Satellite Servicing Robot: Canadarm to Otter and ABB

In April 1984 two astronauts on the Space Shuttle Challenger repaired a broken satellite in orbit for the first time, after the shuttle's arm had pulled it into the payload bay. Four decades later machines are taking over the job. A satellite servicing robot can now dock with a spacecraft in geostationary orbit, hold it in place for years and, if it has arms, fit new propulsion pods to it. This post follows that path from Solar Max and Hubble to Canada's Canadarm and Dextre, then to Northrop Grumman's servicers and Starfish Space's Otter, which launched on 1 October 2026, and asks where ABB robots fit.

Canadarm2 with Dextre on its end, seen from the International Space Station above the Arabian Sea, January 2019. Photo: NASA (public domain)

How astronauts fixed satellites before robots did

Solar Max, a satellite launched in February 1980, became the first uncrewed satellite repaired in orbit. During STS-41-C in April 1984, George Nelson flew to it on the Manned Maneuvering Unit with a capture tool called the TPAD, but its jaws could not lock on because of a grommet that was not on the blueprints. A grab at a solar array by hand then made the satellite tumble faster. Ground engineers steadied it, the shuttle's arm caught a grapple fixture and moved it into the payload bay, and Nelson and James van Hoften replaced its attitude control module and the electronics of one instrument. The repair added five years to its life.

George Nelson, flying the Manned Maneuvering Unit, reaches the Solar Max satellite during STS-41-C, April 1984. Photo: NASA (public domain)

That arm came from Canada. Spar Aerospace built Canadarm, a 15.2 metre arm that first flew on Columbia in 1981 and could retrieve, repair and deploy satellites. It was busy again on Hubble's first servicing mission. Endeavour launched on 2 December 1993 to fix the telescope's flawed mirror, whose outer edge had been ground too flat by 2.2 microns. In five spacewalks totalling 35 hours and 28 minutes, the crew fitted the WFPC2 camera and the COSTAR corrective optics. Story Musgrave rode on the end of the arm to reach the telescope, and Kathryn Thornton stood in a foot restraint on it while lifting COSTAR into place.

Story Musgrave holds a handrail on the Hubble Space Telescope during the STS-61 repairs, December 1993. Photo: NASA (public domain)

On the International Space Station, robots took over more of the work. Dextre, built by MDA in Brampton, Ontario, arrived on Endeavour and was installed in 2008. Each of its two arms has seven joints, its hands work like Swiss Army knives with a camera inside each, and it can handle anything from refrigerator-sized gear to parts the size of a toaster, precise to a few millimetres. Teams at the Canadian Space Agency and NASA operate it from the ground. The last shuttle mission brought NASA's Robotic Refueling Mission in July 2011, and Dextre later handled small caps, cables and wires on a simulated satellite, all controlled from Earth.

Mike Fossum, standing on Canadarm2, holds the Robotic Refueling Mission payload, with Dextre at upper left, July 2011. Photo: NASA (public domain)

Satellite servicing robots at work in 2026

The first commercial servicer had no arms and simply docked. Northrop Grumman's Mission Extension Vehicle MEV-1 launched on 9 October 2019 and docked with Intelsat 901 on 25 February 2020, and the satellite was back in service on 2 April 2020. MEV-1 stayed attached for about five years, undocked on 9 April 2025 and went on to Optus D3, a geostationary communications satellite. MEV-2 docked with Intelsat 10-02 on 12 April 2021. In August 2026 Optus said the first phase of its Project Aurora was complete: after more than a year of attitude control and station-keeping, the servicer undocked. A Mission Extension Pod due to be fitted in late 2027 could add up to six years.

NASA's OSAM-1 auto-capture test bed, where a robot arm reaches for a satellite mock-up, at Goddard in February 2023. Photo: NASA/Mike Guinto (public domain)

Fitting those pods takes a robot. On 21 July 2026 a Falcon 9 launched Northrop Grumman's Mission Robotic Vehicle from Cape Canaveral with DARPA's RSGS payload, a pair of dexterous arms designed by the US Naval Research Laboratory. NASA Goddard supplies simulation tools and a team of flight robot operators, and the pod installation on Optus D3 is planned for late 2027. On 1 October 2026, SpaceX's Transporter-18 rideshare carried Starfish Space's Otter 24C for NASA's SSPICY mission. The craft is about the size of a washing machine. From early 2027 it will use computer vision and electric thrusters to inspect up to four defunct objects, such as old satellites and rocket bodies, without touching them.

One of the OSAM-1 robot arms on ground support equipment in a Goddard cleanroom, April 2024. Photo: NASA/Mike Guinto (public domain)

None of the sources for this post puts an ABB robot on a servicing spacecraft, so ABB's role is a possibility, and it is on the ground, where docking gets rehearsed. In September 2025 City St George's, University of London, opened a space robotics facility where KUKA industrial robots, one of them on a 10 metre steel track, rehearse docking, refuelling and deorbiting, and Orbit Fab's UK arm tests its refuelling interface there. ABB makes the same kind of equipment. Its IRT 710 track moves a robot at up to 2 m/s with a repeatability of ±0.02 mm, and a test cell like that can be laid out first in RobotStudio.

An ABB IRB 6700 on a track picking crates of fresh food at Heemskerk's facility in the Netherlands. Photo: ABB

What satellite servicing robots will do next

On 23 September 2026, Col. Scott Carstetter of the US Space Force's Space Systems Command outlined two commercial servicing demonstrations planned for 2027. An Astroscale U.S. servicer is to dock with a military satellite in geostationary orbit, transfer hydrazine or a green propellant, then refill its own tanks at a commercial depot. Starfish Space's Otter tug is to dock with several national security satellites, change their inclinations and move them to new orbital slots. Both missions will use standard docking fixtures and robotic capture interfaces, so that the servicer does not damage thermal blankets, solar arrays or antennas.

Japan's Prime Minister Sanae Takaichi and French President Emmanuel Macron visit Astroscale in Tokyo, 2 April 2026. Photo: Cabinet Secretariat of Japan / Wikimedia Commons (CC BY 4.0)

For factories, more servicing means more hardware to build and test. Docking fixtures, refuelling tools and pods all have to be checked against each other on the ground, often with industrial robots standing in for spacecraft. ABB's Integrated Force Control lets an arm react to contact forces instead of following a fixed path, and the IRB 7710 and IRB 7720 reach path accuracy down to 0.6 mm, so they could plausibly drive such a rig. The plants that build the spacecraft are covered in our post on satellite manufacturing. For homes, the payoff is longer-lived satellites: NASA notes that working satellites are often retired early when they run out of fuel, and Optus D3 kept carrying telecom services while its servicer was attached.

An ABB IRB 7710 or IRB 7720 robot set up for friction stir welding. Photo: ABB

Carstetter said the Space Force wants to learn when refuelling or life extension pays off compared with launching a new satellite, and that cost question is still open. So is safety. Solar Max showed how one grommet missing from the drawings can spoil a capture, which is why the 2027 missions use standard fixtures and the SSPICY Otter keeps its distance. Operator skills matter too, since Dextre and RSGS are still guided by trained people on the ground, while the Otter steers itself with little input. On 12 October 2026 ABB added an AI Robot Trainer to OmniCore EyeMotion, which turns camera images into robot motion with automatic collision-free path planning, the same see and act problem on a factory floor.

An ABB cobot picks items from trays in a 2026 demo of OmniCore EyeMotion AI vision. Photo: ABB

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