[WIP] Mass Driver

[Daemascus]

Any possibility of using the launch part of this mod to convert the runway into a carrier style catapult? It would be a great alternative to rocket assisted take off on larger air and space planes. It would only boost to about 80 meters per second but it would help get the craft moving. It would make for a fun and useful mod while the necessary mods for the full scale mass driver are fixed/made.

[MaverickSawyer]

If there's anything that should be added to the runway, it's a ski jump arrangement at the end to help those overweight spaceplanes into the air.

[Northstar1989]

Yes, a lot of delta-v is wasted. Much of that is due to drag. Because drag is proportional to the square of the velocity, this means that going 1000 m/s at 4 km isn't ten times the drag of going 100 m/s, but rather 100 times. Due to this you see very little improvement if you go that fast that low. This is also why you can come racing towards Kerbin at 10,000 m/s and still slow down to 200 m/s before your parachutes deploy. And I don't want to require FAR, because I want to depend on as few other mods as possible.

Like I said, though- the atmosphere is only 40% as thick at 4200 meters. For that reason, terminal velocity is 63.7% greater at 5000 meters than at sea-level...

Aside from that, if you remember the Rocket Equation, you know that you pay the highest cost in mass for those initial few hundred Delta-V. Even if a mass drive that starts at the base of a 4200 meter mountain and ends at 5000 meters only saves the rocket 300 or 400 m/s of Delta-V off its total cost, that's a lot more fuel mass (as well as engine mass and control mass) saved than you think- especially for large rockets.

Once again, the Oberth Effect is also a bit of a contributing factor here- if you leave the mass drive at 2000 m/s, and start burning your rocket engines immediately (even though most of that energy will go to drag), you still get a lot further with the same amount of fuel than if you start burning your engines at 0 m/s...

Finally, that kick-start velocity translates to serious benefits in terms of reduced design constraints. If you start out at 2,000 m/s at 5000 meters, your SRB's will last you until a much greater altitude- which means you may be able to make use of much weaker (but higher-ISP) LFO engines, like NERVA's, for your first LFO engines...

As mentioned, the craft are put on rails while they are accelerated. KSP does not calculate drag for vessels that are on rails.

Good to know. Didn't realize the implications when you said that before...

It depends what it's made of. If the Kerbals have nuclear rockets, they might also have large-scale structures made from carbon nanotubes. But I see your point.

So join me, come over to the mountain-launch side... I know that assisted-launch ending at 5000 or 6000 meters is a lot less valuable than assisted-launch ending at 14000 meters, but it's a lot more realistic. And I try to keep at least *SOME* realism in all my KSP games...

I know Extraplanetary Launchpads isn't so bad - I originally built it before taniwha took it over. But I want to depend on as few mods as possible, because if you depend on EPL then you also depend on Kethane and KAS, and that really starts to eat into your RAM.

Well I can see why you would say it requires KAS (you need some way to hook the EPL up to a command module and RocketParts storage), but it certainly doesn't require Kethane. At least not for on-Kerbin launches where you have an unlimited supply of pre-made RocketParts readily available. I can see why you would say that, though, as Kethane is very complementary to EPL when launching off-planet, but we're not doing that here, are we?

Can you model things? If so, KerbTown is pretty simple to work with - you just need to import the model into Unity and export it as a .mu.

I have no experience whatsoever modeling things , but I'd be willing to learn. IT can't be *THAT* hard, right?

Regards,

Northstar

[wasmic]

So join me, come over to the mountain-launch side...

You have to offer him cookies.

[Northstar1989]

You have to offer him cookies.

Not a bad idea...

Come, Skycooler, to the dark side. Join me, and together we can rule the galaxy from the top of a mountaintop mass drive. And, we have cookies.

- North Vader

Edited March 2, 2014 by Northstar1989

[cttw]

What about all the Bothans that died to bring us this design?

[Northstar1989]

What about all the Bothans that died to bring us this design?

Never mind them. The Emperor will have his revenge on them later!

