Preparing for drop test

Today has been a hectic day. I, Gustav, arrived at lunch and immediately joined David and Mikko in the preparations for the drop test which had been moved to tuesday due to bad weather today. There where some smaller errors in the test FFU´s however we’ve now compensated for those and are ready for the test tomorrow. Since it’s a bit to late for a longer update today I promise that we’ll maker a longer follow up later on with more details around the preparations as well as the outcome of the test. But for now wish us good luck for tomorrows tests.

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Top plate ejection test 1

SQUID special forces test team has news for you all out there!!

After some hectic days of manufacturing parts for the landing system we finally have the target in sight. Attached to this status update is a video where you can find all the attempts performed tonight. Everyone has been working like being in a military bootcamp and the results are finally showing. Our top plate ejection system test can be considered a huge step forward for SQUID as the tests have proven that the design we’ve derived is in fact working in the test setup used.

Next mission is to once again infiltrate the workshop and continue to push through in manufacturing all parts needed for the drop test. Lots of tests and late nights are awaiting us but we will push through to the final end and see to it that we finish our mission successfully.

Ok some serious comments then. The test consisted of activating the cutter through the electronics and switches that are intended in the drop test model. As the cutter is activated the dyneema rope holding the top plate down will melt thus ejecting the plate. The first test was conducted with a weaker spring and was in fact a successfull ejection. However we could not stand to not have a successfull ejection with the stronger springs so sturdy as we are we found a way to compress and secure them. The difference can clearly be seen in the video and we all know that if something can fly higher then of course it also should 😀

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.

Towing test

Georg writes

While all the others are writing on the Documentation for the critical design review which has to be finished tomorrow I am trying to keep you up to

Mario & Mikko running facing the Parachute in the pickup

date on what happened during the last couple of days.

And the most important thing was probably the towing test. On Wednesday last week more or less the whole team gathered to do a drag test at Tierp Airfield a bit north of Uppsala. The goal of this test was to investigate the deployment of the parachutes and to find a working folding technique.

Gustav is adjusting the RIG

In order to be able to do the test we all had a busy Monday, Mario and Gustav built a rig to mount the FFU onto the car and I had to produce something to attach it in different angles. Unfortunately the mounting device from bent aluminium wasn’t as stable as I expected it to be.

However, after some starting problems with broken swivels and opening problems a couple of runs worked out quite well, the chute deployed when it was mounted with the attacking wind. The two tested folding techniques seem to work equally good and parachutes seem to work fine.

There is already another towing test being planned in order to refine the results a bit, I hope this time the attachment will work a bit better…

SQUID army

Frame and top cover

There is something happening down in the basement, but what is really going on in the workshop?

Well, as the drag test is coming up it would be cool to have two fully functional prototypes in order to prepare one while the other on is being tested. So I started to produce another prototype and be sure, there are more coming.

However, as the prototypes need to have a functioning cover they will get a top frame and a cover according to a design from Mario.

More SQUID prototypes

Unfortunately the manufacturing of the frame doesn’t seem to be as easy as everyone thought. At first cutting the inner part out just using a jigsaw felt right, but cutting aluminium with a jigsaw is no fun.  So I am back to milling again. I just hope this works out without any incidents this time.

The mockup of the FFU is coming together

Soon we will be starting to do tests on the parachute deployment. Therefore the production of mockups of the FFU have begun. George, the team’s new member, is working like crazy down in the workshops to manufacture the models. Great job George!!

Our parachutes that we ordered also arrived a while ago. The parts are starting to come together, at leas a bit 😛 We chose a cross-chute type due to its favorable characteristics such as stability and less drifting with wind than a regular umbrella shaped one.

Before we do the actual test the parachute folding has to be tested and developed. This has proven to be a quite intriguing task due to that we actually have no idea of how to fold it correctly into the FFU. But one thing at least can be concluded, it seems to at least be possible to fit it into the compartments that we have 😛

The test day is set for the towing test. On May 19:th we will head to the airfield in Tierp to conduct the towing test on the parachute deployment. For now we will work hard to plan for this event because we really need to get as much data and results from this day as possible.

We all look forward to this and hopefully it will go well 😀

Cutter test

To improve the cutter design for ejecting the parachute, Gustav and David suggested a new design some time ago. The design has since then been discussed together with some of the members of the LAPLander team and a decision to test the performance of such a cutter where taken. The design of the new cutter is quite simple and consists of a pipe made of ceramics with good heat propagating properties. The pipe is then threaded and a cantal wire is twisted around it. The result is that the cutter works as an owen and melts the rope which is guided through the pipe. The test showed that the cutter performs quite well even in this early stage even if there are a number of improvements that needs to be added to the design.

The new cutter with an enthusiastic David behind it