[1.2 - 1.4] Real Scale Boosters, 0.16 (2018-03-12)

[Kartoffelkuchen]

1 minute ago, NecroBones said:

 

Engine isn't done, but at least the bell is there. Wow, that thing is ridiculous.   And I haven't even started the second stage.

 

 

 

Whaaaaaaaaaaaaaaaaaaaat. :| That's....ow man, don't believe what I'm seeing

[NecroBones]

2 hours ago, Kartoffelkuchen said:

Whaaaaaaaaaaaaaaaaaaaat. :| That's....ow man, don't believe what I'm seeing

 

Yeah, it'll be in a separate pack since it's just a bit on the insane side.

 

[NathanKell]

Yep, dat's nuts.

[komodo]

If you can afford one, I suppose a new launchpad after the thing lights off wouldn't be unreasonable... Of course I am guessing they had to cut a hole in the VAB to get out out in the first place  The contractors must love this rocket. 

Seadragon-Saturn-SLS, anyone? (How much dV does it have?: "Yes")

[NathanKell]

@komodo well, the point is a CVN would tow it out to sea and it'd launch from there. Hence the name.

(Also the CVN would crack water and chill to get the LOX and LH2 for it--that's why a regular CV just wouldn't do.)

Also worth recalling: It's a Nova*-class payload (1 million lb to orbit) but pressure-fed. With only two stages. So start with one of those crazy kilo-tonne mass Nova designs, and then consider it's now only 2 stages and has low efficiency.

[komodo]

20 minutes ago, NathanKell said:

@komodo well, the point is a CVN would tow it out to sea and it'd launch from there. Hence the name.

(Also the CVN would crack water and chill to get the LOX and LH2 for it--that's why a regular CV just wouldn't do.)

Also worth recalling: It's a Nova*-class payload (1 million lb to orbit) but pressure-fed. With only two stages. So start with one of those crazy kilo-tonne mass Nova designs, and then consider it's now only 2 stages and has low efficiency.

I knew of the sea launch, but the CVN hadn't clicked. That makes a certain amount a lot of sense. (Particularly if they were planning on more Enterprise class CVNs; gangbusters of excess power indeed.)

If I didn't know better, I'd say project Orion was a plant to make this thing look sane/reasonable

It'd have been quite the show if you made this the first stage of one of the pulse "rockets"... Soon we'll have the Addons to do it too! 

[NecroBones]

 

The first stage is taking shape...  Oh the humanity!!

 

 

 

 

 

 

[Jodo42]

This will be GLORIOUS!

 

Do you have an idea of what you'll work on after the Sea Dragon is done?

[NecroBones]

 

I'm starting on the second stage, and it looks like I have some design choices to make. From the looks of the diagrams, and the construction proposals, the upper stage engine is pretty much in a fixed position, but has an extendable skirt. I also don't see any mention of a separate interstage, so if I'm reading it right, the fuselage around the upper stage engine is just part of the second stage, and the engine bell would just extend outward somewhat after separation. So, I could build the engine directly into the upper stage (one big part), or make it a separate part and just have people stick it way up inside that upper stage's exterior. I could animate the engine bell extension either way.

 

I'm thinking the upper stage auxiliary engines can just be surface-attachable parts, and let people use more (or fewer) of them if they want.

 

The freaky thing is that the upper stage makes the first stage look puny.

 

 

55 minutes ago, Jodo42 said:

Do you have an idea of what you'll work on after the Sea Dragon is done?

 

Not yet. I mainly go wherever my enthusiasm takes me.

 

[NecroBones]

 

That second stage tank is still a huge (see what I did there?) work in progress. But check this out. See the flat top on the nose? That's a 5m diameter attachment point. You could put a whole SpaceY third stage on that.

 

[Red Iron Crown]

The launch clamps around the engine bell are making me giggle.

[NecroBones]

 

Some texturing tests in an album below. The upper stage still needs engines, and I also need to make fairing bases, but otherwise the exterior looks pretty good.