Now, where we... Ahhh yes, Skykooler, we have cookies. And more realism than a 14 km-high mass drive. Come, to the dark side.

[CSVoltage]

So I think my main issue with this mod is that it is seriously advanced tech. I would be a lot more inclined to get it if it was only available in sandbox or by being unlocked late in the tech tree. Mission Controller also lets you unlock specific things with science outside of the tech tree, which is another way this might make it a little more balanced. Just my 2 cents. Take it or leave it. That said, nice work!

[skykooler]

So I think my main issue with this mod is that it is seriously advanced tech. I would be a lot more inclined to get it if it was only available in sandbox or by being unlocked late in the tech tree. Mission Controller also lets you unlock specific things with science outside of the tech tree, which is another way this might make it a little more balanced. Just my 2 cents. Take it or leave it. That said, nice work!

I'd like to have this integrated into the tech tree; the thing is, it relies on KerbTown to make it show up, and as far as I know there's no way to keep a structure from appearing in KerbTown until a certain tech level is unlocked. But I will keep looking into it.

[icemonkey]

I want one. Now. Please.

I want to build a Jeb Cannon.

[Hooligan Labs]

I want one. Now. Please.

I want to build a Jeb Cannon.

This does work with KerbTown. I've tested it.

BTW, I noticed the comment about making this a part. Sorry if this has already been suggested, but one idea might be to make a little "Mass Driver Comlink" part or something. It would be a normal visible part, but hidden in the file would be the mass driver model with everything except the mesh renderer and collider turned on. Maybe then use the normal right click menu on the comlink to place it. Something like...

namespace MassDriverCode
{
public class MassDriverComLinkPartModule : PartModule
{
public GameObject MD_Template; // Set in Unity Editor or find at start
[KSPAction("Order Mass Driver Construction")]
public void MDC_Action(KSPActionParam param)
{
MDC_Event();
}
[KSPEvent(guiActive = true, guiActiveUnfocused = true, unfocusedRange = 2000, guiName = "Order Mass Driver Construction")]
public void MDC_Event()
{
GameObject MD_Clone = Instantiate(MD_Template, transform.position + new Vector3(0, 2000f, 0f, Quaterion.identity) as Transform; // Plops a copy of the Mass Driver 2 km ahead with the same orientation as the part.  Obviously could be done better, but a start.  
MD_Clone.transform.parent = null;
MD_Clone.renderer.enabled = true;
MD_Clone.collider.enabled = true;
}
}
}

Maybe that would be a good challenge for Northstar?

Edited April 16, 2014 by Hooligan Labs

[skykooler]

This does work with KerbTown. I've tested it.

BTW, I noticed the comment about making this a part. Sorry if this has already been suggested, but one idea might be to make a little "Mass Driver Comlink" part or something. It would be a normal visible part, but hidden in the file would be the mass driver model with everything except the mesh renderer and collider turned on. Maybe then use the normal right click menu on the comlink to place it. Something like...

namespace MassDriverCode
{
public class MassDriverComLinkPartModule : PartModule
{
public GameObject MD_Template; // Set in Unity Editor or find at start
[KSPAction("Order Mass Driver Construction")]
public void MDC_Action(KSPActionParam param)
{
MDC_Event();
}
[KSPEvent(guiActive = true, guiActiveUnfocused = true, unfocusedRange = 2000, guiName = "Order Mass Driver Construction")]
public void MDC_Event()
{
GameObject MD_Clone = Instantiate(MD_Template, transform.position + new Vector3(0, 2000f, 0f, Quaterion.identity) as Transform; // Plops a copy of the Mass Driver 2 km ahead with the same orientation as the part.  Obviously could be done better, but a start.  
MD_Clone.transform.parent = null;
MD_Clone.renderer.enabled = true;
MD_Clone.collider.enabled = true;
}
}
}

Maybe that would be a good challenge for Northstar?

Interesting idea! I'll take a look at implementing it this weekend.

[thutmose]

It depends what it's made of. If the Kerbals have nuclear rockets, they might also have large-scale structures made from carbon nanotubes. But I see your point.

