Flight Question Is a docking possible in Neptune orbit?

[SuprunP]

The distance problem is not just you; it's a limitation of Orbiter's core, and a very reasonable one. As the distance to the Sun (the centre of the Orbiter universe) increases, its accuracy decreases.
Example:
If Orbiter could only carry three significant digits for whatever reason, it would look like this:
10.0 m from the Sun (let's call this stable)
1.00e2 m from the Sun (0.1m lost)
1.00e3 m from the Sun (1m lost, docking impossible)
And so on...
So accuracy decreases by an order of magnitude for every order of magnitude in distance from the Sun. By the time you get to to 1.50e11 m (1 AU), calculations would be so wildly inaccurate that it would be impossible to tell where the smegging Earth was. Obviously, this is on a much smaller scale than Orbiter, but the principle still applies, as far as I understand. Now thikn of how much accuracy even Orbiter would lose over the distance between Sol and the galactic core (2.46e20 m)?

Unnecessarily long and wordy post is unnecessarily long and wordy. :shifty:

I might not understand everything correctly, but a question popped into my mind when I was reading this:

Is a docking possible in, let's say, Neptunian orbit? Is Orbiter as accurate there as it is in Earth orbit?

Incidentally, I've got an object called 2006 SQ372, aphelion of which is around 1570 AU - can I land on it around this distance (theoretically) or the loss in accuracy would be too big?
(If the second question requires a new thread - please inform me.)

Thanks.

 

[blane]

In a Neptunian orbit, Neptune also is the reference body so it is the primary gravitational force which will be sufficient for any docking maneuvers.

 

[N_Molson]

Yeah, what matters is the local frame of reference ; Neptune in your case. Sun is the global frame of reference and has no effect on docking.

BTW, you can always try.

 

[SuprunP]

What about landing on 2006 SQ372? I suppose the reference body for it and my ship is the Sun (which is 1570 AU away), isn't it?

 

[garyw]

Once you get within it's SOI it'll become the reference body.

 

[blane]

Not sure what 2006 SQ372 is in Orbiter, what add-on? If it's a stellar object i'd expect it to have mass. Which then would be the local reference frame so the sun's influence would not matter.

 

[N_Molson]

There's no confusion there. In the Orbiter Universe, objects are conveniently sorted in classes. You have the PLANET, VESSEL, BASE classes etc...

An object orbiting the Sun can only be a VESSEL or a PLANET.

 

[Ark]

Wait, so if entering an SOI would fix the accuracy bug (if you can call it a bug), then why is semi-interstellar flight impossible? If you parked a star with a massive SOI at a light year away, once you enter that SOI wouldn't things function just as normally as in the inner solar system? The target star could be classed as a planet with it's planets classed as moons.

 

[jedidia]

I'm really not sure if Orbiter recalculates the coordinates relative to a reference frame. I always thought it used a global coordinate system...

 

[Jarvitä]

I'm really not sure if Orbiter recalculates the coordinates relative to a reference frame. I always thought it used a global coordinate system...

float64 is more than accurate enough for a single star system.

 

[N_Molson]

Wait, so if entering an SOI would fix the accuracy bug (if you can call it a bug), then why is semi-interstellar flight impossible? If you parked a star with a massive SOI at a light year away, once you enter that SOI wouldn't things function just as normally as in the inner solar system? The target star could be classed as a planet with it's planets classed as moons.

Well, aside from the accuracy problems, if there is any, I see two main issues :

- Light : if the other star is defined as a planet, it will not emit any light. And anyway, Orbiter supports only 1 global light source. So that second planetary system would be very dark and the angle of the light would be relative to the Sun.

- Moons : if the star is defined as a planet and if the planets are defined as moons, then you won't have any moons in your system.

 

[jedidia]

- Moons : if the star is defined as a planet and if the planets are defined as moons, then you won't have any moons in your system.

This is not an issue. The feature is not documented, but you can define moons of moons, the engine can handle it. The lightsource is trouble, though. I'm still hoping that Martin's going to put in support for binaries, but he probably won't do it before he tackles multiple solar system as a whole.

 

[N_Molson]

This is not an issue. The feature is not documented, but you can define moons of moons, the engine can handle it.

Interesting, I didn't knew that.

 

[Ark]

Yeah, I hadn't thought about the light source. So it's easy enough to slap something together to simulate a mini-interstellar flight, but it won't be very convincing.

Plus, Orbiter's time acceleration doesn't really go high enough for lightyears-long flight. Even if you hit light speed, sitting through three or four years of accelerated time takes a while.

 

[Hielor]

Yeah, I hadn't thought about the light source. So it's easy enough to slap something together to simulate a mini-interstellar flight, but it won't be very convincing.

Plus, Orbiter's time acceleration doesn't really go high enough for lightyears-long flight. Even if you hit light speed, sitting through three or four years of accelerated time takes a while.

Only about five minutes a year at 100000x, I think...