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.

A brief look into the ongoing work

After a weekend of well deserved rest this week has been crazy as always. As you all know we’re really trying our best to get things ready ahead of delivery. Therefore the blog has been a bit low prioritized but to at least give something I´ll add some pictures from the last preparations ahead of the real EAR last week.

 

Team night

Some weeks ago, at October 23:rd to be more precise. The SQUID team had another of their much beloved team nights. This time it was time for a more informal night at my (Gustav) place. So I Georg and David gathered at my place at two to start the preparations, the plan was to start of with some swedish and spanish specialties together with sparkling wine and then continue with tex-mex burgers and last finish of with  some great austrian dessert dumplings stuffed with nougat cream or apricot marmalade.  Somehow we succeeded with the intended menu and when the rest of the team arrived we where ready. I think I can speak for all of us when I say that we had a wonderful night, the food was delicious and the drinks never stopped coming 😉

You are welcome to judge by your self based on the attached pictures!

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 😛

KTH catalogue

So yesterday  I finally found the next KTH (Royal Institute of Technology) catalogue which contains information about the different programs that are available on KTH. In the catalogue where also an interview made with me and Jiangwei earlier this fall. The interview is well worth reading (however it is in swedish) even if it contains some wrong facts about the project. So check it out at page 17-18 in  Utbildningskatalog 2011/2012 (2,9 MB).

Picturea of Gustav and Jiangwei from the KTH catalogue 2011-2012

Disaster strikes…

Last night actually became a sad story. After all testing and working during last night everything turned out to a small disaster. So what happened really, well we’e not yet entirely sure but I’ll tell you what we observed. Last thing on the task list last night was to mount all hardware in their specified places. Due to that we had been using the eBox (the rectangular middle aluminum box where all the electronic boards are mounted) for some time it had not yet been modified to hold the ovenCutter. This meant that we had to move all the boards to a new eBox. Somewhere here something went wrong cause when everything had been mounted and we tested the communication with the experiment, suddenly magic white SMOKE started to rise out of the eBox. We’re not sure what had really happened but our theory is that during the mounting (which took place at midnight last night) somethng most have been short circuited. This lead to that the MOSFET which is used to switch of the batteries started to boil.

Burned MOSFET

Suddenly white smoke started to rise from the MOSFET

Due to this small disaster we where forced to postpone the EAR until friday. So please wish us better luck for that time.

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!

Ground support software

So the time has come to give a brief story about the ground support software (GSS). So what is the GSS? Well, actually it is quite simple to explain. The software used by the SQUID project can be divided into two different main categories. First the software which is loaded on to the probe it self and secondly the software used to monitor and communicate with the probe as well as post flight data analyzes.

The software used in the probe is written in VHDL and will be covered in a separate blog post. In general however one can say that this software controls almost everything that happens on the FFU during the mission. It also logs all sample data from the different sensors onboard the probe.

The GSS consists out of two totally different softwares,readOut and liveCom. The readOut is a Matlab script which reads out the memory data and displays it in form of plots. The tricky thing is to construct a fast script since data is stored in a rate of 2000 Hz while in flight which means that even short tests performed on the probe results in large amounts of data.

 

A example of how the data can be displayed by the plots genereated from the readOut. In this case it´s the data from the gyros in the eBox.

The liveCom in turn is pretty well explained by its name. The software is run by a computer which druing tests is connected by an old fashioned serial interface with the eBox. While in flight the connection will be wireless and go through the REXUS rockets service module. The software is written in python and makes use of the Tkinter TCL graphical interface. This combination enables the software to be run on a variety of platforms since most platforms supporting Python also suports Tkinter. The software mainly visualizes the low data rate output (LDRO) from the probe but also features a simple interface for controlling the probe which is used during system tests. However the main idea is to provide a fast way to follow the probe during the mission while it´s still in the rocket.

 

A screenshot from the liveCom software