Astronauts Brave Brief Ammonia Snowstorm As They Conclude Fix To Space Station

Toxic snowflakes in space were just one obstacle astronauts faced down today (Dec. 24) as they successfully replaced an ammonia pump that will, if all goes to plan, put the space station back in full service in a few hours.

“They’re just completely surrounding us now,” radioed NASA astronaut Rick Mastracchio of the ammonia flakes as the astronauts clipped four fluid lines into place on to the spare pump. NASA said the ammonia was just residual fluid and not indicative of a leak. “Some little ones, some big ones,” he added.

Within a few minutes, however, the ammonia dissipated. Some flakes did strike the spacesuits of Mastracchio and fellow NASA spacewalker Mike Hopkins, causing NASA to do a modified decontamination procedure where the astronauts stayed in a vacuum for a few extra minutes inside the airlock. (The sun’s heat bakes off ammonia over time, and the crew was outside long enough for most ammonia to dissipate, NASA said.)

The spacewalk completed with no further drama at 7 hours and 30 minutes, earning high praise for the participating astronauts from Mission Control in Houston.

“It’s the best Christmas ever,” radioed CapCom and NASA astronaut Doug Wheelock from the ground as the spacewalkers entered the International Space Station’s Quest airlock at the end of the repair job. “We got it,” Mastracchio responded.

NASA astronaut Doug Wheelock (left) and Japanese astronaut Aki Hoshide served as CapComs during two tricky ammonia pump replacements in December 2013. Wheelock assisted Expedition 38 spacewalking astronauts Mike Hopkins and Rick Mastracchio, while Hoshide helped Japanese astronaut Koichi Wakata with robotic maneuvers. Credit: NASA TV (screenshot)
NASA astronaut Doug Wheelock (left) and Japanese astronaut Aki Hoshide served as CapComs during two tricky ammonia pump replacements in December 2013. Wheelock assisted Expedition 38 spacewalking astronauts Mike Hopkins and Rick Mastracchio, while Hoshide helped Japanese astronaut Koichi Wakata with robotic maneuvers. Credit: NASA TV (screenshot)

Preliminary tests show the spare pump is working perfectly. The pump is a welcome present for the six-person Expedition 38 crew, which saw a reduction in science and backup systems for two weeks after a valve in the last pump failed, causing one of the station’s two cooling loops to shut down automatically. The loops are needed to regulate the temperatures of electronics and systems on station.

The Expedition 38 crew was so quick with the repair that they finished the job in two spacewalks instead of the planned three. The astronauts fell behind the timeline today as they struggled with some of the fluid connections to the new pump, but the final steps — putting the electrical connections in place — took just minutes. The pump was brought from another location on station today, and installed into its permanent spot to help ammonia flow through the cooling system.

Anywhere between hundreds and thousands of people at NASA and international partners scrambled to put spacewalks together to fix the cooling problem after it happened. Wheelock, himself a veteran of a tricky ammonia pump repair in 2010, communicated with the spacewalkers. Japanese astronaut Aki Hoshide filled the other CapCom slot, helping Japanese astronaut Koichi Wakata who handled robotics in orbit.

Japanese astronaut Koichi Wakata controlled Canadarm2 during two spacewalks to replace a faulty ammonia pump in December 2013. Credit: NASA TV (screenshot)
Japanese astronaut Koichi Wakata controlled Canadarm2 during two spacewalks to replace a faulty ammonia pump in December 2013. Credit: NASA TV (screenshot)

Mastracchio marked his eighth spacewalk with today’s repair while Hopkins, who rode Canadarm2 for the first time in a last-minute decision, was on his second. As with a spacewalk on Saturday (Dec. 21), the astronauts reported no helmet water leaks — comforting words for agency officials who put in new procedures and parts after an incident in July. (Mastracchio experienced a water problem during repressurization Saturday that was unrelated to the first incident, and wore a backup suit today to let the primary one dry out.)

Should the ammonia pump work as planned, this clears the way for the Russians to do a spacewalk Dec. 27 to install the Urthecast high-resolution camera that will beam live views of Earth, among other tasks. Expedition 38 has the day off tomorrow (Dec. 25), NASA TV added.

The only other Christmas Eve spacewalk in NASA history took place Dec. 24, 1999 during Hubble Space Telescope servicing mission STS-103. Another Christmas Eve milestone for NASA took place 45 years ago today, when the Apollo 8 crew made a now-famous broadcast while orbiting above the moon.

Can Astronauts Fix The Space Station In Two Spacewalks? Watch Live Tuesday To Find Out

Two astronauts are oh-so-close to fixing the International Space Station cooling system that shut down Dec. 11. NASA astronauts Mike Hopkins and Rick Mastracchio will head “outside” on a spacewalk around 7:10 a.m. EST (12:10 p.m. UTC) to replace a faulty pump that led to the problem.

