The earliest modules are inseparable, maybe literally. Zarya is attached to Unity on the US side, which has the truss. Zarya has been so intertwined and might be cold welded to Unity. Zvezda, on the other side of Zarya, still handles a lot of station control. You could replace Zarya with basically a new self-sufficient space station, and, at that point, why take on the baggage of the rest of it.
Oh yeah, I forgot that was a thing. I agree, if literally the entire station is cold-welded together, that might make it too difficult. But if it’s “just” Zarya and Unity that have the cold-welding problem, why not at least disconnect and reuse some of the modules on the other side of Unity, or at least some solar panels and stuff?
If you think about it, even just attempting to salvage part of the station could be an interesting and useful experiment in and of itself, regardless of whether they expect for it to be successful.
at that point, why take on the baggage of the rest of it.
Because being attached to the legacy ISS, at least in the short term, would preserve a lot more space for activities than launching a single module standalone and letting the rest burn up? I mean, sure, if we already had a half-built replacement station in orbit right now, I’d say let the ISS go. But we don’t. Right now it’s very questionable whether we’d have anything flying by the time it’s scheduled for de-orbit, and I find both that and the notion of replacing the relatively-gigantic ISS with something Skylab-sized (at least for a few years) to be an unacceptable downgrade.
A big part of the motivation for moving on from the ISS is simplifying maintenance and upgrading systems. That reduces the crew time and system volume needed to run the station and needs fewer different spare parts.
What’s wrong with switching to multiple smaller stations? I’m not optimistic about Orbital Reef or Axiom being fully up and running by 2030, but a handful of Vast and Gravitics modules in orbit should more than cover what the ISS does now.
Bio contamination is my guess. Even the ISS is getting quite a few gross spots that are becoming mini ecosystems. Of course the experiments are on purpose, but there is a lot of astronaut filth and other basic growth. Much like how an old house cannot be kept up to date by making additions and rennovations for ever, the ISS cannot go on for ever. At least not without something akin to a serious rennovation, but at that point…
Much like how an old house cannot be kept up to date by making additions and rennovations for ever
FYI, houses do not work that way. They can, in fact, last forever as long as you keep up with the maintenance. The main reason they don’t is that people either abandon them or want to build something else in their place (i.e. they become functionally obsolete).
Now, if you want to argue that the ISS is functionally obsolete, I could see your point… but then again, it’s hard to argue that a thing is obsolete when nothing exists to replace it. Even if the engineers aren’t thrilled about trying to interface new modules with the decades-old stuff, I don’t think that’s a good enough excuse to throw away the entire existing thing and start over from scratch.
Well, houses can be stripped down to a state where they can’t support their primary function while they are renovated. Space stations are harder to handle in that way.
Okay, but if we’re intending to have a permanent presence in space, it’s unreasonable in the long run to have to keep throwing stations out completely and launching new ones from scratch every few decades. We’re going to have to figure out how to do “space renovations” sooner or later. Why not try now?
The easiest way to do that in the long term will likely be to have several space stations in orbit at a time so you can renovate one while using the others for habitation for the people who do that work.
Depends. Not even many stone buildings last many centuries. Wooden structures tend to be much less, and humanity has seen many stone structures slowly turn uninhabitable.
Besides, in space, there is much, MUCH more space. There is only a little need to fight over orbital space, let alone literal adjacent space. We don’t need to rennovate the ISS to reclaim ideal space.
Whether or not you know about them, there are also several plans ongoing for replacing the ISS, too, so your inability to grasp this is… kinda’ weird.
Besides, in space, there is much, MUCH more space. There is only a little need to fight over orbital space, let alone literal adjacent space. We don’t need to rennovate the ISS to reclaim ideal space.
What? Room inside a space station is incredibly expensive because we have to design, build and launch it!
Whether or not you know about them, there are also several plans ongoing for replacing the ISS, too, so your inability to grasp this is… kinda’ weird.
Key word: “plans.” I.e., things that aren’t actually built yet and in fact might not ever get built.
Throwing out the ISS before we have at least part of a replacement in orbit is an excellent way to risk failing to have a space station completely.
Throwing out the ISS before we have at least part of a replacement in orbit is an excellent way to risk failing to have a space station completely.
