260" SRM - as an ICBM

[Christopher Wang]

Would the 156-inch and 260-inch ICBMs have used a cold launch system?

 

[publiusr]

I can't imagine what it'd take to thump those things upwards.

They would have more general overall utility to humanity than SLBMs that can only kill.

 

[Byeman]

I can't imagine what it'd take to thump those things upwards.

They would have more general overall utility to humanity than SLBMs that can only kill.

not true.
a. older SLBM's are used as sounding rockets and target launchers.
b. 260" has no utility

 

[Dilandu]

In pure theory, if you could combine a bunch of 260-inch boosters with another as central/upper stage, it could be a delivery vechicle for Teller's gigaton-scale "skyburner" superbombs...

 

[Scott Kenny]

I can't imagine what it'd take to thump those things upwards.

A gas generator that makes roughly the total stack weight in thrust for a fraction of a second, if I understand the basics correctly.

Which sounds terrifying but isn't that bad since you use a superexpansion rocket nozzle to get the temps and pressures down.

 

[Yellow Palace]

A gas generator that makes roughly the total stack weight in thrust for a fraction of a second, if I understand the basics correctly.

You presumably need to exceed the stack weight, that being how physics works, and provide enough energy to lob the thing out of the silo to whatever height you've deemed safe for main stage ignition. It's presumably similar to an interior ballistics calculation.

 

[Scott Kenny]

You presumably need to exceed the stack weight, that being how physics works, and provide enough energy to lob the thing out of the silo to whatever height you've deemed safe for main stage ignition. It's presumably similar to an interior ballistics calculation.

That "enough energy to lob the thing clear" part usually comes from further expanding gasses continuing to push.

I'd also assume that it's basically an interior ballistics calculation.

The gas generators for a Trident are about the size of a water heater. So yes, whatever you'd need for a 260" monster rocket would be a lot bigger than that, but mostly in terms of diameter not length. So, more like a hot tub full of solid rocket fuel instead of a water heater.

 

[publiusr]

Doable then.

I'd like at least 4 in Florida for asteroid intercept, with warheads that can be swapped out below ground in case of another Oumuamua...a small probe and upper stage.

 

[A Tentative Fleet Plan]

The words "Florida" and "below ground" do not belong together. If you want some form of underground basing, do it somewhere where the water table is lower.

 

[publiusr]

Wallops or somewhere on the East Coast.

 

[sferrin]

You presumably need to exceed the stack weight, that being how physics works, and provide enough energy to lob the thing out of the silo to whatever height you've deemed safe for main stage ignition. It's presumably similar to an interior ballistics calculation.

 

[Christopher Wang]

I understand that Aerojet and Thiokol had competing designs for the 260-inch solid rocket motor. Aerojet won out in the end when Thiokol's test chamber burst at 56% of proving pressure during a stress test (Srawley & Esgar, Investigation of Hydrotest Failure of Thiokol Chemical Corporation 260-Inch-Diameter SL-1 Motor Case, 1966).

Did Aerojet had its own proposal for a 260-inch ICBM?

 

[Christopher Wang]

For comparison, there is also the Weapons System 120A (WS-120A) aka ZBGM-75 AICBM which was projected to have a 10-foot diameter and 70-foot length (ICBM Basing Options: A Summary of Major Studies to Define a Survivable Basing Concept For ICBMs, December 1980, p. 45).

 

[Boldgambit]

It was implied to be a Saturn V derivative but I haven't been able to dig up anything more so far.

I am wondering if anyone has been able to find any information about the TABAS proposal?

TABAS sounds to grandiose to be a serious 1980s era proposal, it sounds more like something from the 1960s, or like it was something Jerry Pournelle cooked up to frighten a journalist. As far as I am aware this is the only proposal to weaponize the Saturn V and I haven't seen it talked about in any of the Saturn histories.

The only source I've been able to find external to these posts is in Christy Campbell's Airland Battle: 2000, I'm laughable amaturish at research so I haven't had much luck. I am trying to reach out to Christy Campbell to see if he still has his notes (Quite the tall ask) but so far I haven't been able to find any contact info for him.

*Edit: I've reached out to him and I am hoping to hear back