Why a Rask and Rusk Infinite Cycler without thrusting would not work (explained using LOGIC!)

[Akagi]

41 minutes ago, Pthigrivi said:

Yeah like, your Ap is going to lift perpendicular to the angle to rusk as you’re headed directly away from rusk, and your Pe is going to fall on the opposite side of rask as you’re headed directly toward rusk until eventually you crash—right?

i suppose

[t_v]

Interestingly, the lunar lander from Apollo 11 might have survived through the decades, as someone did an analysis of its orbit and found that the point of largest fluctuation might not have hit the surface. 

[Akagi]

2 minutes ago, Pthigrivi said:

...And that Akagi and t_v are right that a cycler doing a figure 8 around them wouldn't work because rask and rusk are proceeding around each other and your incoming vector is going to shift on each orbit. 

So, we'd have to burn radial each time we got at the intersection of the figure 8 to keep things stable. Best bet is to have a ship so far out that R&R act like one body.

Heyyyy...

I'm going to make two identical bases. R&R (rest and relaxation) on R&R (Rask and Rusk)!

I can't draw, OK?

(The squiggles are explosions)

[Akagi]

So, this makes TWO reasons an R&R cycler would not work:

1. Gravity assists would fling you out of the system
2. You would eventually (even with retroburning) slam into either Rask or Rusk.

[Maria Sirona]

42 minutes ago, Pthigrivi said:

...And the Akagi and t_v are right that a cycler doing a figure 8 around them wouldn't work because rask and rusk are proceeding around each other and your incoming vector is going to shift on each orbit. 

Yeah exactly

[Akagi]

astrofizik time

edit: yay 300 rep

Today: Rask and Rusk

Spoiler

So, now that we've found those TWO ways of this cycler not working, what about a THIRD?

The barycenter is the point of attraction between Rask and Rusk. The cycler would have to go near this point. Now, bear with me here, this is complex: If you go through a place where gravity goes in two directions, your ship, your precious torchship that can do ascents from Ovin, will go in two directions. Your ship will fall apart like a sardine can.

 

Edited April 21, 2022 by Akagi

[t_v]

1 hour ago, Akagi said:

So, now that we've found those TWO ways of this cycler not working, what about a THIRD?

The barycenter is the point of attraction between Rask and Rusk. The cycler would have to go through this point. Now, bear with me here, this is complex: If you go through a place where gravity goes in two directions, your ship, your precious torchship that can do ascents from Ovin, will go in two directions. Your ship will fall apart like a sardine can.

This isn’t exactly true- at the barycenter, the place right between the two planets, there won’t be much gravity at all, because each planet pulls the entire craft equally so the forces cancel out. It is like being at the center of a planet- if you ignore the pressure of the core, you wouldn’t feel any force because gravity is pulling you towards the surface equally in all directions. 

[Maria Sirona]

2 hours ago, t_v said:

Yes, earth orbit is actually unstable - in real life, satellites and space stations have to deal with stuff like orbital decay and fluctuations which, if you are in a bad orbit or are really unlucky, can push you into denser atmosphere. Similarly, nothing left in low lunar orbit is thought to survive because the fluctuations caused by Earth’s tug causes orbit altitudes to fluctuate a lot. 

What does that have to do with the way the planet(s) rotate?

Also that anime girl in @Akagi's post has the flags of Norway and Thailand on her bowtie, and the flag of Denmark on that thing on her head

[Akagi]

14 minutes ago, Maria Sirona said:

What does that have to do with the way the planet(s) rotate?

Also that anime girl in @Akagi's post has the flags of Norway and Thailand on her bowtie, and the flag of Denmark on that thing on her head

they're just patterns

18 minutes ago, t_v said:

This isn’t exactly true- at the barycenter, the place right between the two planets, there won’t be much gravity at all, because each planet pulls the entire craft equally so the forces cancel out. It is like being at the center of a planet- if you ignore the pressure of the core, you wouldn’t feel any force because gravity is pulling you towards the surface equally in all directions. 

science fixed! if you go near it, there would be 2 forces:

1. the planet you're nearest to
2. the other planet

so I think that might rip a weaker ship apart, or a long thin ship pointed , , , or 

 

[t_v]

19 minutes ago, Akagi said:

they're just patterns

science fixed! if you go near it, there would be 2 forces:

1. the planet you're nearest to
2. the other planet

so I think that might rip a weaker ship apart, or a long thin ship pointed , , , or 

 

But you wouldn’t see one side of the ship being pulled in one direction and the other being pulled in the other direction, at least very much. The difference in gravity between one end of the ship and another is so small that it wouldn’t pull anything less than 20km long apart, I would bet. If you want a similar result, build a ship that you think would get ripped apart and put it in orbit of a planet. The difference in gravity is about the same, and the only way the ship breaks apart is via kraken or under thrust. 
 

