Astronauts on the International Space Station “could have ignited flammable materials” on station while drying out a spacesuit that experienced a major leak during a spacewalk in July 2013, a new report reveals.
NASA Mission Control directed the Expedition 36 crew to use a vacuum cleaner to suction out the water, a procedure that inadvertently sucked up oxygen from the suit’s secondary high pressure oxygen tank, says a mishap report into the spacesuit leak incident. This “potentially hazardous risk” of electricity and pure oxygen created a fire hazard, the report added.
In a phone call with reporters yesterday (Feb. 27), report chair Chris Hansen added that the “levels of oxygen were perfectly safe” in this particular incident and that the “the risk to the crew in the end was none”, but said the incident still warranted attention in the 222-page report, which mainly deals with the spacesuit leak.
The incident occurred on July 17, 2013, one day after a “life-threatening” amount of water leaked into a spacesuit helmet used by Luca Parmitano, the report said. The astronauts and NASA were doing looking for the source of the leak. Astronauts reported no damage to the water bag and no water in the suit (which had been cleaned up after the spacewalk).
Next, they turned on the fan to the portable life support system (or backpack) with a secondary oxygen pack (SOP) check-out fixture. The fixture covered a vent port and oxygen switch for about 14 minutes. All appeared to be running normally, with no water detected. When the crew then removed the fixture (following procedure), they heard a “sucking” noise and the fan ceased moving, the report said.
“The crew was directed to turn off the suit fan and move the O2 Actuator to OFF. The crew then turned the suit fan back ON and again set the O2 Actuator to [the] IV [setting]. The fan briefly began spinning and then shut down almost immediately, with the crew reporting a water “sucking” or “gurgling” sound,” the report added.
The crew found “a few drops” of water in a canister outlet and “about a spoonful” of water in the suit inlet ports, as well as a few drops of water in a neck vent port. As the ground decided what to do, an infrared carbon-dioxide transducer in the suit “began to show an increase in its reading and eventually went off-scale high, most likely due to moisture in the vent loop near the CO2 [carbon dioxide] transducer,” the report stated.
With water in the suit, Mission Control then asked the crew to remove the water with a vacuum (one that is designed for wet or dry cleanup) as soon as the astronauts had the chance. Everything was normal until after the station emerged from a routine loss of signal, at which point controllers saw the secondary oxygen pack was turned on and reading 500 pounds per square inch lower than before the loss of communication.
“They quickly realized that their procedure had resulted in the EMU releasing 100% oxygen from the SOP into the vent loop, which was then sucked into the vacuum cleaner. This was a potentially dangerous situation involving unintended consequences,” the report said.
“During interviews, system experts indicated that they should have been able to anticipate SOP activation due to the reduced pressure created by the vacuum cleaner. The procedure was immediately stopped. No fire occurred and the crew was not harmed.”
In interviews after the incident, individuals spoke of “perceived pressure” to do the dry-out procedure quickly instead of first testing it on the ground with similar hardware. They instead used a non-functional spacesuit before directing the crew to do the procedure.
There were at least three factors contributing to that pressure, the report added: the desire to avoid corrosion in the suit, limited crew time, and the impending loss of signal.
The report did not identify any “additional causes, findings, or observations” from this event, noting that it is not technically an anomaly and was not classified as such in the NASA literature.
While NASA’s Mission Control “performed admirably” during a spacewalk water leak crisis in July, a report on the incident showed that controllers did not send astronaut Luca Parmitano back to the airlock until after he made three calls saying the water didn’t appear to be from a drinking bag.
There are several reasons this happened, the mishap report says, such as inadequate training, the crew members and ground misunderstanding the severity of the situation, and a (false) perception that any water leak is likely due to a problem with the drinking bag.
Another big problem was the “normalization of deviance”, similar language to what was used during in reports describing the Challenger and Columbia incidents. In this case, small amounts of water in the helmet was expected, and controllers also misunderstood the cause of a carbon dioxide alarm (a fairly regular occurrence during spacewalks).
The report pulls no punches when it describes how bad things were: “The presence of this water created a condition that was life threatening.”
While talking about what is in the report, it’s also important to point out what the investigators did not find. There was no evidence that contractors were afraid to bring up problems (such as what happened during the 1986 Challenger explosion), chair Chris Hanson told reporters yesterday. Also, while the suits are 35 years old, no aging problem was detected.
Another couple of cautions: the report is preliminary (the exact cause of the leak is under investigation), it’s lengthy (222 pages) and much of the technical information is unavailable to the public due to export control restrictions. Any news story will just scratch the surface of what happened and the recommendations to fix it.
That said, here are a few key points we found in the report.
Parmitano warned controllers multiple times. The transcript shows three separate calls from Parmitano saying it wasn’t the drinking bag at cause: (1) “I feel a lot of water on the back of my head, but I don’t think it is from my bag.” (2) “The leak is not from the water bag and it is increasing.” (3) “I’m thinking that it might not be the water bag.” (In between 1 and 2, he also sent another call saying his “only guess” was it was the drinking bag, but the report adds that Parmitano may have softened his stance after speaking to controllers). Misunderstanding about the severity, lack of training, “cognitive overload” of controllers, and space-to-ground-to-space communication difficulties are all cited as contributing factors.
