[request] F and G class asteroids

[Sharpy]

Not only do I haul class E asteroids with little effort, by the time I bring them into LKO they are mostly depleted.

Is there - and if not, would it be hard to make it - a mod to introduce much larger asteroids than in stock? Something of order of 10,000 and 100,000 tons? Something to challenge people using various 'interstellar' mods?

[DStaal]

You might try putting in USI's Asteroid Recycling Technologies.  As a side-effect it makes asteroids about four times larger and thirty times as massive.

[Arugela]

I requested this in the suggestion forum. It would be nice. There is a general approximate amount difference per asteroid level. I think I gave the general amount that would be needed for each based on the general multiplier up to H asteroid or something. It would be nice to see.

NVM, it was only to F asteroid:

I think the the multiplier is approx 4.5. So, G asteroids would be approximately 17,200-77,283 tons, H would be approximately 77,283-347,773.5, I = 347,773.5-1,564,980.75, etc.

I think we got into a discussion as to when asteroids would develop micro gravity and whatnot also and shapes etc.

If we made them big enough for micro gravity it could either make it easier to capture at some point(a natural aide) or start to become a challenge depending on the effect and spaceship. Could be a cool addition. Would gravity be affected by density of the material or only the fact that a given amount of material is there?

Edit: I forgot we also referenced moving asteroids with asteroids. It was another discussion at the time(older actually, and where the micro gravity discussion may have started from.). And a video showing it was possible. So, this opens this up more... Which could also leads to more discussions on things making it more possible realistically to make them hit each other... Maybe calculations or advanced physics maybe? so minimum calculation could help for trajectories of smaller objects. Would also double as being good for helping docking if not overpowered. Or whatever alternative methods work best.

 

Edited December 25, 2016 by Arugela

[Sharpy]

Reading the files of ART, and KSP API if we sacrifice class A and B (I never really found any use for these),

@PART:HAS[@MODULE[ModuleAsteroid]]
{
	@MODULE[ModuleAsteroid]
	{
		maxRadiusMultiplier = 19.08 //Default is 0.95 
		minRadiusMultiplier = 25.1  //Default is 1.25
	}
}

this should simply bump all the asteroids two classes up size-wise. "New class C" would be "Old class E".  New class E would be  around 17 to 76 thousand tons. Further testing required.

[Astrofox]

To be honest, I kind of wonder about how painful it'd be to push or tug a gilly-sized asteroid across the solar system - especially if you are using modern rocketry (including NTRs/NERVAs).

[MinimalMinmus]

5 minutes ago, Astrofox said:

To be honest, I kind of wonder about how painful it'd be to push or tug a gilly-sized asteroid across the solar system - especially if you are using modern rocketry (including NTRs/NERVAs).

As in, very very painful. As scott manley explained in a video I'm too lazy to link to, sending Gilly on a collision course with Eve would require, well, basically, one fuel tank the size of Gilly, and an unbearable lot of patience to get those NERVs to work. And for this, efficiency isn't even good, 'cause remember doing a hohmann transfer only would take even more of your already precious time.

[Kerbart]

Why stop at G? Give us at least two more classes - an H class to fill every file on the chess board, and a "yo mama" class for mass extravaganza.

[Arugela]

Asteroids up to H and I are only like 1.5milliion tons or more. 4.5 multiplier per class. Its completely moveable given modern parts. The biggest ones would just be giant movable space stations. It would be cool to get some with microgravity. Or big enough to have kerbals walk around on and build bases or whatnot on conveniently. There is a lot you could do with a massive moving space mining rig.

[Sharpy]

Yup, people like to joke about Gilly being just another asteroid but having a massive operation going there I can say there is really no comparison.

Or... 1.242 * 10^15 ton - following the asteroid mass to class formula - Gilly is class Y asteroid.

So, F, G, H - that all would be movable, although obviously the top ones only with great difficulty - and we're still 16 classes below Gilly. And respectively, we really should forget asteroids that are movable and have gravity.

I don't think class I would be doable without a serious engine modifications though - since it would likely exceed the 2.3km physics bubble size! But class H would be roughly 1km in diameter, making it a very interesting object to explore.

[Sharpy]

4 hours ago, MinimalMinmus said:

As in, very very painful. As scott manley explained in a video I'm too lazy to link to, sending Gilly on a collision course with Eve would require, well, basically, one fuel tank the size of Gilly, and an unbearable lot of patience to get those NERVs to work. And for this, efficiency isn't even good, 'cause remember doing a hohmann transfer only would take even more of your already precious time.

 

1) Mammoths instead of NERVs. Because you have more than enough fuel.

2) Moderately sized fuel tank. Huge ISRUs and huge drills.

3) Extraplanetary Launchpad, deploying more drills, ISRUs and engines right on site.

4) You'd likely want to go with bi-elliptic transfer: first raise Gilly apoapsis to the edge of SOI, then drop its periapsis. Should take considerably less delta-V than Hohmann.

 

[Arugela]

5 hours ago, Sharpy said:

Yup, people like to joke about Gilly being just another asteroid but having a massive operation going there I can say there is really no comparison.

