Kerbal Space Program Update 1.5 Grand Discussion thread

[Kroslev Kerman]

NEXT VERSION WE WANT SRB FUEL TANKS!(Maybe you can configure the current LFOX Fuel tanks so you can put Solid fuel)

[Chel]

57 minutes ago, Kroslev Kerman said:

NEXT VERSION WE WANT SRB FUEL TANKS!(Maybe you can configure the current LFOX Fuel tanks so you can put Solid fuel)

Ok, putting on caps lock and demanding won't help. Maybe you could put a request in Suggestions and Development Discussion instead

[Terwin]

7 hours ago, Kroslev Kerman said:

NEXT VERSION WE WANT SRB FUEL TANKS!(Maybe you can configure the current LFOX Fuel tanks so you can put Solid fuel)

So you want bombs?

If you change solid rocket fuel enough to make it pump-able, you are basically back to liquid fuel, and probably with an awful ISP.

Solid Rockets are cheap because they are so simple.

You cast the fuel into the correct shape, light the fuse and that is it.

If you had to pump the fuel, you need a turbo-pump to keep up with the fuel needs, and the lack of a turbo-pump is the biggest difference between a SRB and a LFE.

(Liquid engines are often called a turbopump with an engine bell, as the turbopump is by far the most complicated and expensive component of the engine)

[Tyko]

8 minutes ago, Terwin said:

So you want bombs?

If you change solid rocket fuel enough to make it pump-able, you are basically back to liquid fuel, and probably with an awful ISP.

Solid Rockets are cheap because they are so simple.

You cast the fuel into the correct shape, light the fuse and that is it.

If you had to pump the fuel, you need a turbo-pump to keep up with the fuel needs, and the lack of a turbo-pump is the biggest difference between a SRB and a LFE.

(Liquid engines are often called a turbopump with an engine bell, as the turbopump is by far the most complicated and expensive component of the engine)

Yea, pumpable solid fuel doesn't make any sense.

I would like to see stackable solid fuel cannisters though - kind of a kerbal version of how the Shuttle / SLS SRBs are built. You'd start with the bottom component containing some fuel and the nozzle, then stack additional cans on top to increase the burn time.

[Terwin]

3 minutes ago, Tyko said:

Yea, pumpable solid fuel doesn't make any sense.

I would like to see stackable solid fuel cannisters though - kind of a kerbal version of how the Shuttle / SLS SRBs are built. You'd start with the bottom component containing some fuel and the nozzle, then stack additional cans on top to increase the burn time.

So basically the same thing we currently have, but make the separators free and automatic when the previous stage finishes burning?

[Tyko]

24 minutes ago, Terwin said:

So basically the same thing we currently have, but make the separators free and automatic when the previous stage finishes burning?

No, only the bottom would have a nozzle. The others would be just fuel and the entire stack of cans would burn as one unit. Read up on the how the Shuttle & SLS SRBs are built

 

Edited November 15, 2018 by Tyko

[Terwin]

12 minutes ago, Tyko said:

No, only the bottom would have a nozzle. The others would be just fuel and the entire stack of cans would burn as one unit. Read up on the how the Shuttle & SLS SRBs are built

 

The multiple welded together components of the shuttle SRBs do not provide additional burn time, they provide additional thrust.  (and the need to assemble them from multiple pieces is actually a very worrisome thing, as it provides lots of opportunities for gaps that can cause catastrophic failures, that is what cause the Challenger disaster after all)

The burning surface of the Shuttle(and most other) SRBs are actually a channel up the entire length of the SRB that burns from the center outwards.

You can even read up on how they can shape the thrust profile by altering the shape of the hole(s).

 

Edited November 15, 2018 by Terwin

[Tyko]

1 hour ago, Terwin said:

The multiple welded together components of the shuttle SRBs do not provide additional burn time, they provide additional thrust.  (and the need to assemble them from multiple pieces is actually a very worrisome thing, as it provides lots of opportunities for gaps that can cause catastrophic failures, that is what cause the Challenger disaster after all)

The burning surface of the Shuttle(and most other) SRBs are actually a channel up the entire length of the SRB that burns from the center outwards.