The spacewalkers were so quick on their first outing (on Saturday, Dec. 21) that they accomplished many of the tasks planned for their second spacewalk. They unhooked the first pump module and stowed it safely, then elected to wait until their second to retrieve the replacement pump, swap it in and turn it on.

Below the jump, here are some things to watch for — including why Hopkins is getting a ride on the Canadarm2 robotic arm this time instead of Mastracchio.

The suits. NASA has new safety procedures and measures in place to protect against helmet water leaks, and everything worked perfectly the first time. In an unrelated incident, while the astronauts were in the airlock, an inadvertent switch-throw introduced some water into Mastracchio’s sublimator. The suit is airing out and Mastracchio is wearing a backup suit. While sublimators need water to function, this water could have ended up in the wrong spot. If he had used the one with the water in it, it could have frozen during the second spacewalk and caused problems, Judd Frieling, the Expedition 38 lead flight director, explained on NASA TV Monday.

The background personnel. While it’s easy to shine the spotlight on the two guys outside, also remember that Japanese astronaut Koichi Wakata will be piloting the robotic arm under direction from CapCom and fellow Japanese astronaut Aki Hoshide. Giving advice to the spacewalkers will be CapCom and NASA astronaut Doug Wheelock, who did a similar repair on the International Space Station in 2010. As Wheelock told Universe Today, there are literally hundreds (likely, thousands) of people working the procedures to get this done.

The timeline. NASA really, really wants to wrap this repair up soon, and it’s not because of the holidays. Dec. 27 marks a planned spacewalk for the Russian side of the station that is totally unrelated to what is going on right now. The Americans are hoping they won’t disrupt the schedule so that the Russians can proceed with their experiment swapouts and foot restraint installation as originally planned.

Image above: Expedition 24 Flight Engineers Doug Wheelock (right) and Tracy Caldwell Dyson work to replace a failed ammonia pump module outside of the International Space Station. Credit: NASA TV
Image above: Expedition 24 Flight Engineers Doug Wheelock (right) and Tracy Caldwell Dyson work to replace a failed ammonia pump module outside of the International Space Station. Credit: NASA TV

The robotic arm. Hopkins is a much more junior spacewalker than the experienced Mastracchio, who has seven spacewalks underneath his belt before today. Hopkins, who is on his first spaceflight, is in a situation where he can expect more flights in the future. So any training he can get in orbit would be fantastic as he would be a stronger asset on future missions. So, Mastracchio was supposed to ride the Canadarm2 on the second spacewalk, but at that time NASA anticipated it would take three to do the repair. Since the crew finished the work so swiftly, it’s likely only two will be needed. As such, giving Hopkins the slot would be the best practice, NASA and the crew determined.

The future pump move. NASA decided not to move the faulty pump from its temporary stowage location until later. Due to thermal conditions on station, it can stay in its temporary spot until June. This saves the spacewalkers extra work now, but someone will need to head outside by summer to move it to a more permanent location.

We’ll let you know how the spacewalk went.

Speedy Spacewalkers Ahead Of Pace As Next Repair Moved To Tuesday

The ghosts of spacewalks past did not haunt the quick-working pair of astronauts who began replacing a faulty ammonia pump on the International Space Station today (Dec. 21).

Unlike a difficult spacewalk to do a similar repair in 2010, NASA astronauts Rick Mastracchio and Mike Hopkins were so far ahead of schedule that they began doing tasks scheduled for the second in their expected trio of spacewalks.

In better news yet for the spacewalkers, a water leak in Hopkins’ spacesuit this past July — one that sent astronauts scrambling back to the airlock for safety — did not happen again, showing that the part replacement NASA directed had worked. An unrelated water issue in Mastracchio’s suit, however, made agency officials decide to delay the next spacewalk one day to Dec. 24.

The pump replacement is needed to put the space station at full fighting weight. Since Dec. 11, science experiments and other non-critical systems have been offline since a valve in the pump broke. While the astronauts are in no immediate danger, one of their two cooling loops is shut down and there is not a big margin of safety if the other loop fails.

Since this is NASA’s first spacewalk since the leaky suit was last used, the agency emphasized two new measures it has to protect the astronauts if another leak occurs. The first is a new helmet absorption pad (HAP) to soak up any water in the helmet. The second is a pipe — a snorkel — that would let astronauts breathe air from another part of the suit, if required.

But with every “HAP check” that CapCom and astronaut Doug Wheelock called up to the astronauts today, they reported that the suits were dry and everything was fine. The new water issue happened after the spacewalk, while the astronauts were repressurizing the airlock. In a statement, NASA said water could have entered Mastracchio’s suit sublimator and decided to switch him to a backup suit as a precaution.

