- is a 1U cubesat from Aalborg University
- is designed and constructed by students
- is a PBL based engineering study
- is from Department for Electronic Systems
- is launched as part of ESA's Fly Your Satellite Program
- is our 1U cubesat number 4
- is soon coming to an orbit near you :-)
Test campaign at ESTEC
The purpose of our stay at ESTEC is to expose AAUSAT4 to two different environmental tests: a thermal vacuum test and a vibration test.
The purpose of the thermal vacuum test is to place AAUSAT4 in an environment like the one present in orbit. This means placing AAUSAT4 in a thermal vacuum chamber which can pump out all the air thus creating a vacuum, and then also heat and cool the satellite while it's inside. The satellite will undergo several hot and cold cycles like it would in space. While these thermal cycles are performed we will be monitoring the health of the satellite by performing small functional tests which are designed to test all satellite functionalities work as expected.
The vibration test will expose the satellite to g-forces and vibrations it will experience during the rocket launch in to space. This will be done by placing the satellite on a shaker which is able to shake the satellite at specific frequencies with specific loads (g-forces). We will be performing functionality tests both before and after in order to establish the health and functionality of AAUSAT4.
140711 Day 4 at ESTEC
With the satellite already at 0 degrees we were already well on our way to reach the minimum non operational temperature of -20 degrees. Most of the day was spent on waiting for the temperature to first settle at the minimum non operational temperature and afterwards get it up to the minimum operational temperature (at -10 degrees). At this point a new RRFT was performed in order again establish the health and well being of AAUSAT4. While the RRFT was passed without any problems, we encountered some discrepancies during temperature readings.
In this case it was a temperature sensor on one of the sides that was giving a reading outside of the acceptable range (a difference of over 10 degrees). Also an internal temperature sensor was giving a reading which was outside of the expected range (over 2 degrees). It was concluded that the non acceptable reading of the side was due to a wrong bias (the sensor not being callibrated correctly), which we will be able to handle after the thermal vacuum test. For the internal sensor the difference was attributed to the subsystem being in thermal transition. We had just turned the subsystem on, prior to making the reading so the temperature sensor under test and the control temperature sensors were giving different measurements do to th distance between them. So in reality the reading is most likely thermally delayed.
After these non conformances had been reported the day was at an end, and we turned off the satellite and the thermal vacuum chamber was set to ambient temperature for the weekend.
140710 Day 3 at ESTEC
So after a night in vacuum we were eager to see if AAUSAT4 was still well. The thermal vacuum chamber had reached a pressure of 10 nanobar during the night and by visual inspection the satellite seemed okay. We proceeded to start the hot cycle.
The goal of the day was to reach the maximum non operational temperature (55 degrees), stay there for 1-2 hours, then go down to the maximum operational temperature (45 degrees) and do an RFT and then go down to 0 degrees preparing for the cold cycle to be done next day.
The maximum non operational hot temperature was reached faster than expected, using only 3 hours. We dwelled there for a little over an hour and then proceeded to lower the temperature down to the maximum operational temperature.
At this point we performed a "Reduced Reduced Function Test" (RRFT) which is a reduced version of the RFT in order to save time. The RRFT test only takes between 15-20 minutes to perform where the RFT takes between 35-40 minutes to perform. This RRFT was done succesfully. However, we encountered a peculiar result. The malfunctioning temperature sesnor from day 2 was now reading temperatures in the correct range. From here we decided to not do anything about it and see how the temperature sensor will act in the coming days and temperature cycles.
After the RRFT was done and passed during the hot cycle, we set a new set point for the thermal vacuum chamber at 0 degrees, where it would dwell for the night while AAUSAT4 would be turned off.
140709 Day 2 at ESTEC
The day started off where the other left off. Basicly we were to finalize all of the integration of AAUSAT4 in to the thermal vacuum chamber. While it had been established that we could charge the satellite and monitor voltage, we still did not know whether communication was possible through wire or radio.
We attempted to perform a RFT with the satellite hanging inside the thermal vacuum chamber with attached wire, but with the door still open. However, it was not possible to communicate with AAUSAT4 via our groundstation. At first we were concerned that the cable through which we were attempting to communicate was too long, though the cable was tested at AAU.
It was established that it was a simple case of using a wrong software version for the groundstation. A quick restart with the correct version and we were able to do an RFT. During the test we discovered that one of our temperature sensors on our side panels are giving incorrect readings. When working with ESA this means that we had to submit a "Non Conformance Report" (NCR) explaining what was wrong and what action we recommend be taken. Since the component is not mission critical we recommended that the test should proceed.
After the RFT was done we could now close the chamber. Before the thermal vacuum test could be initiated though, we were to have Test Readiness Review (TRR) which is a meeting that will establish if the test is allowed to be initiated. At this meeting we had the ESA education department personel and the test facility personel present. The status of AAUSAT4 was reviewed, as well as the integration and the NCR with the faulty sensor was discussed. It was finally agreed by all parties that the thermal vacuum test could be initiated.
Directly following the TRR we started pumping out air of the thermal vacuum chamber and which will establish an environment with vacuum but ambient temperature levels.
