The International Space Station crew is safe right now. I just wanted to clear that up at the beginning.
So, what happened? An alarm went off in the pre-dawn hours this morning that can indicate an ammonia leak.Increased pressure was noted in the station’s water loop for thermal control system B. Then, flight controllers on the ground saw what appeared to be an increase in cabin pressure.
“We saw an increase in water loop pressure, then later saw a cabin-pressure increase that could be indicative of an ammonia leak in the worst case scenario, so we protected for the worst case scenario and isolated the crew is the Russian segment of the space station while the teams are evaluating the situation,” NASA spokesman Bob Jacobs said.
Officials on the ground and the Expedition 42 crew erred on the side of caution and began evacuating.
The Expedition 42 crew donned masks and sealed themselves in the Russian segment of the station. No ammonia was detected in the Russian side of the station and the crew took their masks off.
Officials at Mission Control in Houston continue to pour over data. But at this point, it’s likely the spike in pressure was due to a faulty sensor or computer relay. Officials believe no ammonia was leaked into the station’s atmosphere.
NASA officials will be triple checking everything. All indicators are pointing to a faulty reading. Let’s hope it stays that way.
Astronaut Chris Hadfield has been talking about the situation all morning on Twitter. He says an ammonia leak is one of the most practiced scenarios for ISS crewmembers.