NASA is suspending all but the most urgent spacewalks after water was found in an astronaut’s helmet after a March field trip, agency officials said on Tuesday (May 17).
NASA will conduct an assessment of its extravehicular mobility unit (EMU) spacesuits after water was found in the helmet worn by European Space Agency (ESA) astronaut Matthias Maurer after a spacewalk on March 23, agency officials said.
This means astronauts won’t go out and perform extravehicular activities (EVAs) unless urgent repairs to the International Space Station are needed. Since the stricken EMU won’t return to Earth for analysis until July, non-emergency spacewalks will be off the table for at least several months.
“Until we better understand what the causative factors may have been during the last EVA with our EMU, we can’t use a nominal EVA,” Dana Weigel, deputy station program manager at NASA’s Johnson Space Center in Houston, said at a news conference Tuesday.
Spacewalks: how they work and key milestones
NASA astronaut Jack Fischer gives a thumbs up for a May 2017 spacewalk at the International Space Station. (Image credit: NASA) This is the second time spacewalks have been suspended due to unexpected water leakage, although the last time in July 2013 was much more severe.
During that incident in 2013, ESA astronaut Luca Parmitano experienced a serious water leak that eventually covered most of his face. His spacewalk with NASA’s Chris Cassidy was cut short due to the volume of water Parmitano reported, about an hour after the work started. Parmitano, however, emerged from the incident safe and uninjured.
NASA suspended all spacewalks at the time during an investigation, which culminated in a December 2013 report that identified multiple factors, from the construction of the spacesuit to NASA procedures, that could be changed to prevent such problems in the future. (For example, water had previously been reported by spacewalking astronauts, and NASA determined that a shutdown and investigation should have occurred before Parmitano’s excursion.)
ESA astronaut Luca Parmitano works on the International Space Station during a July 16, 2013 spacewalk, which was aborted when he reported water in his helmet. (Image credit: NASA) The incident report identified the direct technical cause for the 2013 incident as “inorganic materials causing clogging of the drum holes” in an EMU water separator. This, in turn, caused water to flow into a vent loop.
NASA finally determined that the materials penetrate “because of a water filter facility at Johnson” [Space Center] failed to check for silica,” NASA’s Office of the Inspector General (OIG) wrote in April 2017. Was used in four spacesuits in orbit.”
The agency addressed the silica situation and also made backups for astronauts in case of leaks. As of 2014, astronauts used a “helmet absorption pad” on the back of the helmet to absorb excess water. In addition, a breathing tube was inserted into the helmet in case water sticks to the face, as is the case with microgravity. The incident in Maurer’s spacesuit appears to be the most serious water problem since NASA implemented the 2014 fixes.
Matthias Maurer during his first-ever spacewalk outside the International Space Station. (Image credit: ESA) Maurer reported about 8 to 10 inches (20 to 25 centimeters) of water in a very thin layer, covering the inner surface of the helmet. The suit sometimes generates a little water, Weigel said during Tuesday’s press conference, but “this was a little more than what we normally experience. It was mainly the amount of water that caught our attention.”
The agency plans to return both the water samples and the spacesuit filters to Earth as part of the ongoing investigation. “We’re looking for obvious signs of contamination or contamination or something else,” Weigel said.
More helmet absorbers flew on SpaceX’s Crew-4 mission, which arrived at the space station last month, and 16 more pads are scheduled to launch Thursday (May 19) aboard Boeing’s unmanned Orbital Flight Test-2 (OFT-2). (OFT-2 will use a Starliner spacecraft that will later take humans to space, but this effort will have no humans on board.)
“We have additional … very thin kind of absorbent pads that we can put on the inside of the helmet,” Weigel said. “One of them is on the back of the crew headset, and the other is like a band that goes up over the head. [It’s] kinda like in the shape of a headband, but it’s attached to the inner layer of the helmet bubble. And that would offer some relief.”
Weigel emphasized that these extra pads represent a contingency plan in case the astronauts need to fix something in space before the study is completed. The investigation will take some time, she said; the leaking EMU is expected to return to Earth in July, on a SpaceX Dragon freighter, for ground analysis.
“The hardware we send provides solutions in case we have an unforeseen event” [spacewalk] and we have to get out the door,” she said.
Peggy Whitson dons a training version of the Extravehicular Mobility Unit spacesuit before being submerged in the waters of the Neutral Buoyancy Laboratory near the Johnson Space Center. (Image credit: NASA.) Two versions of the EMU have been used in space, starting during the space shuttle program. A basic version was used by astronauts between 1983 and 2002, while an upgraded EMU has been available since 1998. The main manufacturers for the spacesuits were ILC Dover and Collins Aerospace.
As of the April 2017 OIG report, only 11 of the 18 railcars manufactured were available for use in the International Space Station. (Five were destroyed on various space missions, the sixth was lost in a ground test, and a seventh was a certification unit.)
In its report, the OIG said there are concerns that “inventory may not be sufficient to sustain the planned retirement of the ISS in 2024,” “a challenge that will escalate significantly as station operations expand.” (NASA hopes to continue operating the station through the end of 2030, but the other ISS partners would have to agree to that plan.)
However, the agency is currently working on several next-generation spacesuits, most notably Artemis spacesuits on the moon. Delays in space suit development were one of the factors pushing back NASA’s planned first manned moon landing of the Artemis program from 2024 to 2025.
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