ISS Spacewalk: astronauts try to solve the battery problem by running cables outside the International Space Station

Two astronauts floated in front of the International Space Station on Monday to participate in NASA's third spacewalk in less than three weeks, aimed at replacing a defective solar panel battery installed at the first exit, to route the Ethernet cabling to extend wireless connectivity and install backup power. lines for the lab robot arm.

Anne McClain, NASA flight engineer, and the EV-1 call sign, as well as Canadian astronaut David Saint-Jacques, EV-2, switched their battery-powered space suit to 7:31 (EDT), officially giving the kickoff It will be a six-hour, 29-minute tour, the 216th since the assembly began in 1998.

Space walkers achieved all their main goals without any major problems. But the two astronauts had problems with their headphones near the end of the tour and McClain reported moisture on the visor of his helmet after returning to the airlock. But she said that there was no sign of actual water leakage that could pose a threat to safety.

Anne McClain, wedged between two space station modules, is working to connect electrical cables to provide a backup power channel to the robot arm of the lab.

NASA

Santiago was originally scheduled to release space in space on Monday with NASA astronaut Nick Hague. Hague and McClain made the first of three spacewalks on March 22, while McClain and Christina Koch planned to run the second on March 29, becoming the first women's team to walk around space.

But after the first tour, McClain decided that she was more comfortable wearing a medium-sized suit, the same one that Koch needed. As it would take almost a whole day to team up to resize an outfit to wear to McClain, Hague took his place on the second outing in the space and McClain replaced him for the third time.

It turned out that team exchanges are just one of the changes the team had to deal with.

Upon release to space on March 22, McClain and Hague continued their work on the robotic arm of the station to replace six old nickel-hydrogen batteries of the solar power system of the laboratory with three batteries lithium-ion more efficient. Astronauts have installed "adapter plates" allowing a single Li-ion battery to replace two of the old nickel-hydrogen power packs.

At the second spacewalk on March 29, Hague and Koch participated in the installation of three other Li-ion batteries. However, in the tests that followed the first EVA, the engineers had problems with one of the initially installed Li-ion batteries and an electronic component called a battery charge / discharge unit, or BCDU.

After unsuccessful attempts to solve the problem, NASA officials decided to remove the defective battery and replace it with two of the recently removed nickel-hydrogen batteries. They also decided to replace the BCDU with a spare part.

Astronaut Anne McClain, left, and Canadian astronaut David Saint-Jacques pose with the spacesuit they donned Monday to work outside the International Space Station in order to solve a solar power system battery problem and install power and ethernet cables.

NASA

Using the robotic arm of the station, the flight controllers removed the suspect battery and the BCDU, and then reinstalled one of the recently removed nickel-hydrogen batteries. They also replaced the failed BCDU in a robotic way.

McClain tightened the bolts now the battery charge-discharge unit before removing, with Saint-Jacques, an adaptation plate installed at the first exit in the space to allow the 39 installation of a second nickel-hydrogen battery.

After exiting in space, the flight controllers will use the robot arm to reinstall the second nickel-hydrogen battery, restoring the 4A power channel to its normal output.

Kenny Todd, head of operations and integration of the space station, said the faulty lithium-ion battery would be thrown away while the BCDU would be sent back to Earth for inspections to determine what was going wrong not. A new lithium-ion battery will be routed to the station during a future cargo flight and will eventually be installed in place of the two older batteries.

David Saint-Jacques goes Monday on a construction site outside the International Space Station.

NASA

As for the use of a mixture of new and used batteries in the 4A power channel, "we expect to be able to use this configuration for a while and allow us to regain our nominal power capacity on channel 4A", a- he declared. "So we are very happy to know where we are going to be at the back of these EVA and robotics activities."

With the adapter plates removed, McClain and Saint-Jacques continued their work to connect Ethernet cabling to the front of the station's Destiny lab module, which will expand the wireless connectivity of outdoor-mounted scientific instruments. from the station.

A cable thrown on the right side of the solar structure of the station was deferred to allow time for movement of the adapter plate.

The last major task on the crew's agenda was Monday to run power lines from the Unity central module to the central S0 segment of the farm to provide a backup power source to the arm laboratory robot.

Although the arm already has redundant power supplies, the cables installed by McClain and Saint-Jacques will allow it to continue operating even if any of these other power sources fail.

Saint-Jacques was also working at the front of the station where4, the Columbus laboratory module of the European Space Agency is installed to install the necessary fittings to the eventual addition of a platform of commercial payload for holding various remotely controlled scientific instruments.

He successfully installed a secondary attachment accessory, but could not mount the main unit due to unexpected interference issues. He took documentary photographs to help the engineers better understand the problem before any subsequent attempt to exit into space.