 

 

[komodo]

The first stage I suppose was just an "alley-OOP!" to get it going before the second stage did most of the lifting? The scale seems odd, with most (admittedly sane) rockets seeming to favor a beefy first stage and working down from there. Looks like I'm off to read about the Seadragon!  

[Red Iron Crown]

23 minutes ago, komodo said:

The first stage I suppose was just an "alley-OOP!" to get it going before the second stage did most of the lifting? The scale seems odd, with most (admittedly sane) rockets seeming to favor a beefy first stage and working down from there. Looks like I'm off to read about the Seadragon!  

It's a bit misleading. The lower stage uses CH₄ RP-1, which is much denser than the LH₂ used in the upper stage. The lower tank also nestles inside the engine bell of the upper stage, plus the top third or so of the upper stage is actually payload space.

[NecroBones]

50 minutes ago, Red Iron Crown said:

It's a bit misleading. The lower stage uses CH₄ RP-1, which is much denser than the LH₂ used in the upper stage. The lower tank also nestles inside the engine bell of the upper stage, plus the top third or so of the upper stage is actually payload space.

 

Yeah, as we were talking about elsewhere, I totally missed that the top portion is "payload". I'll cut the tank down and probably make a full-diameter fairing.

 

In the meantime, second-stage main engine, zoomed out as far as possible in the stock-VAB. :)

 

[Norcalplanner]

I recall watching a video where the engineer in charge of the F-1 engines for the Saturn V described all the problems they had to overcome to ensure even and balanced combustion (and no failures or explosions) in such a large engine bell. Looking at this, I can't help thinking that the issues to be overcome would be at least an order of magnitude greater. Was there ever any serious investigation into the feasibility of such a large engine?

[Kerbas_ad_astra]

23 meters should probably be sorted under size 8 (20 m, size 9 would be 30)...I'll get those icons to Filter Extensions...

[lurkoholic]

24 minutes ago, Norcalplanner said:

I recall watching a video where the engineer in charge of the F-1 engines for the Saturn V described all the problems they had to overcome to ensure even and balanced combustion (and no failures or explosions) in such a large engine bell. Looking at this, I can't help thinking that the issues to be overcome would be at least an order of magnitude greater. Was there ever any serious investigation into the feasibility of such a large engine?

I think it would be less likely to explode since it would have much lower combustion chamber pressure and wouldn't have turbopumps (and probably extra thick chamber walls). I wonder if it would difficult to ignite (that would be a large dud!), or if pressure fed engines could experience pogo.

@NecroBones How large will the expanded nozzle be in the upper stage engine? I tried to calculate it based on the expansion ratio, but I couldn't make sense of the chamber diameter and throat area dimensions. Maybe the diameter was an outside diameter. My 'calculation' seemed relatively small based on the throat area.

[NecroBones]

 

Yeah, I'm not really sure. Some of the documents describe details slightly differently than the diagrams seem to show, so I'm modeling things more after the diagram, but using the documents to get mass and thrust numbers. In the end it'll be a lot like my other rockets here, in that I use what I can find, but also take some liberties. To that end, I've modeled the second stage engine to just be a static bell that fits within the diameter of the fuselage, going by the diagram I've used for all of the sizes/shapes:

 

[NecroBones]

 

This looks really strange to me, having the engine hidden inside the fuselage. However, since the verniers attach there (not modeled yet), it looks like that's how it was intended to function:

 

 

 

[NecroBones]

 

[NecroBones]

 

Tweaked the audio and particle emitters a little more. Second test recording:

 

 

[NecroBones]

 

Fairing base added.

 

 

[CommanderSpock]

Will we be able to launch this from the sea?

[NecroBones]

18 minutes ago, CommanderSpock said:

Will we be able to launch this from the sea?

 

Unfortunately I don't know yet. I probably won't have the ballast tanks in the first release. After that, it may depend on whether the ballast can actually be used to turn the rocket upright in the water, and that will depend a lot on how well that works with KSP's buoyancy system.