Is it possible to build a rocket so tall the top part spawns at orbital altitude?

[Croak90]

I had a random thought. Since when you launch a rocket that has parts that have clipped through the floor, it automatically sets the lowest parts at ground level, could you potentially build a rocket that has a sort of tail of structural parts that have been stacked so far the top part, the actual rocket starts in space? I doubt it does work, and if it does I doubt any standard computer wouldn't crash from trying to figure out that many parts, but if you could potentially do it, there would be a lot of things you could do with it. Especially since Saved parts are coming. It could just be a universal launch platform called "The Tower of Babel" that automatically puts massive rockets into orbit, completely negating the need for atmospheric escape. I'm planning on testing it a little just to see if there's a height limit on parts that clip through the floor as well.

[Dispatcher]

I'm guessing that Whackjob might have an answer to this, but ya never know who may have a lead on this.

[whistlehead]

I think Scott Manley did a video on this a while back. I'll have a look for it.

EDIT:

[Specialist290]

Given that the loading distance for a craft is much shorter than that, I'd imagine that trying this could cause problems.

[Croak90]

I did an initial test and successfully launched a small craft starting at 604 meters in the air. It was beautiful watching the thing dance.

[Andrew Hansen]

The physics will only load objects 2500 meters away, so in theory you could only spawn a rocket at that altitude (unless there was a way to change that limit).

[tstehler1]

The physics will only load objects 2500 meters away, so in theory you could only spawn a rocket at that altitude (unless there was a way to change that limit).

I think even if you could load objects more than 2500 meters away, a rocket covering more area than that would probably cause your processor/video card to be instantly exploderized.

(Disclaimer: This is an opinion based on my personal machine, which is somewhere between "meh" and "good." People with better systems than mine are free to commence calling me an idiot )

[Vonar]

Yeah, as far as I'm aware the physics engine is limited to 2500 meters away so it is impossible to build a space elevator or anything like that.

[Croak90]

I successfully launched a spacecraft at 3105 meters. I would have taken a screenshot but it LITERALLY took half an hour for it to load, so by the time I realized it actually worked the command pod had disconnected and was falling. When it crashed I checked the mission log and the max height reached was 3105. As long as this is true I just made something more than the supposed 2500 meter limit. First few things that come to mind is that maybe the limit is 2500 KILOmeters, or my ship was so big I made the physics engine go wacky and I got thrown up in the air.If people want I can upload the saved ship file and link the download so they can test for themselves.

I realize that people will be wary of a potential virus instead of an actual file, so if no one can trust me I will try to take a picture of at least the mission log. I just have to force myself to be patient and stare at the damn thing for half an hour.

[Specialist290]

I think the loading distance is actually calculated from the center of mass, not the ends of the craft. You might want to try with a segment more than 5 km long for the next test, just to be sure.

[shoveycat]

Even if you could, it wouldind quite be in orbit, it has no horizontal velocity

[Octagon]

Scott Manley have this answer:

EDIT:

I think Scott Manley did a video on this a while back. I'll have a look for it.

EDIT:

Sorry, I didn't noticed you have already posted it.

Edited October 14, 2013 by Octagon

[Croak90]

I think the loading distance is actually calculated from the center of mass, not the ends of the craft. You might want to try with a segment more than 5 km long for the next test, just to be sure.

That's if my computer doesn't kick the bucket loading it first lol.

[DaveofDefeat]

I have tried it, you run into memory issues.

[Kerbart]

A good way to answer a question is: "what if you did"

Let's imagine that the Unity Physics Engine does allow structures taller than 2.5km.

And let's imagine that, somehow, you can put a 70km structure (as that is what seems to define "space" in Kerbin) on the launching pad.

As Shoveycat observed, you'd be in space, but not in orbit, as your tangential velocity would be inadequate for that. BUT... you would have some velocity, as Kerbin rotates around its axis in 6h. At 670km from the center (600 km for the Kerbin surface, 70km for the height of your "rocket") that would be a circumference of 670×2×À=4210km, divided by 6 is 700km/h or 194m/s.

As your tower is moved out of the VAB and onto the launching pad, the top will have to accelerate from 0 to 194m/s in a matter of seconds -- It's hard to imagine that it's going to survive that.

[DaveofDefeat]

A good way to answer a question is: "what if you did"

Let's imagine that the Unity Physics Engine does allow structures taller than 2.5km.