Or... 1.242 * 10^15 ton - following the asteroid mass to class formula - Gilly is class Y asteroid.

So, F, G, H - that all would be movable, although obviously the top ones only with great difficulty - and we're still 16 classes below Gilly. And respectively, we really should forget asteroids that are movable and have gravity.

I don't think class I would be doable without a serious engine modifications though - since it would likely exceed the 2.3km physics bubble size! But class H would be roughly 1km in diameter, making it a very interesting object to explore.

I think in my old F class suggestion thread someone said it only needed 137 KM for micro gravity... although I don't know if it took into account gravity differences from reality to kerbin... I think another thread back then went into more detail but I forget. I don't remember which answers were supposed to be accurate.

I haven't looked at what determines the radius so I wasn't sure. And there was always the idea of those larger micro gravity ones becoming bases and simply being too big to move. This would make them good objects to make refueling stations in the asteroid belts and possibly around dres or even an ort cloud sized object farther out then Eeloo! I think there are potential usages for it. But if there are physics limitations there might need to be special things done if they are generated to allow them to work. Maybe stuff like they do to the planets with segments or other special coding to let them be off rails and have gravity properly. Maybe they could simply project the gravity from the core to the surface grid or something. But, yea, a 1KM asteroid would be cool. I'm not sure when the micro gravity would pop up according to class.

And I think "I" could be move-able if you use enough attachments to it. If it's large enough you can just put a bunch of large engines and mine it. 375 Mammoth engines to match it's max size. That is still doable. I think from my past large ship experience you can move it with much less if you really wanted too(1/3 possibly). It would just depend on how much fuel you want to drain...(Although I think at those sizes I wouldn't be surprised if you drained the whole asteroid or a large part of it) That or I guess that is our base sized asteroid... It would be fun to try to make vehicles that stick on the surface regardless.

How do you figure out the diameter of an asteroid in KSP per class?

Edited December 28, 2016 by Arugela

[Sharpy]

7 hours ago, Arugela said:

I think in my old F class suggestion thread someone said it only needed 137 KM for micro gravity... although I don't know if it took into account gravity differences from reality to kerbin... I think another thread back then went into more detail but I forget. I don't remember which answers were supposed to be accurate.

Depends what you define as microgravity. 5km will have an acceleration of roughly 1m per hour per hour. (meaning a thing suspended 1m above the surface will fall to it about an hour later).

 

[Tyko]

Back to @Sharpy problem of Class E's being more or less depleted of ore by the time they are captured - wouldn't a larger, heavier asteroid still face the same problem because they contain more ore, but require a lot more fuel to push them around.

As a solution, try using Atomic Age Lightbulb engines. They have a vacuum ISP of 1500 and can capture a class E with quite a bit of ore remaining. The 30-45 minute burns are a "joy" though  

[Sharpy]

1 hour ago, Tyko said:

Back to @Sharpy problem of Class E's being more or less depleted of ore by the time they are captured - wouldn't a larger, heavier asteroid still face the same problem because they contain more ore, but require a lot more fuel to push them around.

Matter of percentages vs raw values.

I can bring an asteroid into LKO depleting, say, 70% of its mass. If we assume the tug mass is negligible comparing to the asteroid, the percentage of asteroid surviving comes directly from the Rocket Equation; constant ISp, the same delta-V, so for result to be the same, initial to final mass ratio must remain the same - regardless of what that initial mass was.

10% or so remains as dirt. 20% of initial mass is resources that can be used up.

If I started with as 750t asteroid , that will be measly 150t of ore in LKO. If I start with a 3500t - that's a much nicer 700t.

If I use engines of 1500 ISp instead of 350, there's still no way to squeeze 700t of ore out of a 750t asteroid...

 

[techgamer17]

On 12/23/2016 at 10:57 PM, Sharpy said:

Not only do I haul class E asteroids with little effort, by the time I bring them into LKO they are mostly depleted.

Is there - and if not, would it be hard to make it - a mod to introduce much larger asteroids than in stock? Something of order of 10,000 and 100,000 tons? Something to challenge people using various 'interstellar' mods?

What do you mean by "they are depleted"? Thanks.

[RA3236]

2 hours ago, techgamer17 said:

What do you mean by "they are depleted"? Thanks.

He mines the ore out of them and refines it into fuel.

[Tyko]

On 12/24/2016 at 5:26 PM, Sharpy said:

Reading the files of ART, and KSP API if we sacrifice class A and B (I never really found any use for these),

@PART:HAS[@MODULE[ModuleAsteroid]]
{
	@MODULE[ModuleAsteroid]
	{
		maxRadiusMultiplier = 19.08 //Default is 0.95 
		minRadiusMultiplier = 25.1  //Default is 1.25
	}
}

this should simply bump all the asteroids two classes up size-wise. "New class C" would be "Old class E".  New class E would be  around 17 to 76 thousand tons. Further testing required.

This is great! Would it modify asteroids that I've already captured and attached things to?