Drink bags don’t actually leak as much as people think they did. Unequivocally, the mishap investigation board says “the perception that drink bags leak, especially as a frequent occurrence, is false.” There has never been an instance of a bag leaking substantially during a spacewalk, the report says. After the crisis passed and investigators had the luxury of time, they in fact identified seven separate possible sources of water: (1) the bag; (2) the waste collection garment; (3) cooling water from the sublimator heat rejection component of the suit; (4) the Liquid Cooling Ventilation Garment connector or the tubing itself; (5) transfer lines through the Hard Upper Torso; (6) water storage tankage through the pressurizing bladders; (7) the water separator circuit (which is where the problem was eventually found).
It was a risky decision to send Parmitano back alone. Twenty-three minutes after Parmitano warned of water in his helmet, NASA terminated the spacewalk and as per procedure, had the astronaut head to the airlock while crewmate Chris Cassidy performed cleanup tasks before doing the same. (“Terminate” has a specific meaning as opposed to “abort”, which means both crew members leave immediately.) By this time, water was in Parmitano’s eyes and the station had passed into the shadow of the Earth, forcing him to feel his way back to the airlock along the tether. (This was only his second spacewalk on station, too.) Also, the water affected his communications equipment, as he made several calls “in the blind” that were not heard. At this time, Cassidy and the ground controllers did not know how severe the situation was. “Additional risk exposure that the team could have considered was the aspiration of water, failure of comm equipment, and impaired visibility,” the report said.
The emphasis on science on station can hinder with maintenance tasks. NASA and other space station partners are eager to demonstrate how great the station is to science, but crew time is divided between that and doing maintenance tasks. “Due to this knowledge, team members felt that requesting on-orbit time for anything non-science related was likely to be denied and therefore tended to assume their next course of action could not include on-orbit time,” the report states. To give a specific example of how this affected Parmitano’s suit: After water was found in the suit during a previous spacewalk, the crew and ground essentially determined it was due to the drink bag and did not probe further, partly because of the perception that doing an investigation would take an inordinate amount of time for little return (as they believed they knew the cause). On a related note, there was also the concern that investigating this occurrence (which happened on July 9) would delay the July 16 spacewalk. (Again, this sounds a bit like Challenger, where time pressure was cited as a reason to launch despite icy conditions.)
More needs to be done to understand the physics of water in a spacesuit. A few examples: it was believed the fan would have failed if water got through the separator unit, which did not occur. It was also believed that any water in the helmet would cling to the helmet, and not the crew member’s face. Not only that, the training for crew and ground was inadequate to seek out water causes on the fly. “Had this been done, the crew and ground team may not have attributed water in the helmet to just the drink bag,” the report stated.
Water in the helmet was normalized. If you’ve read Chris Hadfield’s An Astronaut’s Guide to Life On Earth, there’s an account in there about how Hadfield (who also was a junior spacewalker in 2001) became temporarily blind due to an anti-fog agent on the helmet getting into his eyes. This has happened during other spacewalks, too, which meant that the ground team was used to small amounts of water in the helmet — even though this wasn’t a normal condition. Another aspect: a carbon dioxide alarm went off in Parmitano’s suit after it became saturated with water. This happened six minutes before he felt the dampness. The team attributed this to “nominal accumulation of moisture in the vent loop,” which can happen at the end of the spacewalk. Having it happen less than an hour in, however, did not trigger a fault-finding process.
While there are many, many causes in the report (with aspects ranging from the technical to the procedural to the training), members identified three main ones to the incident: (1) inorganic materials in the water separator drum holes, for reasons still unknown (2) a lack of understanding that meant the team’s response took longer than usual (3) a misdiagnosis of the water found during the July 9, 2013 spacewalk.
There are 49 separate recommendations ranging from “Level 1” priority to “Level 3”, which are still important but less urgent. NASA has pledged it will clear all “Level 1” and “Level 2” items before doing any normal spacewalks, although contingency ones are still possible. They expect this to be finished by June, but say they will take as long as needed to get the investigation done. There are no pressing spacewalk tasks on station right now.
Looking to the long run, the report noted that there should be more backups available if a fault is found in the spacesuits, as NASA is relying on these devices to perform essential station maintenance as far as 2028. Also, the investigators say that the six-year certification of these suits for orbital tasks is likely inadequate, and calls for a review of that. So although aging was not identified as an issue, maintenance and backups of the spacesuits could be key features of NASA thinking in the months and years to come.
It took NASA almost the same amount of time as a sitcom episode to send Luca Parmitano back to the airlock when the Italian astronaut experienced a leak in his spacesuit last summer, a new report reveals.
