This tutorial tries to explain how to create and use action groups by adding an escape tower.
Prior to any action group modification the escape tower needs to be build. As the escape tower usually placed on top a rocket the Mk1 Cockpit can't be used without making it very complicated. Additionally only the radial parachute, the Mk2-R Radial-Mount Parachute, can be used, as all other would block the top node on which the tower sits.
The escape tower usually uses multiple Sepratron I solid fuel engines which are ignited either to dispose the tower when it is not needed or to pull the command pod away. As the thrust is relatively low many of them needs to be used. Also only the command pod should be rescued when needed so placing a decoupler below it is a good choice.
As docking ports can be detached even when they are connected to something different than a docking port it is possible, if wished, to place the tower directly on top of the port. If the craft shouldn't use docking ports, a decoupler facing down would do the same trick.
Above the docking port multiple girders are placed on top of each other to get a tall tower. The Cubic Octagonal Strut is usually a good choice. radial on those girders are the engines placed. They needed to be angled so that they don't thrust directly on the command pod.
Creating the action groups
- More will follow …
The escape tower uses two action groups:
- Abort which pulls the tower and command pod away. It fires all engines and disconnects the command pod from the rest of the rocket.
- Any custom action which discards the tower. It fires also all engines but disconnects the tower from the command pod.
After a failure seems unlikely the custom action should be executed to lower the mass.
When the launch was aborted and the engines stopped firing, it can be discarded with the custom action. This will cause both parts to slowly drift away. The parachutes needs to be deployed too, also this shouldn't happen as long as the command pod is still near the rest of the rocket or the escape tower.