Mining for SRBs

[KerikBalm]

The Mk1 LF fuselage would like a quick word with you.

And now... all my craft feel suboptimal, using the Mk2 or mk3 LF tanks... and I am face with the horrible dilemma of using many many mk1 tanks and driving up part count, or using inferior parts, but fewer parts

[NecroBones]

Yep, seawater is highly corrosive to equipment. I know it sounds counter-intuitive compared to everything else that the equipment is subjected to, but it pretty much destroys machinery. SpaceX is aiming for a platform on a barge (and eventually targets on land) to avoid this.

Nuclear power plants have this problem as well. If they flood the chamber with seawater in an emergency, as a last resort to cool the reactor core, they're pretty much accepting that the core is going to be ruined.

[TimePeriod]

Yep, seawater is highly corrosive to equipment. I know it sounds counter-intuitive compared to everything else that the equipment is subjected to, but it pretty much destroys machinery. SpaceX is aiming for a platform on a barge (and eventually targets on land) to avoid this.

Nuclear power plants have this problem as well. If they flood the chamber with seawater in an emergency, as a last resort to cool the reactor core, they're pretty much accepting that the core is going to be ruined.

We have to remember that we are talking about two different category's of engines. The SRB's and the bi-propellent type.

The SRB's would not need to have a total refurbishing done I think as the parts are fairly simple. (Its a tube full of propellent as far as I know)

Now the bi-propellent, that's a whole other story. There's all manner of places where sea-water could cause havoc. Imagen sea water inside a turbo-pump, Ugh.

[KerikBalm]

It is not at all a stretch to say that the ISRU unit should also make Ablator, SolidFuel, and even Xenon from this magical "Ore".

I think Xenon gas would be one of the easiest things to do ISRU with... you basically just compress and chill air (ok, its a bit more complicated fractional distillation)... I've made an ISRU that will produce Xenon gas from any atmosphere, and O2 anywhere on Kerbin or Laythe.

[fchurca]

What about refilling Sepratrons? Those don't look too difficult to refurbish mid-mission.

[TimePeriod]

What about refilling Sepratrons? Those don't look too difficult to refurbish mid-mission.

I think your onto something there.

[Guest]

I think Xenon gas would be one of the easiest things to do ISRU with... you basically just compress and chill air (ok, its a bit more complicated fractional distillation)... I've made an ISRU that will produce Xenon gas from any atmosphere, and O2 anywhere on Kerbin or Laythe.

Yep. Atmospheric products are the easiest resources to access. Quite frankly drilling into the ground, shallowly, and sitting there for days pulling up resources is pretty darn magical in and of itself.

[LethalShade]

We need bigger drills then. Or a cave system.

[Sharpy]

How fast are these things hitting the water again? 5m/s ? 10 m/s? 30? 50? I don't know.

What I do know is anything going above 30m/s (60miles/h- 100km/h) will yield some serious kinetic energy upon contact with water. It might as well land on concrete.

"Nose" first? Compare the impact into water at 100km/h to what they face when moving through the air at some mach 10. Pretty much the same thing.

Plus they withstand equivalent to a good TNT load from the inside, sustained. Why wouldn't they withstand it from the outside?

And I seriously doubt saltwater is more corrosive than solid rocket fuel at the time of burning.

You think reactor flooded with saltwater is bad? Flood it with kerosene mixed with concentrated peroxide and set it on fire.

edit: as for SpaceX: That's a liquid fuel engine. Only the nozzles are exposed to the sustained explosion. Unlike SRBs where it's not the fuel moving to the engine where it burns in one narrow, hardened place, but instead the flame travels across the volume of the fuel. Whereas most of LF rocket is pretty fragile with only the bell of the engine being extra hardened, in SRBs about the whole volume of the booster is the bell.

Edited August 4, 2015 by Sharpy

[TimePeriod]

"Nose" first? Compare the impact into water at 100km/h to what they face when moving through the air at some mach 10. Pretty much the same thing.

