On board the International Space Station (ISS), there are two main and extremely critical risks for the crew: fire and depressurization. And a Russian crew had the misfortune to test both aboard the former Soviet Mir station.
The space shuttle Atlantis docked with the Russian station Mir. The Russian station, aging and out of breath, will have known some difficult events, including the two worst hauntings for astronauts: a fire and a collision causing rapid depressurization. Credits: NASA/Roscosmos
But before that, it must be understood that the ISS is an extremely complex environment, an extraordinary achievement and a jewel of technology and engineering of a kind that is rarely done, and that it is complex to appreciate at its fair value . This implies that everything is extremely controlled and verified and that nothing is done lightly. The systems are very often present in two or three copies so that the station can continue to operate and that the safety of the crew is not engaged in the event of equipment failure. The system is robust. Illnesses are rarely an issue today, as crews undergo a period of quarantine before takeoff, and their health is monitored throughout their mission. Similarly, the crews train together and are monitored during their mission, to avoid tensions on board the station as much as possible. Astronauts are trained to be able to react to an incalculable number of situations (there is always an astronaut who has followed a medical apprenticeship, being able to perform a few operations ranging from the pulling of a tooth to an appendicitis operation , piloted by a medical specialist from the ground – a complete workout, really) and can tackle almost anything. And during their training, they learn that the two riskiest situations in normal times are fires and depressurizations. During a spacewalk, the risks are different for astronauts, but I have already addressed this in another answer Astronauts are trained to be able to react to an incalculable number of situations (there is always an astronaut who has followed a medical apprenticeship, being able to perform a few operations ranging from the pulling of a tooth to an appendicitis operation , piloted by a medical specialist from the ground – a complete workout, really) and can tackle almost anything. And during their training, they learn that the two riskiest situations in normal times are fires and depressurizations. During a spacewalk, the risks are different for astronauts, but I have already addressed this in another answer Astronauts are trained to be able to react to an incalculable number of situations (there is always an astronaut who has followed a medical apprenticeship, being able to perform a few operations ranging from the pulling of a tooth to an appendicitis operation , piloted by a medical specialist from the ground – a complete workout, really) and can tackle almost anything. And during their training, they learn that the two riskiest situations in normal times are fires and depressurizations. During a spacewalk, the risks are different for astronauts, but I have already addressed this in another answer capable of carrying out a few operations ranging from pulling a tooth to an appendicitis operation, piloted by a specialist doctor from the ground – a complete training, really) and can cope with almost anything. And during their training, they learn that the two riskiest situations in normal times are fires and depressurizations. During a spacewalk, the risks are different for astronauts, but I have already addressed this in another answer capable of carrying out a few operations ranging from pulling a tooth to an appendicitis operation, piloted by a specialist doctor from the ground – a complete training, really) and can cope with almost anything. And during their training, they learn that the two riskiest situations in normal times are fires and depressurizations. During a spacewalk, the risks are different for astronauts, but I have already addressed this in another answer
First of all, in space, nothing is simple. And putting out a fire is anything but simple. Already because if you have already seen Wall-E (or Gravity), you already know that the use of a fire extinguisher is more than complex: by the principle of action/reaction, activating the fire extinguisher will have the additional consequence of throw you back. And above all, you are in a micro-gravity environment: the smoke does not rise to the top (which makes it possible to have the bottom of the rooms less dangerous for the lungs). Finally, it is also necessary to be able to locate the fire: if it breaks out behind a wall (the space on board being used to the maximum, the walls are filled with instruments, control systems, storage, behind which cables pass electrics and other essentials), you have to be able to find it. Once identified, it must be limited quickly, otherwise it can spread quickly and fill a module with toxic smoke… And the fire can end up damaging the structure of the station. The fire in space is a real calamity.
