Purpose

The Hermes recovery system follows a dual-separation, dual-deploy architecture. The drogue deployment event is initiated at apogee by a pyrotechnically operated piston. The main parachute is retained via a Tender Descender until approximately 2,000ft. Subsystem and component designs, testing procedures and results, and research is summarized here.

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The design considerations associated the Hermes recovery system are summarized in the following pages:

• Pathfinder Webbing Lengths
  • Webbing Material
• FireBolts
• Shear Pins
• Hermes Parachutes
  • Disk Gap Band Drogue
    • Disk-Gap-Band Design
    • Disk-Gap-Band Construction
  • Semi-Ellipsoidal Main Parachute
  • Hermes Deployment Sequence
  • Parachute Analysis
• HADES ("Piston-Cup-Diaphragm" System)
  
  • Pyrotechnically Operated Piston (POP)
  • HADES Piston Selection and Development (SRAD Redesign)
  • HADES Cup
  • HADES Diaphragm
• Packing Procedures and Volumes
  • Hermes Parachute Packing Procedures

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• Ground Test November 10, 2017
• December 2, 2017 Ground Test

Analysis

Failure Tree

Planned Areas of Research and/or Improvement

As of 1/10/2018, there are several planned areas of research and/or improvement as well as "things to do" regarding Hermes' Recovery System. A more complete list of tasks and details can be found for team members on Asana.

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1. Consider dampening system at the end of the piston (eg. spring) so that it doesn't slam violently
2. Verify margin of safety on premature piston firing due to pressure buildup during ascent
3. Consider small orifice to prevent premature piston firing

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1. Gather data from P-tap: Unknown User (jhz@mit.edu)
2. Gather data from accelerometer: Unknown User (janssonm@mit.edu)
3. Finish theoretical model: Unknown User (janssonm@mit.edu)
4. Machine testing assembly: Unknown User (jhz@mit.edu)

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