Launch campaign, Tuesday

So, now the launch campaign has officially started. All the teams have arrived, the “church” is really crowded and we do have a lack of chairs, power outlets and network connections. Not to mention that we are short of working space.

However it feels cosy and with the outside temperature it feels really nice to have enough people in here to keep the assembly hall warm.

We have conducted our last landing system test by putting the system it in a vacuum chamber and making sure that the pressure sensor and the oven cutter work in a proper way.This was done under time pressure, as there were still some things to be sorted out with the rocket service module and they found out that they needed us on the spot when we had just left for the test. On the other hand it was actually really tricky to find a feasible power outlet for the test because the building there is taken by the French from CNES and thus most of the power outlets there were french at the moment. Eventually the pressure test went really well and the top plate ejected as it should at the matching pressure for 5500 metres.

In the evening we prepared the SCALES with the flight cable and conducted a couple of tests in order to be sure they work.

Unfortunately Mikko and I were missing out on the sauna as we are accommodated in Kiruna and this means a one hour ride from Esrange. We almost had an accident with a reindeer instead.

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 😀

Day 3 ….. Vibration test….and much much more

After a lot of stress and quick assembling and disassembling of the experiment we finally managed to put everything together after a few changes on the top plate ejection system (which by the way will keep us busy for a few weeks in order to test a new design deeply). One of the problems of vibration is that the screws fall down extremely easily and we have to make sure that all of them are properly secured with a special adhesive, which makes even more difficult and specially time consuming the assembly of the system.

Unfortunately, when everything was ready we found that something was not working as it should as we couldn’t manage to insert properly the umbilical connectors (probably because of a sudden change on the usual assembly procedure) so we were unable to have communication with the experiment, which would basically mean that the vibration test would only allow us to test the structural integrity of SQUID, which in any case was scary enough, specially after the problems we had both with the top plate ejection system and the FFU ejection system.

The next step was to assemble the experiment together with the magic hat in the shaker and place the accelerometers in the different interesting components of the system in order to get the response of the vibration. The test consisted in three different ‘steps’, first a sine sweep, which is basically a sinusoidal excitation of the experiment that is used to obtain the eigenfrequencies of the system without introducing high loads, then the random vibration, which is the real and tough test, as it simulates the vibration levels on the launcher and finally,  a second sine sweep, in order to check if something was broken inside the experiment, as if something got damaged during the random vibration test the responses from the first and second sine sweeps would differ.

As usual we had bad luck. The first sine sweep showed that around 500Hz there was a resonance between the shaker and the FFU, meaning that the signal or the vibration of the shaker would be amplified in the FFU. The worse thing was the magnitude of the amplification, as on the sine sweep seemed to be of 10 times, which was everything but funny. Fortunately, the random vibration test went very well (we didnt see any parts of the experiment flying) and the resonance was finally as bad as expected (the signal was ‘only’ amplified by a factor of 3)  and the second sine sweep was the same as the first one.

The test did show however a couple of minor problems. After the shaking we tested the electronics and the SCALE systems. The electronics were working perfectly, but when we tried the deployment of the SCALEs we saw that one of them was failing. The reason seemed to be that the screw holding the driving gear to the motor shaft went loose during vibration, probably because  the adhesive we were using for the screws was not suitable for plastic (the cogwheels are made of Delrin). Also, and when we removed the e-box we found out that the clamp of the steel wire of the FFU was deattached from the bottom plate (it was originally glued), which means that we will have to make some minor changes on its design in order to be able to screw it to the bottom plate instead of gluing it. In any case, and after all the problems we had during the previous days the test was quite successful.

Mario Valle

Day 2 in DLR Bremen…..Time event simulation

Written by Monica

Today has been a very exciting day, all the experiments in the Rexus 10 (GAGa, FOCUS,M-BEAM and SQUID) were connected together and we simulate the time event, our SQUID communication with the rocket service module is as we expected,for now we just run with  the test mode, i.e. we control everything that happens in the experiment, but tomorrow after a vibration test we will run the mission mode, where the functions should perform automatically.

Of course, watching the experiment working feels very  nice, but it also has represented long days and an incredible amount of work, everything is  small scale and every single screw has its own way to be put.

Right now, the time is devoted to prepare the rope that goes into the cutter that will release parachute… once it is done we can then pack the parachute into the FreeFlightUnit … for 2nd time today 😉

Tomorrow..vibration test..and right after …test ejection of the booms…Lets hope everything works !!!!

Ejection testing night

As everyone probably has noted the delivery is really closing in so yesterday we decided on trying to do three different tests, all of them with ejection system as a common dominator. First of was the top plate ejection system test. This system has been the focus for a server amount of testing. The system is important since it covers the parachute, when activated the parachute is exposed to the surrounding air. This time the focus was how the dynema rope moved. The test was successful and ca be seen in the following video.

 

 

Next up was the spring ejection test. This test have been performed earlier but the big difference this time was the use of the distance ring which enables another cm of tensioning. It also secures that the spring gets pressed down in the gully fully. The video covering the ejection can be seen below.

 

 

Last of during the night was the long term ejection spring test. The idea is to ensure that the system does not lose tension during a longer period of time. This also means that we won’t have access to the system until next monday when we also will perform a new ejection test to ensure that we get the same ejection force after that the spring have been compressed during a longer period of time.

 

Screws and Logistics

Alongside all the manufacturing and testing we have to sort out things like ordering standard components, like screws. It was easier said than done to get a hold of screws for this project. The small size, specific material and low number made it harder to get a hold of. So we got some help from the staff here to find a company that could deliver all of this. When we talked to the suppliers here in Sweden they told us they only deliver orders by the pallet and so we had to go elsewhere. In the end we had to order from Switzerland. However, they were nice and fast in the delivery so in less than a week we had our longed for screws. It ends up being about 30 variations and about 100 to 400 of each so to manage this we decided to keep it well organized. See some pictures below.

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!

The first launches of SQUID: Spring and RID testing

Yesterday the rocket interface disc, RID, finally arrived. This is the piece that actually mounts the free-flying unit, FFU, to the rocket. The custom made wave spring that will eject the FFU arrived a couple of weeks ago, and now we could finally mate them together.

The rocket interface disc (RID) with the ejection spring

However it soon became apparent that the spring had a tighter fit in the spring gully than we had expected, and to determine whether this would affect the ejection or not me and Mikko carried out some spring testing.

Soon half of the team had gathered around to watch and help out as we covered a sturdy table down in the workshop with foam and devised a clever way of holding the bottom plate of the FFU down against the spring. An unlucky Mario was selected sit under the table and cut a rope going down through a hole in the bottom plate and rid, and down through the table where it was hooked up to a tightening mechanism. To document the ejection we borrowed a Casio high-speed camera from the department of mechanics.

We did two “launches” today, and while the launches weren’t as straight as they could have been the results seem positive, especially since the weighted-down bottom plate was not perfectly balanced. However, since the radius of the spring is slightly lower than expected the very top part of it easily gets jammed between the bottom plate of the FFU and the RID. More testing will be done soon, but until then enjoy the fancy high-speed videos! Sorry for not having turned them right way up, but this would decrease the video quality.

The flickering is due to the flourescent lighting in the room,  and the towel in the first video was an attempt at catching the falling plate. 🙂