In the photo: astronaut Samantha Cristoforetti during an emergency simulation.
Don’t panic is written in large letters across the Hitchiker’s guide to the galaxy in Douglas Adam’s novel of the same name. Don’t panic was also our motto yesterday in the Columbus Control Centre in Oberpfaffenhofen, Germany as well as in the International Space Station control centres in Houston, Moscow and Tsukuba, Japan.
At 9:44 CET an emergency alarm was triggered on the International Space Station that implied ammonia from the external cooling circuit could have leaked into its interior. Following emergency protocol the astronauts quickly went to the Russian part of the Station as no ammonia is used for the cooling circuits in those modules. The astronauts could see from air measurements that they were perfectly safe in the Russian segment.
From the start there was some doubt as to whether ammonia really was leaked but for safety the crew was told to stay in the Russian segment while the situation was analyzed in detail. The astronauts were fast to inform us that they were fine: Samantha tweeted to the world: “Thanks for your concern, we are all doing well!”
In this type of emergency the external ammonia cooling circuit is quickly shut down and working pressure is reduced to prevent further inflow of toxic gas to the modules. Yesterday the ammonia loop B was shut down meaning half the cooling performance of the Space Station was no longer available. The Columbus Control Centre had to partially shut down the Columbus space laboratory to reduce heat production. While the astronauts waited for the call to reopen the hatch, the control centers were busy trying to get a first idea of what was happening and adapt the Station’s configuration to the new situation. While we were doing this experts were called in to find out why the emergency alarm sounded. In the afternoon we came to the conclusion that the reported measurements that triggered the alarm could not be trusted. Detailed analysis based on other measurements indicated a computer problem and not a real emergency scenario.
In the evening the crew was given a “Go” to enter the American part of the Space Station wearing gas masks and take measurements – no ammonia was detected. At around 21:00 CET the astronauts opened the hatch and could sleep in the American part of the station.
Although the danger was a false alarm the B Loop is still shut down – we do not want to rush things but bring the Station slowly back to full operations from its present configuration. The emergency has evolved into a scheduling problem for us as we try to readjust the schedule to make up for the lost time.
In a way the situation happened at the best possible time. The astronauts were just about to set up experiments with living fruit flies and other biological experiments. These experiments would have failed if they had left them alone during their time in the Russian segment. ‘Luckily’ the alarm was triggered just before they started so the experiments will be able to run safely in the near future.
The experiments and hardware in the Columbus laboratory seems to have survived the emergency power down as well. Tomorrow we think Samantha and Terry will be able to conduct the first session of the Airway Monitoring experiment as planned despite yesterday’s problems.
In conclusion: if there really had been an ammonia leak, the astronauts and control centres had the situation fully under control. But this is a reminder to us all of the importance of training for emergencies over and over again and to play them out in our minds, so when they happen we don’t panic…
Thomas Uhlig, Columbus Flight Director
Original blog post (in German): http://www.dlr.de/blogs/de/desktopdefault.aspx/tabid-9260/15960_read-791/