The ageing shuttle-era spacesuits aboard the Worldwide House Station have been declared “no-go” for operational, usually deliberate spacewalks pending evaluation to find out what led to extra water entering into an astronaut’s helmet throughout a March tour, officers confirmed Tuesday.
However the cumbersome spacesuits — “extra-vehicular mobility models,” or EMUs — can nonetheless be used for emergency repairs or to resolve different sudden points if company managers agree after assessing the general danger.
“Till we perceive higher what the causal components may need been over the past EVA with our EMU, we’re no-go for nominal EVA (spacewalk),” mentioned Dana Weigel, deputy supervisor of the house station program on the Johnson House Middle in Houston. “So we received’t do a deliberate EVA till we’ve had an opportunity to actually tackle and rule out main system failure modes.”
Water intrusion has been a supply of concern ever since a July 2013 spacewalk wherein European House Company astronaut Luca Parmitano’s helmet flooded with water, a daunting, probably life-threatening malfunction that pressured an early finish to the tour.
Parmitano was not injured, however after the spacewalk NASA mentioned he reported “impaired visibility and respiratory with water overlaying his eyes, nostril and ears.” The astronaut’s “calm demeanor within the face of his helmet filling with water presumably saved his life.”
The “high-visibility shut name” triggered a serious investigation to pin down the supply of the leakage. An in depth inspection revealed clogs in a element that inadvertently diverted water right into a vent line that allowed intrusion into the helmet.
Whereas working to resolve swimsuit servicing to stop such clogs sooner or later, NASA carried out two steps to assist a spacewalker make it again to the station’s airlock in an identical emergency.
A “helmet absorption pad,” or HAP, is now positioned behind the helmet to absorb any extra water which may make its approach into the headpiece and a separate straw-like respiratory tube was added to offer an unobstructed provide of air if wanted. Astronauts now report the standing of their HAPs all through a spacewalk.
Extra lately, Weigel mentioned, one other absorbent pad has been added to kind a dam of kinds, impeding the motion of any water towards the entrance of the helmet.
There have been no severe situations of water intrusion since Parmitano’s spacewalk, however on the finish of the latest EVA on March 23, astronaut Kayla Barron, serving to German astronaut Matthias Maurer out of his spacesuit, discovered water contained in the helmet.
“It’s a bit bit troublesome to evaluate the quantity as a result of it’s unfold throughout the entrance of his visor,” Barron mentioned. “However I believe we should always speed up the steps to get him out of his swimsuit right here.”
As soon as the helmet was off, the crew estimated as much as 50 p.c of the visor was coated with a skinny movie of water and that the absorption pad behind the helmet was damp.
“The HAP is a bit bit moist, however I believe it could have been troublesome to detect by a comm(unication) cap,” Barron reported. “Roughly, possibly an eight- to 10-inch diameter circle, a skinny movie of water on the helmet. And there may be water in his vent port behind his neck ring.”
NASA plans to ship Maurer’s EMU again to Earth in July aboard a SpaceX Dragon cargo ship for an engineering evaluation.
4 spacewalks to proceed upgrading the station’s solar energy system had been tentatively deliberate over the remainder of the yr, two in August and two in November, however such EVAs at the moment are on maintain pending evaluation of Maurer’s swimsuit.
“Up to now, we haven’t discovered something uncommon,” Weigel mentioned of inspections aboard the house station. “We’re searching for any apparent indicators of contamination or fouling or one thing else which may have gotten into our system. We’re not seeing that but.”
Whereas deliberate spacewalks are on maintain, she mentioned a contingency EVA may very well be authorised after evaluate and a “risk-versus-risk” evaluation.
“Relying upon what has failed and what the danger is to the spacecraft and to the mission total, we’ll take a look at the place we’re with the investigation, the place we’re with the extra mitigations that we’re setting up and we’ll particularly make a name primarily based on the contingency and the place we’re on the given second,” she mentioned.