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.

1. 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.
2. Springs push against the staging cone which pushes against the inside of the sustainer nozzle.
3. 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: