PARACHUTE DEPLOYMENT MECHANISM
Project Redshift is a part of AerospaceNU, a group of undergraduate students at Northeastern University interested in the aerospace field, aiming to build a liquid-powered rocket for the Dollar Per Foot Competition. As a member of Redshift's Internal Mechanics Team, I work on what are typically smaller devices that perform various functions to take place inside the body of the rocket. More specifically, I have designed a mechanism capable of a three-parachute deployment as the rocket's recovery system.
3-STAGE RECOVERY MECHANISM
OVERVIEW
- Create a three-stage parachute recovery system for a liquid-powered rocket
CONSTRAINTS
- Be both mechanically and electrically redundant to increase chances of successful deployment
- Fit inside an 8" diameter rocket
- Handle a shock load of 250 lb with a factor of safety of at least 2
- 3 separate deployment events must be controlled by the rocket's avionics, not purely mechanical
- Interface to the airframe below with threaded rods
CHALLENGES
- Creating a small mechanism capable of handling such large shock loading
- Speccing springs with desired spring constants while also fitting inside linear bearings and having appropriate minimum and maximum displacements
- Must not activate and deploy at the wrong time due to engine vibration
- Minimizing mechanism weight to increase maximum altitude
RESULTS
- I used concentric springs to maintain a high force in a space with many constraints
- I used springs to combat engine vibration moving parts prior to deployment events
- I ran FEA simulations to validate parts for shock loading
- I printed and assembled a prototype [pictured to the left] of the triple-deploy mechanism
- I scaled the mechanism down to two deployment operations to fit in a smaller test rocket
- I began manufacturing of the test mechanism, but stopped due to new sizing constraints on the full-scale rocket the mechanism could not overcome