Introduction

This​ ​project​ ​is​ ​a​ ​continuation​ ​of​ ​our​ ​efforts​ ​from​ ​the​ ​Summer​ ​2017​ ​semester.

Typically,​ ​upper​ ​tier​ ​hobbyist​ ​rockets​ ​utilize​ ​chemical​ ​reactions,​ ​such​ ​as​ ​a​ ​controlled​ ​black powder​ ​detonation,​ ​to​ ​achieve​ ​separation​ ​and​ ​parachute​ ​release​ ​after​ ​the​ ​apogee​ ​altitude​ ​is reached.​ ​These​ ​methods​ ​are​ ​relatively​ ​straightforward​ ​and​ ​reliable,​ ​but​ ​they​ ​are​ ​also​ ​dangerous due​ ​to​ ​an​ ​inherent​ ​risk​ ​of​ ​fire,​ ​and​ ​accidental​ ​detonation.​ ​Additionally,​ ​substances​ ​such​ ​as​ ​black powder​ ​leave​ ​behind​ ​a​ ​messy​ ​residue,​ ​and​ ​must​ ​be​ ​reloaded​ ​before​ ​each​ ​flight.​ ​Consumable resources​ ​add​ ​to​ ​the​ ​cost​ ​of​ ​launching​ ​a​ ​rocket.

The​ ​goal​ ​of​ ​the​ ​mechanical​ ​separation​ ​project​ ​is​ ​to​ ​develop​ ​an​ ​alternative​ ​method​ ​of​ ​rocket separation​ ​that​ ​does​ ​not​ ​rely​ ​on​ ​the​ ​use​ ​of​ ​chemical​ ​reactions​ ​or​ ​consumable​ ​resources (excluding​ ​batteries).​ ​A​ ​mechanically​ ​separating​ ​rocket​ ​will​ ​be​ ​able​ ​to​ ​launch​ ​and​ ​recover​ ​several times,​ ​requiring​ ​only​ ​a​ ​new​ ​propulsion​ ​motor​ ​(and​ ​perhaps​ ​batteries)​ ​between​ ​flights.

Progress to​ Date​

Since​ ​the​ ​end​ ​of​ ​the​ ​2017​ ​Summer​ ​semester,​ ​great​ ​progress​ ​has​ ​been​ ​made​ ​in​ ​the​ ​design​ ​and development​ ​of​ ​our​ ​two​ ​distinct​ ​prototype​ ​systems:​ ​A​ ​purely​ ​mechanical​ ​system,​ ​and​ ​an electromagnetic​ ​system.​ ​Much​ ​of​ ​the​ ​Summer​ ​1​ ​semester​ ​was​ ​utilized​ ​to​ ​brainstorm​ ​together and​ ​develop​ ​our​ ​designs​ ​in​ ​sketches​ ​and​ ​CAD.​ ​We​ ​didn’t​ ​want​ ​to​ ​begin​ ​ordering​ ​materials​ ​until we​ ​had​ ​at​ ​least​ ​one​ ​promising​ ​design.​ ​Summer​ ​2​ ​saw​ ​the​ ​beginning​ ​of​ ​fabrication​ ​and​ ​testing​ ​of our​ ​designs.

The​ ​purely​ ​mechanical​ ​system​ ​utilizes​ ​a​ ​servo​ ​driven​ ​power​ ​screw​ ​(made​ ​of​ ​a​ ​threaded​ ​stud​ ​and a​ ​threaded​ ​hexagonal​ ​standoff)​ ​to​ ​control​ ​a​ ​latching​ ​mechanism​ ​which​ ​holds​ ​the​ ​two​ ​halves​ ​of the​ ​rocket​ ​together​ ​under​ ​spring​ ​compression.​ ​By​ ​activating​ ​the​ ​servo,​ ​the​ ​latch​ ​will​ ​be​ ​released, and​ ​the​ ​compressed​ ​springs​ ​will​ ​force​ ​the​ ​two​ ​rocket​ ​halves​ ​apart.​ ​The​ ​system​ ​is​ ​already partially​ ​assembled,​ ​with​ ​the​ ​exception​ ​of​ ​a​ ​few​ ​components.​ ​The​ ​software​ ​for​ ​this​ ​system​ ​must also​ ​be​ ​written​ ​and​ ​tested.

The​ ​electromagnetic​ ​system​ ​involves​ ​fewer​ ​moving​ ​parts.​ ​Rather​ ​than​ ​a​ ​mechanical​ ​latch​ ​holding the​ ​springs​ ​compressed,​ ​a​ ​permanent​ ​electromagnet​ ​will​ ​be​ ​utilized.​ ​This​ ​magnet​ ​attaches​ ​itself to​ ​a​ ​strike​ ​plate​ ​on​ ​the​ ​upper​ ​rocket​ ​half,​ ​and​ ​“turns​ ​off”​ ​when​ ​it​ ​is​ ​given​ ​power.​ ​The​ ​switch which​ ​allows​ ​power​ ​to​ ​the​ ​magnet​ ​will​ ​be​ ​controlled​ ​by​ ​the​ ​same​ ​stratologger​ ​signal​ ​which​ ​is typically​ ​used​ ​to​ ​fire​ ​off​ ​e-matches.​ ​The​ ​circuitry​ ​was​ ​difficult​ ​to​ ​troubleshoot.​ ​What​ ​should​ ​have been​ ​a​ ​simple​ ​circuit​ ​to​ ​set​ ​up​ ​actually​ ​had​ ​the​ ​issue​ ​of​ ​floating​ ​current​ ​coming​ ​from​ ​the​ ​apogee signal​ ​pin​ ​on​ ​the​ ​stratologger.​ ​This​ ​system​ ​has​ ​been​ ​successfully​ ​ground​ ​tested,​ ​and​ ​has​ ​been proven​ ​to​ ​be​ ​repeatable​ ​(video here).

Plan for​ the​ Spring​

This project has been ongoing since Summer 2017 and has plans to launch a rocket with a mechanically separating system on-board at the end of the Spring 2018 semester!​