Space Station Crew Prepare for Emergency Spacewalk
Close-up of Christopher Cassidy’s spacesuit helmet visor during his second STS-127 spacewalk in July 2009. Seen mirrored in the visor is astronaut Tom Marshburn. Both Expedition 35 astronauts are expected to pair up again if the emergency EVA is approved to fix the ammonia leak on Saturday. Credit: NASA
Image: A view of the shuttle's payload bay wi
July 15, 2011 --
The final space shuttle mission (STS-135) to the International Space Station (ISS) continues. Supplies have been delivered by shuttle Atlantis and the final "shuttle era" spacewalk has been successfully completed. Here are a selection of photographs from the busy ISS since Atlantis docked with the orbital outpost on July 10.
While Atlantis was docked to the space station, a member of the STS-135 crew snapped this picture of some of the islands in the Bahamas, off the coast of the Florida peninsula (right). Miami can be seen toward the top right of the photograph. Cape Canaveral and Kennedy Space Center are located out of shot in the bottom right of the photo.
Welcomed... Fruit? Shortly after docking with the space station, the Atlantis crew (including STS-135 pilot Doug Hurley, left) gave the resident space station crew supplies of fresh food. With a smile, Expedition 28 flight engineer Mike Fossum (right) receives a bag of fruit.
While aboard the space station, the STS-135 crew are working on many tasks during their short stay. STS-135 commander Chris Ferguson (right) can be seen here working with Japanese astronaut and Expedition 28 flight engineer Satoshi Furukawa in the Quest airlock inspecting space suits assigned to NASA astronauts Mike Fossum and Ron Garan prior to the July 12 spacewalk.
Say "Cheese"! During the six and a half hour spacewalk to retrieve a failed ammonia pump module from an external storage platform and install a robotic refueling demonstration apparatus, NASA astronaut Mike Fossum takes a picture while Atlantis is docked behind him. Fossum can be seen restrained on the end of the space station remote manipulator system (Canadarm2).
Mike Fossum points at the camera as he waits at an International Space Station pressurized mating adapter (PMA-2) docked to the space shuttle Atlantis, as the station's robotic system moves the failed ammonia pump module (out of frame) over to the spacewalking astronaut and the shuttle's cargo bay.
Robotic Assistance Mike Fossum, while attached to Canadarm2, holds the Robotics Refueling Mission payload -- one of the main tasks to be carried out during the spacewalk. The failed pump module can be seen with the two-armed robot, Dextre, on left side of the photo.
Shuttle Stowage With his feet secured to Canadarm2, NASA astronaut Ron Garan carries the failed ammonia pump module toward shuttle Atlantis' open payload bay. When Atlantis returns to Earth on July 21, engineers will study the module to see how it failed and how the problem can be avoided in the future.
In addition to installing/removing space station hardware, STS-135 delivered up to a years-worth of supplies. STS-135 mission specialist Sandy Magnus can be seen here floating inside the Raffaello multi-purpose logistics module that Atlantis carried to the space station. Magnus is surrounded by the supplies for consumption of the space station residents for the months ahead.
A Picnic, Shuttle Style Seven astronauts -- six from NASA and one from the Japan Aerospace Exploration Agency (JAXA) -- and three Russian cosmonauts participate in a special meal on the Space Shuttle Atlantis' middeck on July 14. The STS-135 crew consists of NASA astronauts Chris Ferguson, Doug Hurley, Sandy Magnus and Rex Walheim; the Expedition 28 or station crew members are JAXA astronaut Satoshi Furukawa, NASA astronauts Ron Garan and Mike Fossum, and Russian cosmonauts Andrey Borisenko, Alexander Samokutyaev and Sergei Volkov. All photographs can be found in NASA's Human Spaceflight Gallery.
After the discovery of a leak of ammonia coolant supplying one of the International Space Station solar arrays on Thursday, NASA managers have decided to plan for an unscheduled spacewalk on Saturday to repair the problem. The final decision about whether to go ahead with the extravehicular activity will be made late on Friday.
Although the crew are not in danger, the affected portion of the station’s huge football pitch-sized solar array that supplies the orbiting outpost with electricity will be inoperative and work is currently underway to reroute electricity from the other fully functioning arrays to ensure all systems remain powered up.
The ISS crew reported seeing “white flakes” floating away from the station, emanating from the far left-side of the station’s truss structure, late on Thursday morning. It was quickly identified as the ammonia leak. It appears to be coming from the general location of where astronauts troubleshooted a leak on Nov. 1, 2012, on the P2 truss structure, but photography by the station’s astronauts can only provide so much information about the leak’s location. Video imagery from the astronauts, however, have been able to estimate the loss rate of ammonia and that rate appears to be increasing.
The ammonia supply from the impacted 2B power channel was expected to be depleted late Friday morning.
“Station’s power relies on ammonia coolant. A few hours ago, we determined that the ammonia was leaking out of the Station and into space,” Expedition 35 Commander Chris Hadfield reported via Twitter on Thursday.
This morning, as plans were underway for a potential emergency spacewalk, Hadfield was upbeat about the situation.
“Good Morning, Earth! Big change in plans, spacewalk tomorrow, Chris Cassidy and Tom Marshburn are getting suits and airlock ready. Cool!” he said. “The whole team is ticking like clockwork, readying for tomorrow. I am so proud to be Commander of this crew. Such great, capable, fun people.”
NASA astronauts Cassidy and Marshburn are currently working in the station’s Quest airlock, checking out the U.S. spacesuits they would wear if a spacewalk is approved, according to a NASA news release. Hadfield is also preparing to assist as the “intravehicular” crew member, or spacewalk choreographer.
“Suddenly very busy! Ammonia leak on the outside of station means that Cassidy and I will be doing a spacewalk tomorrow to try and repair it,” Marshburn tweeted Friday morning.
Cassidy and Marshburn are no stranger to working on the space station’s exterior. Both astronauts have conducted three EVAs, all during the Space Shuttle mission STS-127 in 2009. They collaborated on two of those spacewalks (pictured top).