Lol at the 7km tower above you.

[Croak90]

A good way to answer a question is: "what if you did"

Let's imagine that the Unity Physics Engine does allow structures taller than 2.5km.

And let's imagine that, somehow, you can put a 70km structure (as that is what seems to define "space" in Kerbin) on the launching pad.

As Shoveycat observed, you'd be in space, but not in orbit, as your tangential velocity would be inadequate for that. BUT... you would have some velocity, as Kerbin rotates around its axis in 6h. At 670km from the center (600 km for the Kerbin surface, 70km for the height of your "rocket") that would be a circumference of 670×2×À=4210km, divided by 6 is 700km/h or 194m/s.

As your tower is moved out of the VAB and onto the launching pad, the top will have to accelerate from 0 to 194m/s in a matter of seconds -- It's hard to imagine that it's going to survive that.

The main idea wasn't necessarily to already be in AN orbit, just be at orbital height. Accelerating from 0 to 194m/s wouldn't be difficult at all if you launched a ship that would normally be able to escape Kerbin's atmosphere in a single stage at 70,000 meters above sea level. The problem I always come back to is the memory based issue, but maybe if the welding plugin was used to make the entire tower a single part a computer would be able to handle it.

[DaveofDefeat]

The main idea wasn't necessarily to already be in AN orbit, just be at orbital height. Accelerating from 0 to 194m/s wouldn't be difficult at all if you launched a ship that would normally be able to escape Kerbin's atmosphere in a single stage at 70,000 meters above sea level. The problem I always come back to is the memory based issue, but maybe if the welding plugin was used to make the entire tower a single part a computer would be able to handle it.

Once again ive done exactly that, it doesn't work.

[Croak90]

I have tried it, you run into memory issues.

This is amazing. Also proves the 2.5m limit doesn't exist, at least not anymore.

[Croak90]

Once again ive done exactly that, it doesn't work.

So basically we need to borrow a super computer?

[Pds314]

It is, but you still need to reach orbital velocity, with Vanilla aerodynamics, this shaves off 50% of the required delta-V.

[DaveofDefeat]

So basically we need to borrow a super computer?

Its ksp 4gb ram limit, I suppose it would be possible with the linux 64 bit version and i would be happy to give the cfg file to someone who has it.

Also while the game will load the part the 2.4 limit still exists, it wont calculate physics for it beyond 2.4 and if you move your kerbal away from the command pod? it will unload at 2.4 km

Yet at the same time you can still make it stand up on the launch pad so these parts are kinda like the twilight zone in ksp.

[Croak90]

Its ksp 4gb ram limit, I suppose it would be possible with the linux 64 bit version and i would be happy to give the cfg file to someone who has it.

Also while the game will load the part the 2.4 limit still exists, it wont calculate physics for it beyond 2.4 and if you move your kerbal away from the command pod? it will unload at 2.4 km

Yet at the same time you can still make it stand up on the launch pad so these parts are kinda like the twilight zone in ksp.

A batch file could fix the gig limit issue, and someone posted a picture of a rocket spawned at 7km, which means either the limit was removed in an update (whether on purpose or accident, I don't know) OR they went into the game files and removed the limit themselves. I feel like with a powerful enough computer and running KSP on 12 gigs or more using a batch file combined with the welding mod and maybe some toying with the game files just to remove limiters could have really interesting results. Might turn out to be kind of a bootleg orbital assembly operation if someone could get it to work.

[DaveofDefeat]

A batch file could fix the gig limit issue, and someone posted a picture of a rocket spawned at 7km, which means either the limit was removed in an update (whether on purpose or accident, I don't know) OR they went into the game files and removed the limit themselves. I feel like with a powerful enough computer and running KSP on 12 gigs or more using a batch file combined with the welding mod and maybe some toying with the game files just to remove limiters could have really interesting results. Might turn out to be kind of a bootleg orbital assembly operation if someone could get it to work.

Yes that was me, and the 2.4 load limit still exists it just gets kinda wierd with long parts.

[Croak90]

Yes that was me, and the 2.4 load limit still exists it just gets kinda wierd with long parts.

Ah, sorry, I should really pay more attention to the names. I did watch the video Scott Manly did and he mentioned the physics engine would just shut down, so maybe someone could alter the settings in the files or make a mod to extend the limit as long as there's enough running memory to calculate it all.