Astronauts aboard the Inter-national Space Station prepared for an unexpected series of spacewalks by fabricating spacesuit snorkels they can use for breathing in case of another helmet water leak, Nasa officials said on Wednesday.
The spacewalks, the first of which is slated to begin at 1210 GMT tomorrow, are needed to replace one of two cooling pumps outside the $100 billion complex.
US spacewalks have been suspended since July after a spacesuit helmet worn by Italian astronaut Luca Parmitano filled with water, causing him to nearly drown.
The underlying cause of the leak remains under investigation, but engineers have learned enough to make modifications so the problem will not happen again.
“I would be surprised if we have a problem with the suits,” said space station programme manager Mike Suffredini.
As a contingency, the spacewalkers’ helmets will be outfitted with absorbent pads and home-made snorkels to funnel air from the body of the water-cooled suits into an astronaut’s mouth, if needed.
“This is your last resort,” said Allison Bolinger, lead spacewalk officer. “If water encroaches your face, like what happened to Luca, the crewmember can lean down and use this (the snorkel) to breathe.”
First-time spacewalker Michael Hopkins will wear Parmitano’s spacesuit, but it has been outfitted with a new fan pump separator, a device that circulates water and air and removes moisture from air.
The fan pump separator from Parmitano’s suit was flown back to Earth for analysis and engineers found that tiny holes in the water-separator portion of the device were clogged.
That allowed water to back up into the fan portion, get into a vent loop and enter the helmet, said Space Station flight director Dina Contella.
Still unknown is how the water was contaminated.
“Unfortunately, it’s a pretty complicated water chemistry problem,” Contella said.
Suffredini said: “We believe the lines we’re using today are clean. We’ve put in new filters and we think the filter system works.”
A new fan pump separator is among the cargo aboard Orbital Sciences Corp.’s first supplyship to the station which had been slated to launch this week. But it is being delayed until mid-January so Nasa can tackle the higher-priority work of getting the station’s cooling system back in operation.
One of two ammonia cooling systems shut down on Decemb er 11, forcing astronauts to turn off unnecessary equipment and suspend some science experiments.
Hopkins will be joined by six-time spacewalker Rick Mastracchio for three spacewalks to replace the faulty cooling system with a spare that is in storage outside the station.