Difference between revisions of "Decoupler and separator"

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(Explosive decoupling: clean up formatting)
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'''Decouplers''' are [[parts]] that separate [[stage]]s of craft either vertically or radially. They don't transfer of [[liquid fuel]] and [[oxidizer]] automatically, preventing that the upper stages are drained first. All commands in the same stage as the decoupling are executed too, even when they are on then detached stages without a [[command module]] or above the decouple command in the same stage.
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'''Decouplers''' are [[parts]] that allow detachment of once vehicle section from another. They do not provide [[liquid fuel]] [[crossfeed]], and thus isolate fuel consumption within the respective sections.
  
 
== Usage ==
 
== Usage ==
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The [[TT18-A Launch Stability Enhancer]] can also be classified as a decoupler, although one side is fixed to the ground. But the sound effects are similar and they share the same functionality, separating two parts. It was also be officially defined as a decoupler, but was changed into strut.
 
The [[TT18-A Launch Stability Enhancer]] can also be classified as a decoupler, although one side is fixed to the ground. But the sound effects are similar and they share the same functionality, separating two parts. It was also be officially defined as a decoupler, but was changed into strut.
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=== Sequencing ===
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All actions in the same stage as the decoupler are executed simultaneously, including those on the detached section, even if that section is isolated from all [[command module]]s by the decoupling event itself.
  
 
=== Explosive decoupling ===
 
=== Explosive decoupling ===

Revision as of 05:23, 15 April 2014

Decouplers are parts that allow detachment of once vehicle section from another. They do not provide liquid fuel crossfeed, and thus isolate fuel consumption within the respective sections.

Usage

Decouplers, like the Rockomax Brand Decoupler, remain completely attached to one side of the rocket. That directionv can be determined by a small arrow facing away from the side it stays attached to. The mass of the decoupler remain on one side, even if there are still attachment points visible on the other side.

Particular care must be taken to ensure that jettisoned engines have finished burning before, as there is the risk that they will collide with the rest of the rocket. Because the decoupler stays on the jettisoned stage it usually makes it imbalanced. As the decoupler is mounted on the side facing the rest of the rocket, this imbalanced stage then slowly rotates inward. Almost empty booster stages are also relatively light causing a higher acceleration and overtaking the rocket. Both effects cause jettisoned stages which are still running to crash into the rocket in most cases.

Types

The first unlocked type is the stackable decoupler. The first small decoupler is in the first research node and is mandatory for further developing of any part.

The symmetry modifier in the VAB

Radial decouplers, such as the TT-70 Radial Decoupler, attach to the sides of a rocket and eject stages horizontally. This can be useful for setting up asparagus staging, among other uses. As the ejection force may not be enough to avoid collision afterwards Sepratron I can be used to push detached stages away. Those decouplers also allow the usage of the symmetry modifier of the VAB combined with adding booster stages.

Separators, such as the TR-XL Stack Separator are a special type of vertical decouplers, which separate from both sides, leaving three crafts: Both sides of the separator and the separator itself. Separators mass slightly more than the similarly sized decouplers. Each one separator and one decoupler cost more than their same sized counterparts. The tiny sized decoupler and separator cost the same.

The TT18-A Launch Stability Enhancer can also be classified as a decoupler, although one side is fixed to the ground. But the sound effects are similar and they share the same functionality, separating two parts. It was also be officially defined as a decoupler, but was changed into strut.

Sequencing

All actions in the same stage as the decoupler are executed simultaneously, including those on the detached section, even if that section is isolated from all command modules by the decoupling event itself.

Explosive decoupling

A RT-10 Solid Fuel Booster

As decouplers and separators have to be developed first, it is not possible to have multiple stages at the first launches of Career Mode. However there is an art of staging by placing RT-10 Solid Fuel Boosters next to each other, either connected at the side or arranged vertically so the exhaust of the upper booster fires onto the lower (they don't have to be directly joined). The idea is to build up heat through contact and rocket exhaust to cause overheating resulting in an explosion, decoupling the segments below it approximately when desired, like normal staging.

KSP YouTuber Scott Manley exploited explosive decoupling for a technique he calls "rocket surgery" describing it as more an art form than a science. Using this he was able to go all the way to Minmus and return with only Start technology in his video "Kerbal Space Program - 0.22! Lets Do Science! Lots Of Science".

Although explosive decoupling is possible with other engines, the first decoupler is already in the first research node. The decouplers are the more flexible and reliable staging method and become available before other engines capable of explosive decoupling. So it is particularly useful in the start of the career mode in version 0.22 when there is no decoupler but the RT-10.

Decouplers

Image Part Radial size Cost
(Funds)
Mass
(t)
Max. Temp.
(K)
Tolerance
(m/s)
Tolerance
(g)
Ejection impulse
(kgF∙s)[Note 1]
TT-38K.png
TT-38K Radial Decoupler Radial mounted 600 0.025 2 000 8 50 250
TT-70.png
TT-70 Radial Decoupler Radial mounted 700 0.05 2 000 8 50 260
TT38K flat.png
Hydraulic Detachment Manifold Radial mounted 770 0.4 2 000 8 50 450
TD-06.png
TD-06 Decoupler Tiny 150 0.01 2 000 6 150 50
TD-12.png
TD-12 Decoupler Small 200 0.04 2 000 6 150 100
TD-25.png
TD-25 Decoupler Large 300 0.16 2 000 6 150 150
TD-37.png
TD-37 Decoupler Extra large 375 0.36 2 000 6 150 200
TS-06.png
TS-06 Stack Separator Tiny 215 0.01 2 000 6 150 50
TS-12.png
TS-12 Stack Separator Small 275 0.05 2 000 6 150 100
TS-25.png
TS-25 Stack Separator Large 400 0.21 2 000 6 150 150
TS-37.png
TS-37 Stack Separator Extra large 500 0.48 2 000 6 150 200
  1. In the game the values are without unit, but by the physics their "missing unit" is equal with 1 kgF∙s.