37 minutes ago, Maria Sirona said:

What does that have to do with the way the planet(s) rotate?

Could you clarify your question? I’ll answer from what I think you are asking. My response was to a question of whether Earth orbit was unstable, to which I answered yes. Almost  every orbit in real life is unstable to some degree. Orbiting Mars closely is pretty stable since Phobos and Deimos are relatively small and do not influence orbits much, whereas orbiting Pluto or Charon will diverge from the initial orbit much more quickly. This applies very much to Rask and Rusk, where the bodies are very close together and of similar masses and you will see your orbit very quickly change and probably hit a planet. This just applies to any orbit in an n-body system. 

[snkiz]

16 hours ago, shdwlrd said:

Not everyone will find it at the same point in the game. Player 1 can take 50 yrs to find and travel there. Player 2 takes 150 yrs, player 3 takes 300 yrs.

I don't think you are thinking big enough. I don't know what the math works out to but that untastable isn't believable at all. Kerbals happen to arrive mere centuries before they collide? It would make more sense for the orbits to be unstable on the order of millions of years not hundreds. 

[SSTO Crasher]

What about polar orbits, they might last longer 

[Akagi]

14 hours ago, SSTO Crasher said:

What about polar orbits, they might last longer 

Around one or both?

[SSTO Crasher]

Around one. If you time it right you could in theory stay in orbit

[JoeSchmuckatelli]

On 4/20/2022 at 1:24 PM, Akagi said:

If Rask and Rusk aren't tidally locked to their star, I might -- key word being might, I don't know -- hit the planets as their positions change.

Rask and Rusk are tidally locked to each other - but they effectively orbit one another with the presumed barycenter being the Lagrange Point between the two... and like the Moon (tidally locked to Earth) - while we see only the one face, from the vantage of the sun, the moon is actually rotating.  So from its sun (DebDeb?) they're rotating - but tidally locked to one another.

I'm bad at maths too - but it may be possible to do a figure 8 orbit (you know some of our better at maths players will be doing this challenge!).  All you have to do is make sure your orbit hits the barycenter (ahem) center and you prolly have a good chance of pulling it off.

Time for my Rask and Rusk question: Is any orbit possible other than one aligned with their plane of orbit with each other?  If we call that plane the equatorial, can you get a Polar orbit on one presuming you're closer to the planet than the Lagrange Point?

[Pthigrivi]

10 hours ago, SSTO Crasher said:

Around one. If you time it right you could in theory stay in orbit

I think if you were to reach a polar orbit that was perpendicular to the other planet it would be more stable initially, but as the planets proceed in their orbits that perpendicular orbit would be come more and more parallel, and the same disturbances with an equatorial orbit would occur. Your Ap and Pe would start rising and falling respectively in the normal/antinormal directions until you crashed near one of the poles. 
 

8 hours ago, JoeSchmuckatelli said:

I'm bad at maths too - but it may be possible to do a figure 8 orbit (you know some of our better at maths players will be doing this challenge!).  All you have to do is make sure your orbit hits the barycenter (ahem) center and you prolly have a good chance of pulling it off.

Time for my Rask and Rusk question: Is any orbit possible other than one aligned with their plane of orbit with each other?  If we call that plane the equatorial, can you get a Polar orbit on one presuming you're closer to the planet than the Lagrange Point?

I think they're all still unstable in the end because even if you pass through the barycenter the planet you're approaching has moved relative to your motion and so on each orbit the figure 8 will distort until you hit something. Its possible on a very wide orbit you could oscillate between min and max orbits without hitting anything.... maybe?

Edited April 23, 2022 by Pthigrivi

[Catto]

Listen: I'm not sure HOW it will work, but it's going to.

 No science needed.

[Pthigrivi]

Follow up... it might be possible to enter a cycler orbit with really high Ap's that match the orbital period (or half) of Rask and Rusk around each other such that your angle of approach is always the same. 

[t_v]

50 minutes ago, Pthigrivi said:

Follow up... it might be possible to enter a cycler orbit with really high Ap's that match the orbital period (or half) of Rask and Rusk around each other such that your angle of approach is always the same. 

Also, L2 and L3 should be stable. I think most people will have bases at L2 and L3 with some people having some at L1 and the maniacs making a perfectly timed figure-8 orbit to make it stable.