The partial evacuation of the International Space Station (ISS) may have been the result of a faulty computer card and not due to feared ammonia gas leak.
Six astronauts were forced to seal themselves in a segment of the orbiting outpost after alarms went off on the ISS indicating possible leakage of the ammonia gas. This happened not once but twice, and the astronauts had to repeatedly undergo the safety precautions.
Again, the #ISS crew is safe inside the Russian segment after an alarm indicated a coolant pressure spike. No ammonia leak confirmed.— NASA (@NASA) January 14, 2015
Fortunately, the situation has returned to normalcy aboard the ISS, and the exact cause that mandated the partial evacuation is being probed. However, preliminary investigations indicate that no gas had actually leaked.
During a briefing from the Johnson Space Center in Houston, administration officials confirmed that teams are investigating whether or not ammonia leaked into the American segment of the station, but they added that it is highly unlikely. Officials are fairly certain ammonia did not leak into the cabin. Instead, the alarms went off owing to a faulty computer card aboard the ISS’ systems monitoring mainframe.
Update: #Exp42 crew informed by controllers that it's starting to look like a false indication, either a faulty sensor or computer relay.— NASA (@NASA) January 14, 2015
At about 4 a.m. Eastern Time, systems on the ISS indicated that measurements in the cabin appeared to be off-scale. In other words, the system sensed that the level of gasses on board the ISS were not “ambient.” The system then issued a visual as well as an audible alarm, prompting all six Expedition 42 members to quickly don masks and seal themselves inside the Russian segment. After a few moments, systems showed a spike in cabin pressure, forcing the crew members to repeat the safety drill once again.
Only after verification from the command center back on Earth were the astronauts allowed to venture back into the section that showed the alleged leak. NASA is confident that ammonia did not leak into the cabin, but they do not take chances, shared Michael Suffredini, manager of the International Space Station Program.
“We also saw an increase in pressure in the cabin. If you’re leaking ammonia into the water loop and it finds its way into the cabin, you’d expect its pressure to go up.”
Ammonia is an essential “coolant” that is used to draw heat generated aboard the ISS. Since it is dangerous to humans, water is used as a “heat transfer medium.” In rare circumstances, ammonia could find its way inside the cabin through the water, which would be sensed by onboard sensors installed for this express purpose. Perhaps it was this system which malfunctioned, triggering the evacuation.
Not taking chances and necessitating another evacuation, the entire crew is being temporarily housed in the Russian segment. As expected, everyone aboard the ISS is quite healthy.
[Image Credit | NASA]