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In Artifexians newest video he discusses how you can have a habitable near earth world that still has rings. Fast forwarding to the end of the video, he points out that due to their pull on any leaving spacecraft that it would be extremely hard for a world with rings to develop into the world of space. The main problem is that the easiest, safest and cheapest location to launch a rocket is near or on the equator. The problem, rings also form around the equator.

How would a society with modern of near future technology combat the problems the rings present to space flight?

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  • $\begingroup$ Does the problem still apply once in orbit? Once you've left the atmosphere (but are still "under" the rings") couldn't you skim it to one of the poles and then just take off? $\endgroup$ – AndreiROM Jan 5 '16 at 20:11
  • $\begingroup$ Rings orbit just outside of a planet up to the end of their influence $\endgroup$ – TrEs-2b Jan 5 '16 at 20:13
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    $\begingroup$ I think he is greatly over-estimating the effect of rings and the importance of launching at the equator. Cape Canaveral isn't at the equator, after all, and we have a very large moon - larger than any mass you'd see in a ring system - that doesn't prevent us from getting to Mars and beyond. $\endgroup$ – GrandmasterB Jan 5 '16 at 20:16
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    $\begingroup$ @GrandmasterB The moon is a singular object that orbits at over 230,000 miles away from Earth. Saturn's rings (a whole lot of stuff in there) are around the entirety of Saturn and start at about 41,000 miles away from Saturn. Also, space debris is an issue even when tiny. More debris, more issues. The issue may be overstated but I feel there's important nuance here. $\endgroup$ – The Anathema Jan 5 '16 at 22:55
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    $\begingroup$ Debris is only an issue when it isn't in the same orbit you are. If you match orbits, the ring is a destination not an obstacle. Every rock is a place you can go and visit, mine, or use as a station. $\endgroup$ – Oldcat Jan 6 '16 at 1:19
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For the most part, rings should not be much of an issue. Most of the rings we know of in our own solar system are made of dust and ice, and outside of Saturn, most of these rings are fairly nebulous. A spaceship moving at orbital or even interplanetary velocity will have a reasonably low chance of impacting anything large (and larger objects like shepherd moons will be fairly visible and easily tracked. Their orbits can be calculated with a high degree of precision and launches timed to avoid them.

That being said, there is still a finite chance for a collision with orbiting space debris (which is really what a ring system is), so a spacecraft operating in the region of the rings would need to be protected with Whipple Shields surrounding sensitive areas (light metal shields held away from the craft by a system of posts. The impact of a hypervelocity particle penetrates the shield, but vaporizes or severely degrades the incoming particles. These shields will need to be frequently renewed the more often you enter the zone of the rings.

Whipple Shield

Avoiding the equatorial plane is another relatively easy fix. With proper orbital adjustments and timing, the ship could launch on a polar orbit and "pass through" any clear spots (gaps, or coming in over or under the ring)to minimize the possibility of impact. The key issue here is that plane change manoeuvres are very energetic, and require a lot of deltaV from the spacecraft, potentially limiting the amount of manoeuvre possible later as much fuel or reaction mass has to be depleted.

For most work in space, highly elliptical "Molniya orbits" seem to be good work arounds for orbital satellites, providing a long period of "dwell time" in high orbit over the target area for surveillance, communications or other needs, while passing through the rings for only short time.

Molniya orbits

Highly inclined orbits can also be used to make it more difficult for ring debris to hit the spacecraft. At the most extreme, a ship in a highly inclined geostationary orbit will appear to be doing a figure of 8 over a fixed point on the equator.

So a combination of waiting for good opportunities to present themselves, avoiding the ring altogether (or choosing flight path to minimize exposure), followed by providing some sort of defense to the ship. Sailors navigated treacherous shoals for thousands of years, often with nothing more than a piece of rope for sounding depths and keen eyed lookouts searching for approaching danger. A spacefareing people can do much better of course.

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To continue on from Oldcat's comment on the question:

Strangely, the orbital speed you'll have to match in order to orbit at the height of the rings is... The orbital speed of the rings. That means that as long as you launch in the same direction as the rings are travelling, you'll actually be moving at a relatively low velocity when compared to the rocks around you.

At that point the issue becomes a navigational one, not one of hypervelocity impacts (Any particles moving in the wrong direction or in highly eccentric orbits will have hit the rings, slowed down and de-orbited). That makes the shielding requirements less stringent (though not completely gone). The main issue will be avoiding large clumps or asteroids, which will be moving in a fairly turbulent fashion. Luckily for you: You're moving fairly slowly compared to everything else in the ring, and you're the only one with thrusters.

It's true that your choice of orbits is now limited, and getting from inside the rings to outside the rings is tricky, but once you've got out near the edge of the rings you can set up a waystation (possibly on one of the larger asteroids) and spend time capturing other particles to use as reaction mass for station keeping. If you use that station as a jump-off point for your interplanetary missions you can finally realise the dream of an orbiting shipyard, especially if the rings are rich in minable/refinable substances.

So: Getting up there is harder by the amount of fuel you need to navigate amongst the rings, but once you are up there the worlds are your seafood platter.

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  • $\begingroup$ Passing the rings would be easier on an orbit with a different inclination than the rings. You can then easily perform a Hohmann transfer from an orbit below the ring to above the ring as long as you don't do it near the points where your orbit intersects that of the ring. The best point would be just after intersecting the ring, because then your next intersection would be at the apoapsis. $\endgroup$ – Philipp Jan 6 '16 at 17:21
  • $\begingroup$ But then you miss out on navigating an asteroid field using grappling hooks!! ;D $\endgroup$ – Joe Bloggs Jan 7 '16 at 11:24

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