NASA is suspending all but the most urgent spacewalks after water was discovered in an astronaut’s helmet following a March excursion, agency officials said Tuesday (May 17).
NASA will conduct an evaluation of its Extravehicular Mobility Unit (EMU) spacesuits after water was discovered in the helmet worn by European Space Agency (ESA) astronaut Matthias Maurer after a spacewalk space on March 23, agency officials said.
This means that astronauts will not go out and perform extravehicular activities (EVA) unless there is an urgent need for repairs on the International Space Station. Since the affected EMU will not return to Earth for analysis until July, non-emergency spacewalks will be ruled out for at least several months.
“Until we better understand what the causal factors may have been during the last EVA with our EMU, we’re not going for the nominal EVA,” said Dana Weigel, the station’s deputy program manager. at NASA’s Johnson Space Center in Houston, during a press conference. tuesday.
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This is the second time spacewalks have been suspended due to an unexpected water leak, although the last time in July 2013 was much more serious.
During this 2013 incident, ESA astronaut Luca Parmitano suffered a severe water leak that ended up covering most of his face. His spacewalk with NASA’s Chris Cassidy was halted due to the volume of water reported by Parmitano, about an hour after work began. Parmitano emerged safely from the incident and injury-free, however.
NASA suspended all spacewalks at the time amid an investigation, culminating in a December 2013 report that identified several factors, from spacesuit construction to NASA procedures, which could be modified to avoid 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 taken place before Parmitano’s excursion.)
The incident report identified the immediate technical cause of the 2013 incident as “inorganic materials causing drum holes to clog” in an EMU water separator. This, in turn, caused water to spill into a vent loop.
NASA ultimately determined that the materials got in “because a water filtering facility at Johnson [Space Center] had not been successful in controlling silica,” NASA’s Office of Inspector General (OIG) wrote in April 2017. “As a result,” the OIG continued, “silica-laden water was used in flight hardware filter processing was used in four spacesuits in orbit.”
The agency looked into the silica situation and also created backups for astronauts in the event of a leak. Beginning in 2014, astronauts used a “helmet absorption pad” on the back of the helmet to absorb excess water. Additionally, a breathing tube has been inserted into the helmet in the event of water clinging to the face, as is often the case in microgravity. The Maurer spacesuit incident appears to be the most serious water issue since NASA implemented the 2014 patches.
Maurer reported about 8 to 10 inches (20 to 25 centimeters) of water in a very thin layer, covering the inside surface of the helmet. The suit generates a bit of water at times, Weigel said at Tuesday’s press conference, but “it was a bit beyond what our normal experience faces. That’s precisely 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 any obvious signs of contamination or fouling or whatever,” Weigel said.
Other helmet-absorbing pads flew on SpaceX’s Crew-4 mission, which arrived at the space station last month, and another 16 pads are set to launch aboard Uncrewed Orbital Flight Test 2 ( OFT-2) from Boeing Thursday, May 19. (OFT-2 will use a Starliner spacecraft that will later ferry people into space, but this effort has no one on board.)
“We have extra…very thin absorbent pads that we can put inside the helmet,” Weigel said. “One of them is towards the back of the crew helmet, and the other is a kind of band that goes up above the head. [It’s] much like in the form of a headband, but it is attached to the inner layer of the helmet bubble. And so that would provide some mitigation.”
Weigel pointed out that these extra pads represent a contingency plan in case astronauts need to fix something in space before the investigation is complete. The investigation will take time, she said; the leaked EMU is scheduled to return to Earth in July, on a SpaceX Dragon freighter, for ground analysis.
“The material we send will offer mitigation measures in case we have an eventuality [spacewalk] and we have to get out the door,” she said.
Two versions of the EMU have been used in space, starting with 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 spacesuit manufacturers were ILC Dover and Collins Aerospace.
According to the April 2017 OIG report, only 11 of the 18 EMUs manufactured were available for use on the International Space Station. (Five were destroyed on various space missions, the sixth was lost during ground testing, and a seventh was a certification unit.)
In its report, the OIG said there were concerns “that the inventory will not be sufficient to last until the planned retirement from the ISS” in 2024, “a challenge that will worsen significantly if the station operations are extended”. (NASA hopes to continue operating the station until the end of 2030, but other ISS partners will have to agree to this plan.)
The agency, however, is currently working on several next-generation spacesuits, in particular the Artemis lunar spacesuits. Delays in spacesuit development were among the factors that delayed NASA’s planned first crewed moon landing of the Artemis program from 2024 to 2025.