Practicing emergencies is necessary so I accept that the volunteer fire department near our home at Hochstadt runs their siren in the evening, even though it excites our 3-year-old daughter just before bedtime. We also need to practice emergencies on the International Space Station in space you cannot phone highly-trained rescue workers to come to the rescue. Astronauts must be able to fend for themselves, extinguish a fire and protect themselves from any fumes. Even radio contact with experts in control centers cannot be assumed to work in a worst-case scenario.
In today’s emergency exercise the control centres and astronauts worked together on a so-called On-Board Training or simply OBT. We had “stage directions” that defined for example that a leak would appear in the Japanese Kibo module through which air would escape.
The alarm sounded on the Space Station with its penetrating noise and the computer screens of our Flight Controller filled up with numerous error messages, proving that the International Space Station had configured itself in emergency mode. The astronauts onboard reported shortly afterwards to Mission Control Houston with the news that they had a pressure drop on the Space Station to contend with. All radio communication between crew and flight controllers began with the words “For the workout exercise:” to ensure that everybody knew it was not a real emergency, but an exercise.
The flight director in Houston declared a “Space Craft Emergency” – of preceded by “for the training exercise”. Sinje Steffen of the STRATOS team at the Columbus Control Centre checked whether Columbus was automatically reconfigured for this Rapid Depress scenario.
The astronauts convened in the meantime 350 km above close to their Soyuz spacecraft. Since the Russian capsules are the Station’s lifeboats, each astronaut has a well-defined place there. They are usually the first assembly point of crew in an emergency. Once there, they decide together on how to proceed based on the scheme “Warning – Gather – Fight”. In our emergency script scenario, the astronauts had about five hours until critical low pressure (designated as T.Res) would be reached – time enough to try to find the leaking module and possibly stop the International Space Station from ‘bleeding out’.
The astronauts followed the well-defined sequence to close various hatches to measure on which side the pressure dropped further. Slowly they were able to find their way closer and closer to the actual leak.
Columbus Flight Director Katja Leuoth and her team was busy keeping up with the falling pressure values: a long list of minimum air pressure certification values exist for all Columbus components – each of these elements had to be switched off before their critical pressure was reached. Today’s commands were “for the training exercise”, so actual commands were not issued and power was not actually switched-off…
The rapid pressure-drop (rapid depress) is one of three major emergency scenarios that are defined for the International Space Station.
Depending on the size of the leak, there are various ways to “clog the hole”: from an oversized bicycle-patch to a plasticine-like material. All sealing is done of course from inside the space station – and is easy: Compared to the vacuum of space the pressure inside the ISS is considerable higher and pushes any seal onto the leak – a clear advantage compared to repairing a bicycle inner tube…
Thomas Uhlig, Columbus Control Centre
Time for farewells!! The Dragon spacecraft left the International Space Station earlier this week and today ESA’s ATV spaceship with the catchy name Georges Lemaître detached from the Station and will plunge after several orbits into Earth’s atmosphere. Due to the enormous heat from friction caused by its deceleration through the upper layers of air layers the spacecraft will turn into a huge fireball – a fitting end to the spacecraft that is named after one of the founding fathers of the Big Bang theory!Unfortunately, this will be the last ATV – after five very successful missions, the project is now complete. At the Columbus Control Center (Col-CC) we provided for each flight the ground infrastructure and supplied our colleagues at ATV Control Centre in Toulouse, France, with data, video and voice connections to the International Space Station network. After ESA astronaut Samantha Cristoforetti and cosmonaut Alexander Samokutyaev closed the hatches of ATV yesterday, the Space Station was prepared for the last hours of undocking of ATVs. We turned off our little amateur radio station [http://www.ariss.org/] in Columbus as well as the external Rapidscat experiment [http://www.jpl.nasa.gov/missions/iss-rapidscat/], any radio interference with ATV’s navigation from the International Space Station should be avoided.
Slowly the Space Station turned to an appropriate orientation for undocking. When the moment arrived the Space Station’s active position control was turned off completely: Georges Lemaître needs to push away from the Space Station without the mothership trying to compensate for this force.
