25 years of the International Space Station

This month marks a quarter of a century since the International Space Station was sent into orbit. It’s a remarkable achievement, but we’re not sure what will become of the vast structure. The space agency NASA hasn’t ruled out keeping it in operation beyond 2030, but it looks far more likely that the ISS will be decommissioned and sent hurtling to a watery end in the Pacific Ocean. James Tytko went along to the Royal Observatory in Greenwich to meet their senior astronomer, Ed Bloomer.

Ed - 25 years is a long time. What it has become is our permanently occupied space lab. It's able to run a huge number of different projects, different experiments, and it's also a sign of international collaboration and co-development.

James - Almost unique international collaboration in the domain of science.

Ed - Yeah, I think that's correct. As I say, permanent occupation for about 25 years from different space agencies, members of different countries, many of whom have not been getting on, let's say, politically during that time. The international collaboration is absolutely necessary to run the place: it has to happen regardless of what else is going on. I think there's something interesting in that.

James - We better expand a bit on what a space station actually is. You mentioned it being our permanent home up there, but it's got more of a function than that, hasn't it?

Ed - The conditions are completely inhospitable to human life normally, so you have to construct something specifically to survive there, to remain there. It's not the first space station. I think, off the top of my head, ISS is the ninth one with occupation and it's got lots of different things that go on all the time within it. Not just the stuff that the astronauts are conducting personally but experiments on the astronauts themselves to see what effect space life has on the human body is a big part of it as well.

James - Is it those sorts of astrobiology learnings that you'd say have been one of the hallmarks of the work that's gone on, on the ISS?

Ed - I mean, there's other things, like we have a potential dark matter detector on there - hard particle physics. But certainly, life sciences, seeing how plants grow, seeing how cells develop, seeing how the astronauts bodies themselves... keeping them under basically constant monitoring. Yeah, I would agree that life science is a big part of it.

James - Because there's some discussion to be had, I think, that whether it's been a good use of resources or not comes down to this idea of whether humans in space is really a happy marriage in the first place and whether we're forcing a square peg into a bit of a round hole here. With the hundreds of billions of dollars worth of investment that's gone into the ISS, how do you view those quiet voices of descent which are starting to grow a bit louder as the space station comes towards the end of its life and people are looking at it retrospectively?

Ed - It's a big question. You're right, it's an inhospitable environment and humans are not naturally built for it. We're not naturally built for lots of things that we end up conquering, so I think there's definitely a spirit of investigation and figuring out what it takes and some of that will end up with some hard answers about what we can do, what we can't do, how much we would have to change ourselves to live on Mars or live on the Moon. There's big questions to be asked there. I think when we talk about costs, the money generally speaking is used here on Earth. You use up fuel, rocket fuel is pretty expensive, but the majority of the cost is about the development of industry here on Earth and that has all sorts of spinoff applications and tangential relationships. This gets discussed when we talk about things like the Apollo Moon programme. As a function of the time, it was very expensive, but the amount of stuff that came from it, the development of technology that came from it, means that we live in the space age anyway; personal computers, the glass on your mobile phone. It's not like we're chucking a crate of dollar bills and throwing them out the airlock. It doesn't really work like that.

James - As we are looking back at the 25 years it's been up there, we're also looking forward to the ISS being decommissioned in 2031. What's that as a result of?

Ed - So unfortunately nothing lasts forever and complicated machinery, though you can repair, eventually gets to a stage where it's perilous to keep it going for longer. Safety is a big concern and, in general, you wouldn't be surprised if your car of 25 years had an occasional breakdown or if you're still trying to use a laptop 25 years later. Now they don't exactly compare, but at some point you've got to have a plan for decommissioning this stuff. They can't just go on forever.

James - But presumably this is not the end of space stations as we know them? There will be ones that supersede it? What are the plans to replace the ISS? Do we need to?

Ed - Well, that's a complicated question and I think different space agencies around the world have different answers to that. Roscosmos has a plan for a third generation Russian space station. The Chinese Space Agency has all sorts of plans for permanent occupation. So the interesting question I think maybe is, do we get something similar again or do different space agencies only go their own way or do we have different partnerships? Certainly, I think there's still ambition for occupation in space, but whether there is consensus and the funding and all the rest of it that you would need for ISS version two, that's not clear at this stage.