On October 9, the seven astronauts occupying the International Space Station received an unfortunately very familiar message: there is a coolant leak! Located on a permanent Russian module, it does not prevent life on the station for the moment, but for safety reasons, two exits have been postponed.
For just the third time in a year, control center operators observed a drop in pressure in a cooling system. And, it’s still on the Russian side. After Soyuz MS-22, then a Progress cargo ship last winter, this time it involves refrigeration equipment installed on the permanent Nauka module. This large module, dedicated to Russian scientific experiments, is considered almost new, since it docked with the international station in 2021. However, the leak took place on an element which has already been in orbit since 2010, and which had been stored outside all this time.
Rushing ahead
If the sudden leaks of the cooling elements of the Soyuz and Progress vehicles caused a lot of talk over the past year, it is because they had a direct impact on the ability of astronauts and cosmonauts to travel to and from the International Space Station. But a leak on a permanent module’s equipment could be even more annoying, depending on which one is affected. The consequences can go as far as having to turn off all the equipment, or even condemning the laboratory.
Also this October 9, by detecting a coolant leak, the astronauts and ground controllers took the time to fully understand the situation. If the exact cause is still unknown (an investigation is open), at least we know that the leak is isolated on the RTOd radiator, and does not prevent the module from functioning. There is no danger for the occupants of the ISS.
An (old) radiator?
The RTOd has a relatively turbulent history. Originally intended to be connected to the Nauka module, it complements its standard radiator to evacuate more heat and allow the operation of the numerous scientific equipment which are supposed to operate in the Russian laboratory module.
The fact that it is now broken will not change the lives of cosmonauts too much, a large part of this equipment is in any case not installed in the module or not in orbit. But the RTOd has already been outside for a long time. As it is heavy (more than 200 kg) and bulky equipment, it did not wait for Nauka to be in orbit to be brought to the ISS and it made the trip in 2010 with another module, Rassviet, in the hold of an American shuttle. As a result, even though it was only installed on Nauka last April, it had already spent 13 years in orbit.
Two diving trips postponed
Although Roscosmos assures that the leak is minor and will not disrupt future operations, this is not entirely correct. It will first have an impact on the activities of Russian cosmonauts: either the future contribution of new scientific equipment will be abandoned, or they will have to go out and attempt a possible repair on a cooling circuit which is not designed for that. The agency must still evaluate its options.
On the other hand, two spacewalks in spacesuits were planned for October 12 and 19 on the USOS (non-Russian) side, notably with the participation of the Danish commander of the station, Andreas Mogensen… They are postponed by a few days or weeks, the time to better understand the impact of the leak, and to ensure in particular that the astronauts’ equipment will not be soiled or contaminated by deposits outside.
At this time, it is unclear whether the schedule for other upcoming milestones will change. This will undoubtedly depend on future inspections, in particular the HD photos taken with the robotic arms. On the evening of October 10, Roscosmos indicated that there were no more particles escaping from the circuit, indicating that it is probably purged.
Source : Space News
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