Astronauts aboard the International Space Station will team with NASA ground controllers over the U. S. Labor Day weekend to replace a water relief valve and gas trap filter in the space suit worn by European Space Agency astronaut Luca Parmitano during a July 16 excursion that was cut short when his helmet began to fill with water.
Investigators are hopeful the swap out will point to a "smoking gun" behind the alarming incident that allowed 1 to 1 1/2 liters of water to flow into Parmitano's helmet and collect over his ears, eyes and nose. NASA spacewalks were suspended in the aftermath, and the U.S.-led, ISS mission management team is eager to restore the capability.
His shuttle-era space suit, or Extravehicular Mobility Unit (EMU), was re-activated in the ISS U.S. segment airlock on Tuesday as part of the troubleshooting to verify the leak that released water from an air flow vent at the back of Parmitano's helmet was still present. The 36-year-old Italian Air Force test pilot was not in the protective garb during the test.
The same protocol will be followed this weekend as Parmitano joins NASA astronauts Chris Cassidy and Karen Nyberg for the latest round of troubleshooting, according to NASA spokesman Josh Byerly.
The strategy calls for the astronauts to replace the suit’s water relief value and reactivate the suit, then replace the gas trap components. Both are part of the suit's Primary Life Support System, or backpack, which was identified early on as the likely source of the difficulties.
The valve and gas trap could return to Earth for further analysis aboard the Soyuz TMA-08M capsule carrying ISS commander Pavel Vinogradov, Cassidy and cosmonaut Alexander Misurkin late Sept. 10.On July 16, Cassidy and Parmitano embarked on what was to be a six- to seven- hour multi-mission spacewalk. The excursion was stopped about an hour into the outing after Parmitano felt water at the back of his head. His return to the safety of the airlock quickly grew more challenging as water continued to move along an airflow guide just outside his communications cap. Working largely by feel, Parmitano made his way hand over hand to the airlock, where Nyberg and the station's Russian cosmonauts waited to help him out of the suit.
Though wearing a long safety tether, Parmitano at one point prepared for the possibility he might have to activate a pressure relief value in his suit to expel the water. Had he choked, Parmitano might have drowned, flight controllers said after the incident.
The spacewalk came to an end after 92 minutes.
Cassidy and Parmitano teamed for a July 9 spacewalk in the same suits without similar difficulties.
In addition to the troubleshooting under way in Mission Control, NASA formed a five member Mishap Investigation Board after the incident. The board is responsible for identifying contributing factors as well as a root cause and making recommendations where appropriate for changes in procedures and operations.