The type of nuclear rocket they used could be build with technology we had in the 1960s, all it is is a nuclear reactor where the heat from the reactor is used to propel the fuel backwards, nuclear rockets are much lower tech than large scale use of nanotubes.

[Railgunner2160]

You're forgetting the Orion Nuclear propulsion system that while not built was scale tested using High-Explosives and was quite capable theoretically at propelling even skyscrapers into earth orbit....

The basic idea is you use a nuclear bomb under a push plate to lift even huge masses into earth, of course you need multiple explosions so it's a pulsed system...

Nyrath made an excellent re-creation for KSP http://forum.kerbalspaceprogram.com/threads/28428-Orion-aka-Ol-Boom-boom

Edited April 17, 2014 by Railgunner2160

[HoneyFox]

I'd like to have this integrated into the tech tree; the thing is, it relies on KerbTown to make it show up, and as far as I know there's no way to keep a structure from appearing in KerbTown until a certain tech level is unlocked. But I will keep looking into it.

Perhaps the acceleration capability can be affected by TechLevel, so that the building can always be there but you cannot utilize it (completely) until certain Tech Level(s) is/are unlocked.

P.S. KerbTown's launch site feature has been fixed, check recent posts of that thread.

[Hooligan Labs]

In a way... When you research mass drivers the inventors often propose doing it in steps. It usually begins with something that we could just about build now, basically a very tall monorail, and then they add in things like monopole magnets as they are made reliable and cheap enough.

[Warq]

Waaaaanttttt!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[qnistNAMEERF]

There's definitely something funky about the orbits it puts you in. I don't mean their eccentric nature, I mean that an eastward facing launch is somehow putting me into a polar (sub)orbit... the eccentricity I understand, but how is it getting this incredible inclination from an equatorial eastward launch?

It shouldn't do that, but sometimes it does. I'm still trying to work out why myself.

I just stumbled upon this a day ago, so I apologize for the necro. But I love this thing. It's just fun. I only tried one launch so far since that's all I had time for after getting everything set up. Does the direction you're travelling prior to mass driver launch affect what sort of orbit it throws you at? I spawned a rover on the runway and went straight for the mass driver (north), and ended up getting thrown to the north. Haven't had a chance to test it further yet. Also wanted to ask if there's any way I can change the distance at which it launches, since I'd rather it wait until I got to the entrance (within 5 meters or so), instead of within 500 meters. It doesn't appear to be possible in this version. Just figured I'd confirm whether that's the case.

[dreadicon]

Love the idea! Will have to try it out later.

Some thoughts and suggestions:

-KerbTown has launch site options. Why not set this up as a launch site you can select, and put it a little further away?

-Offer some method of configuring launch velocity, letting it start with zero (rocket sled), and scaling up to full-on mass driver with tech?

-Ejection angle would be nice to change, but making it to being procedural I could see being something of a difficulty, as nice as that would be.

Finally, I know there's another mass driver mod in progress, but it currently doesnt seem to work anything like yours, or honestly overlap in utility; yours is a large-scale, gradual, powerful launcher which is good for more delicate/complex payloads. Hope you get some time to flesh this out a bit!

[Thomas988]

So cool!

[Kerbin- We have a problem]

Download link pls

[Gaunt596]

Is this mod dead? with Kerbal konstructs coming out placing buildings in KSP and having them functional is possible.... i know absolutely nothing about modding but i could learn how if it means saving this

[skykooler]

Does Kerbal Konstructs support actions for structures like KerbTown did? If so, I'll try to update it.

Edit: from what I gather it does not yet but it's a planned feature.

Edited October 17, 2014 by skykooler

[Joshwoo70]

Does Kerbal Konstructs support actions for structures like KerbTown did? If so, I'll try to update it.

Edit: from what I gather it does not yet but it's a planned feature.

Sorry for update.

yes kerb constructs support it.

[_Augustus_]

I'm using the mass driver model for Kerbol Expanded's next update. I already posted on your profile, but is this OK? There appears to be no license.