August 19, 2016 – Expedition 48 Commander Jeff Williams and Flight Engineer Kate Rubins conducted a five-hour and 58-minute spacewalk today. The NASA astronauts successfully installed the first of two international docking adapters (IDAs) with the help of a Canadian robot named Dextre.
The spacewalk was designed to convert an existing docking port on the ISS into a spaceport that can be used by U.S. commercial crew vehicles. The adaptor will allow future astronauts and cargo to move safely from docked vehicles at this port to the ISS in a pressurized environment.
The IDA was shipped to the ISS on board SpaceX’s Dragon-9 spacecraft and arrived at the station July 20. Both Canadarm2 and Dextre (riding on Canadarm2) are used to do heavy lifting and are capable of removing equipment from Dragon’s trunk, but because of the way Dextre moves, he is the only robot on the ISS that could reach and handle the IDA.
Steps Dextre Took During The Mission:
Extracted the IDA from Dragon’s trunk using his Arm2
Rode on Canadarm2 to the installation position, in front of the existing docking port called PMA2 (Pressurized Mating Adapter-2)
Using Arm2, maneuvered the IDA as close as possible to PMA2
Waited for the two astronauts to begin their spacewalk by exiting the Station’s airlock and making their way to PMA2
After the astronauts strapped their feet into foot restraints, Dextre opened his grippers (fingers) to “hand” the IDA to the astronauts so they could finish the installation
Backed away from PMA2 and provided camera views of the astronauts’ work for ground controllers to see
Click here to view an animation of this sequence in high-speed.
This delicate operation marked the first time that Dextre was responsible for handing off a payload directly to an astronaut. Expedition 48 Commander Jeff Williams and NASA astronaut Kate Rubins conducted the spacewalk to install the equipment. The operation could not be done by Dextre alone, simply due to the design of the IDA and PMA2. The work required extreme care on the part of the ground controllers and the astronauts to ensure that neither the IDA nor Dextre were damaged.
This was the fourth spacewalk in Williams’ career, the first for Rubins, and the 194th for the Space Station. Spacewalkers have now spent a total of 1,210 hours and 46 minutes working outside the station.
Implications For The Future
In addition to being yet another first for robot-kind, the new spaceport will restore America’s human spaceflight launch capability to the ISS and will be a gateway for spacecraft built by Boeing and SpaceX. This will increase the number of opportunities to fly astronauts, and consequently, allow for more crew time dedicated to science. The new IDA will allow vehicles to dock in a gentler manner and will be more efficient than existing ports.