Movie from bench-test

Laaadies and Gentlemen, aliens and alienesses!!

SQUID productions is proud (TBD :p ) to present a true action movie full of drama and comedy, the ultimate adventure and sci-fi movie ever, a war-story, thriller and documentary  it is:

REXUS 10 bech-test, a very short summary from Thursday and early Friday.

Enjoy 😀

Top plate ejection testing

So as (almost) usual we’re at the lab on a Sunday, as most of the testing doesn’t seem to fit in our timetables. However as the sun is not showing up as often as you’d want her to, working seems like a fairly good way of killing time.

So what’s happened is first of all, that we all came in pretty late and somehow tired between 3 and 4 pm. Then we needed some time to find ll the stuff and to remember what we actually wanted to do. Eventually we figured out that we needed some small modifications from Gustav so David and I could do a test on the top-plate ejection system which i a crucial part of the landing system. Hence it is really important that it works cause otherwise the parachute will not open and the experiment might be lost for good.

Our first attempts to test the system failed due to the rope holding down the lock broke while we where still trying to close it. Just as we started to become desperate and thought we’d have to redesign the whole thing Gustav came up with an idea. He suggested to put some tube around the wire at the place where we are joining it with another wire. This “cushion” worked fine and so we consider the Sunday a successful one.

SQUID PASSED EAR!!! (Hurray :D)

The battle is won but the war is not yet over.

Today SQUID had it’s EAR (Experiment Acceptance Review) which is the last review before delivery. We pushed through limited time, stressfull days, missing components, late workshop evenings, burning electronic boards, short circuited batteries, system failures, moodswings etc. and finally got through the EAR with positive results.

Mikael Inga was visiting us from the Swedish Space Corporation to carry out the EAR and most of the team was present to discuss and demonstrate the experiments current functionality. The day started of at 9:30 in the morning with a check through what has been done on earlier comments recieved from REXUS and what tests we have performed since last IPR.  Just before lunch we started of by demonstrating the functionality and workings of the experiment interface electronics and after lunch followed a more thorough experiment functionality demonstration in which we let the system run through parts of the intended operational phases finally leading to the moment of thruth, the decision. SQUID has passed EAR but as always there are comments and things to care about but nothing came up that we weren’t already aware of.

Next up is delivery and the team will now take the weekend off to recuperate from the last two weeks of battle because on monday we need to pick up the pace even further. Systems have to be fully tested, fligh boards assembled to the ebox and tested, assembly of a second FFU has to start and everyone should be happy and prepared for hard work (at least us slaves have to be) otherwise the big boss will come after us with his grand master-whip which he talks so much about nowadays 😛

Busy night before EAR

So today has been busy as always. The day started of with that I (Gustav), Jacob and Amer (from the RAIN team) visited Bergtorpskolan, just north of Stockholm. There we held two lectures which where really well visited. During the first one we had 33 pupils listening and during the second one we had as many as 47 pupils listening on how our project works. This was actually some kind of record for us, we’ve never had as many pupils listening to us during a school visit and of course we loved it! The pupils where all very quiet, seemed interested and asked plenty of question so it was a rather success.

However the main thing about this blog post is not the school visit but instead the much more worrying Experiment Acceptence Review which will be taking place here at KTH tomorrow. The whole team is really fighting to get everything to work in time, and as it looks right now most things will actually work tomorrow. Something which however seems to be a huge problem is the reliability of the SCALE. In the future we hope to be able to deal with it by using more standard parts but since some of the has yet to be delivered they have been custom made in the inhouse workshop. This has led to that the two different SCALE systems really seems to have different personalities and most of the times at least one of them have problems when being run. When it comes to the rest of the mechanical parts they however seems to be on place, and the electronics and software also seems to be in a working stage.

So to end this blog post I beg you all to wish us good luck for tomorrows challenge!

Parachute load test with an unexpected outcome

Last Thursday it was time to determine once and for all how much the parachutes we use in the landing system could handle. Having failed to break them in both the car towing test and the actual drop test, me and our supervisor Gunnar Tibert resorted to more brutal methods.

One of the 70″ parachutes was hung upside down from a hook in the Structures Lab at KTH, supported by a single line of paracord which was to brake the fall. This is the same type of cord that was successfully used in the drop tests above Esrange. The parachute was loaded with about 19 kg of extra load, and dropped with 1.5 m of slack paracord.

Sometimes it's best to use what you have closest at hand! 19 kg of old newspapers have just the right density to fill out the parachute nicely.

Much to our surprise, it turned out the paracord, which we thought was rated to the equivalent of a couple of hundred kilograms in force, was the weakest link:

View from the hook of the crane, filmed with the GoPro HD Hero.

420 FPS high speed footage shot using a Casio consumer camera. This doesn’t show the paracord breaking, but is cool nontheless!

Right now we’re trying to determine the speed right before and after the line broke so we can calculate the force in the cord. At any rate, it is likely we will switch this cord for the real system to be sure that the same won’t happen during our flight! However, the cord still needs to be flexible so the shock to the experiment isn’t too great.

