International Space Station crew do spacewalk to address leak | CNN

‘No leaks!’: Emergency spacewalk to fix ammonia seeping from space station

Greg Botelho, CNN
3 minute read
Published 4:18 PM EDT, Sat May 11, 2013
The crew of the space shuttle Atlantis took this picture of the International Space Station after leaving it in July 2011. Atlantis was the last shuttle to visit the station, which was first launched in 1998 and built by a partnership of 16 nations.
The crew of the space shuttle Atlantis took this picture of the International Space Station after leaving it in July 2011. Atlantis was the last shuttle to visit the station, which was first launched in 1998 and built by a partnership of 16 nations.
NASA
The crew of the space shuttle Endeavour initiates the station's first assembly sequence in 1998. The International Space Station includes several large modules, each launched separately and connected in space by astronauts.
The crew of the space shuttle Endeavour initiates the station's first assembly sequence in 1998. The International Space Station includes several large modules, each launched separately and connected in space by astronauts.
NASA / GAMMA LIASON
The Zarya control module, on the left with the solar panels, floats above Earth with its newly attached Unity module after the first assembly sequence in December 1998.
The Zarya control module, on the left with the solar panels, floats above Earth with its newly attached Unity module after the first assembly sequence in December 1998.
nasa
The first crew of the International Space Station, seen on board in December 2000. From the left are cosmonaut Yuri P. Gidzenko, astronaut William M. Shepherd and cosmonaut Sergei K. Krikalev.
The first crew of the International Space Station, seen on board in December 2000. From the left are cosmonaut Yuri P. Gidzenko, astronaut William M. Shepherd and cosmonaut Sergei K. Krikalev.
nasa
The Endeavour crew installs the first set of U.S. solar arrays on the station in 2000.
The Endeavour crew installs the first set of U.S. solar arrays on the station in 2000.
Courtesy NASA
In March 2001, a space shuttle delivered the station's second crew and brought the first one home. It also brought Leonardo, the station's first Multi-Purpose Logistics Module, to the station. Leonardo carried supplies and equipment.
In March 2001, a space shuttle delivered the station's second crew and brought the first one home. It also brought Leonardo, the station's first Multi-Purpose Logistics Module, to the station. Leonardo carried supplies and equipment.
Courtesy NASA
In September 2006, the space shuttle Atlantis docked with the space station, delivering solar wings and a new truss.
In September 2006, the space shuttle Atlantis docked with the space station, delivering solar wings and a new truss.
Courtesy NASA
The space shuttle Discovery leaves the space station in March 2008 after its crew successfully delivered and installed the Japanese-built Kibo lab.
The space shuttle Discovery leaves the space station in March 2008 after its crew successfully delivered and installed the Japanese-built Kibo lab.
Courtesy NASA
The unmanned SpaceX Dragon spacecraft connects to the space station in May 2012. It was the first private spacecraft to successfully reach an orbiting space station.
The unmanned SpaceX Dragon spacecraft connects to the space station in May 2012. It was the first private spacecraft to successfully reach an orbiting space station.
Courtesy NASA
An unmanned Russian cargo craft disconnects from the space station in April 2013. The station relies heavily on ships to bring up supplies.
An unmanned Russian cargo craft disconnects from the space station in April 2013. The station relies heavily on ships to bring up supplies.
nasa
Commander Koichi Wakata of the Japan Aerospace Exploration Agency peers out of the space station's Cupola observatory on April 27. The Cupola is a dome-shaped module that allows station crew members to observe and guide activities outside the station.
Commander Koichi Wakata of the Japan Aerospace Exploration Agency peers out of the space station's Cupola observatory on April 27. The Cupola is a dome-shaped module that allows station crew members to observe and guide activities outside the station.
NASA
A Russian Soyuz spacecraft is docked with the space station on May 5. Since the U.S. shuttle program ended in 2011, all crew members are ferried to and from the space station on Russian rockets.
A Russian Soyuz spacecraft is docked with the space station on May 5. Since the U.S. shuttle program ended in 2011, all crew members are ferried to and from the space station on Russian rockets.
nasa
A Soyuz spacecraft is seen on May 13 as it lands in Kazakhstan with Wakata and other members of the his Expedition 39 crew.
A Soyuz spacecraft is seen on May 13 as it lands in Kazakhstan with Wakata and other members of the his Expedition 39 crew.
bill ingalls/nasa/ap
Notable moments of the International Space Station

Story highlights

2 astronauts did a spacewalk to address ammonia leaking from the International Space Station

They inspected the site of the leak and replaced a pump controller box on the orbiter

Afterward, initial tests showed no sign of a continuing leak, which was spotted Thursday,

3 of the 6 men involved in the 5½-hour spacewalk are set to leave for Earth on Monday

CNN  — 

Two astronauts conducted a spacewalk Saturday to address an ammonia leak in the International Space Station’s cooling system, a mission that ended with NASA optimistic the potentially major problem had been fixed.

In addition to inspecting the site of the leak, NASA astronauts Chris Cassidy and Tom Marshburn removed and replaced a 260-pound pump controller box, NASA explained.

Afterward, Cassidy and Marshburn couldn’t detect any sign of a leak – which might have been manifest, in this case, as ammonia snow flakes – when space agency officials back on Earth ran the new pump. Still, NASA noted that the area needs to be monitored long-term to prove that the problem has been fixed.

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“No leaks!” tweeted Chris Hadfield of Canada, the space station’s commander, who choreographed the spacewalk. “We’re bringing Tom & Chris back inside. … This is an amazing place & time.”

The entire spacewalk took 5 hours and 30 minutes – an hour less than expected.

First detected early Thursday morning, the leak was causing ammonia to enter space at a rate of 5 pounds per day, Mike Suffredini, NASA’s space station program manager, told reporters Friday. Ammonia is used to cool the solar arrays that provide electricity to station systems.

The discovery spurred teams at NASA, over a busy 24-hour stretch, to go into “a full-court press to understand what the failure is” and how to address it, NASA flight director Norm Knight said Friday. That set the stage for the spacewalk involving three of the space station’s six-man crew.

The leak was in a cooling loop in a solar array that has leaked before, and astronauts tried to fix it in November. It’s unclear whether the leak detected this week was the same one or a new issue.

The ammonia coolant for the power channel, one of eight used to supply electricity to the station, would likely have run out by late Friday morning had it not been shut down, NASA said.

“It is a serious situation, but between crew and experts on the ground, it appears to have been stabilized,” Hadfield tweeted Thursday.

Still, the space station’s crew – which also includes three Russian cosmonauts – were never in danger because of it, NASA said. Moreover, the agency has said the rest of the orbiter was otherwise operating normally.

Both Marshburn and Hadfield are scheduled to leave the space station at 7:08 p.m. ET Monday with Russian cosmonaut Roman Romanenko, and NASA said Friday that the spacewalk wouldn’t affect those plans.

Cassidy and Russian cosmonauts Alexander Misurkin and Pavel Vinogradov will stay behind. They’ll eventually be joined by NASA astronaut Karen Nyberg, Russian cosmonaut Fiyodor Yurchikhin and European Space Agency astronaut Luca Parmitano, who are due to launch aboard a Russian Soyuz spacecraft on May 28.

CNN’s Laura Smith-Spark contributed to this report.