ESA astronaut Andreas Mogensen is making the most of his time aboard the International Space Station. Yesterday, Mogensen took the ESA developed force-feedback control system for a test drive.
Mogensen put a round peg into a round hole. Sounds easy enough, right? Except Mogensen was 400 km above where the experiment was taking place. He was remotely operating a rover and its robotic arm on the ground while he stood 249 miles above aboard the International Space Station.
Mogensen successfully placed a metal peg into a hole that had just 0.15 mm of clearance.
The team at ESA’s Telerobotics and Haptics Laboratory couldn’t be happier with the results.
“Andreas managed two complete drive, approach, park and peg-in-hole insertions, demonstrating precision force-feedback from orbit for the very first time in the history of spaceflight,” said André Schiele, who led the experiment.
What’s even more impressive is that Mogensen never practiced before yesterday’s experiment. “He had never operated the rover before but its controls turned out to be very intuitive. Andreas took 45 minutes to reach the task board and then insert the pin on his first attempt, and less than 10 minutes on his follow-up attempt, showing a very steep learning curve,” said Schiele.
The key was force feedback
Letting Mogensen feel when the rover’s arm met resistance was vital for the experiment’s success. Placing the round peg in a round hole would be nearly impossible without force feedback to tell you when you met resistance.
Distance was the biggest obstacle for the scientists to overcome. The ISS travels at five miles per second at an altitude of nearly 250 miles. The signal has to travel from the station to satellites that are more than 22,000 miles up and then to a US ground station in New Mexico before reaching the ESA laboratory in the Netherlands.
The two-way time delay is about one second. Scientists at ESA’s Telerobotics and Haptics Laboratory tackled this problem using advanced software dubbed ‘model mediated control.’ This software compensates for the lag and keeps the operator and the rover arm in sync.
Mogensen used a force-feedback joystick to feel when the rover’s arm met resistance. With all the systems working in sync Mogensen was able to drop the round peg into the round hole.
This force-feedback system is in its early stages, but the future is limitless. The ESA describes how one day a similar system could be used to clear debris around the Earth or even build a base on the moon. Imagine astronauts in orbit around Mars or other planets/moons controlling rovers on the surface.
Watch André Schiele give a fascinating TED talk about remote robotic operations below. Towards the end of the video, he dons an exoskeleton to control a robot over 400 km away. Incredible stuff.
Mogensen’s time on the ISS will be brief. He will be back on Earth Saturday after spending about a week aboard the ISS.