Medusa Soft Goods

Responsible Engineers: Jenna B, Jack A, Cruz S, Ben L, Sera H, Dylan G, Sophia, Max, Ezra, Annika, Sydney, Zandra, Hermanus, Jacky

Past Research:

Phoenix Lines: Soft Goods, https://docs.google.com/document/d/1SKiAfh83ogKPZqLmz7E7ntsD3G2yFT4Yhq7cu9cdZG4/edit 

Staging Demo Lines: https://wikis.mit.edu/confluence/download/attachments/142940446/DEMO_LINES_DEPLOYMENT.pdf?version=1&modificationDate=1579390640000&api=v2 

Hermes Lines: https://wikis.mit.edu/confluence/display/RocketTeam/Hermes+III+Drogue+Parachute

Hermes Quicklink and Swivel Analysis: Hermes Quicklinks & Swivels

Separation Type

Single Separation & Dual Deployment

• Done on Hermes, Staging Demo Sustainer and Phoenix Sustainer
• Combined drogue & main bay takes up less space in mpt
• 1 separation system isn't as heavy
• Would have to use TDs or cable cutters
  • TDs may not work at high altitude (issues w/ heat transfer and combustion in low pressure)
  • May be good to test TDs in vacuum chamber at lower pressure
    • 2nd gen tender descender (works at "high altitudes"): https://www.tinderrocketry.com/td-2
      • Doesn't require black powder, only e-match(es)
  • Use a cable cutter?
    • https://aeroconsystems.com/cart/launch-recovery/cable-cutter-by-archetype-rocketry/
    • Still uses bp so might not work at high altitude but could have better pressure seal
    • Vacuum tested according to the website: https://www.tinderrocketry.com/improved-piranha-line-cutter
  • 3 ring release system

Dual Separation & Dual Deployment

• Heavier (two separation systems vs one) and takes up more space
• No reliance on TDs
• Don't have to worry about main tangling while drogue is deployed
• How do we signal the dual deploy? (Wires don't swivel very easily, want to avoid having wires extend between deployment stages)
  • Load bearing avionics bay? Put the avionics bay in between the two deployment mechanisms?
  • Not all flight computers are created equal: put smol computers in the nose of each stage that are just there to actuate the first deployment

Parachutes:

• Parachute Sizing

• Sustainer (estimated weight: 15.8 lbs)

• 1 drogue: 18 inch diameter (approx 1.16 oz 18, 6.4 in^3 packing volume)

   

• 1  main: 48 inch diameter (approx 7.5 oz, 41.5 in^3 packing volume) 

• Booster (estimated weight: 103 lbs)

• 1 drogue: 36 inch diameter (approx 3.3 oz, 18 in^3 packing volume)

• 1 main: 96 inch diameter (approx 25 oz, 139.5 in^3 packing volume)

• Goal terminal velocity: 30 ft/sec, main parachute Cd: 2.2

• Research on parachute manufacturers:

  • 
    

Deployment Bags/Cloth: 

• Deployment

• Multistage recovery system

• Think about the snatch load - reduce snatch load by keeping it in a deployment bag or shell

• Should have two sections - a section for the canopy and a section for the lines - to reduce tangling

• Individual lines stored in individual sleeves to prevent tangling

• ****want lines first deployment

• Could put the lines in a bag and put the canopy inside a sleeve which is stored in a protective flap

• Material - fire-resistant Nomex (to shield parachute from heat of expulsion charge)

• Drogue shell?

• parachute liner as replacement?(Fruity chutes sells them lol)

• simplified parachute bag; good for CO2 deployment?

Lines:

• Research into line materials:

• Currently technora; will co2 have any effect on the lines?

• Lines Diagram:

• Phoenix: https://wikis.mit.edu/confluence/download/attachments/147325224/Phoenix%20Lines%20Diagram%20Printout.pdf?version=1&modificationDate=1596563231000&api=v2 

• Line Sizing Resources
  • Hermes Webbing Line Sizing: Hermes Webbing Lengths

• • https://wiki.rit.edu/pages/viewpage.action?pageId=229713880
  • https://richsrockets.wordpress.com/2015/10/02/shock-cords/

Soft Goods Testing:

• What we want to test:

• Deployment and inflation behaviour of the parachute.

• Stability of the parachute throughout the entire flight envelope.

• Opening load of the parachute.

• Tensile Testing Procedure: https://docs.google.com/document/d/1-n-A-MbSnujLylDCPT35ef-At09ltjjxZ-DWiKTpzdI/edit

Soft Goods Failure Modes:

• Webbing failure modes: Hermes Webbing Failure
• LINE TANGLING!!!!
• TD failures
  • e-match shorting
  • wet black powder or TD isn't pressure sealed so black powder can't combust