a 4:00 am alarm indicated an ammonia leak, crewmembers of Expedition 42 were forced to don masks and move into the Russian segment of the International Space Station. After some very tense moments, NASA confirmed that everyone is safe although they were required to move out of the US section.
As noted by Bob Jacobs, spokesman for NASA, once the crewmembers were evacuated to the Russian segment they were allowed to remove the masks. Although an alarm was sent, at this time there is no hard data that suggests a leak actually took place.
Currently, flight controllers are working to determine if a pressure spike in a water loop within the thermal control systems is what triggered the alarm. If so, the problem could have something to do with a computer relay box or faulty sensor opposed to an ammonia leak.
As stated by Jacobs, an increase in water loop pressure was recognized, followed by an increase in cabin pressure. Together, these changes indicate an ammonia leak as the worst possible scenario. Because there was a potential risk identified, all crewmembers were isolated inside the Russian segment of the International Space Station. With this, teams now have the opportunity to better evaluate the situation without anyone being in danger.
In communications between Houston’s Johnson Space Center and ISS at 6:02 am, an ammonia leak may not have been the problem. In Houston, flight controllers are in the process of gathering more information and evidence and at this time, it appears a faulty sensor is to blame.
Chances are good all crewmembers will remain in the Russian segment of the International Space Station until tomorrow. However, this segment is stocked with enough provisions to last up to a week if they need to remain there longer.
A statement was also released by Roscosmos, the Russia space agency, saying that a leak of harmful substances associated with the cooling system is why the American crewmembers were isolated. They too confirmed everyone’s safety.
As expected, experts in mission control in Houston, as well as Moscow, worked together efficiently and quickly, with the safety of each crewmember being the primary focus.
This particular outpost is manned by both American and Russian astronauts to include Terry Virts and Barry Wilmore from NASA and Alexander Samoukutyaev, Elena Serova, and Anton Shkaplerov from Russia, although there is also an astronaut from the European Space Agency onboard by the name of Samantha Cristoforetti.