When we reached an acceptable vacuum level (in this case 90 nanobar), we did a new RFT to ensure that AAUSAT4 was still functioning. After the good health of the satellite had been establiblished we (and the satellite) were ready for the first hot temperature cycle. However, the day was at an end and the AAUSAT4 was turned off and left in vacuum during the night.
140708 Day 1 at ESTEC
After a long nights drive we arrived at our Bed n Breakfast at 1:30 in the night only to be at ESTEC the next morning.
Upon arrival at ESTEC we were greeted by the Fly Your Satellite! team who are going to be helping and overseeing us throughout our stay at their facility.
Almost immediately we went to the testing facility with all of our equipment and of course our satellite AAUSAT4. The first test we are to perform is the thermal vacuum test. So most of our first day was spent on establishing a testing station beside the thermal vacuum chamber. After the testing station had been established it was time to turn our attention to AAUSAT4. It had been almost a 9 our drive here, so it was of great interrest to perform a visual inspection of the satellite and also to perform what we call a "Reduced Functional Test" or "RFT". The RFT is a test designed to quickly establish if AAUSAT4 is in good health and that nothing is broken (electrically). The visual inspection did not show any signs of damage from the trip, and during the RFT only a few kinks were encountered which were caused by issuing a wrong command during the test. But the RFT was also passed and the satellite was in fact in good health after the long trip.
After these initial tests the satellite was intergrated in to the thermal vacuum chamber. This meant hanging the satellite in suspension inside the thermal vacuum chamber and attaching electrical connections through wire to monitor the satellite health. During this thermal vacuum test the satellite will primarily be operated by wired electrical connection, but we will also be testing the radio communication and attempt issuing commands by radio.
Finally after the thermal chamber integration it was established that our most basic electrical connections to the satellite worked and that we could charge the satellite batteries through wire. At this point it was late afternoon and it was time to go home to our hotel.
As of July 2014 we are now in test at ESA/ESTEC. Follow news below.
140707 Test at ESTEC
The team has now started testing at ESTEC. It will last until July 25th so that will our best tested cubesat ever !
140708 - Updated sponsorlist
To put it very short - Without sponsors no satellites !
- Gold++ Sponsor
- Sparnord Fonden
- Gold Sponsors
- Marel Denmark
- Hytek Aalborg
- Silver Sponsors
- Bronze Sponsors
140707 - On way to test AAUSAT4
Now the team has lelft Aalborg heading ESTEC in the Netherlands.
AAUSAT4 will tested for 2 weeks at ESTEC's pro facilitites.
We will come back with more news the coming days.
140313 - FYS Phase 2 Kick-Off Workshop at ESTEC
Yesterday we had our first day of visit at ESA for the kickoff workshop for FYS phase 2. We heard a lot of people present the different tests that AAUSAT4 and AAUSAT5 are going to undergo. The tests are mainly a thermal vacuum and vibration test. The picture below shows one of the big vacuum chambers that ESA has in their laboratory.
140207 - ESA Phase 1 Review
We have now come through af number of RIDs and have now the best documentation we have made on any our satellite - thanks to ESA. The documentation has now to pass a Phase1 Review at ESA.
131203 - October Assembly of AAUSAT4
During the assembly of AAUSAT4 back in October a lot of pictures were taken. These pictures have now been combined to a gif, showing the steps of the AAUSAT4 assembly procedure.
As you can see the whole stack is assembled and is operational before integration in the Frame. The modular structure of the AAUSAT4 eases development both in the early and later stages of the project.
131125 STATUS - 100 days
Since August we have upgraded an documented AAUSAT3 according to ESA requirements.
We do call it AAUSAT4 and will fly a modernized version of our AIS receiver which has shown very good performance on AAUSAT3. Furthermore an upgrade of our ADCS system and removal of our static ADCS (read magnet) will give an even better performance - we hope.
So all are very tired but also happy with the result.
As time of writing - June 2013 - we are happy to announce that we have been pre qualified together with five other cubesat projects to be on ESA Educations cubesat flight.
We hope we can fulfill their requirements.
The first workshop at Estec is 26-28. June 2013 and we will be there :-)
If you want to ... build satellites as part of studying for electronic engineers we have room for you this autumn :-)
Email us and lets have a discussion
Jens(jdnATes.aau.dk) and Jesper(jalATes.aau.dk) - management
FM is based on AAUSAT3 HW and SW. AAUSAT3 has gained flight heritage since 25. February 2013 and we are happy to say that all our sub systems are working beyond expectations.
On AAUSAT4Background is why we - only 100 days after launch of AAUSAT3 - is very close to FM for AAUSAT4 and an ESA launch.
This has been a very pleasant surprise for us and has given birth to our fourth generation of space students - mainly from 6th semester.
Stay tuned for the coming weeks :-)
So until further notice please visit AAUSAT3 for a description of AAUSAT4.
AAUSAT4 STATUS 20130809
The AAUSAT3 mechanical design is currently being updated for the AAUSAT4 mission. Changes includes simplification of production and integration, and solar panels on all 6 sides. Hence we have to change the frame and the antenna to fit the 1U height, why not make some performance enhancements to the antenna. Spoiler alert: Will AAUSAT4 include antenna (polarization) diversity for AIS?
For more information please contact Jens (jdnATes.aau.dk) or Jesper (jalATes.aau.dk)