Overview

Recovery is a critical, but often overlooked, rocket system. Project Prometheus had one of the most successful recovery systems in MIT Rocket Team’s recent history. Its two members were Ariella Blackman (Class of 2027) and Elizabeth Jackson (Class of 2027), with assistance and guidance from our Team Lead, Ezra Eyre (Class of 2026), and Project Phoenix and Medusa Recovery Engineer, Jenna Blair (Class of 2026). Overall, the subteam accomplished a lot and was able to test new experimental deployment systems, design and manufacture their own parachutes, and test their system during Prometheus Test Launch. 

Timeline was as follows:

October: First Design Cycle

November: PDR, Second Design Cycle

December: CDR

January-March: Manufacturing and Testing

April: Test Launch

May: Failure and Success Analysis

The Design was based off of the requirements from Spaceport that required a drogue parachute if hitting above 2,000 ft of altitude. Each of our two stages (Booster and Sustainer) had two parachutes (Drogue and Main), both mains were purchased from Rocketman Parachutes and the drogues were designed and  manufactured by the team. The new deployment mechanism that we used was a black powder ejection technique that was for three of our parachutes. Due to altitude, the fourth parachute had a piston assembly instead.

We had a 75% success rate (three out of four total parachutes) with deployment during Test Launch. While we were not satisfied with this result, this is the most successful Recovery System in the last 4 years. After Test Launch we completed a failure analysis and discussed important changes that we want to make going forward.

In summary, Project Prometheus’s Recovery System went through an entire engineering cycle with successes and important lessons about recovery learned. Below are details on components and guides to how we accomplished what we did, and what we would like to do better.

Subsections:

Deployment Mechanisms

Parachutes and Bags

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Test Launch and Failure Analysis


Parachutes and Bags

Parachutes

Sizing

Our guiding equation for sizing parachutes:

We used our calculator (linked here) to help us determine how we would size our rocket based on the original values we were given for terminal velocity and the coefficient of drag. We made this calculator so that we would be able to change the sizes of the parachute as both the terminal velocity and the coefficient of drag were things that could change over the course of the semester.

Design

For our two main parachutes we decided to buy them from Rocketman Chutes, (linked here). For our drogue parachutes we decided that we wanted to design and manufacture them ourselves. To do this we chose a simple octogonal design with a small eye hole (based off of previous drogue parachutes on Phoenix). We finalized these designs before the end of the design cycle in December.

Manufacturing

Manufacturing of the drogue parachutes took place during IAP 2024. Overall, this was one of the more time consuming and careful manufacturing jobs that recovery completed for Project Prometheus and included some failures in addition to successes.

Materials

*Note on Nylon Webbing in Successes and Failures section

Process

  1. Sizing a pattern out of paper
  2. Pinning Fabric to pattern then cutting out fabric
  3. Pinning ½ inch seams on the edges of the main section and the lower ring)
  4. Lower Ring:
    1. Sewing seams along the top and bottom
    2. Sewing sides together (double stitching, folding over so there are no raw edges showing)
  5. Main Section:
    1. Sewing the bottom rim seams (no raw edges showing)
    2. Sew Webbing folded over along the eye hole on the top side (to cover raw edges)
  6. Connection 
    1. Pin webbing (8 pieces, all in line with the corners of the octagon) so it has two extra inches near the eye, two inches left as space between the ring and the main section, and three inches after the lower ring
    2. Start by sewing the webbing onto the lower ring **sew two lines on either side of the webbing**
    3. Then sew up to about an inch and a half away from the eye of the parachute
    4. Fold over the extra two inches and leave a small loop over the eye
    5. Sew the final part from the eye to where you stopped before
  7. Final Steps:
    1. Thread through a small piece of tough string through the top loops you made
      1. Use a needle to get it through the top loops
      2. Insert it into itself
      3. Sew over insertion
    2. Check for any loose threads
    3. Check for holes in the parachute (see *section yet to be written* for how to fix holes in a parachute

Successes and Failures

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Test Launch and Failure Analysis

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Moving Forward

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