Plus they withstand equivalent to a good TNT load from the inside, sustained. Why wouldn't they withstand it from the outside?

And I seriously doubt saltwater is more corrosive than solid rocket fuel at the time of burning.

Go - read - about - salt water and - engines.

Nuf said.

[Sharpy]

Go - read - about - salt water and - engines.

Nuf said.

What engines?

It's not a flimsy jet or a semi-rugged diesel with many moving parts and nooks and crannies where saltwater could get in, cause rust and jam the mechanisms. After the fuel is depleted the structure of SRB most resembles a blast chamber used by SWAT to safely detonate bombs.

[NecroBones]

We have to remember that we are talking about two different category's of engines. The SRB's and the bi-propellent type.

The SRB's would not need to have a total refurbishing done I think as the parts are fairly simple. (Its a tube full of propellent as far as I know)

Now the bi-propellent, that's a whole other story. There's all manner of places where sea-water could cause havoc. Imagen sea water inside a turbo-pump, Ugh.

That's true, I'm mainly thinking liquid engines and turbopumps here.

[TimePeriod]

What engines?

It's not a flimsy jet or a semi-rugged diesel with many moving parts and nooks and crannies where saltwater could get in, cause rust and jam the mechanisms. After the fuel is depleted the structure of SRB most resembles a blast chamber used by SWAT to safely detonate bombs.

*Sigh*

SRB's are not waterproof.

What happens to delicate electronics when it comes into contact with corrosive salt water? Have you ever throw a bucket of water onto your motherboard and seen what happens to it?

SRB's are not built like a tank.

What happens when a 45 ton aluminium tank, comes down onto something which reassembles concrete at several hundred kilometres an hour? Nose first.

SRB fuel is not corrosive as it is covered in a rubbery substance known as a binder.

[Nich]

Ok I agree you should be able to refill SRBs, however why would you ever want to? Even getting off Eve LFO engines pack more dV per pound and have more then sufficient TWR to get off the planet. xenon is a must.

[CalculusWarrior]

Ok I agree you should be able to refill SRBs, however why would you ever want to? Even getting off Eve LFO engines pack more dV per pound and have more then sufficient TWR to get off the planet. xenon is a must.

Exactly, SRBs are primarily useful for a short boost to get a spacecraft off the launchpad, not for extended missions on other planets. I fail to see how refuelling them would be useful.

[Hagen von Tronje]

Yep. Atmospheric products are the easiest resources to access. Quite frankly drilling into the ground, shallowly, and sitting there for days pulling up resources is pretty darn magical in and of itself.

If someone makes a "roughneck" mod where drills require kerbals to trip pipe, I will totally play it.

[Lighthawk]

How to refill SRB using ISRU

Step 1: Tip over SRB to be filled. (Removal from vessel optional but recommended)

Step 2: Insert volunteered kerbal into SRB.

Step 3: Supply volunteered kerbal with an adhesive, preferably one that can double as an accelerant.

Step 4: Process solid fuel with ISRU. Pack into tight spheres.

Step 5: Bowl fuel spheres down the length of the SRB to the volunteered kerbal.

Step 6: Volunteered kerbal attaches fuel spheres to the interior of the SRB with accelerant adhesive until full.

Step 7: Remove volunteered kerbal from SRB (optional)

Step 8: Set SRB back upright. Reattach to vessel if formally removed. (Highly recommended)

Step 9: Launch vessel

Step 10: Pray the SRB's lack of throttle or ability to be shut down does not result in either a fiery crash or stranding your vessel out in the cold vacuum of space.

Why to refill SRB using ISRU

Step 1: Consider the question.

Step 2: Toss the whole silly idea away and use liquid fuel engines like a sensible individual.

[Sharpy]

*Sigh*

SRB's are not waterproof.

What happens to delicate electronics when it comes into contact with corrosive salt water? Have you ever throw a bucket of water onto your motherboard and seen what happens to it?

