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Comment by mlyle | Hacker News Reader

I guess the point he's making is that the orbital velocity is pretty slow, so it's not too different to "get there" and "orbit there".

Of course, the rocket equation often makes "just add a few percent more delta V" pretty hard ;)

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> so it's not too different to "get there" and "orbit there".

But to "get there" within any reasonable timespan requires going really fast - which is currently highly impractical. And then once you get there, you have to them cancel pretty much all of that velocity which is not just a "few percent more delta V".

We can do 7-8 AU per year right now using tech we have. Voy 1 and Voy 2 are moving at 3.59 and 3.25. A starship sized rocket could also possibly get a small payload that separates to 15 AU. This is all using conventual propellent. If you consider using nuclear explosive as a prepulsion technique the math starts to change substantially and you can achieve even 25 AU / year.

https://ntrs.nasa.gov/api/citations/20140013260/downloads/20...

Sure. But then how do you go from 7-8 AU/yr (33-38 km/s) to whatever the orbital speed is at that distance and also point that velocity vector in the correct direction for the orbit?

Technically, you don't need to stop. Gravitational lensing does not work like regular lenses, there is no "focal distance".

You have to be so far because that's the minimal distance where the Einstein ring becomes larger than the Sun's apparent diameter.

If time is no object, sure.

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