Saturday March 17 2012, Copenhagen Suborbitals had a great day at Space Test Center Lindoe (STCL) where we performed the first drop tests of the main parachutes for space capsule Tycho Deep Space.
It was a beautiful and sunny day with only mild winds so we couldn’t have asked for more.
At STCL we had access to the 110 meters tall gantry crane from which the parachutes were dropped from a height of 89 meters.
The primary goal for the tests was to see if the packing and deployment system worked. And it did! Secondly, we wanted to test the various slider systems which can be attached the parachute before packing.
The slider is a piece of fabric or webbing used to control the canopy opening shock. Through the slider, all canopy lines passes and the slider is initially placed all the way up by the canopy creating a slow drag area. When the canopy is catching air the slider will be forced to slide (hence the word) down the canopy lines and the parachute will be fully deployed. A fast moving slider provides a hard and fast opening while a slow moving slider gives you a gentle opening.
The same effect can be done using a parachute reefing system. Reefing is basically a line or wire attached around the lower edge of the canopy preventing canopy opening. When the canopy has caught air you cut the wire and get full deployment. However, at this point we have decided to use sliders.
Since we were only capable of dropping the parachute from 89 meters we knew that tests with sliders would not give us height enough for a complete canopy opening. But slider tests are still viable if you are able to see the canopy creating a water-drop like shape and begin to catch air before it touches ground.
Throughout the day we performed 5 drops/tests:
1. Plain drop with no slider.
Result: Perfect canopy line detachment from the bag and perfect (hard/fast) parachute opening
2. Plain drop with fast slider.
Result: Perfect canopy line detachment from the bag and water-drop shape identified. Parachute not fully opened before touching ground. A ground test was also done letting the canopy catch air and identified that the slider moved down the lines.
3. Plain drop with fast slider (test 2 repeated)
Result: Same as 2
4. Plan drop with slow slider
Result: Just plain crash because the slider requires additional height for testing
5. Plain drop with last years parachute model with slider (much smaller canopy)
Result: Perfect canopy line detachment from the bag and perfect slider movement and slow canopy opening
Conclusions so far:
- Bag design, packing procedure and deployment are all approved for the main parachute design.
- Slider designs are still not validated. We suspect issues related to slider/canopy lines entanglement. The sliders must be tested during high speed deployment from a plane or other means. If the sliders seems to be working "fine" on ground the plan is to push Mads Stenfatt out of a plane with our parachute.
It was long 18 hours for 10 guys from Copenhagen Suborbitals, personnel from Lindoe and Blue Water Shipping who were a part of this test as sponsors. Thank you so much for this support!
It was a fantastic experience; we all had much fun and got back home much wiser.
Ad Astra
Kristian von Bengtson