I agree. We are not doing that though. Haven-1 is scheduled to launch NET 2025, the Axiom orbital segment is NET 2026, Orbital Reef is targeting 2027, and Starlab is targeting 2028. Even if these schedules slip a couple years, they would still be ready in time for the ISS deorbit in (or after) 2030.
I still don’t understand why they can’t just replace the oldest modules as they wear out and keep the station as a whole flying indefinitely.
The earliest modules are inseparable, maybe literally. Zarya is attached to Unity on the US side, which has the truss. Zarya has been so intertwined and might be cold welded to Unity. Zvezda, on the other side of Zarya, still handles a lot of station control. You could replace Zarya with basically a new self-sufficient space station, and, at that point, why take on the baggage of the rest of it.
Oh yeah, I forgot that was a thing. I agree, if literally the entire station is cold-welded together, that might make it too difficult. But if it’s “just” Zarya and Unity that have the cold-welding problem, why not at least disconnect and reuse some of the modules on the other side of Unity, or at least some solar panels and stuff?
If you think about it, even just attempting to salvage part of the station could be an interesting and useful experiment in and of itself, regardless of whether they expect for it to be successful.
Because being attached to the legacy ISS, at least in the short term, would preserve a lot more space for activities than launching a single module standalone and letting the rest burn up? I mean, sure, if we already had a half-built replacement station in orbit right now, I’d say let the ISS go. But we don’t. Right now it’s very questionable whether we’d have anything flying by the time it’s scheduled for de-orbit, and I find both that and the notion of replacing the relatively-gigantic ISS with something Skylab-sized (at least for a few years) to be an unacceptable downgrade.
A big part of the motivation for moving on from the ISS is simplifying maintenance and upgrading systems. That reduces the crew time and system volume needed to run the station and needs fewer different spare parts.
What’s wrong with switching to multiple smaller stations? I’m not optimistic about Orbital Reef or Axiom being fully up and running by 2030, but a handful of Vast and Gravitics modules in orbit should more than cover what the ISS does now.
“Because it is hard”
I thought being hard is why we went to space to begin with!
A space station of Thyseus
Bio contamination is my guess. Even the ISS is getting quite a few gross spots that are becoming mini ecosystems. Of course the experiments are on purpose, but there is a lot of astronaut filth and other basic growth. Much like how an old house cannot be kept up to date by making additions and rennovations for ever, the ISS cannot go on for ever. At least not without something akin to a serious rennovation, but at that point…
FYI, houses do not work that way. They can, in fact, last forever as long as you keep up with the maintenance. The main reason they don’t is that people either abandon them or want to build something else in their place (i.e. they become functionally obsolete).
Now, if you want to argue that the ISS is functionally obsolete, I could see your point… but then again, it’s hard to argue that a thing is obsolete when nothing exists to replace it. Even if the engineers aren’t thrilled about trying to interface new modules with the decades-old stuff, I don’t think that’s a good enough excuse to throw away the entire existing thing and start over from scratch.
Well, houses can be stripped down to a state where they can’t support their primary function while they are renovated. Space stations are harder to handle in that way.
Okay, but if we’re intending to have a permanent presence in space, it’s unreasonable in the long run to have to keep throwing stations out completely and launching new ones from scratch every few decades. We’re going to have to figure out how to do “space renovations” sooner or later. Why not try now?
The easiest way to do that in the long term will likely be to have several space stations in orbit at a time so you can renovate one while using the others for habitation for the people who do that work.
Depends. Not even many stone buildings last many centuries. Wooden structures tend to be much less, and humanity has seen many stone structures slowly turn uninhabitable.
Besides, in space, there is much, MUCH more space. There is only a little need to fight over orbital space, let alone literal adjacent space. We don’t need to rennovate the ISS to reclaim ideal space.
Whether or not you know about them, there are also several plans ongoing for replacing the ISS, too, so your inability to grasp this is… kinda’ weird.
What? Room inside a space station is incredibly expensive because we have to design, build and launch it!
Key word: “plans.” I.e., things that aren’t actually built yet and in fact might not ever get built.
Throwing out the ISS before we have at least part of a replacement in orbit is an excellent way to risk failing to have a space station completely.
I agree. We are not doing that though. Haven-1 is scheduled to launch NET 2025, the Axiom orbital segment is NET 2026, Orbital Reef is targeting 2027, and Starlab is targeting 2028. Even if these schedules slip a couple years, they would still be ready in time for the ISS deorbit in (or after) 2030.