The other critical element is depressurization, which can happen for several reasons. The first we think of is a collision with debris, which would pierce the hull of the station. Everything is done to avoid this: the walls of the station are reinforced, and the debris is monitored from the ground to ensure that no significant debris can damage the station. If potential debris is detected, an avoidance maneuver is planned: the ISS increases its orbit. If it is detected too late, the crew is warned, and they will place themselves in the Soyuz, ready to return to Earth in the event of a collision. This procedure has happened a few times since the ISS has been inhabited, no major collisions have occurred and the crew has always been able to resume their activities. When connecting with the outside, namely the docking and undocking of a vessel (cargo or manned), or extra-vehicular exits (EVA), if the seal is not sufficient, air can escape from the walls and empty the station of its air. This is why the pressure is constantly monitored in the station. This is also why the preparation time for EVAs, or the time between the docking of a Soyuz and the entry of the crew into the station is so long: it is necessary, among other things, to check that the pressure is stable . Finally, and this is a bit of a first that took place in 2018, a manufacturing defect in an element that reveals itself after several months in orbit can cause depressurization. Fortunately, the hole was extremely small and never endangered the lives of the crew. if the seal is not sufficient, air can escape from the walls and empty the station of its air. This is why the pressure is constantly monitored in the station. This is also why the preparation time for EVAs, or the time between the docking of a Soyuz and the entry of the crew into the station is so long: it is necessary, among other things, to check that the pressure is stable . Finally, and this is a bit of a first that took place in 2018, a manufacturing defect in an element that reveals itself after several months in orbit can cause depressurization. Fortunately, the hole was extremely small and never endangered the lives of the crew. if the seal is not sufficient, air can escape from the walls and empty the station of its air. This is why the pressure is constantly monitored in the station. This is also why the preparation time for EVAs, or the time between the docking of a Soyuz and the entry of the crew into the station is so long: it is necessary, among other things, to check that the pressure is stable . Finally, and this is a bit of a first that took place in 2018, a manufacturing defect in an element that reveals itself after several months in orbit can cause depressurization. Fortunately, the hole was extremely small and never endangered the lives of the crew. This is also why the preparation time for EVAs, or the time between the docking of a Soyuz and the entry of the crew into the station is so long: it is necessary, among other things, to check that the pressure is stable . Finally, and this is a bit of a first that took place in 2018, a manufacturing defect in an element that reveals itself after several months in orbit can cause depressurization. Fortunately, the hole was extremely small and never endangered the lives of the crew. This is also why the preparation time for EVAs, or the time between the docking of a Soyuz and the entry of the crew into the station is so long: it is necessary, among other things, to check that the pressure is stable . Finally, and this is a bit of a first that took place in 2018, a manufacturing defect in an element that reveals itself after several months in orbit can cause depressurization. Fortunately, the hole was extremely small and never endangered the lives of the crew.
Mir experienced fire and (severe) depressurization a few months apart. Two crew members, Russians, experienced these two events.
Vasily Tsibliyev, Jerry Linenger and Alexandr Lazutkin aboard Mir. Credits: Roscosmos/NASA/SpaceFacts
On February 23, 1997, crew rotation was underway. It takes a few days, during which two Soyuz are docked at Mir and the station is busy. Contrary to the ISS planned to be occupied by 6 astronauts and being 3 during the rotations (a crew of 3 leaves, and about a month later, 3 other astronauts arrive, forming a crew of 6 for 2 months before the departure of 3 astronauts), Mir works in reverse (2 cosmonauts, and 2 new ones arrive, cohabitation with 4 then departure of a Soyuz to return to a normal number). The aging Soviet station is crowded. And a fire breaks out in one of the modules. Some oxygen masks don’t work. Some fire extinguishers do not work. And the fire is between the crew and one of the two Soyuz: if the situation becomes truly catastrophic and forces the abandonment of the station, some astronauts will be doomed and not all will be able to return to Earth. Officially, the fire lasted 90 seconds, according to Russian authorities. Jerry Linenger, American astronaut on board during the event, will indicate that it lasted at least 14 minutes. The Russian astronauts on board were Valery Korzun, Alexandr Kaleri (these two returned to Earth on March 2, 1997), Vasily Tsibliyev and Alexandr Lazutkin (who had just arrived, February 10, 1997). On board the station was also the German astronaut Reinhold Ewald, who arrived on February 10, 1997 and left on March 2, 1997. according to the Russian authorities. Jerry Linenger, American astronaut on board during the event, will indicate that it lasted at least 14 minutes. The Russian astronauts on board were Valery Korzun, Alexandr Kaleri (these two returned to Earth on March 2, 1997), Vasily Tsibliyev and Alexandr Lazutkin (who had just arrived, February 10, 1997). On board the station was also the German astronaut Reinhold Ewald, who arrived on February 10, 1997 and left on March 2, 1997. according to the Russian authorities. Jerry Linenger, American astronaut on board during the event, will indicate that it lasted at least 14 minutes. The Russian astronauts on board were Valery Korzun, Alexandr Kaleri (these two returned to Earth on March 2, 1997), Vasily Tsibliyev and Alexandr Lazutkin (who had just arrived, February 10, 1997). On board the station was also the German astronaut Reinhold Ewald, who arrived on February 10, 1997 and left on March 2, 1997.
