The Space Shuttle may be gone, but one part of it is still going strong. The Canadian-built Canadarm robotic arm first flew on the Shuttle in 1981 and its successor, Canadarm2, is still working on the International Space Station (ISS) helping with experiments, supporting space-walking astronauts, and aiding unmanned cargo ships to dock. Not content to rest on its laurels, the Canadian Space Agency (CSA) is working on the Next Generation Canadarm (NGC). More flexible and compact than its predecessor, it’s part of a new 5-part system designed to fulfill the need for robotic arms to help with satellite repair and refueling.
The NGC project is not only updating the robotic arm technology, but expanding it to form a new system with the aim of not just improving a robot arm, but to make it part of an improved way of developing techniques for dealing with the approach, docking, servicing and undocking of spacecraft for maintenance and refueling. As part of this, the NGC project is working on five components.
The Next-Generation Large Canadarm
Built by MacDonald, Dettwiler and Associates Ltd, the Next-Generation Large Canadarm (pictured below) is designed as a more compact version of Canadarm2. Like Canadarm2, it’s 15 m (49 ft) long and is the largest of the five components. With six degrees of freedom and advanced hardware and software, it’s capable of handling the docking of large spacecraft and refueling operations, but it’s also built of retractable, telescopic sections, so it folds into less than five cubic meters (176 ft³), so it can fit into the smaller spacecraft currently being developed.
The Next-Generation Small Canadarm
This is a smaller 2.5-meter (8.2-ft) arm based on the Dextre arm, also used on the ISS, that can work independently or as an extension of Canadarm2. It’s intended for experiments in satellite repairs using a set of specialized tools. This allows it to replace components, remove protective blankets, cut wires, and open and close valves either autonomously or under remote control.
The Proximity Operations System Testbed
The third part of the system is the Proximity Operations testbed. This uses two industrial robotic systems that simulate the movements of two docking spacecraft as they make their approach maneuvers, as well as realistic lighting and camera views to aid in simulation tests.
The Semi-autonomous Docking System
This component is designed to test the procedures for docking two spacecraft together. Spacecraft docking has been done for nearly half a century, but it’s one thing to bring two cooperating spacecraft into contact and another doing it when one is in need of repair, so there’s still room for improvement. Unlike the Proximity Operations Testbed, this system is used for practicing the actual docking itself. The idea is to advance beyond docking by means of robot arms under remote control, to a completely autonomous operation by arms and craft.
Missions Operations Station
The previous four components are coordinated from the NGC Missions Operations Station. According the CSA, the Mission Operations Station acts as a mini-mission control, able to handle all four of the other components either as hardware or in simulation.The video below outlines the NGC project.
Source: Canadian Space Agency via IEEE Spectrum
