[0.19.1] Supernova SHLLV - 160 tons to LKO

[Temstar]

It's back in 0.18.4 when I first had the thought of "let's build the largest rocket possible with a single 2.5m core". The result was the Nova SHLLV capable of 110tons to LKO. From Nova then came the Zenith rocket family covering the whole spectrum between 15-110 tons.

But then as with all things in engineering, when you build something really big people immediately start to wonder about how to build another one even bigger. Nova is no exception and I received quite a few messages proposing even bigger lifters. So I started seriously thinking about a Supernova.

The problem is Nova was specifically designed with the goal of "largest 2.5m core possible". When you look at the back of its core stage:

...you'll see the problem of making it bigger - basically there's nowhere to put any more engines under a 2.5 stack, even after adding the tail connections to increase the area. The only option left is then to use a bigger stack. Without resorting to 3.75m mod parts the only way to get a fatter stack is to create "synthetic" stacks made up of multiple stock stacks. Thus this was my solution to the problem:

A synthetic stack made up of a 1.25m stack at the centre surrounded by three 2.5m stack clustered around it, enough area for much more engine power than the 2.5m Nova core.

And this is the final result:

Supernova Super Heavy Lift Launch Vehicle

• 160.6 tons to LKO (75km x 75km)
  
• Payload fraction: 15.01%
  
• Thrust at lift off: 18,000kN
  
• Cost: $369,560
  
• Cost/ton to LKO: $2301.12
  
• Part count: 267
  

You may have noticed one other difference from the Zenith family of rockets - no 1.25m engine clusters. This was a deliberate design choice: I noticed that many 100ton+ rockets have part counts well above 300. The problem with a lifter using up that much part is that a payload that weighs more than 100 tons is itself going to take up A LOT of parts. If you're lifting 160 tons to orbit and your rocket is 350 parts and you load another 350 part of payload on top you're going to get something too laggy to fly for most people's computers. What is the point of designing and sharing a booster if it's a painful experience to fly? Engine clusters whilst highly efficient is very part heavy. The 12 engines of Nova core alone takes up 32 parts, if I put three Nove cores together that's almost 100 parts before I add struts. Mainsails bring the part count down at the cost of efficiency. Compared to the Zenith family Supernova has a lower payload fraction than all of them. However on the other hand mainsails give excellent value for money in terms of thrust/dollar. Thus being purely powered by mainsails Supernova has a lower per ton cost to LKO than all members of the Zenith family.

Let's have a look a the ascent profile:

Before lift off, hit action group 1 twice to turn off gimbling for all booster engines. Turn on ASAS, throttle up to max and hit ignition.

At about 2600m your first set of boosters will run out, stage them. You'll notice that Supernova stages mainsail boosters in threes rather than the more conventional pairs. This is partly due to the size of the rocket and partly due to the geometry. At around 9000m your second set of boosters will run out so stage them too and then start to pitch down to 45 degrees for gravity turn.

At 26000m your last set of three boosters will run out. At this altitude and without any control surface left you will usually have some roll motions. Turn off ASAS and turn on RCS to correct the roll. From this point onwards I recommend switching off ASAS and switch on RCS for all steering manoeuvres.

Supernova core accelerating to high sub-orbital velocity.

With the target AP reached, throttle down engines and coast to AP. I noticed one interesting thing - if you instantly turn off the throttle with X the sudden jolt can knock loose/ explode some of the nose cones on top of the 2.5m stacks. It doesn't seem to cause any damage or affect the structural integrity of the rocket so I wouldn't really worry about it, but if you want to avoid it then throttle down with Ctrl instead of X.

Supernova just before throttling up for final circularisation.

Payload released.

As with the Zenith rocket family, Supernova is equipped with probe core, RCS system and electrical system for self-deorbiting after payload release to ensure compliance with the Clean Space Policy.

Craft file:

http://www./download.php?kcs8op66cpst9yc

Edited May 10, 2013 by Temstar

[Allister]

Nice Temstar! The A-Tech green team is very interested in your BA rocket. May we order 30 or so?

[Gojira]

Love the name, haha. Will download when I'm on my computer. Also, what's the payload capacity to, say, Duna?

[Spanier]

Nice design, Temstar.

@Gojira: You use lifters to bring up the stuff into a basic orbit, if you want to go to other planets, you take a transfer stage with you, that's part of the payload, not of the lifter.

[GusTurbo]

Very impressive, as always. Do you suppose having four 2.5m tanks surrounding the 1.25m core would yield even more lifting capability?

[Temstar]

Love the name, haha. Will download when I'm on my computer. Also, what's the payload capacity to, say, Duna?

It's certainly possible and if I were to guess it would be around 80 tons to Duna orbit. I did something similar with Nova where I sent 58 tons to Mun orbit instead of the 110 tons to LKO. Duna is a little bit further in terms of delta-V compared to Duna and Supernova's engines are bit less efficient so I reckon it will just about manage 80 tons.

That said launch vehicles are optimised for launching payload to LKO and not interplanetary travel so I wouldn't recommend it - it's too unwieldy to fly for a long trip. 80 tons to Duna or 160 tons to LKO, you have to ask yourself: can I ditch the rocket in LKO and design a interplanetary transfer stage that can send 80 tons to Duna while weighing 80tons or less itself?

I'm guessing with nuke engines the answer would be yes.

Very impressive, as always. Do you suppose having four 2.5m tanks surrounding the 1.25m core would yield even more lifting capability?

