Tripoli Level 3 Project work - Parallel Staged Rocket

I am about to start working on my project proposal for my level 3 certification with Tripoli. My project will be a 3 stage rocket that is parallel staged (Delta III Launch Vehicle) The Delta III will be the basic idea, but with 6 boosters instead of 9.

I have 2 flight computers already, but I want to use an arduino to handle staging.

My general idea is to use the arduino to actuate a piston that will release pins retaining the boosters. I believe I will hold the boosters on with tabs sandwiched between a base plate with holes in it () and a plate with pins ()which will feed through the tabs into corresponding holes into the base plate. --- Sorry, I see it clear in my head, but it's kinda difficult to articulate ---

So, I want to lift the plate retaining the boosters (ideally 3 boosters at a time) and either trigger a solenoid to push the boosters off or just use relatively heavy springs to start the pushoff and use aerodynamic drag to pull the boosters off. I've considered using a recovery charge to power the pistons (still an option too).

Once the boosters are separated, start a countdown to fire the next set of boosters.

Rinse and repeat the separation process for the remaining boosters.

Fire the main booster.

As I said, I have flight computers (Flight Computer) which could be used to control all of the events, but I want to do it with arduino.

By trade, I'm in IT, with 15 years programming, and looking at the code it should be relatively simple to code. I'm interested in opinions and ideas for attaching the boosters (or comments on my proposed idea), and ways to mechanically separate the boosters to guarantee a clean separation (ideally symmetrical and perfectly timed).

note : using a separation charge might reduce the total components as all three could be linked to a single central retaining pin...

I'm interested in opinions and ideas for attaching the boosters (or comments on my proposed idea), and ways to mechanically separate the boosters to guarantee a clean separation (ideally symmetrical and perfectly timed).

I think this is a mech eng question, rather than being related to the Arduino???

Partly yes.
The main problem i see is that a solenoid will add considerable weight.
Also it may not be strong enough for the job without springs and precision engineering.

Thinking a bit more, i agree, best taken to a rocketry forum