Author: Tomasz Tarnawski
As we mentioned in our previous post, designing an appropriate parachute is crucial for the safety of our probe. After additional simulations and consultations, we decided to implement significant changes to the specifications. The most important modifications include reducing the diameter from 50cm to 35cm and decreasing the ventilation hole from 10cm to 7cm. These changes will ensure an optimal descent rate for our final probe configuration.
We moved from theory to practice - the purchased ripstop nylon in bright orange color went under scissors and sewing machine. The color choice wasn't random - orange will be highly visible both during descent and after landing on grass or other natural surfaces.
With the smaller parachute diameter (35cm), every millimeter matters even more. We used precise templates and special scissors for technical materials to accurately cut eight triangular panels and a smaller circle for the ventilation hole (7cm). The edges were additionally secured against fraying.
Contrary to our initial plans, we opted for double flat seams instead of standard overlock stitching. This technique provides greater strength for the smaller diameter parachute, which is crucial when dealing with higher unit loads on the material.
The suspension lines were attached to 8 reinforced attachment points using a special bartacking technique (dense zigzag), which ensures maximum connection strength. Each line was carefully measured to provide perfectly even load distribution across the entire canopy.
The smaller parachute required more rigorous testing. We conducted a series of drops from different heights:
The new design with a 35cm diameter and 7cm ventilation hole demonstrated significantly better stability during descent than the original concept. The descent rate was approximately 7 m/s, which meets our design requirements and will ensure safe landing of the electronics.
Sewing the smaller parachute proved technically more demanding but yielded better results. The most important findings:
Our next steps include integrating the parachute with the triggering mechanism and testing the entire probe recovery system. We'll tell you about that in our next post.
Keep your fingers crossed for further tests and follow our progress!