The launch of the Rexus 16 from Kiruna on 14.05.2014 was a full success for the experiment and our team! Everybody was excited to see the rocket actually launch and monitor the live results and the livestream camera mounted to the rocket.

You can see the full launch campaign foto album here and a video (recorded by other teams) here.

Our experiment was in science, technology and teamwork a big success. We were able to show that the miniaturized sensors survive the rough rocket launch conditions and work properly in near vacuum.

All experiment requirements have been fulfilled!

The German Aerospace Center (DLR) has greatly improved the website on the REXUS project. Now you can find there more detailled technical information as well as two videos of launch and recovery of a previous REXUS mission!

“The launch vehicle is composed of an Improved Orion motor with exhaust nozzle extension, a tailcan, three stabilizing fins and a motor adapter with an integrated separation system. See Figure 1. The total mass of the rocket is around 515 kg comprising a propellant mass of 290 kg, motor and vehicle hardware of around 125 kg and a payload mass of around 100 kg. The total rocket vehicle has a length of approximately 5.6 m depending on the size of the experiments and the diameter is 356 mm. The standard configuration of this payload comprises the recovery module, the service system, an ejectable nosecone and two experiment modules. The mass of each experiment module structure and bulkhead is approximately 5 kg. The total available mass for the student experiments is normally about 30 kg.” (DLR)

http://www.dlr.de/irs/en/desktopdefault.aspx/tabid-4363/7110_read-12143/

This is our box for all the boards we need. It is easy to demount in case we have to work on the boards very fast. They regulate the power, controll heating of the sensors and handle the measured data.

It sounds simple, but it took a long time to design the PCBs (Printed Circuit Boards). After that there was a loop of testing and redesigning pass trough to come to the current design.

Our experiment module, provided by the DLR, has arrived in Dresden. We are going to re-use the bulkhead from the previous TUD Rexus team, CaRu. CaRu was launched on Rexus 11 and researched the influence of milligravity on the creation of Runge pictures, which come to live through the combined effects of capillarity and a chemical precipitate reaction.

We are currently waiting for some manufacturing parts from the TU workshop and the delivery of several commercially available parts. After all necessary elements are assembled, the vibration test will be performed under Nathanael’s management.

Due to the fact that some critical components are vertically arranged within the module, they are susceptible to vibrations during takeoff. It is necessary to ensure that these parts are not excited at their resonance frequency. We plan to measure the resonance frequency of this component, therefore we need to place several sensors at specific positions of our module.

On 11. september we had our IPR (Integration Progress Review). First the team leader Alexander Mager and Bastian Klose (responsible person of electronics) had a talk about the current status of our experiment and what we planned to do next. After the visitors Dieter Bischoff and Simon Mawn from ZARM and Alexander Schmidt from DLR-Moraba introduce themselves, we discussed the project status.

So we could report that all prefabricated parts and boards of electronics are ordered and a critical vacuum test is realised. The next time the placement is going to starts and the complete system should going to be tested.

Also the software is as far as complete and tested except the test for the software code with the complete hardware and the communication between software and Rexus-Service module.

The drawings of our mechanics part are delivered to the fabrication. Next we are going to assemble all parts and going to test the function. In addition we are going to make some vacuum, vibration and thermal tests. Currently, the launch campaign has been scheduled for May 2014!

Finally hot Summer has arrived in Dresden. Nevertheless we want to proceed in our rocket project. Here you can see the mechanical Teammembers discussing detailed parts of our rocket module. Hatch things are clear, the electronic box and other little stuff too, but we improoved our inner measure project and so there are a lot details to discuss. Pressure sensor mounting is also still in progress but we think we have found a good solution with a local distributer: check out their website if you want to: Schwiedaem

The development of our software has been under great progress. With this groundstation we can test our electronic components. This interface is as well important for our launch campain. We can see if the sensors work correct, if the Hatch opens correctly and can see all values of the temperature and pressure sensors.

Also the Microcontroller Software, written in pure ANSI-C, has done great progress. Altough there is not much more to see than blinking lights at this point, you can see the development using the IDE (CoIDE) for the Microcontroller we choose, an STM32F103 with 72 MHz.

Of course it is necessary to simulate the environment to adjust the experiment parameters. A simulation using SimuLink has been performed to analyze the heat loss of the sensors during flight to determine the correct control parameters. We will most likely use a PID control.

All software from this project is licensed under a Creative Commons license. Why? To support fellow and future Rexus Teams.