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Right now, I think only three things have been assembled from multiple launches like you are proposing: Mir, ISS, and Tiangong. All of which were super expensiv

Right now, I think only three things have been assembled from multiple launches like you are proposing: Mir, ISS, and Tiangong. All of which were super expensive and the result of years of careful design work. Definitely not the way to make something cheap! There was some talk about using ISS as a base for on-orbit assembly but the orbit (half-way between best orbit from KSC and Baikonur) isn't great for that and it turns out that constant docking and un-docking ruins scientific experiments requiring microgravity, so ISS really isn't a great base for assembly. Ideally, if you want to start on orbit assembly you'd have another station in the right orbit for KSC which isn't doing any microgravity research, but now we're talking about massive up front investment to save money on research satellites, is NASA ever going to get the scale of research budget for that savings to be worth it? If something like Space Based Solar Power ever become a thing then such an on orbit assembly station would make sense, but the case for assembly for science missions really only closes if you have the station already for something else.

Asraelite 2y ago
> only three things have been assembled from multiple launches like you are proposing: Mir, ISS, and Tiangong I would also count the Apollo missions. They launched on a single rocket, but the docking between the CSM and Lunar Module was for all intents and purposes equally difficult to assembly on orbit. There are multiple commercial companies planning to assemble stations over the next few years. This in addition to the on-orbit refueling that SpaceX will be doing should hopefully enable a new generation of larger, assembled interplanetary probes.
- mandevil 2y ago
  I was using multiple here to mean 3 or more launches, because otherwise the Gemini missions that docked to a separately launched Agena-D booster (G8, G10, G11, G12) would all qualify: GX and GXI even restarted the ATV's engine to set new altitude records (which I think still holds today- if you ignore the 21 men who went to the moon on a Apollo capsule from 1968-1972). But that is closer to what I meant, because they had to worry about separate launches that might fail (GVI, GIX) and find and dock with something you need to use orbital mechanics to approach (basically anything under 30m distance you can just eyeball and fly, but anything over that distance requires the full set of orbital calculations).

Asraelite 2y ago

> only three things have been assembled from multiple launches like you are proposing: Mir, ISS, and Tiangong I would also count the Apollo missions. They launched on a single rocket, but the docking between the CSM and Lunar Module was for all intents and purposes equally difficult to assembly on orbit. There are multiple commercial companies planning to assemble stations over the next few years. This in addition to the on-orbit refueling that SpaceX will be doing should hopefully enable a new generation of larger, assembled interplanetary probes.

mandevil 2y ago
I was using multiple here to mean 3 or more launches, because otherwise the Gemini missions that docked to a separately launched Agena-D booster (G8, G10, G11, G12) would all qualify: GX and GXI even restarted the ATV's engine to set new altitude records (which I think still holds today- if you ignore the 21 men who went to the moon on a Apollo capsule from 1968-1972). But that is closer to what I meant, because they had to worry about separate launches that might fail (GVI, GIX) and find and dock with something you need to use orbital mechanics to approach (basically anything under 30m distance you can just eyeball and fly, but anything over that distance requires the full set of orbital calculations).