The 23-minute gap of time between when Parmitano first sent a report of water in his helmet, to when NASA told him to go back to safety, exposed the astronaut “to an increased level of risk”, the report said. While Parmitano emerged from the incident safely, in his last minutes inside the spacesuit the water was covering his eyes, getting close to his nose and mouth, and affecting the communications equipment.
“There wasn’t an issue of anything being hidden or surprised. It was a lack of understanding about the severity of the event. It was believed a drink bag caused the leak,” said Chris Hansen, the chair of the mishap investigation board, in a press conference today (Feb. 26).
This misunderstanding, added Hansen (who is also the chief engineer of the International Space Station Program) also led to a problem when a leak occurred in the same suit just the week before.
Parmitano’s water leak occurred July 16 when he and Chris Cassidy were preparing a part of the International Space Station for a new Russian module. Until today, however, few knew about the existence of a second leak in the same spacesuit that happened on July 9, when Cassidy and Parmitano were doing another spacewalk together.
After the conclusion of “EVA 22” on July 9, as NASA called the extra-vehicular activity, Parmitano took off his helmet and crew members discovered between 0.5 and 1 liters (0.13 to 0.26 gallons) of water inside. Cassidy told the ground that he could not see any water during the spacewalk or repressurization, leading NASA to conclude the water got into the helmet in the airlock.
“Also,” the report noted, “[Parmitano] was looking down and leaning forward and likely had pressed on the drink bag with his chest and could have pinched the bite valve open with his chin, releasing water into his helmet. The ground team accepted the crew’s drink bag leak assessment and the presence of excessive water in the helmet was not investigated further … The ground team instructed the crew to use a new drink bag for the upcoming EVA 23, which they did.”
Hanson emphasized that the crew did not make the final call, and that the ground team did ask some questions about what was going on, but the assumption that a drink bag caused the water was also a key feature of the July 16 spacewalk when the leak began to show itself in earnest.
Also, NASA did not well understand the physics of how water worked inside of the suit, assuming there was no way for liquid to make it past a fan pump separator into the helmet unless the fan itself shut off. If that scenario arose, NASA would have kicked into a 30-minute return-to-airlock procedure, and that was in the back of controllers’ minds as they were working through the fault tree during the July 16 spacewalk, officials said in the phone call today.
In the short term, the authors of the report have several “Level 1” or priority recommendations that they should be implemented before normal spacewalks resume. NASA said it’s planning to work through these and “Level 2” recommendations in time for June, with the aim of getting spacewalks going again in July or August.
Emergency spacewalks can still go forward, as the agency has new safety measures in place (including snorkels). This happened in December as the astronauts replaced a faulty ammonia pump.
The agency has no pressing spacewalk tasks at this time. The broken pump, sitting in temporary stowage outside the station, was initially safed to stay there until summer, but further analysis shows that it could sit there for several months more.
You can read the entire 222-page report here. We’ll pull out more highlights tomorrow after we have some time to look over it in more detail, too. The exact cause of the leak is still under investigation.
Here’s the latest attempt to hunt down the water leak that aborted Luca Parmitano’s spacewalk in July: two astronauts aboard the International Space Station removed and replaced a fan pump and water separator inside the spacesuit earlier this week.
All spacewalks with NASA suits are on hold while the agency investigates the leak, and they have been trying mightily. In late July, then on-station NASA astronaut Chris Cassidy demonstrated how the pool of water spread within the helmet (as you can see in these YouTube videos).
This week, on-orbit NASA astronauts Mike Hopkins and Karen Nyberg delved further. While the astronauts are trained before their missions on some suit repairs, this particular type was not something that was covered before they left Earth. After Mission Control walked them through what to do, the astronauts proceeded cautiously as they did the work, NASA said.
“Our engineering teams have identified several different components of the suit, designing a big fault tree, and this is just one of the components that we think could have contributed to the leak in the suit,” said Alex Kanelakos, an extra-vehicular activity flight controller and astronaut instructor, in a new YouTube video.
“Specifically, the water separator is what we’re concentrating our efforts on today.”
As Kanelakos explained, a motor inside the suit drives the fan pump and water separator. The fan circulates oxygen, and the pump pumps the coolant fluid. The water separator, meanwhile, takes out moisture (water) from the ventilation loop and gas that could be trapped inside the water coolant loop. The dried-out air is then returned to the crew member for breathing, and the cycle continues.
As any astronaut is trained to do, Parmitano did consider other contingencies while the leak was happening, he wrote:
“The only idea I can think of is to open the safety valve by my left ear: if I create controlled depressurisation, I should manage to let out some of the water, at least until it freezes through sublimation, which would stop the flow. But making a ‘hole’ in my spacesuit really would be a last resort,” he wrote.
That fix, however, was not implemented as Parmitano and Cassidy made their way back to the station in time for their crewmates to repressurize the hatch and bring their Italian crewmate safely inside.
Here’s our Weekly Space Hangout for July 19, 2013. Watch as a team of space and astronomy journalists discuss the big space stories of the week. We do this every Friday at 12:00 pm Pacific Time / 3:00 pm Eastern Time. You can join us live, or watch the archive here or on Google+.