Dextre, the International Space Station's Canadian-built robotic handyman, is wrapping up a successful three-day experiment to show how space-based robots could service and refuel satellites.

"We're so proud of our guy," said a Friday tweet from Dextre's developer, the Canadian Space Agency (CSA).

"Dextre made history while [you] were asleep." the agency crowed. "Last night’s wire-cutting task was his most dexterous task ever."

The agency also said its robot successfully retrieved and stowed three specialized tools built as part of NASA's robotic refuelling mission.

"Dextre will stow his tools today after a job well done," the CSA said.

Dextre has been tasked with performing delicate precision manoeuvres to test the feasibility of refuelling satellites in space.

Satellites are not designed to be touched following their launch, so many satellites become useless space junk once they run out of fuel. More than 1,000 satellites are currently in near-Earth orbit and another 180 decommissioned satellites are still orbiting the planet.

Refuelling satellites could save millions

"The ability to refuel satellites in space could one day save satellite operators from the significant costs of building and launching new replacement satellites," says the CSA.

Dextre's first R&D mission was to simulate accessing the fuel system of a typical satellite. This week's mission began with the removal of three tools from the module — a safety cap tool, a wire cutter and a blanket manipulation tool. It then inspected and stowed them.

Dextre's tasks also include cutting through the simulated satellite's exterior, removing the blanket insulation, and cutting away wiring covering the fuel cap. 

Late Thursday, Dextre used a specially designed tool to cut a thin wire that fastened a mock gas cap to the module. "With surgical precision, Dextre used his new tool to slide a tiny hook under the wire with about a millimetre of clearance to make the cut," the CSA said in an update Friday.

Dextre's mission will last about two years as it moves through a variety of tasks designed to test servicing capabilities.

Dextre — short for Special Purpose Dexterous Manipulator — was launched in a shuttle mission back in 2008. The hardware Dextre is using in the current mission was developed by NASA and was sent to the space station aboard the final shuttle mission in July 2011.

Dextre's operations for the robotic refuelling mission are remotely controlled by scientists at NASA's Johnson Space Centre in Houston and at the Canadian Space Agency's mission operations centre in Saint-Hubert, Que.