The spacewalk tasks themselves, however, went far more swiftly than problems Wheelock experienced in 2010, such as when an ammonia line on the pump refused to unhook as required and caused a lengthy delay. NASA made some changes (such as lowering the pressure on the lines, as Wheelock told Universe Today), and this time, Mastracchio powered through the line and electrical removals. The astronauts quickly moved 1.5 hours of schedule and then beyond. A few stray ammonia flakes hit Mastracchio’s suit, but not enough to cause concerns about contamination since the traces of substance baked off in the sun as he worked.

“I don’t know if you believe in miracles, but I got it on the first try,” Mastracchio radioed early in the spacewalk as he got a tricky part of a Canadian robotic arm foot restraint threaded. Mastracchio rode the arm for much of the spacewalk while Hopkins was the “free floating” colleague hovering and doing other tasks nearby.

NASA astronaut Rick Mastracchio (right) pulls an 800-pound ammonia pump module out of its spot on the space station Dec. 21, 2013. At left is fellow NASA astronaut and Expedition 38 member Mike Hopkins. Credit: NASA TV
NASA astronaut Rick Mastracchio (right) pulls an 800-pound ammonia pump module out of its spot on the space station Dec. 21, 2013. At left is fellow NASA astronaut and Expedition 38 member Mike Hopkins. Credit: NASA TV

The most spectacular television shots occurred towards the end of the five-hour, 28-minute spacewalk when Mastracchio carefully wrestled the 800-pound ammonia pump module out of its spot on the space station while riding aboard Canadarm2. (Controlling the arm was Japanese astronaut Koichi Wakata, guided by CapCom and fellow Japanese astronaut Aki Hoshide on the ground.)

After he stowed the module, Mission Control gave the astronauts the go-ahead to put in the spare. Mastracchio, however, said he felt it was best for the astronauts to leave it for next time. While the pair have three spacewalks (including today’s) slated to finish the task, it’s possible they could wrap it up in two — but only if things go as smoothly as this time.

The next spacewalk will take place Dec. 24 at 7:10 a.m. EST (12:10 p.m. UTC), and will be available on NASA Television. We’ll keep you up to speed as the next spacewalk occurs. Today’s excursion was Mastracchio’s seventh and Hopkins’ first.

NASA astronauts Rick Mastracchio and Mike Hopkins of Expedition 38 worked outside for more than five hours Dec. 21 to begin replacing a faulty ammonia pump on the International Space Station. Credit: NASA TV
NASA astronauts Rick Mastracchio and Mike Hopkins of Expedition 38 worked outside for more than five hours Dec. 21, 2013 to begin replacing a faulty ammonia pump on the International Space Station. Credit: NASA TV

 

After Facing Down Ammonia Leak, This Astronaut Will Help Crew During Spacewalks

When you learned to drive a car for the first time, remember how comforting it was to have an experienced driver beside you, able to anticipate the hazards and keep you on schedule?

That’s surely how the Expedition 38 crew feels about one of the voices “on the line” as two astronauts prepare to venture outside to replace a crippled ammonia pump. One of the “CapComs” or people communicating with the crew on Saturday, Monday and Wednesday will be astronaut Doug Wheelock — who just happens to be known for co-replacing a broken ammonia tank himself in 2010. (The other CapCom is Japanese astronaut Aki Hoshide, who will chat through robotic procedures with Koichi Wakata).

Wheelock is the visible edge of hundreds — likely thousands — of people working feverishly at NASA and its international partners this past week to get the spacewalks ready through pool simulations, a virtual reality lab and other means. Several backup and non-critical space station systems are offline because of that pump, which has to regulate temperatures properly for vital electronics to work.

“I am their choreographer,” Wheelock told Universe Today of his plan for the astronauts. While spacewalkers Mike Hopkins and Rick Mastracchio already know what they are supposed to do when, Wheelock said he will be “their eyes and ears on the timeline.” If something needs to be stopped or changed, he’ll help them figure out what to do next.

NASA astronaut Doug Wheelock anchored to Canadarm2 during an August 2010 spacewalk. He and Tracy Caldwell Dyson ventured outside three times during Expedition 24 to swap out and replace a broken ammonia pump. Credit: NASA
NASA astronaut Doug Wheelock anchored to Canadarm2 during an August 2010 spacewalk. He and Tracy Caldwell Dyson ventured outside three times during Expedition 24 to swap out and replace a broken ammonia pump. Credit: NASA

Wheelock and fellow astronaut Tracy Caldwell Dyson had to spring into action themselves in August 2010. A pump in the same location broke, forcing space station systems offline and requiring them to go outside a few days later. With astronaut Shannon Walker piloting Canadarm2, the astronauts accomplished their tasks in three spacewalks — but encountered obstacles along the way.

