December 17, 2010 Leave a comment
We would like to take the opportunity to share our warmest christmas greeting to all you readers out there, check out the greeting by following the link.
A REXUS project
December 16, 2010 Leave a comment
So as most of you already know me (Gustav), Malin, Mario and Monica went down to Bremen last week to deliver the experiment. What happened down there have already been told in a number of blog posts so I’ll try to write some about a few events which have yet not been told on the blog and then I’ll add some pictures which have yet not been published.
Oil needs to be refilledSo just as we where about to leave Denmark on out way down I noticed that the warning light for the Oil level started to flash. Since we where not the owners of the car we figured it was best to try to find the specified oil for the engine and where would you try to find a oil for a Volkswagen? well in Germany of course. So we continued the drive and took the ferry over. Well in Germany we stopped at the second fuel station and tried to find the right oil. I and Malin went in to the store, however the personnel did not speak very much english and we did not speak german. Somehow though we succeeded to explain what we wanted and also understood that they where out of the specific oil in the shop however they had it in a barrel in the workshop at the backyard. So we joined the mechanic (who by the way did not speak a word of english) back to to workshop. There we could not see the right markings on the barrel but he insisted on that it was the right one, suddenly he disappeared and we started to hesitate about the whole idea so we went back to the shop to say that we would leave. But the cashier just wanted us to wait so there we stood until the mechanic came back, it turned out that he had went away to get his glasses. Well back in the workshop again we soon found the right markings on the barrel and we agreed so he took an old oilcan and pumped up 3/4 of a liter in it. When we came out to the car Mario and Monica seemed really surprised looking at the old oil can. The mechanic was however very helpful and refilled the car. At the end we only had to pay 9€ so I must confess it was very service for the low price!
Mario brakes the locks
So first night in Bremen we carried the experiment up to the girls room just to be on the safe side and not leave it in the car. Well there Mario decided to check the status of the parts so he tried to open the box not knowing that it was in fact locked. However Mario is strong so in the close combat with Mario they soon gave up and went to thousand pieces. To bad the box was not ours but instead belonged to M-beam (who kindly enough have now let us continue to barrow the box). Somehow though Mario and Malin put the locks back together so even if they do not work any longer they are at least in the right place.
Well at the hotel we where asked if we where going to have breakfast there each morning since it was extra and quite expensive (9€ a day). I thought that we could just as well do so but the next morning i really regret my decision since the breakfast was definitely not worth the money. So the next the day we instead joined some of the other teams over to the central station where we found a great bakery where we had breakfast which tasted a lot better and was half the price. It ended up with us eating breakfast there every morning for the rest of the week.
Lost in Bremen
So last night in Bremen all REXUS teams went out to eat together. I convinced the others that we could just as well walk to the restaurant (yes I’m cheap, i did not want to pay for tram tickets). On our way we walked through the Christmas market and there I just stopped to get a good photo. Somehow though i missed that the others made a sharp turn so I continued straight forward and sone i realized that I was on my own. I called Malin and she somehow managed to get me on the right track. Soon however I could not longer recognize here description of the road so I tried to call Adam from ESA who somehow explained how I could find the others. Soon enough I once again where in the safety of the group.
Last day spent in the christmas market
Last day we spent an hour in the christmas marked. This was something we had been trying to do the whole week but since we had been working so much we had never had the time. So we took the chance to at least have a quick look on the market. It was definitely worth it, we goth a good view of the market and also went in to the cathedral which where very impressing!
So after criticizing the germans for not being able to speak very much english I where very surprised on our way home. Somewhere in the middle between Helsingborg and Stockholm we made a coffee break. First to order was Mario who made his order in english to the young girl in the restaurant. I must say that I was quite surprised when i realized that she where not able to reply and probably not understood very much of what he said either. I really thought that basic english skills where a part of every young swedes knowledge but this event proved me to be wrong.
So all in all we had a great week, even if there was plenty of work. We also managed to get good results on our tests and we are know back to work in Stockholm. As it seems most of us will have a couple of weeks well deserved vacation during christmas. But we will soon be back.
December 10, 2010 Leave a comment
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.
December 8, 2010 Leave a comment
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 !!!!
December 7, 2010 Leave a comment
So after a very busy and chaotic night it was time to leave for Germany and DLR in Bremen. We had decided to drive here and we had to leave on saturday if we were going to make it. The plan was to finish all the packing friday night and leave early saturday morning… However, it did’t go exactly like planed on friday, as you may have read. So at 1.30am we decided I wold go home to sleep so we could have one driver who had gotten some hours of sleep. It proved to be a good decision since the others got no, or almost no sleep that night. But we managed to pack almost everything and get going after lunch on saturday.
We rounded of the evening together with some of the other teams and some of the ESA, DLR and SSC personnel at a restaurant in town.
December 4, 2010 Leave a comment
Ok, so its well past the midnight hour on december the 4th and yes, the SQUID team is up and working at SPP, should i say as usual??? The hour for delivery has come upon us quicker than what we actually wanted and we don’t have time to invent a time-stopping machine, unfortunately (yeah like we probably could if we wanted right?? who knows, if you have the answer please call 3920539236289306235) ;P
Yes we are starting to get tired and so with tiredness the humor drops quite exponentially so this blog post should not be taken seriously, except for the parts which are serious of course.
What’s happening at this hour that still keeps us together, awake and here then?? well we certainly are not having a nice party, even if we laugh part of the time (due to tiredness ;P). No in fact we started preparing the experiment for delivery, yesterday (friday) and somehow the SQUID just does not want to travel to Germany and DLR (=PROBLEMS!!), even though it actually is a nice trip.
So all assembly procedure documents are precent and we have the parts and a ready for assembly…. point after point is checked off and the assembly of the eBox continues. Ok, good its done, nice HURRAY… now let’s just make sure it works…………………… there really are no words to describe the following set of events, but here is what happened. While running the test on the electronics we encountered that the read write procedure of our FPGA had suddenly, due to some cosmic far away strange black hole mystery thing which gave it and own free will, created and placed a random password upon itself. Now how can that actually occur??? but I am quite sure that if something would create and do something like that it would have chosen exactly this day, place, time and space project to annoy.
What we did afterwards is actually already described in the title. We decided to switch the flight eBox main board to the one inside our test eBox which should be identical according to specifications but of course it was not. Anyway the switch took place and about 45 minutes later when we had unscrewed all the locktited screws and everything and replaced it with the spare main board from the test eBox (and once again locktited the screws) we could conclude that something was fishy here as well. Fortunately Monica had soldered a new FPGA on the fligh main board while the rest of us were spending our time playing trivial pursuit with the other one (no one got a single piece of the cake). So doing everything backwards we now arrived at the point where we actually started off, but without the possessed FPGA this time so HURRAY success! And now let us test it….wait….wait…HURRAY it works!!!! Time to start working again, oooh how i have waited for this moment. I don’t really know how it is going over in the lab as I am currently sitting in a separate room (the library) and writing but as no one is coming here it can either be good news due to that everyone is busy with continuing to work and prepare for assembly… or bad news due to that some are working on fixing fishy stuff while others are sleeping.
No in fact we are finally making progress and I just recieved word from the BIG BOSS that Im soon needed so time for me to wrap up this blog post and join the rest for a coffee.