Drop test video first extended version

In preparation for our guest presentation tomorrow, friday, at the rocket science course we made a new version of the drop test video. It now includes some preparing tests and also a last surprise. Check it out!

Drop Test at Esrange – David’s Story

So Me (David) and Mikko arrived at Esrange on sunday the  22:nd of August feeling quite prepared but at the same time knowing there were still a few issues to be solved. We began working on preparing the DT-FFU’s first thing after brekfast on monday morning in what is called the “Cathedral” next to the balloon pad. After lunch Gustav arrived and joined the team. The weather outside was unstable with low clouds and during the morning it had been raining. So the verdict from Olle was to cancel flight and drop on monday and instead focus on planning and fixing everything thoroughly and do an early bird on tuesday morning.

The drop test team was supposed to concist of Me, Olle, Mikko and Gustav and the test itself was supposed to be a relatively small operation, or at least that was the picture we of the SQUID team had. But before we knew it this had in fact turned out to be quite a large opearation with the risk analysis having to go through the Esrange safety board, two more people joining us (Mark and Tomas from Esrange), mission overview and briefing etc, people in the operations central both in the Esrange main building and at the balloon pad.

During the afternoon we had the first mission meeting where we went through the drop procedure, checked from which direction the aircraft would fly in over the balloon pad, commands that were gonna be used, where people were supposed to be posted and so on. After the mission overview meeting everything finally started to feel very serious and real, and cool of course, this was the moment I started to feel a bit anxious.

Afterwards the team continued preparing the Drop-Test FFU’s for being thrown out from the airplane. We encountered a problem with cutter times not being consistent but pinpointed the problem to a manufacturing error. Fortunately we had one spare cutter which made two of the cutter units working as expected. Finally having this problem solved we proceeded to packing the parachute for the final time. When placing the top plate, closing and locking the FFU you could not help but feel even more anxious as this could be the last time we actually saw these models and the thought “hope we did everything correctly” was ringin through my head the rest of the night.

But anyhow finally the two units were ready and we proceeded to go to sleep. Falling asleep was not that hard as we were extremely worn out but I could not help going through the test procedure in my head as I was the one who was going to sit in the aircraft behind Olle and throw out the FFU’s. The anxiety was starting to take over completely but could not, fortunately, overwhelm the tiredness, so I fell asleep.

Next morning the first thing the team did was to run up to the “Cathedral” and check that the FFU’s were ok, which they were. The sky was clear and the sun was shining, weather looked perfect and we knew that today will be the day. Proceeding to have a nice breakfast which afterwards immediately was followed by the final mission breifing made the nervousness start to come back and tension started to build up a bit. Going through the mission everything seemed clear and ok for drop test. So me and Olle packed the FFU’s and headed to the amphibious aircraft which was stationed about 1 hour ride away from Esrange, while the ground crew did their preparations and got into positions.

Finally at the aircraft me and Olle practiced the drop procedure with a dummy (cookie jar) about five times before both of us felt confident with the commands and procedures.  Afterwards we loaded the units and took of heading for Esrange.

Well over Esrange we established contact with ground operations, checking we had the go for commencing the test. Upon reciving clearance from operations we turned in on a base leg for the balloon pad and the door was opened. The wind was really strong and it became really cold inside the aircraft. Finally turning in towards the final for the first practice drop with a dummy Olle called out “One minute” which meant one minute to drop and I switched on the imaginary power switch to the FFU (cookie jar in this case) and screamed confirmed, meaning the unit was activated and ready. Shortly after that Olle called “activate” whereafter i pushed the imaginary cutter start button and started the count to drop 1 2 3 4 5 6 7 8 9 10 then I threw it. Now I had felt how it was to actually throw something out of an aircraft and must say its not as easy as it sounds, the wind is blowing really hard which makes things hard and also it was very cold.

So now we proceeded with the first sharp drop after recieving clearance from operations. The same procedure as above took place but now with the real DT-FFU unit A. When switching on power i got confimation of system ok by the LED light installed. Then the signal cam to activate and the button was pushed and i started counting. Positioning myself into the practice drop position while counting the LED flashes up to ten the DROP. The FFU was deployed and fell, immediately Olle turned the aircraft and we got very good visual on the falling unit. Waiting waiting, hoping to see the red parachute and finally I saw it. The parachute deployed perfectly and the unit was slowly descending beautifully down to earth. Wohoooo! Confirmation came from ground that they had visual on the parachute and tracked it.  Second drop could commence with DT-FFU B which was equipped with a camera.

So same procedure again, power activation, status ok, cold air blowing and finally “Activate”. The unit fell and once again we turned around and tracked it. Falling, falling but no parachute. By this time it had fallen much longer than the A unit and both me and Olle was sure that this one would impact and be completely destroyed when suddenly we saw the red parachute deploying. Not long afterwards the unit touched ground and we laughed inside the aircraft at those margins. Calling on radio and concluding the test it was time to have some fun so we turned the aircraft around and came in low above the ground team for a victory flyby which was awesome 😀 then we left Esrange and returned to where we had started.

I felt great and on my way back I was also given controls of the aircraft 😀 Could simply not wait to see the videos and pictures of the test 😀