An American astronaut has reported that water leaked into his helmet during a six-and-a-half-hour spacewalk at the International Space Station on Wednesday, a reminder of a nearly lethal accident two years ago.
Nasa astronaut Terry Virts was outside the station together with his colleague Barry Wilmore installing cables around the docking ports of the station’s US modules as part of preparations for next year’s arrival of Nasa’s new private space taxis. Upon return to the airlock he found water floating inside his helmet and an absorption pad was wet.
Unlike in the case of European spacewalker Luca Parmitano, who nearly drowned in July 2013 when his helmet started filling with water while outside the station, the Wednesday incident neither put Virts at risk nor required the mission to be aborted, Nasa said.
"I really can't see any immediate danger," station flight engineer Samantha Cristoforetti of Italy radioed to ground control teams at Mission Control in Houston after helping Virts after the space walk.
Nasa said engineers do not know the cause of the leak and whether it’s in any way related to the problem experienced by Parmitano. They are currently analysing the data and will decide on Friday whether to go ahead with the next spacewalk planned for Sunday.
The Parmitano incident, which saw the astronaut's communication equipment malfunctioning and his vision getting completely blocked by a huge buble of water, resulted in Nasa suspending operations outside the station requiring the use of US-designed space suits. The issue was later attributed to a faulty pump.
During their outing on Wednesday, Virts and Wilmore removed a cover protecting the space shuttle's docking port, one of two sites being reconfigured for the new spaceships developed by Boeing and SpaceX.
The work is the first step in the complex reconfiguration of the $100bn orbital outpost that will continue later this year with installation of two international docking port adapters, to be delivered by SpaceX's Dragon capsule.
The spacewalkers finished routeing two power and data cables and greased the grapple fixture at the end of the station's robot arm.
They also prepared the Tranquility connecting node for the September arrival of an experimental inflatable habitat built by privately owned Bigelow Aerospace.
If Sunday’s spacewalk receives a green light, the astronauts will set up a new communications system for the visiting vehicles.
The station, probably the most challenging engineering project ever attempted, is a partnership of 15 nations including the USA, Japan, Russia, Canada and several European nations.
Earlier this week, Russia's space agency Roscosmos confirmed that despite earlier indications it may no longer wish to continue its participation, it will remain part of the team until 2024.