The row over a leak on the International Space Station

The International Space Station has been a great source of collaboration between the NASA and Roscosmos space agencies for decades. But the extent of a five-year-old leak on board the ISS has put Washington and Moscow loggerheads. Here’s Richard Hollingham from the Space Boffins on what we know about the leak…

Richard - It's months or years old and no one quite knows exactly where it is or what caused it. It could be around the welds in the structure of this section of the space station, or it could just be in the integrity of the metal as well. This section, it connects the Russian spacecraft to the station itself. They have this little tunnel, you have the progress freighters, which are uncrewed spacecraft, they dock with the station, they go into this tunnel to get all the stuff out, and they put all the rubbish in and they send the freighter back to burn up in the Earth's atmosphere. It's quite a crucial module, but right now they can close the door, so although it's leaking it's not affecting the integrity of the rest of the station.

Chris - What's the scale of the leak? How much are they actually losing in gas terms?

Richard - It's really not a huge amount. It's not like there's a *hiss* of air going out. It's just a gentle leak over time, like a slow puncture, I guess, on a car or a bike. This module is really old. This has been in space since the year 2000. These were actually built before then, so it's really getting on in years. It's got this harsh environment, it's got pretty much constant bombardment by micro meteoroids, little tiny space rocks, the risk of space debris also hitting the station too. It's reaching the end of its life and it looks like this is the first section to really be showing that. It could have happened to another part of the station as well. When you look at the actual fabric, the basic whole structure of the station, this is not thick metal. This is centimetres thick. It's not a massive structure because you have got to launch it into space and then it doesn't have to be particularly thick once it's in space. But that does mean any leaks or any welds, anything like that is going to deteriorate over time.

Chris - Why are NASA and Roscosmos having argy-bargy about it?

Richard - Russia never seems to admit a problem with its side of the space station, or with any of its space programme. We see this on the ground of course as well. Very thin skinned, I would say, are the senior officials of the Russian space programme. I do think it's extraordinary that, if you think about it, 400 kilometres above our heads on the International Space Station, the Americans and the Russians are cooperating. Meanwhile, on the ground, there's a proxy war between NATO and Russia in Ukraine. I think it's almost extraordinary they've been cooperating for so long, but there's just this constant pushback on things. Meanwhile, in space, actually the crew get on really well because they're in this harsh environment. Everything's safety critical, they have to get on well! They're all astronauts.

Chris - So what happens if they just carry on rubbing along as they are and they don't fix this?

Richard - It'll probably be fine, until it's not. That's the problem with these things, particularly as they haven't actually identified what the specific problem is, where the leak is. All the time now they're closing the door to this section of the space station. If the leak gets worse, they will have to close that door permanently. If that happens, that means they will not be able to dock the progress cargo spacecraft to the station. They'll be then solely probably relying on the American SpaceX. They need to fix it. They need to find the leak and fix it or decide, well, is it fixable? Is there a pinprick there, is there a failed weld, or is this something they're gonna have to live with? If it is a faulty weld, and there was some sort of knock to that or it suddenly gave, then you are in a potentially very dangerous situation if that hatch is open. They've got to keep the space station alive working for another six years or so. That's the plan at the moment, till 2030, which means this stuff has got to limp on. It would've been in space operating with people on board for 30 years. That is extraordinary.

Chris - Can you repair stuff in space in the same way? If that was a blow up boat on the ocean, you'd put a patch on it, wouldn't you? Is that sort of thing feasible in space?

Richard - Exactly the same. In the past, when there was the Mir space station, you may remember, in its dying days, there was a massive collision with a cargo module when it hit the space station. That was a catastrophic loss of air with the crew having to really shut the hatches to stop it. They went outside, they repaired it. You can use tape! There is a lot of tape used on the space station to hold stuff to walls and things. You could just stick some tape over it. It will be absolutely fine. So it is fixable, the issue seems to be, with this particular leak, they don't know exactly where it is or what it is, and no one seems to be investigating to find that.