Final tests!

Good morning!

After few days of intensive working, fixing some bugs and problems that we discover, and preparing the experiment, we are ready!


Status white board of REXUS15 rocket

However that doesn’t mean that now we are free :(. Today we have the whole day full of flight tests, cold and hot (without and with firing pyro-cutters). Moreover, today is the last time when we can access inside our experiment since all the payloads of the rocket will be assembled today!!!

Finally, now we are finishing some testing before the hot count down that will be in few minutes. Then, if everything was fine for all the teams, we will say bye to our experiment until it is recovered after the launching. But don’t panic, we will be in contact with it through the communication systems 😉

Vi ses!


When engineering and art meet

Some time ago we show you in here our work on the PCBs, and today, I want to bring it up again.

Past week the electronics team had been working in finishing most of the schematics and the layouts of all our units, mainly the RxSU. More in detail, I have been spending my time on the RMU PCB. I know that experts can complain and some improvements can be done, but I think that it is good enough for being my first one. It also may not look really nice, I’m not an artist! However, I like it, it’s my little baby. But by finishing it we are not done, a lot of work is still remaining, and tomorrow a new day will come, where we will be working on other PCBs and/or firmware while our friends in the mechanical team play with heavy machinery making holes, sanding or cutting metals.

Finally, after a long path working on ‘paper’ we are getting close to have the real stuff to play with. The real stuff that we aim to launch into the sky.

And as if a proud father I were, here is a photo of my baby.RMU PCB

History of binning a picture

Dear followers,

After a very long time, we finally managed to solve a simple problem, perform an on-live 4×4 binning to the pictures taken from the camera. This process is quite simple, we just need to take the pixels, make the columns binning by summing up each 4 of them and storing them into a FIFO queue (First Input First Output). Then, when the next line of pixels arrives, it is just to add them as before and add to them the previous 4 and store them again. After 4 times we have a full line make of 4×4 binned pixels. Then, it is just to save into our memory and later one retrieve the picture for plotting on Matlab.

Okay, once you get the concept, it is easy, isn’t it? However I was fighting a problem, the pictures were always wrong, the pixels shifted and strange values where in all of them. I checked the algorithm hundred of times, I discussed with other people about it in order to find the error, I tested it in different ways, and it was okay but some small issues. However it didn’t work, it was frustrating! Indeed, time was running and it wasn’t working yet.

Fortunately, few days ago, during a long simulation on ModelSim (a special software for checking the VHDL firmware without loading it into a device) shows something unusual. At one point, a COST component, generated by the tool that I was using for designing the firmware got an unexpected value. That gave me the key! This COST component was the FIFO, the same in which I was saving the values before sending into the memory. It wasn’t behaving in a normal mode. After that, I decided to make some modifications on that component, which shall be said, has been used successfully in different projects. The point is that we have a lot of free space in our FPGA but a small amount of RAM memory, which is used to build up the FIFO. For this reason I decided to use FIFO sizes different from a power of 2 (in digital electronics, that is magic). That strange manipulation is possible and the tool says that it is supported, however, after changing the size values to a power of 2, by wasting some RAM on it, the binning got life! The problem was solved!

Now, we have to keep working and take the next steps, we already have lost a lot of time with this bug, but now we know that this bug exists, and we can take care about it. However, and even after the fact that now the binning it’s working just by changing in there, I would like to double-check that the error is in there and if after that we think so, report it for the sake of all possible engineers which are dealing or will deal with the same problem.

And as a prof of that it works, here is the first picture taken with the binning fully operative!


Okay, it’s not the best picture ever, National Geographic won’t use it but remember, we will use this camera for tracking a powerful light, not for taking team pictures! or maybe…..

Running out of battery

Or at least that is the feeling in part of the electrical team this week.