Edited January 5, 2017 by Tyko

[Sharpy]

2 hours ago, Tyko said:

This is great! Would it modify asteroids that I've already captured and attached things to?

Unfortunately, yes. Tried it, the tug was turned literally to dust.

[Sharpy]

Umm... I might have bitten more than I can swallow.

That's ONLY a Class D!

[diomedea]

Sorry if I'm late to this discussion. The idea of having asteroids with larger masses than they currently are in KSP is very sound.

The average size (mean radius of the mesh) of each asteroid class allows to compute volume (V = 4/3 π r³); mass of each asteroid class (from the wiki) against volume gives the average density. In KSP asteroid densities are around 20 Kg/m³. There are few solid materials in nature with such low density (from this table: expanded polystyrene, glass-wool, polyurethane foam) all rather improbable as materials for a natural space object.

Actual asteroids have much larger densities. They are classed based on composition; densities for the three most common classes (C, S, M) are shown here to be 1380, 2710 and 5320 Kg/m³ respectively.

If a density =1380 (C class) was true in KSP, the mass of a class A asteroid would make a sphere with a diameter of 1.14-1.88 m; the largest class E would only be 13.92 m wide. To match the asteroid sizes with believable densities, masses in KSP have to be multiplied by 70 (for C class), 136 (for S class) or even 265 times (for M class). Of course such larger masses (a class E roid would then have mass 59,000-264,000 tons with the lowest 1380 Kg/m³ density) may create more difficulty trying to redirect those "rocks".

About microgravity: even with the highest density of a M class, a KSP class E asteroid would exert a gravity = 0.053 mm/s² at its surface (Gilly has a surface gravity = 0.049 m/s² = 49 mm/s²). It's such a tiny amount to hardly produce any effect on a nearby object (actually, so tiny it would take very little, e.g. a small centripetal force from rotation, for the asteroid to break).

Considering larger classes than actually exist in KSP (each one a mass 4.5 times larger then the earlier class), would be possible to arrive at a hypothetical "class L" (7 classes larger than "E") with a diameter = 2390 m, so to stay entirely within the "bubble". If with the density = 1380 Kg/m³ it would arrive at a mass = 200,000,000,000 tons and a surface gravity = 1.25 mm/s². Can't think anything that massive may be successfully redirected in KSP, however would make an interesting object to play with.

 

[Sharpy]

1 hour ago, diomedea said:

The average size (mean radius of the mesh) of each asteroid class allows to compute volume (V = 4/3 π r³); mass of each asteroid class (from the wiki) against volume gives the average density. In KSP asteroid densities are around 20 Kg/m³. ...]

Considering larger classes than actually exist in KSP (each one a mass 4.5 times larger then the earlier class), would be possible to arrive at a hypothetical "class L"

 

...what mass would be correct for classes F and G with stock density?

[diomedea]

1 hour ago, Sharpy said:

...what mass would be correct for classes F and G with stock density?

Great you asked . With the stock density (~20 Kg/m3) a KSP class F asteroid mass ranges from 3,828 tons to 17,226 tons; a class G from 17,226 to 77,517 tons (each class is about 4.5 times heavier than the earlier one).

With the density corresponding to a real C class asteroid (1380 Kg/m³), mass with a KSP class F ranges from 264,100 tons to 1,189,000 tons; with a class G from 1,189,000 to 5,349,000 tons.

Let me know in case you wish info about asteroids of different composition.

[Sharpy]

2 hours ago, diomedea said:

Great you asked . With the stock density (~20 Kg/m3) a KSP class F asteroid mass ranges from 3,828 tons to 17,226 tons; a class G from 17,226 to 77,517 tons (each class is about 4.5 times heavier than the earlier one).

With the density corresponding to a real C class asteroid (1380 Kg/m³), mass with a KSP class F ranges from 264,100 tons to 1,189,000 tons; with a class G from 1,189,000 to 5,349,000 tons.

Let me know in case you wish info about asteroids of different composition.

I'd rather verify the radius adjustment. If I want new Class E to be Class G, I should multiply the radius by 4.5^(2/3)or 2.72, right?

[diomedea]

1 minute ago, Sharpy said:

I'd rather verify the radius adjustment. If I want new Class E to be Class G, I should multiply the radius by 4.5^(2/3)or 2.72, right?

The 4.5 ratio from one class to the next applies to mass. Mass is tied to volume by density (so, assuming same density with all asteroid classes), volume scales by 4.5 as well.

Assuming asteroids to be roughly spherical, volume V = 4/3 π r³, therefore radius r = ³√(3V/4/π); the difference in radius from one class to the next is ~= 1.65  (please note this works with average radius even with non spherical objects as the asteroids are).

[Sharpy]

2 minutes ago, diomedea said:

 the difference in radius from one class to the next is ~= 1.65  (please note this works with average radius even with non spherical objects as the asteroids are).

1.62^2=2.7225 so two classes up seems to be it. Gonna wait some time for new asteroids to spawn - while radius changes dynamically, mass seems to be assigned at spawning time (basing on radius) and saved. The fixed patch got size in check, but the asteroid remained as heavy as before.