Towing Test extended story

On June 3 the SQUID team set out once more towards Tierp airfield in order to conduct the second towing test. The main goal of this test was to prove that the parachute can be deployed no matter how the FFU top is oriented. In order to improve on the design since Towing Test 1 some modifications had been done to the system out of which some proved to be very effective while some a little more vague.

Towing test 2 started off with 2 test runs to determine whether the regular streamer, used during Towing Test 1, or a new modified one with a pocket at the end provided more drag. It could be determined from these two runs that the modified one provided about 10N more at about 30m/s. Therefore this modified streamer was used for all deployment tests.

Afterwards followed the main test runs and the team was extremely efficient and we dispatched the FFU:s with an average time of about 30 minutes including all the times for the modifications and everything inbetween the runs.

The main issue from Towing Test 1 was that deployment could not be achieved when the FFU was mounted facing straight up on the rig. The results from that time where thus not sufficient to conclude that deployment should be reachable under the conditions we will face during descent.

However starting the test runs with the FFU facing straight up deployment failed on the 1:st run in this configuration. This was determined due to the parachute getting snagged by one of the hinges holding the top cover. The complete hinge and spring mechanism was afterwards removed and replaced with the old mechanical and manual half cookie jar used during the first towing test. The 5 following test runs with the FFU facing straight up were a success with deployment achieved during all of these. However during two the ropes broke after the parachute inflated. The last run even proved that the parachute could be deployed at 80km/h instead of 110km/h.

These results mean that our parachute should be able to deploy during the re-entry conditions. The next step will be the largest one this far in the landing system development and also the most critical namely the Drop Test. On August 23 three SQUID members will be present at Esrange conducting these tests, myself being the main responsible for the landing system being of course one of them. So now awaits a really hard road in order to prepare thoroughly for this critical test.

We have come a long way but now its getting really serious, the fighting gloves are on and the bell has sounded.

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