The electrical team is currently formed by 6 people, Kevin, who spends his time in playing with our infra-red system. Georgi, who has been including an small component into the system libraries for using it in our PCBs. Babak, Ruslan, Jiazuo and me, Jorge, all we have been spending part of the last week and what is gone of this, which isn’t still over, fighting for 5 minutes more of sleeping time. And maybe you are asking yourself, “why is that?” (others just are thinking that we are lazy…). The reason of this is really simple, all we are in the same master programme, and unless one course, we have the same this period, which can be said, is the harder one in academic load in our master with around 25 credits instead of the usually 15. The point is that this week we have had to submit two different assignments and still tomorrow we have to submit another two more, and just to make a whole day, a presentation of one of those assignments. So, with 4 assignments in 3 days, and having access to start some of them less than one week ago, sleep time has become a valuable good for us….

However, if you have been following the REXUS project, you may be noticing that something is missing, and you are right!, Murphy is with us! Yesterday we submitted our SED v3.1! In this one we addressed several comments mainly in the formatting and we expanded our explanations in some chapters since ISAAC never stops! Fortunately, we have a really good team which supported us with the modifications and also addressing some of our supervisor comments. Thanks to their help, it can be said that we ow them at least 1 or 2 sleeping hours!

Thank you guys!



Hej again!

Yesterday we had the IPR (Integration Progress Review) conducted by Mikael Inga from SSC (Swedish Space Corporation) in our place at KTH. After several hours explaining him all our experiment, and the status of each single part of the work. We review with him all the points, got comments and suggestions from Mikael and now, we are starting to work in processing and addressing them.

However ISAAC is changing faster than that! But don’t worry, I don’t mean changes in the design, or at least big ones. I just mean that again, we have three new members in the team. They are going to help us with all the electronics, specially with testing but also in finishing some details in the design. All they are my partners from the System-on-Chip master and will stay with us until the end of the year, at least!

The work division haven’t take place yet since they are still reading through our last SED version learning not only what is done or expected in the electronic side but also in the full project. Indeed they are asking about some design decisions, forcing us to think over them again and confirm why they were taken. I have the feel that they will mean a good boost for ISAAC, not only in electronic but in the full project.



Movements on ISAAC

A new semester is starting here at KTH and a lot of new exchange students are spending their first days walking around and learning as much as they can about this new life they are living.
We, ISAAC, knew about that and we did our movement. Before summer some of our team members left us after doing really good work, but we still need hands, and a new one is always welcomed. For this reason we started to look for and we have found three new ISAAC members. They are one mechanical and two electronic engineers. And they are:

Georgi Olentsenko, from Estonia, who is studying electronics and will work with the tracking system.
Kevin Mead, from the US. He is going to start the Electrophysics Master at KTH, so he will take care about the infrared spectroscopy and the optics.
And Ernest Company, who will work on the mechanical side ensuring the proper balance of both FFUs.

All they are really excited to join us in a project like this and we know that they will do their best on their works.

Unfortunately not all are good news in ISAAC, few days ago one of our bachelor students, Emil, let us after finishing his summer job with us. He worked on tracking and Georgi and me will follow his steps. So from here we want to wish him the best.

Long day

Today have been a long day, very long indeed. All we are working preparing the CDR, updating again the SED document and finishing all our designs, but that has nothing special at all since it is our project!

Today have been a long day since all we have been looking at our screens, following the REXUS 13 launching campaign. As probably you know, in the REXUS 13 will flight our ‘big brother’ MUSCAT. We have talked about them to you several times, we will follow their steps using some of their designs, ideas, lessons learned….

However today we were looking at our screens waiting for their launching not for those reasons but because they are our friends. And it has been a long one since they had scheduled the launching today at 11 am but due to the weather conditions they have been waiting with all the other teams and the Kiruna crew for a break in which launch the rocket. Delaying the last 15 minutes count down each 15 minutes first, then each 30 and then, an undefined time until it was finally postponed. Unfortunately, the next launching window has been rescheduled for tomorrow at 6 am. It means that the count down will start around 3:45! From here we, all the ISAAC team, want to wish them the best and we hope that tomorrow morning the weather gives them a break and they can finally launch.

Good luck tomorrow!