Dev Tracker

Quote #7613644


LORE (Story, Background, Character, etc.)
2017-04-11 15:26:40

Hi @Foulwin42,

I'm not sure if the cables are meant to be rigid or not. I'd have to ask Design about their intent for that.

For my own education, if the asteroids are in an orbit around the star, wouldn't decreasing the mass change their orbital path (cause them to drift out)?


@Godwin answered that question perfectly. I just want to add it's very unlikely we'll see asteroids changing orbits in Star Citizen. All objects (planets, stations, asteroids) are placed on a fixed orbit by the devs. There isn't a real physics model for the gravity interactions between objects in the engine. (The asteroids may be animated so it looks like they're moving but all they really do is holding their relative orbit position.)
But even if we have "only" a fake planetary/sun system it's one of the things I wanted the most for Star Citizen. Wasn't sure it would ever happen but you guys nailed it.

For my own education, if the asteroids are in an orbit around the star, wouldn't decreasing the mass change their orbital path (cause them to drift out)?


Yes, removing mass will weaken the gravitational force between asteroid and thing it orbits. The orbit will be affected. The question is whether it's noticeable. You'd have to compare the mass you removed from the asteroid to the mass of the moon or planet or sun the asteroid belt is orbiting.
It's imho far more likely that drilling and landing with one of the drill machines we've seen would destabilize the orbit (if they have stable orbits at all in the first place, which imho isn't necessary or a given: could be chaotic anyway) and cause them to drift a bit, potentially hitting others again etc. Still, that couldn't really be the reason for the tethers, I assumed, since those few would be empty too soon and it would be so much work to tether-release-tether etc. (especially in terms of getting them into and out of place, safely).

When I saw the ropes anchoring the asteroids I assumed (I studied astrophysics by the way, so maybe my assumptions are slightly slightly more valuable in this regard?) that they were put into place to shield the base from stray asteroids.
I assumed the tethers were paired with some boosters fitted onto the large asteroids, which then could be moved around a bit to protect the base from incoming loose asteroids, like shields.

It was the only thing that really made sense to me.

It seems rather likely at least once a drunken rookie would crash head-first into an asteroid, maybe additionally setting off his rockets in the explosion(or a fight erupts somewhere and a missile hits an asteroid), thereby setting that one asteroid on a rogue path that may well cause it to collide with the station a month later. With the asteroid shields, the station can angle them to deflect the blow and fire boosters at the correct time to prevent them from, billiard-style, crashing the tethered asteroid into the station (also, tethers being very stiff but not so much as to break easily or be brittle or push the station too abruptly would make sense to me).

EDIT: PS: by the way, 'crashing into' etc. may give the wrong mental image. It's more likely that the asteroids would drift at a slow velocity relative to the station's orbit velocity and the rest of the field, on average. High speeds would be very hard to attain imo, so the low-velocity bumps would be deflected well enough by the big tethered asteroids, and the boosters can burn for quite a time to counteract the momentum change.
Still necessary though, as a 100 by 100 meter rock, even at 1 cm per second, will obliterate a stations walls/landing pad etc.

I very much like that idea.

For my own education, if the asteroids are in an orbit around the star, wouldn't decreasing the mass change their orbital path (cause them to drift out)?

No, an object's orbit isn't changed by it's mass, A heavy rock will fall at the same rate as a lighter rock. Decreasing the mass of the asteroid would change the orbits of anything orbiting the asteroid, but it wouldn't change the asteroid's orbit around other objects.

If the change of mass is high enough to influence the gravitational force the orbit would change. Because of the huge difference in mass between planets/moons and asteroids we can assume loosing mass will have no influence on the asteroids orbit though.

Unless the station is rotating or the lines are rigid, there would be a tendency for the asteroid to get pulled in.

More to the point, there wouldn't be anything pushing it away, so either by getting bumped from something or by the microgravity of the station, it would seem likely to eventually either wrap the cable around the station or fall straight into it.

From the perspective of an orbit of one object in the gravitational field of another; the mass of an object isn't important as both the objects momentum and the gravitational force are proportional to the object's mass. (This obviously gets more complicated when objects are of similar mass and/or there are more then 2 objects orbiting eachother.)

Hi @Soralin @Drake-Enterprises and @aviphysics

Some great discussion here. Just wanted to preserve the conversation. Thanks for chiming in with your thoughts.


Source - Quote #7613644