Day 3 - The Launch Campaign

The day we had all awaited and worked towards had finally come. Having made the last preparations such as attaching the parachute to the satellite´s rods as well as tensely assembling our CanSat for the very last time, we were ready to leave for the launch. 

It seemed as if the weather conditions, namely a thick cloud cover at a low height as well as unfavorable  wind gusts, wanted to prevent our satellites´missions from being  carried out. The launch was delayed several times, which let our nervousness arise to an almost unbearable level. Nevertheless, we pretty much enjoyed spending time with the other teams whilst waiting.

Having passed the satellite´s last check, it turned out that we were to be the last team whose satellite would be launched with a rocket.

During the pre-launch, we already had to face the first problem as we were not able to properly align our antenna due to the steep descent to the rocket´s starting place, which we were able to solve by using a table increasing our antenna´s mobility.

The start signal sounded and we couldn’t help but watch the rocket disappear in the cloud cover, whilst detecting that we hardly received any data. We were not able to accurately track the satellite due to the missing mobility of our antenna as well as the impossibility to make out our CanSat´s position. During the landing, we finally received data again despite the long horizontal distance which allowed us to hand out it´s location measured be the GPS.

Since a successful recovery is crucial for our secondary mission, we were relieved when hearing that we were about to receive out satellite in the evening.

A long night including the analysis of any received data and the failure of our antenna as well as the gas chromatograhical analysis is ahead of us since the outcome of our mission is to be revealed in tomorrow´s final presentation.  

Day 2 - Test Flight and Initial Presentation

After the opening ceremony that took place this morning, we started to do the last preparations for our test flight. Before the test flight, each CanSat had to be completely mounted. There was also a safety briefing that made sure that everyone followed the most important directives, like the maximum height and diameter of the CanSat.

During the test flight itself, each team was expected to put up their ground support equipment in order to try and receive data from their CanSat. A so-called Flight Test Student Engineer was then flying in a sailplane and dropped the CanSat from a height of about 100m (the picture below shows ours as well as the UK's and Finland's Flight Test Student Engineer in front of the plane). Dependant on the outcome of this final test, each team got either a GO or a NO GO status. Those with a NO GO then had the opportunity of improving what went wrong and repeating the test.

Fortunately, we were able to receive our CanSat's data and could see very well that our parachute opened without any problems. The calculated descent rate was at 9.81 m/s which is perfectly following the directive of 8-11 m/s. The team that was responsible for the implementation of the test flights was as content as we were, so we got a GO at first attempt. Especially with last year's scenario of receiving no data at all at the back of our heads, this was very relieving.

In the afternoon, there was the initial jury presentation. Within five minutes, we had to present our team, mission, implementation, tests and everything else of importance. During the following five minutes of question and answer, especially our helix antenna and gas chromatograph attracted the jury's attention.

Tonight, we will be carrying out the very last preparations and finishing assembling our CanSat for the lauch that will take place tomorrow.

Day 1 - Arriving at Santa Cruz

The adventure has begun!

Having been through a flight of three hours from Cologne to Lisbon as well as a one-hour bus ride, we finally arrived at our youth hostel in Santa Cruz, a small town 50km northern of Lisbon, at about five o'clock in the afternoon.

After check-in, we were glad to arrive at a very nice apartment that has a lot of space and thus enables us to work really efficiently and all simultaneously. There is currently some preparation work to do for our initial jury presentation as well as the test flight that will take place tomorrow.

The next step for us was the registration at the airfield where the launch as well as all of the presentations, pre- and post-flight work will take place.

We took dinner back at our hostel and had the opportunity of meeting some of the other teams, like the Finns, the Irish and the Poles. All of the others were really nice so that we are now looking forward not only to a lot of work to do but also to a great time together with great people.

Breakthrough of our Gas Chromatography

During the last few series of tests for our gas chromtography, our results were quite ambivalently satisfactory and dissatisfactory. On the one hand, there were clearly identifiable peaks that enabled us to recognise the connection between a large surface area for low air humiddity and a small surface area for high humidity. On the other hand, the modulation of our mobile phase (replacing air as the carrier gas by helium) made our base line appear less even. The better the baseline, the easier the following analysis of the peak. Consequently, most of our ambitions were ever since oriented towards a solution to this problem.

Firstly, we identified the cause of our problem itself. In order to plug our helium support into its aspiration port, we use urine bags. Their capacity as well as structure is overall perfectly suitable for our purpose. There is only one thing that we did not consider early on: The tube that we connect to the aspiration port includes a check valve. While this slows down the stream of helium which is good because of our limited supply in Portugal that is much smaller than the one in our huge gas bottle at school, it also makes the stream only a little inconsistent and therefore the baseline uneven.

We then considered possible solutions. While removing the check valve altogether would make our use of helium go beyond the scope of our local supply in Portugal, given also that there is most likely no change of purchasing a sufficient supply, and while replacing the carrier gas or storage again would not certainly lead to an improvement in performance, the only chance was for us to fool the mechanism.

