After being cramped up on the International Space Station (ISS) for several weeks, NASA astronauts Kate Rubins and Jeff Williams will get to stretch their legs during a six-and-a-half hour spacewalk this Friday. However, this isn’t going to be just a walk in the park. The astronauts will be working on installing a new international docking adapter (IDA) to the outside of the ISS. This is a crucial component of NASA’s Commercial Crew Program.

Image via NASA

A major issue with the ISS is it’s relative inaccessibility. It takes a lot of planning, work and resources to send people or equipment up there. For this reason, SpaceX and Boeing have been working on commercial alternatives. These alternatives — so-called space taxis — would be faster and cheaper than existing possibilities.

SpaceX is building a crewed version of its Dragon cargo capsule, called Crew Dragon, and Boeing is building a brand-new crew capsule called the CST-100 Starliner, the two being slated to work in 2017 and 2018, respectively. However, in order for these to dock at the station, a new docking module needs to be installed to fit the shuttles and astronauts need to get to work.

There is a reason to worry about the spacewalk. This will be the first one since January, and that spacewalk didn’t exactly go swimmingly. Then, NASA astronaut Tim Kopra noticed a small water bubble forming inside his helmet, probably due to an issue with his spacesuit’s sublimator, inducing too much condensation. NASA has already taken steps to fix this issue and hopefully, it  won’t be a problem in the future.

Regarding the space operation itself, NASA writes:

“The two astronauts will venture outside the space station’s Quest airlock to install the first IDA onto Pressurized Mating Adapter-2, located on the forward end of the Harmony module. On Wednesday, Aug. 17, ground controllers will use the Canadarm2 robotic arm, and its attached “Dextre” Special Purpose Dexterous Manipulator, to extract the IDA from the trunk of Dragon, and position it just inches away from PMA-2. There will be no live coverage of the trunk removal and IDA positioning.”

In other ISS news, Russia is reportedly planning on reducing its space crew from 3 to 2. The Russian newspaper Izvestia quoted cosmonaut Sergei Krikalev, who serves as the head of piloted space programs for Russia’s state-run space corporation, Roscosmos.

“They’re exploring the option of going down to two crew on the Russian segment,”said ISS operations integration manager Kenneth Todd, responding to a question from collectSPACE.com editor Robert Pearlman. “We’ll look at it as we do with all these kind of things—we’ll trade it against whatever risk that might put into the program, first and foremost the risk to our crew onboard, and the station itself.”

The whole building operation will be streamed by NASA. You can check out the live streaming, as well as other information and updates on http://www.nasa.gov/nasatv.