Plumbing problems are the bane of many homeowners’ existence. The same could be said for the International Space Station. The last thing the NASA astronauts want or need in the orbiting space station is a water problem. That’s why among the many projects the astronauts are looking to complete in this 13 day Endeavour mission, the one thing they fixed first was the clogged water recycling system, NASA’s unique system that processes urine into drinking water.
Specifically, the group installed the Water Recovery System’s refurbished Distillation Assembly and replacement of the system’s Fluids Control Pump Assembly. According to NASA’s website, the system can recycle about 93% of the water it receives.
The water recycler uses a distiller NASA says compares to a keg tilted on its side. On Earth, distilling is a simple process of simply boiling water and cooling the steam back into pure water. But without gravity, the contaminants in water never separate from the steam no matter how much heat is used, NASA said.
The keg-sized distiller is spun up to produce an artificial gravity field. The contaminants in the urine press against the sides of the drum while the steam gathers in the middle and is pumped to a filter.
The filters use charcoal-like materials to pull more unwanted elements from the water. Another process uses chemical compounds that bond with the remaining contaminants so filters can pick them out of the water, too. The water that we produce meets or exceeds most municipal water product standards, NASA said.
The water recovery system is one part of the key systems known as the Environmental Control and Life Support System (ECLSS) for the Space Station performs several functions. That system provides a number of functions. For example it provides oxygen, removes carbon dioxide from the cabin air; filters particulates and microorganisms from the cabin air; monitors and controls cabin air partial pressures of nitrogen, oxygen, carbon dioxide, methane, hydrogen and water vapor; and maintains total cabin pressure and temperature.
Meanwhile the astronauts are set for their first spacewalk scheduled to start at about 8pm and last six and a half hours. During the spacewalk they will set up the Tranquility module for removal from Endeavour’s cargo bay and connect it to the station’s Unity node.
According to NASA, the Tranquility module will bump out the room for crew members and many of the space station's life support and environmental control systems including include air revitalization, oxygen generation and water recycling. A waste and hygiene compartment and a treadmill also will be relocated from other areas of the station, NASA stated.
Tranquility will be linked to the Earth-facing side of the ISS’ Unity node. The new node will provide an additional docking point for space shuttles and other crew vehicles visiting the station in the future.
Astronauts will also begin attaching the room with a view module known as the Cupola module. NASA says the Cupola node could be considered the ultimate observation deck as the small, dome-shaped module has seven windows, six around the sides and one on top, that can be shuttered when not in use to protect them from micrometeoroids and the harsh space environment.
Just under ten feet in diameter, the Cupola will accommodate two crew members and portable workstations that can control station and robotic activities. The view will let the crew monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects, NASA stated.