Astronauts on board the International Space Station will be donning suits fitted with snorkels during three scheduled spacewalks.
The three emergency walks, due to take place on Saturday, Monday and Christmas Day, will aim to fix a broken cooling system on the orbiting outpost.
One of the two US astronauts taking part will be wearing an American-made suit that had a helmet leak in July, nearly drowning the European astronaut wearing it.
Luca Parmitano was forced to rush back inside the station after his helmet flooded and an investigation into the leak is still ongoing.
Nasa engineers have had to improvise to make the spacesuits safe for use after a valve that regulates the temperature of equipment on the 15-year-old space station failed last week.
The water pump in the malfunctioning suit has been replaced, an extra absorption pad has been installed and a snorkel fitted to offer an alternative breathing route if needed.
Lead Nasa spacewalk office Allison Bolinger said: “Some smart engineers on the ground were able to figure out ‘Hey this is a similar diameter to a snorkel that you have for scuba diving’.
“By just sacrificing one of our spares on board they were able to come up with a way to just snip off the ends and then file it so it is not rough in the crew member’s mouth and then apply Velcro.”
American astronaut Mike Hopkins will be wearing the suit Mr Parmitano wore. Both he and fellow US astronaut Rick Mastracchio will have the new snorkels and pads inside their spacesuits as a safety measure.
Their task is to remove the pump module with the faulty valve and replace it with a spare pump that was already on board the ISS.