We tried out threading a very tiny tube through the check valve with the idea of keeping the stream of helium constantly up, but at a very low volume-per-time rate. The following experiment delivered the best results that we had ever achieved. Measuring a much higher voltage than before, we were able to change the experiment's zoom view which made most unevennesses disappear. We then created several new series of tests that can now serve as a data basis in the time to come.

At this moment in time, we are finally really satisfied with our gas chromatography and are optimistic to have it work smoothly during our post-flight activities at Santa Cruz.

Team Presentations

Information on the participating teams can be found here:
http://www.esa.int/Education/CanSat/2016_CanSat_European_competition_teams

Presentation of our Gas Chromatograph

In terms of gaschromatographically analysing our air simples, we are currently preparing several series of tests tests after having finished building it (see previous post "Improving our Gas Chromatograph").  As we have never had a gas chromatograph at school before, students, teachers and especially chemistry classes are very interested in this part of our secondary mission. Thus, we took the opportunity of giving a short presentation and answering all the questions that they had.
 

The final version of our Cansat's structural design is 3D printed!

Due to several printing errors as well as we measuring inaccuracies it was quite a long procedure to print our final mounting representing our structural design that is composed of 6 layers including 7 several parts that are stabalized by rods. The satellite´s CFK cover is to be cut to size as our sensors are placed at the border of the can which ensures realistic data measurements.The final structure enables us to directly reach several components. This has a far-reaching importance concerning the battery as an energy supply as well as our triggering mechanism that needs to be inspected at every juncture.

satellite, CFK case and parachute

 

printing the final layer of our CanSat

 

final structural design

 

The Countdown has Begun

We are happy to be able to announce that the first part of our team - our antenna - is heading towards Portugal. We would like to thank "Molitor Speditions- und Handels- GmbH" for sponsoring the transport of this really important part of our ground support equipment.

 

Improving our Gas Chromatograph

As mentioned before, we finished assembling and soldering our gas chromatograph some weeks ago so that it is now externally finished. Currently, we are testing and improving  it as well as adapting the mobile phase to our mission.

Gas chromatography uses the interaction of different chemical substances provoked by their chemical polarity or unpolarity. When a sample is injected, it meets two other substances. On the one hand, there is a inert or unreactive carrier gas, the mobile phase. The samples as well as the carrier gas stream through a column that contains the stationary phase, a microscopic layer of liquid or polymer on an inert solid support. Due to different intensities of the interaction of the individual substances of the sample and the stationary phase, these substances elute the column at a particular time for each compound. This retention time is characteristic of each substance so that  it is possible to investigate the composition of a sample as well as the quantity of the individual components based on this time.

Our own gas chromatograph is based on a self-construction kit made for educational purposes (e.g. chemistry classes at school) that suggests air as an inexpensive and easily accessible carrier gas. Obviously, this cannot work out for our mission of analysing an air sample. Consequently, we have replaced it by helium. Helium as an inert, unreactive and noble gas is usually the most commonly used carrier gas for gas chromatography. It is also very suitable for our particular analyse because air contains helium only as a trace gas with an amount of 0.000425% that is not that interesting for our particular investigation. Helium emerges at every radioactive alpha-decay. The tiny atom rises from the ground and as it is much more lightweight than the other components of the air, it can quickly escape the atmosphere and get into space. These circumstances make the gas quite irrelevant not only for our mission of investigating whether there is life "outside of earth", but also for someone observing the environment in the framework of climate change, air pollution and so on.

Having chosen helium as the carrier gas, we faced the challenge of adapting the gas chromatograph itself to the change of the mobile phase. While the stationary phase that is provided in the kit is unaffected of any modifications, the technical settings of the measuring device had to be adjusted. As the whole system is usually supposed to work with air, this constellation up to now has got the best performance in precision and error susceptibility. In the last time, we have experimented with different settings and are in close contact to the manufacturer of our self-construction kit so that we are now receiving pretty reliable chromatograms (although improvements are still to come). Using different equilibrium reactions involving calcium chloride, we prepared samples of different air humidity. When we measured the humidity with our sensor SHT15 and then compared it to our graphs, we were able to see a very clear tendency of a large surface area of the peak at low humidity and, the other way rund, a small surface area at high humidity. In the last few weeks before launch, we will expand this procedure and create more and broader series of tests in order to improve our experiment's scientific significance.

FDR and Team Interview

During the last time, we were busy drawing up, on the one hand, our Final Design Review (for a description of the CanSat design reviews, please see the previous post "Finishing our CDR") and, on the other, our team interview.

A "Meet the Team" section, including the team interview, can be found on ESA's website: http://www.esa.int/Education/CanSat/Meet_the_team_URSinvestigators

One question regarding the team's strenghts and weaknesses had to be answered in a video. Therefore, we created a YouTube channel (see https://www.youtube.com/channel/UCufdFMZZDnvg6qiVhIeaI0g). Besides the video that is there already, we plan to upload several videos on our test plan as well as triggering mechanism.