You can even read up on how they can shape the thrust profile by altering the shape of the hole(s).

 

1. I was responding to the original idea from @Kroslev Kerman about how to add SRB fuel tanks and suggesting a workable way to achieve their goal without worrying about pumps.
2. The burn time of RL SRBs, as you pointed out above, is governed by the shape of the hole. They could tune the shape to have a longer burn time at the same thrust if they wanted to. 
3. I never said these would "work" like the STS/SLS SRBs. I said they would be "built" like those by stacking fuel segments.
4. Engines don't fail in KSP, so Kerbals wouldn't have to worry about a Challenger type problem
5. Even in real life NASA is going to continue using the design, so they must be pretty confident they've solved the "worrisome thing"

Edited November 15, 2018 by Tyko

[Terwin]

1 hour ago, Tyko said:

1. I was responding to the original idea from @Kroslev Kerman about how to add SRB fuel tanks and suggesting a workable way to achieve their goal without worrying about pumps.
2. The burn time of RL SRBs, as you pointed out above, is governed by the shape of the hole. They could tune the shape to have a longer burn time at the same thrust if they wanted to. 
3. I never said these would "work" like the STS/SLS SRBs. I said they would be "built" like those by stacking fuel segments.
4. Engines don't fail in KSP, so Kerbals wouldn't have to worry about a Challenger type problem
5. Even in real life NASA is going to continue using the design, so they must be pretty confident they've solved the "worrisome thing"

If additional 'fuel' would only increase the burn-time, why not go with the option that provides greater total impulse, and have a series of boosters that stage one layer at a time from the bottom up?

You can even adjust the total thrust at each stage by reducing the number of engines that fire at that stage if needed, and all using resources already present in the game.

As the weight of the SRB nozzle is trivial compared to the tank, the only 'benefit' of having a longer burning SRB compared to a series of shorter burning SRBs at the same thrust is that you are required to carry the entire dry weight of the larger SRB until it burns out, instead of being able to drop some of that dead weight as you progress. 

 

[Tyko]

1 hour ago, Terwin said:

If additional 'fuel' would only increase the burn-time, why not go with the option that provides greater total impulse, and have a series of boosters that stage one layer at a time from the bottom up?

You can even adjust the total thrust at each stage by reducing the number of engines that fire at that stage if needed, and all using resources already present in the game.

As the weight of the SRB nozzle is trivial compared to the tank, the only 'benefit' of having a longer burning SRB compared to a series of shorter burning SRBs at the same thrust is that you are required to carry the entire dry weight of the larger SRB until it burns out, instead of being able to drop some of that dead weight as you progress. 

 

Dunno...I wasn't trying to create a better booster. I was offering a suggestion for a way @Kroslev Kerman could have his SRB "fuel tanks" and not have to liquefy the solid fuel - which, to your point, would be silly.

That said, I'd imagine the reason NASA uses one big booster is driven by complexity and cost. Since complexity and cost are the two main reasons SRBs are used at all (in KSP or RL), it would be counterproductive to have multiple stages with multiple nozzles.

[scottadges]

Ahh, I come back to KSP after many months... to find 1.5 has released a little while ago. So now the familiar update and mod re-install process!

Actually, I guess it's as good a time as any to start a new playthrough.  

Edited November 18, 2018 by scottadges

[Nikolai]

On 11/15/2018 at 12:42 PM, Tyko said:

Yea, pumpable solid fuel doesn't make any sense.

No, silly.  We just equip all of our rockets with corkscrews now. 

[tater]

In what version did the career option to pay science AND funds for R&D go away?

I cannot set this option in new careers at all in the difficulty settings (1.5.1), yet one of my career experiments has this turned on, and I have no idea why (no saves from old versions at all exist).

I used to have this setting in my careers:

            BypassEntryPurchaseAfterResearch = False

This is there in persistent files now, but is always "True."

Edited November 28, 2018 by tater

[tater]

Another observation, this time about the parachutes on Kerbals.It would be nice if these could be toggled on and off (visually at the very least). The space suits look terrible with parachutes on them in space.