Canadarm2 captures Cygnus OA-5 S.S. Alan Poindexter in late 2016 (Credit: NASA)

Canadarm2 Scores Milestone With Catching Its 50th Spacecraft

August 16, 2024 by Maya Posch 3 Comments

Recently Canada’s Canadarm2 caught its 50th spacecraft in the form of a Northrop Grumman Cygnus cargo vessel since 2009. Although perhaps not the most prominent part of the International Space Station (ISS), the Canadarm2 performs a range of very essential functions on the outside of the ISS, such as moving equipment around and supporting astronauts during EVAs.

Power and Data Grapple Fixture on the ISS (Credit: NASA)

Officially called the Space Station Remote Manipulator System (SSRMS), it is part of the three-part Mobile Servicing System (MSS) that allows for the Canadarm2 and the Dextre unit to scoot around the non-Russian part of the ISS, attach to Power Data Grapple Fixtures (PDGFs) on the ISS and manipulate anything that has a compatible Grapple Fixture on it.

Originally the MSS was not designed to catch spacecraft when it was installed in 2001 by Space Shuttle Endeavour during STS-100, but with the US moving away from the Space Shuttle to a range of unmanned supply craft which aren’t all capable of autonomous docking, this became a necessity, with the Japanese HTV (with grapple fixture) becoming the first craft to be caught this way in 2009. Since the Canadarm2 was originally designed to manipulate ISS modules this wasn’t such a major shift, and the MSS is soon planned to also started building new space stations when the first Axiom Orbital Segment is launched by 2026. This would become the Axiom Station.

With the Axiom Station planned to have its own Canadarm-like system, this will likely mean that Canadarm2 and the rest of the MSS will be decommissioned with the rest of the ISS by 2031.

Top image: Canadarm2 captures Cygnus OA-5 S.S. Alan Poindexter in late 2016 (Credit: NASA)

Canadian Space Robot Will Repair Itself

May 22, 2014 by Rick Osgood 5 Comments

The video above shows an animation of what the Canadian Space Agency hopes will be the first successful self-repair of the Mobile Servicing System aboard the ISS. The mobile servicing system is basically a group of several complicated robots that can either perform complicated tasks on their own, or be combined into a larger unit to extend the dexterity of the system as a whole.

The most recent addition to the servicing system is the Special Purpose Dexterous Manipulator, otherwise known as Dextre. Dextre is somewhat reminiscent of a human torso with two enormous arms. It is just one of the Canadian Space Agency’s contributions to the station. It was installed on the station in 2008 to perform activities that would normally require space walks. Dextre’s very first official assignment was successfully completed in 2011 when the robot was used to unpack two pieces for the Kounotori 2 transfer vehicle while the human crew on board the ISS was sleeping.

Dextre is constructed in such a way that it can be grabbed by the Canadarm2 robot and moved to various work sites around the Space Station. Dextre can then operate from the maintenance site on its own while the Canadarm2 can be used for other functions. Dextre can also be operated while mounted to the end of Canadarm2, essentially combining the two robots into one bigger and more dexterous robot.

One of the more critical camera’s on the Canadarm2 has started transmitting hazy images. To fix it, the Canadarm2 will grab onto Dextre, forming a sort of “super robot”. Dextre will then be positioned in such a way that it can remove the faulty camera. The hazy camera will then be mounted to the mobile base component of the Mobile Servicing System. This will give the ISS crew a new vantage point of a less critical location. The station’s human crew will then place a new camera module in Japan’s Kibo module’s transfer airlock. Dextre will be able to reach this new camera and then mount it on the Canadarm2 to replace the original faulty unit. If successful, this mission will prove that the Mobile Servicing System has the capability to repair itself under certain conditions, opening the door for further self-repair missions in the future.