CoDR Design:
Separation Mechanism:
This can be done using springs or a piston. The method discussed below involves using springs to push the 2 stages apart.
- The initial design consisted of a mechanical attachment of the two stages prior to separation using shear pins that attach to the sustainer nozzle casing.
- Springs push against the staging cone which pushes against the inside of the sustainer nozzle.
- The staging cone is still connected to the booster using a shock cord.
The phases of separation are shown in the diagram below along with an explanation of what each part is:
Phase 1:
Phase 2:
Phase 3:
The spring constant required can be calculated by a simple energy balance assuming the springs decompress instantaneously:
Where x = compressed spring length, d = distance sustainer travels after separation.
x here is a design parameter and depends on the possible dimension given the staging cone's dimensions whereas d is the required separation distance.
The force needed to break the shear pins must also be factored into these equations.
Actuators:
There are 4 main actuation methods while using a spring system:
- Dyneema and Nichrome
- Rack and Pinion
- Solenoid
- Rotating Plate
Dyneema and Nichrome: