Medusa Deployment Mechanisms

Responsible Engineers: Owen M, Kevin G, Jenna B, Juan A, Nicole C, Max, Sam H, Amanda M

Hermes III Deployment: https://wikis-mit-edu.ezproxyberklee.flo.org/confluence/display/RocketTeam/HADES

Phoenix Deployment: Hardware

Research into other medthods: Nitrocellulose, Separation Events, https://wikis-mit-edu.ezproxyberklee.flo.org/confluence/download/attachments/120175068/Jim_Jarvis_Highaltitude_deployment_2013.pdf?version=1&modificationDate=1491853101000&api=v2, https://docs.google.com/document/d/1-FvnbYQmETId8Ko6nY0LdCxwcloM4aGdy2pHURnmPTc/edit 

Meeting Goals:

Week 1: initial research

Week 2: cost analysis, pick deployment system, have rough sketch with dimensions (calculate amount of co2/black powder necessary), research testing procedures

Week 3: have idea of all components necessary, start on CAD

• Maybe try and get in contact with SPL to do a piston test in the vacuum chamber sometime in the next two weeks?

• Or figure out a way to use the mini vacuum chamber in lab

Piston

• Used on Phoenix, Staging Demo and HADES

• Piston failure experienced on Staging Demo II (resulted in sustainer destruction)

• Pressure sealed so can be used at high-altitudes

• Although risk of no pressure seal on the firebolts (mitigated using hydrostatic testing)

• Overall black powder is less reliable at higher altitudes (lower pressure slows down combustion propagation)

• Test hot glue instead of epoxy as a sealing method for the firebolts

• Takes up 8 inches in length of mpt

• Can be reused

• Look into & test shorter pistons?

• Variety of piston lengths: https://www.mcmaster.com/products/pistons/double-acting-round-body-air-cylinders/ 

• More info on different types of pistons: https://www.globalspec.com/learnmore/fluid_power_components/pneumatic_equipment_components/air_cylinders 

• BP calculator: https://rocketrycalculator.com/rocketry-calculator/bp-estimator/ 

CO2 Canisters 

• Good for use at high-altitudes (20k ft+) b/c completely pressure sealed

• Takes up approximately 5 inches in length of mpt

• USCRPL Recovery Presentation https://docs.google.com/document/d/1-FvnbYQmETId8Ko6nY0LdCxwcloM4aGdy2pHURnmPTc/edit 

• https://ideaexchange.uakron.edu/cgi/viewcontent.cgi?article=3029&context=honors_research_projects 

• This is an article someone wrote about how they designed/built/tested a CO2 deployment mechanism using a solenoid

• CO2 has lower pressure impulse than black powder

• Discusses difficulties with sealing

• Also gives approximate calculations for how to find co2 canister size

• fruity chutes info: https://fruitychutes.com/files/blog/Rocketry%20Recovery%20Technology.pptx

• COTS CO2 Canisters:

• https://www.apogeerockets.com/downloads/PDFs/CD3_Manual2009.pdf

• https://www.tinderrocketry.com/rocketry-co2-ejection-system (instruction manual gives bp to co2 conversion)

• Preliminary Design

  
  

CO2 canister sizing

• Chute packing volumes

• main chutes

• sustainer main: 4.3 oz 48 inches, 26 in^3 packing volume

• booster main: 16.3 oz 96 inches, 90.5 in^3 packing volume

• drogue chutes (estimates)

• sustainer drogue: 1.7 oz 18 in diameter, 9.67 in^3 packing volume

• booster drogue: 4.5 oz 36 in diameter, 21.2 in^3 packing volume

• Multiply the black powder charge size (grams) by 5.0 to determine the amount of CO2 (also in grams) required to achieve the same compartment pressure.

• If using this method we need to remember the compartment for Phoenix (that we used 0.2g for) is the inside of the piston, not the recovery compartment

Canister Size

• 12g CO2 Canisters 

Layout

• Shear Pins

• Phoenix had 3 on sustainer nose cone and 4 on booster

• Medusa needs more shear pins on secondary deployment to ensure there is no early deployment

Other Research

• Pyrotechnic cable cutter

• https://www.youtube.com/watch?v=dixI8KeGacc 

• Misc Links

• http://www.uscrpl.com/traveler-iv 

• http://media.wix.com/ugd//b73de9_5073f5498c5742f5e23ac0728a139904.pdf