This is the period of the Mir Shuttle program: some American astronauts were on long stays and arrived and left in the space shuttle, some Russians were integrated on board the shuttle crews, and the Russians offered foreign astronauts (with funding not negligible on the part of the invited states) to be added to the flights, to be on board the station during the rotation phases.
A view of the Spektr module taken before the collision, during the STS-79 mission, in September 1996. Credits: NASA
In June 1997, Vasily Tsibliyev and Alexandr Lazutkin are still on board the station. Jerry Linenger left and was replaced by Micahel Foale. And Russia has scheduled a manual approach test for June 25, 1997. Soyuz and Progress spacecraft docking is done automatically through an onboard system, Kurs . From memory, these on-board computers are manufactured outside of Russia, in a state that was part of the Soviet bloc. The fall of the USSR had an immediate consequence: the price of Kurs computers rose, and they are extremely expensive. And they are lost when the freighters burn up in the atmosphere. The Russians would like to do without Kurs, and switch to manual approach. An earlier first test failed, and the Progress passed away from Mir, after stressing the crew. On June 24, the Progress M-34, equipped with Kurs , detaches from the station and moves away. On June 25, he approached the station. Kursis extinguished: the crew will attempt a new manual approach. Tsibliyev pilots the Progress manually. Lazutkin watches at the portholes to spot the freighters: the idea is that once spotted, he can measure the distance between them and the ship using a laser. Foale follows the maneuver and helps as he can. On the video screen, Tsibliyev sees a point, which grows bigger and bigger: Mir. But he has trouble judging distance and speed, information he doesn’t have. Neither Lazutkin nor Foale sees the Progress, which should be visible. In reality, it is hidden (behind a solar panel it seems to me). When it finally appears, Lazutkin becomes livid: the Progress is much closer to Mir and going much faster than they had anticipated from the images returned by the Progress showing the station closing in. It is obvious that it will hit the station. Tsibliyev performs a last-ditch maneuver, deflecting the ship a little, which nevertheless collides with the Spektr module. He punctures the station, creating a gaping hole in it, the air from the station escaping into space. Foale receives the order to join the Soyuz and prepare it to undock for an emergency return to Earth. Lazutkin (or Tsibliyev but I think it’s Lazutkin) tries to isolate the module by closing the wall between Spetkr and the rest of the station. The air flees at a dizzying rate and they have very little time in front of them. Problem: Cables are passing through the opening. He cuts them, and closes the sealing panel. Calm returns to Mir. Problem: Spektr was the main source of electricity on board, thanks to its numerous solar panels, and the cables severed to save the station were the power cables. Mir will experience an episode of major energy crisis, which will require major work to recover the power supplied by the damaged panels of Spektr.
A view of the Spetkr module after the collision with the Progress M-34. This photograph was taken from the Atlantis shuttle which notably brought Michael Foale back at the end of his mission. Credits: NASA
To learn more about these two events, and the Shuttle-Mir program, I can only encourage you to read Dragondly by Bryan Burrough (not necessarily easy to find), which I mentioned on my blog (Review – Dragonfly: NASA and the crisis aboard Mir by Bryan Burrough). This book, recommended by the French astronaut Michel Tognini during a space Tuesday at the CNES in Paris, is far from perfect and is open to criticism on several points, but it nevertheless provides a lot of information on the management of a space station on the Russian side, on the Russian mentality in terms of manned flights, and on the difficulties that the Russian and American agencies had to coexist. An enriching and interesting read, which goes much more into the details of the fire and the collision, among others.