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.
Design
The design considerations associated the Hermes recovery system are summarized in the following pages:
Testing
Component Level Testing
Ground Testing
A general description of ground tests can be found here.
Planned Areas of Research and/or Improvement
As of 12/16/2017, there are several planned areas of research and/or improvement as well as "things to do" regarding Hermes' Recovery System:
- Solidify parachute, webbing, and other component packing volumes and arrangement: Unknown User (janssonm@mit.edu)
- Improved SRAD piston design: Unknown User (janssonm@mit.edu)
- Consider dampening system at the end of the piston (eg. spring) so that it doesn't slam violently
- Verify margin of safety on premature piston firing due to pressure buildup during ascent
- Consider small orifice to prevent premature piston firing
- Mass saving cuts to Cup and Diaphragm assembly: Unknown User (amel@mit.edu) and @Shannon Cassady
- Validate landing speed w.r.t webbing lengths and provide this information to all other subteams
- Research Nitrocellulose as an alternative to black powder: Unknown User (janssonm@mit.edu)
- Validate current piston by means of thorough testing: Unknown User (jhz@mit.edu)
- Gather data from P-tap: Unknown User (jhz@mit.edu)
- Gather data from accelerometer: Unknown User (janssonm@mit.edu)
- Finish theoretical model: Unknown User (janssonm@mit.edu)
- Machine testing assembly: Unknown User (jhz@mit.edu)
- Develop and run tests on Firebolts: Unknown User (alexlam@mit.edu)
- Finish drogue parachute design: Unknown User (jcoray@mit.edu)
- Finish alternative webbing research: Unknown User (jcoray@mit.edu)