Actually originally I did start with four 2.5m stacks around the 1.25m centre spine with the aim of 200 tons or more. But I find that for a payload of this size 2.5m parts no longer hold up. The combined forces of a 200ton dead weight being forced down by gravity against the 2G or more acceleration coming up from the engines is just too much for some parts to take. It took a lot of very precise strutting finally make a payload that wouldn't crush it's own 2.5m core while under acceleration so I felt that the 4x design was too unwieldy and with a margin of error for failure too small for comfort. Hence why I settled down on the 3x design.

[Francesco]

very good, definitely will try this.

but you already know that soon someone is going to ask for a 300 tons to LKO Ãœbernova, don't you?

P.S. I was thinking that we may start to add a watermark like this to rockets that comply with the Clean Space Act:

[Akalaël]

Fantastic ! I really like your creations, really !

[CtrlAltEL1TE]

Amazing rocket, extremely tempted to replace my own SHLV which has the same part count pretty much but I could only get 130tons from it =|

[Conarr]

Some of the first rockets I used when I started this game were your Zenith rocket family. They helped me learn a lot of what I think I know now. Looking forward to firing Jeb at something on top of this monster.

[Commander Zoom]

The only thing keeping me from using your creations at this point is that I'm stubbornly committed to my own. u_u

[Drunkrobot]

Excellent work! But you know what's coming next...

"Now, Hypernova!"

Yes that exists. Google it.

[SOJUZ151]

My lifters can take much more to orbit

http://forum.kerbalspaceprogram.com/showthread.php/26372-my-heavy-lifter-and-refueler

[PolecatEZ]

Whats funny is that I've been running a modified version of your Nova, called Supernova, with about a 148 ton capacity. I'll see how they differ though, after about 130 ton payload I have to start strutting to hell.

[bulletrhli]

Awesome man, definitely add this to the Zenith series! That is all I use and to have it all bundled nicely would be fantastic!

Edit: I have actually made a mockup

Download zenith rocket series w/ supernova

Edited May 10, 2013 by bulletrhli

[Francesco]

My lifters can take much more to orbit

http://forum.kerbalspaceprogram.com/showthread.php/26372-my-heavy-lifter-and-refueler

but it's only 20 tons more: a 12% increase in payload for a 54% increase in total mass.

[bulletrhli]

but it's only 20 tons more: a 12% increase in payload for a 54% increase in total mass.

And a LOT more parts

[falofonos]

I was extremely disappointed in the performance of this lifter. My 87 ton payload got to about 40km altitude then the lifter went odd and I had to abort.

Then I realized I had put my payload on top of your fuel depot payload. .. So, the lifter can raise 240 ton or more into a deathspiral from 40km altitude or so!

Currently my payload is in LKO with 1141 Dv in the lifter's tanks for rendezvous with The Drive Section for my Jool expedition.

There does seem to be a fuel line oddity in the final lifter stage. The outer 3 rockets are pumping fuel into the central tank but there's no fuel lines pumping to the last 3 stacks. Not sure if this is a glitch or I messed something up somehow.

-----------------------

I fixed the missing fuel line from sub-assembly loader.

This lifter is magnificent providing the user pays attention to the manual. Sadly, I was so impatient to try it out after spending 2 days creating the most monstrous collections of struts, girders and tangle of fuel pumps that I failed that basic step.

Now I have my Jool ship almost complete and I'm probably looking at a part count of CPU meltingly silly.

Edited May 11, 2013 by falofonos
laptains cog supplimental

[Temstar]

There does seem to be a fuel line oddity in the final lifter stage. The outer 3 rockets are pumping fuel into the central tank but there's no fuel lines pumping to the last 3 stacks. Not sure if this is a glitch or I messed something up somehow.

Oh damn, it's that old missing strut/fuel line bug with subassembly again. Yes there are three fuel lines pumping from the centre spine to the three stacks:

If they're gone then they need to be recreated for the booster to work correctly. You don't have to have the exact same placement of course, just as long as you run three lines from centre to the three stacks and it will work.

[bulletrhli]

I think people should be aware of the bugs with the mod. There is absolutely nothing wrong with this lifter design. You stated in both this and the last thread with the zenith series that sub assembly loader had the mod. If they cannot read, it is their own fault.

[iDan122]

You sir, are a copyright fraud. You have stolen the rights for the SuperNovaâ„¢

[iDan122]

You sir, are a copyright fraud. You have stolen the rights for the SuperNovaâ„¢ ship. Check my interstellar ship thread an remove the stolen name from your ship immediately, otherwise it will be done by force

[HoY]

Honestly you think you we're the first person to ever name something a SuperNova? Nobody is going to back you up on that. Show us your legal trademark documentation with which you trademarked the name if a pile of pixels in an alpha game, or go troll someone else's thread.

[lyndonguitar]

What mod is used for these parts>?

[Temstar]

What mod is used for these parts>?

It's all stock, you can test it out here, that particular one is called Nova:

http://forum.kerbalspaceprogram.com/showthread.php/24787-0-19-1-Zenith-rocket-family

It's built using engine clustering technique. I used to have a thread explaining how to do it but it got eaten by the forum purge. I'll recreate it soon but basically you stick Cubic Octagonal Strut or Radial Attachment Point on the bottom of tanks using the symmetry tool (they're surface attachable) and then you stick engines onto those.