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Raspberry-Famous t1_jc752y1 wrote

Here is the actual posting about it if anyone is interested.

It's an interesting problem, a lot of different factors working against each other. I'm looking forward to seeing what people come up with.

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not_that_planet t1_jc7oqx4 wrote

Indeed. If NASA accepts (is allowed to accept???) this as a project, this will be a big deal.

I'm not going to say propulsion in space is easy, but it is relatively straightforward. Getting into and out of orbit is something we really aren't very good at.

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MrGhris t1_jc7s0ao wrote

I mean, just create a leak opposite to the side you want to go and bobs your drunk uncle

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r_not_me t1_jc7thqc wrote

Wasn’t there a botanist stuck on Mars that used a hole in his glove to “Ironman” his way to the rescue ship?

Seems like we have this whole thrust thing figured out to me /s

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cardboardunderwear t1_jc7ypup wrote

Movie magic.

The real botanist, as depicted in the documentary book, didn't do that.

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Whoelselikeants t1_jc8akdb wrote

How come? Shouldn’t it just be like a cargo dragon that has its Draco’s pointing retrograde and then do a burn?

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ninotalem t1_jc8nwd8 wrote

This is such a load of BS. We literally send satellites to other planets and moons and have no problem getting into orbit

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explodingtuna t1_jc906gv wrote

Maybe he means cost-effectively? It is the most inefficient and expensive part of the process.

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thx1138- t1_jc95qks wrote

Maybe silly question, but would there be any advantage to doing at least a partial disassembly before deorbiting? Seems like it would be easier to control by dividing it into a handful of sections.

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Raspberry-Famous t1_jcaubzw wrote

Yeah, absolutely, you'd solve most of the really hard parts of this problem that way. The downside is that it would pretty difficult at a pure technical level and also that you'd have to coordinate everything around the station being taken apart vs. having everything else drive the decommissioning timeline and then the actual deorbiting basically just being a button you push.

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Polygnom t1_jcfkaoi wrote

And then instead of one problem, you have half a dozen or more problems.

Currently, the problem is somewhat simple:

Attach to Node 2 forward, and be able to produce 47m/s of delta-v attacked to a station of 450 tons.

Boost-de-boost maneuvers of the whole station are well researched at this point, so we know the force vectors and what happens to the station when doing so. The station itself can also help with attitude control.

If you break it up in pieces, you would need to find out where to attach, what the force vectors need to be to properly boost of module through its CoM without spinning out of control. Most pieces won't be able to support the burn with attitude control.

You'd also have to disassemble the station, which in itself might take months or longer. All while diminishing the capabilities of the station further and further while doing so.

Honestly, keeping it as one piece looks a lot simpler. You basically just need to do a stronger de-boost burn. So basically business as usual, just more fuel.

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thx1138- t1_jcgj0wd wrote

Yeah I guess my thought was that CoM on a rather asymmetrical structure such as the ISS may be hard to control from... but then again they have actual rocket scientists so maybe it's not :D

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