Cosmonauts Fyodor Yurchikhin and Alexander Misurkin ventured outside the International Space Station Monday, kicking off a planned six-hour spacewalk to carry out a variety of maintenance tasks, including preparations for attachment of a new Russian laboratory module late this year.
The spacewalk began at 9:32 a.m. EDT (GMT-4) when Yurchikhin, call sign EV-1, and Misurkin, EV-2, opened the hatch of the Pirs airlock compartment as the station sailed 250 miles above the south Pacific Ocean. Misurkin made his way outside a few moments later, followed by Yurchikhin.
For identification, Yurchikhin is wearing a Russian spacesuit with red stripes while Misurkin is using a suit with blue stripes. Both cosmonauts are equipped with NASA helmet cameras.
This is the 169th spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth for Yurchikhin and the first for Misurkin. It is the third spacewalk of 2013. Four more Russian spacewalks are planned this year, along with two U.S. excursions, which will take place on July 2 and 9.
Along with routine maintenance, much of the work planned for today's spacewalk includes installation of cable clamps and other equipment needed to route data and power to and from the Multi-Purpose Laboratory module, also known as Nauka, tentatively scheduled for launch in December.
To make way for the new module, the Pirs docking and airlock compartment will be jettisoned this fall and the MLM will use its own propulsion and guidance system to fly to an automated docking at the Zvezda command module's Earth-facing port.
But first, Russian spacewalkers must route power and data lines on Zvezda's hull and remove docking equipment from Pirs. Much of that gear will be moved to the Poisk docking compartment currently attached to Zvezda's upper port. It will take another three Russian spacewalks and two by NASA astronauts to complete the preparations.
"There are quite a [few] tasks that need to be performed by the Russian EVA crew members before MLM arrives," said Lawrence Thomas, NASA's lead spacewalk planner for Expedition 36. "Not only do they need to route power and data cables and reconfigure [rendezvous] equipment for the arrival of the MLM itself, it's part of a larger reconfiguration effort."
Because the MLM will replace the Pirs module, which serves as the Russian airlock, the Poisk module must be configured to handle spacewalks.
"So there is a lot of hardware we're going to have to move around," Thomas said. "There's EVA hardware on [Pirs] that will have to be removed and re-installed on [Poisk], there are some antennas that will have to be moved around and there's also some science equipment on [Pirs] that's going to have to be relocated before it deorbits."
For today's excursion, Yurchikhin and Misurkin planned to begin by replacing a cooling system flow control valve on the Zarya module and installing additional power and data clamps needed for the MLM.
On the Zvezda module, the spacewalkers will reconfigure KURS docking gear, used by approaching Soyuz and Progress spacecraft to home in for docking at Pirs, and install spacewalk handrails needed during upcoming EVAs. They also plan to retrieve a materials science space exposure pallet from Poisk and install a new experiment.
"The tasks for this EVA in particular, there's not one that's particularly hard in comparison to other things we've done," Thomas said. "One thing that I've always admired about Russian EVA hardware, they always design it to where it's very user friendly, very simple interfaces, very intuitive. So I don't see anything on this that's more complicated [than usual].
"If I was to pick anything out to watch out for on these EVAs it's just the amount of ground they're going to cover and also the amount of hardware they're going to manipulate."
Misurkin, making his first spaceflight, arrived at the space station March 28, along with Soyuz TMA-08M commander Pavel Vinogradov and NASA astronaut Christopher Cassidy. Yurchikhin arrived May 28 aboard the Soyuz TMA-09M spacecraft, accompanied by NASA shuttle veteran Karen Nyberg and Luca Parmitano, a European Space Agency astronaut.
Yurchikhin first flew to the space station in 2002 as a shuttle astronaut on a mission to attach part of the lab's solar power truss. He then completed two long-duration stays, riding aboard Soyuz spacecraft in 2007 and 2010.
He has logged nearly 400 days in space, including five previous spacewalks totaling about 32 hours. When Vinogradov, Misurkin and Cassidy depart in September, Yurchikhin will take over as commander of Expedition 37.
As a routine safety precaution during today's spacewalk, the Zvezda module's hatches to Poisk and the forward part of the station were sealed to protect against the possibility of a problem repressurizing Pirs after the spacewalk.
Nyberg and Parmitano spent the day in the forward portion of the space station, where they had access to the Soyuz TMA-09M spacecraft docked at the Rassvet compartment attached to the Russian Zarya module.
Cassidy and Vinogradov spent the day in the Poisk docking compartment on the upper side the Zvezda module where the Soyuz TMA-08M spacecraft is docked.