With a multi-stage carrier rocket, there are two basic approaches to stage separation.
- Utilizing a continuous structure to carry the payloads, a device is added to cut the structure cleanly on command (a common use of this technique is canopy transfer removal on military jets).
- Using separate structures which are attached by designated mating devices until separation is initiated.
These approaches can be applied to either a conical shaped rocket or the cylindrical sections.
Regardless of the approach, the staging process commences when the burn out of the ongoing stage is detected and continues with the ignition of the next along with the separation of the spent stage. The latter two processes (ignition of the next stage and separation of the spent stage) may occur concurrently or with a time differential. These events may occur in any order, all dependent upon the vehicle configuration, mission requirements and whether they are programmed before lift off or real time during flight monitoring.
We have designed many successful separations using either method. The choice of one particular approach over the other will depend upon the mission, the vehicle and the engineers.