Afterwards all that remained was for the astronauts to wave good-bye … ATVs are part of a large space fleet that supplies the International Space Station. When the American Space Shuttle withdrew from service the Russian Soyuz spacecraft became the only way to get people to the Space Station and back on Earth. Three astronauts share a small space – and so there is little room for other supplies.Despite this there is enough transport capacity to supply the International Space Station with vital cargo: The Russian unmanned Progress cargo has been flying for years as well as the Japanese HTV and the European ATV. Relatively new in the family of cargo ferries are two unmanned American commercial vehicles: SpaceX’s Dragon and Orbital Science’s Cygnus. While the ATV and Progress ships fly to the International Space Station and dock on their own accord, the others need assistance from the Station’s robotic arm. They approach the Station and fly in formation together – not so easy with complex orbital mechanics to calculate – before being gently captured by the robotic arm and moved securely to a docking port. Only then can the astronauts enter and start unloading cargo. It is much more complicated to bring something from the International Space Station back to Earth. The ATV, HTV, Progress and Cygnus spacecraft have no heat shield or other systems that are needed to survive a reentry into Earth’s atmosphere: they are designed to burn up in the upper layers of the atmosphere of Earth. Because of this the astronauts load them full of trash from the International Space Station and they serve as cosmic garbage disposal. Aside from the manned Soyuz only the Dragon is designed to withstand the tremendous energy from decelerating at speeds of 23 faster than the speed of sound. Paradoxically it is more difficult to get things from the Space Station to Earth than vice versa.
Tom Uhlig, Columbus Flight Director at the DLR center in Oberpfaffenhofen/Germany
Cover image by ESA astronaut Samantha Cristoforetti: https://www.flickr.com/photos/astrosamantha/16546104212/ .
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/
After a short glance on my telemetry displays I can see indications, that the power outlet, which feeds the Columbus lights, draws some power: “COL-FLIGHT, STRATOS, Columbus lights are ON!”
The answer comes immediately: “Copy that, STRATOS, so the crew is awake!”
The astronauts are ready to kick off their day!
A standard crew day onboard ISS starts with around 1 hour of post-sleep time. Crew can have breakfast, prepare for the day and read the “Daily Summary”, a sort of newspaper, which we put together with the other control centers and which is used to provide the crew with the ISS big-picture status, comments to the daily plan, the Flight Control Teams roster, as well as a Q&A section and (sometimes) jokes and cartoons
It does not sound that different from the morning routine of any other human being preparing for work on planet Earth, does it?
The first official interaction with the Control Centers around the world is during the mDPC (“morning Daily Planning Conference”): Crew and the Flight Controllers tag-up on the daily operations, discuss deltas to the plan and address any crew question that might arise.
The termination of the mDPC marks the start of the actual work-day for the crew. 6.5 hours of their day will be divided between conducting experiments, installing new payloads, executing repairs and “housekeeping”!
In addition to the work time, 1 hour is always allocated for a midday meal, and 2.5 hours are strictly scheduled for physical exercise: crewmembers use a cycle ergometer (i.e. an exercise bike) for cardiovascular exercise, a treadmill for cardiovascular exercise – loading the skeletal system and maintaining the neuromuscular patterns for locomotion, and a Resistance Exercise Device for maintaining muscles and bones.
Once the daily activities are completed, it is time for the eDPC (“evening Daily Planning Conference”). This is “goodnight” time: interactions with the crew on the Space-to-Ground voice channels are interrupted to allow them some well-deserved rest time, we also switch off any camera inside the space station! Only in case of contingency scenarios the Ground Teams would make contact again.
After a round call to all control centers for any input, crew is off-duty: they can have dinner, check social media and watch TV or movies, or spend some “quality-time” sightseeing from Cupola.
Then it’s bed time: 8.5 hours of good sleep in micro-gravity
One last thing! A dedicated electronic tool is available to both Crew and Ground Teams, called OSTPV (“Onboard Short Term Plan Viewer”): it shows the so-called timeline, the schedule of the ISS and is divided in several bands for Crew and Ground, and each activity is represented by a “bar” It is driving the crew day – and it can drive astronauts crazy, as you can convince yourself …
Should you be interested in the current OSTPV: We give you a little bit of insight here.