What happens to that electronics when it's exposed to moisture condensing at nearly supersonic speeds, then to heat of hypersonic speeds, then to open vacuum and radiation, and then everything of that again in reverse order? With a few thousand degrees right across the wall?

I'll tell you what happens: Nothing. It's sealed. Safely sealed in an airtight, waterproof, fireproof and smash-proof container. It doesn't get wet the same as it doesn't get frozen or burned away.

And even if it got destroyed, that's not a big loss because SRBs have pretty minimal electronics, some cameras for monitoring the flight, altimeter for opening the chutes, that kind of stuff. No throttle, no stabilization, no thrust vectoring, no gyroscopes. It's a glorified bottle rocket. The main value is the massive blast chamber.

*Sigh*

SRB's are not built like a tank.

What happens when a 45 ton aluminium tank, comes down onto something which reassembles concrete at several hundred kilometres an hour? Nose first.

Whoa, whoa! Several hundred? On a parachute? Let's slow down a little, terminal velocity in air is mere 200km/h, that would be the speed without a parachute. I gave 100km/h as an absolute pessimistic top speed variant. The actual speed is considerably lower.

SRB fuel is not corrosive as it is covered in a rubbery substance known as a binder.

Does the binder last through the burn (staying there protecting the walls from saltwater) or does it get burned away exposing the walls to several thousand degrees of extremely violent chemical reaction involving lots and lots of oxygen?

[Laie]

Can't really imagine how re-stuffing the SRB with solid fuel would work.

Oh, I can. It's in no way credible, but I can picture several ways.

You should at least try, it's fun!

[TimePeriod]

-Snip-

I got tierd of arguing in the nitty-gritty details and I quite honestly got sick of you, so I'll maintain my belief that the SRB's are refurbished and checked over before they are used again. I'll also maintain that anything that goes into salt water which is not built to stay in salt water, will deteriorate if it stays in there for any duration longer then absolutely necessary. I've personally seen what salt water can do to both metal and plastics, so I could not care less what you think.

Edited August 4, 2015 by TimePeriod
No thanks to nitty gritty neo-yappie scumbags.

[Guest]

This document should give you a good idea of how corrosive salt water, hell, even an environment near salt water, is and what the Space Shuttle SRBs went through. Corrosion is not a trivial problem.

[Sharpy]

*shrug* Your choice.

Considering SRBs *are* designed for landing in the ocean.

And that they spend there a couple hours.

And yes, they are definitely checked for defects and refurbished as in cleaned thoroughly, any damaged or worn parts replaced, all single-use parts replaced, parachutes probably replaced but maybe just restored after the sea bath and repacked, and finally the fuel, the ignition systems and so on refilled.

But salt water is the least possible of elements that could have damaged anything in the SRB.

[TimePeriod]

This document should give you a good idea of how corrosive salt water, hell, even an environment near salt water, is and what the Space Shuttle SRBs went through. Corrosion is not a trivial problem.

Bloody hell, now that is some serious reading. 7 years, just for the whole corrision problems, in terms of development and research?

Holy .....

[Guest]

And that they spend there a couple hours.

Correction: 48 hours, roughly. Plus their lifetime in a coastal environment.

Bloody hell, now that is some serious reading. 7 years, just for the whole corrision problems, in terms of development and research?

Holy .....

Yeah, pretty crazy. This line in particular was eye-opening:

Readers familiar with seawater corrosion potentials will have already realized that the possible corrosion cells in the aft skirt will be quite active.

Having owned a thirty-year "coast car" I can say I'm at least vaguely familiar with the potentials. Thank the maker it was a Volvo...

[Kaos]

[...]

Whoa, whoa! Several hundred? On a parachute? Let's slow down a little, terminal velocity in air is mere 200km/h, that would be the speed without a parachute. I gave 100km/h as an absolute pessimistic top speed variant. The actual speed is considerably lower.

[...]

I had no free fall in reality, yet, but in KSP my terminal velocity is about 200 m/s, which is rather 700 km/h than 200 km/h. But on parachute it is indeed mostly much slower.