During the first spacewalk, as Wheelock disconnected lines from the broken pump, he not only faced a pipe that wouldn’t let go, but a shower of ammonia snowflakes. That was “what got me on the EVA [extra-vehicular activity],” he recalled. That’s why NASA plans to lower the line pressure on the cooling system before the astronauts head outside this time. Normally the lines are pressurized at 360 pounds per square inch, but they’ll be lowered to 120 psi through commands from the ground.

Other “lessons learned” are more recent. Italian astronaut Luca Parmitano was wearing a NASA spacesuit in July when he experienced a water leak in his helmet, putting him at risk and terminating the spacewalk early. This will be the first spacewalk since that time. NASA believes it has replaced the part of the suit that failed, but the agency has new backups in place. Hopkins and Mastracchio will have soaker pads in their helmets as well as a “snorkel”-like device, or tube that will let them breathe oxygen from a different part of the suit if water flows into the helmet again.

Allison Bolinger, NASA's lead U.S. spacewalk officer, holds up a snorkel-like device that astronauts began using in spacesuits in December 2013. The pipe (modified from spacesuit parts) is supposed to be a backup if a helmet fills with water, as what occurred during a July 2013 spacewalk. Credit: NASA (YouTube/screenshot)
Allison Bolinger, NASA’s lead U.S. spacewalk officer, holds up a snorkel-like device that astronauts began using in spacesuits in December 2013. The pipe (modified from spacesuit parts) is supposed to be a backup if a helmet fills with water, as what occurred during a July 2013 spacewalk. Credit: NASA (YouTube/screenshot)

So what are some key parts of the spacewalks to look for? Wheelock identified a few spots.

‘HAP’ check. That soaker pad is called a “helmet absorption pad”, and as a matter of course the astronauts will be asked to verify that the pad is not wet at the same time that they also check their gloves for tears (another lesson learned from a past spacewalk.) So you will hear Wheelock calling “HAP check” from time to time to the crew.

Unlatching and latching the ammonia connectors on the pumps. Because this is when leaks are most likely to occur — posing a risk to Mastracchio, who is performing the work — Wheelock is going to do a “challenge and response” procedure. He will read up the step, the astronaut will verify it and will do the work. There will be “a lot more chatter on the [voice] loop” during those times, Wheelock said, with everyone on the ground watching through Mastracchio’s head camera feed (visible at the front of the room) to see what is happening. “There will be a lot of people standing in Mission Control at that point,” he joked, himself included.

Leak procedures. If ammonia does start to shower out, Mastracchio will quickly close the valve and wait a few minutes as it could be just residual ammonia in the line. If that doesn’t work out, Mastracchio is trained on a procedure to attach a device to the front end of the connector and move a lever that prevents a cavity in the line from filling with ammonia. Then he can open the valve again, bleed out the ammonia that’s left over and keep going.

NASA astronaut Rick Mastracchio inspects two spacesuits to be used during spacewalks in December 2013. The spacewalks were to remove and replace a faulty ammonia pump. Credit: NASA TV
NASA astronaut Rick Mastracchio inspects two spacesuits to be used during spacewalks in December 2013. The spacewalks were to remove and replace a faulty ammonia pump. Credit: NASA TV

Decontamination procedures. The ammonia makes a distinctive “ping” when it hits the helmet, says Wheelock (who yes, heard that happen himself.) You can also see ammonia on the suit, he said, as it looks a bit like candle wax and obscures the stitching. All of which to say, NASA has procedures in place if the agency suspects or can confirm large amounts of ammonia got on Mastracchio’s suit. (Small amounts would essentially fleck off in the sun.) Hopkins, who will be out of the line of fire, can do a thorough inspection of Mastracchio and scrape off any ammonia with a warm metal tool — without hurting the suit underneath. The astronauts could also do a “bakeout” in the airlock — 30 minutes if suspected, an hour if confirmed — where they will sit with the hatch open and wait for any ammonia to sublimate off the suit. Once they close the hatch, the astronauts can verify if the ammonia is gone using Drager tubes, which have gold crystals inside that turn “purpleish blue” in the presence of ammonia, Wheelock said.

Margin calls. Because NASA needs to make sure the astronauts have 30 to 60 minutes to decontaminate at the end of their spacewalks, officials will preserve a margin of oxygen available for the astronauts to walk through that work. So it’s possible the agency may terminate a spacewalk before all tasks are completed just because they need that bit of margin at the end.

To learn more, Wheelock has been answering questions occasionally on his Twitter account from followers, and you can read through what he posts when he finds the time. Universe Today will also cover the spacewalks (currently planned for Saturday, Monday and Wednesday) as they occur.