one fill/drain valve on the client satellite; an actuator mounted in said housing coupled to the fluid selection and coupling mechanism and the wrench mechanism; c) a sensor system for at least determining a relative displacement between said tool and each fill/drain valve on the one or more fluid storage tanks; and d) a control system in communication with said sensor, said positioning mechanism, said end effector and said actuator for controlling operation of said positioning mechanism, said end effector and said tool based on feedback from said sensor. ### Claim 23 (depends on 22) The system according to claim 22 wherein said actuator includes a motor, a gear shifter, the motor being coupled to the gear shifter, a differential gearbox mounted in said housing coupled to said gear shifter and at least first and second output shafts, the gear shifter being configured to transmit torque from said motor to said differential gearbox, said differential gearbox being configured to transmit said torque received from said gear shifter to said at least first and second output shafts, the gear shifter being configured to be engaged to said fluid selection and coupling mechanism for moving said fluid selection and coupling mechanism between at least two positions in said housing, said wrench mechanism including at least first and second adjustable wrench mechanisms aligned coaxially, said first wrench mechanism being coupled to said first output shaft for transmitting torque received by said first output shaft from said gearbox to a first object engaged by the first adjustable wrench mechanism, said second adjustable wrench mechanism being coupled to said second output shaft for transmitting torque received by said second output shaft from said gearbox to a second object engaged by the second wrench mechanism, the gearbox being configured to split the torque received by the gear shifter evenly between the first and second wrench mechanisms to apply equal and opposite forces to said first and second objects; and wherein said first object is the rotatable feature of a fill/drain valve such that the first adjustable wrench mechanism configured to engage the rotatable features of the fill/drain valve of the second satellite to apply bi-directional torque to the rotatable features, and the second object is the static feature of the fill/drain valve such that the second adjustable wrench mechanism reacts the torque on the static features on the fill/drain valve. ### Claim 24 (depends on 23) The system according to claim 23 wherein the at least one fill/drain valve includes a secondary seal fitting with associated rotatable features, wherein said cam wrench mechanism includes at least a third adjustable wrench mechanism being aligned coaxially with the first and second adjustable wrench mechanisms, said gear box including a third output shaft, said third output shaft being coupled to said third adjustable wrench mechanism, said third adjustable wrench mechanism being configured to engage the associated rotatable features of the secondary seal fitting to apply bi-directional torque thereto while the second of the adjustable wrench mechanisms reacts this bi-directional torque on the static features on the fill/drain valve. ### Claim 25 (depends on 24) The system according to claim 24 wherein said differential gear box is a shifting differential gear box in which an operator can selectively shift between differentially paired output shafts. ### Claim 26 (depends on 24) The system according to claim 24 wherein said differential gear box is a shifting differential gear box in which an operator can selectively shift between said first and second output shafts and said second and third output shafts. ### Claim 27 (depends on 24) The system according to claim 24 wherein each adjustable wrench mechanism includes a housing having a rotational axis, a pair of opposed nut cams pivotally mounted each to a toothed cam lock, said nut cams each including a pawl member, said cam locks being translationally mounted to a cam ring, said cam ring coaxially mounted in said housing and being rotationally movable with respect to said housing, a detent spring mounted between said cam ring and said housing to restrict movement of said cam ring, a toothed drive ring having inner and outer toothed surfaces mounted in said housing and being rotatable with respect to said housing, said cam pawls being engaged with said toothed drive ring so that when said toothed drive ring is rotated by an output shaft from said differential gear box, said nut cams are rotationally driven until they contact opposing outer surfaces of a faceted rotatable element, at which point said toothed cam locks slide radially outward to engage said toothed inner surface of said drive ring thereby locking the drive ring and the cam ring together to permit torque applied by said output shaft to be transmitted to said faceted surface. ### Claim 28 (depends on 27) The system according to claim 27 wherein said each nut cam includes a cam face, and wherein when said adjustable wrench mechanism is rotated within said housing over a fill/drain valve the cam faces on the two nut cams move towards each other until they contact the features on the fill/drain valve. ### Claim 29 (depends on 22) The system according to claim 22 wherein the positioning mechanism is configured to carry one or more fluid lines which are coupled to the one or more selected fluid storage tanks, and wherein the end effector is coupled to the one or more fluid lines on the positioning mechanism. ### Claim 30 (depends on 29) The system according to claim 29 wherein the end effector includes at least one fluid coupling and a coupling actuator for moving the at least one fluid coupling, and said fluid selection and coupling mechanism includes at least one fluid coupling attached on an exterior of the housing, and wherein the end effector and the housing are configured such that when the end effector grips the grapple fixture and the actuator is activated the at least one fluid coupling on the end effector mates with at least one fluid coupling on the exterior of the housing. ### Claim 31 (depends on 30) The system according to claim 30 wherein the end effector includes at least one electrical connector connected to a power source on the servicer satellite, and wherein said housing includes at least one electrical connector located on an exterior of the housing, and wherein the end effector and the housing are configured such that when the end effector grips the grapple fixture and the actuator is activated the at least one electrical connector on the end effector mates with at least one electrical connector on the exterior of the housing to provide power to the robotic tool. ### Claim 32 (depends on 31) The system according to claim 31 wherein the at least one electrical connector on the end effector is a data and electrical connector, and wherein the at least one electrical connector on the housing is an electrical and data connector, and wherein the data connector on the end effector is connected to the control system, and wherein the data connector on the tool is connected to said sensor system and said actuator. ### Claim 33 A method for remotely opening a rotationally removable access component mounted on a client satellite, the access component on the client satellite having rotatable and static features, comprising: activating a positioning mechanism mounted on a servicer satellite and releasibly coupling an end-effector on the positioning mechanism to a tool mounted on the servicer satellite; positioning the tool over the rotationally removable access component and aligning a wrench mechanism mounted in the tool over the rotationally removable access component until a rotational axis of the wrench mechanism is aligned with a rotational axis of the rotationally removable access component so that a first adjustable wrench mechanism section of the wrench mechanism is engaged with the rotatable feature of the rotationally removable access component and a second adjustable wrench mechanism section of the wrench mechanism is engaged with the static feature of the rotationally removable access component; and activating the wrench mechanism for applying equal and opposite forces to the rotatable feature and the static feature to apply bi-directional torque to the rotatable feature while reacting the torque on the static feature. ### Claim 34 (depends on 33) The method according to claim 33 including a step of transferring fluid between the servicer satellite and the client satellite, wherein the rotationally removable access component is a fill/drain valve, engaging the wrench mechanism with a fluid coupling to attach the fluid coupling to the fill/drain valve, wherein the fluid coupling is in flow communication with a fluid source on the servicer satellite, engaging the wrench mechanism to the fill/drain valve to open it and pass fluid between the servicer and client satellites, and once fluid has been transferred, engaging the wrench mechanism to the fill/drain valve to close it, and once closed engaging the wrench mechanism to the decoupling to remove it from the fill/drain valve.