KSat Stuttgart e.V.

MIRKA2-HyEnD (Micro Return Capsule 2 - Hybrid Engine Development) is our second high-altitude experiment based on a rocket launch of the experiment. The MIRKA2 electronic system is the payload of a HEROS rocket, developed and built by the student group HyEnD. Like KSAT, HyEnD is a student group which is tied to the Institut of Space Systems of the University of Stuttgart. The HEROS rockets are developed within DLR's STERN (Student Experimental Rockets) program and launched from Esrange Space Center in Kiruna, Sweden.

The second launch campaign of the STERN program was scheduled mid October 2016 and took place until early November. There were two HEROS launches each with an approximate apoapsis of 30-40 km altitude.


Experiment setup with PCBs (blue), Iridiumantenna (yellow/brown/grey), GNSS module (light brown), battery packs (black), 3D printed mounting structure (white) and the interface plate (black) to the HEROS rocket

The contribution of KSAT to a successful flight will be an independent tracking system from the HEROS on-board electronics. Besides the GNSS data delivered, inertial measurement data such as acceleration and rotation will be provided to monitor the HEROS performance. The thermocouples, which are paced within the heatshield during the capsule missions, are attached to temperature-critical components during MIRKA2-HyEnD such as the HEROS on-board electronic RF amplifiers or the transmitters and power regulators. The MIRKA2-HyEnD electronics therefore serve as an independent monitoring system.

The conclusions which will be drawn from the flight results are used to validate the function of the satellite transmitter moving with high velocities and testing the new GNSS receiver (Ublox8/Navilock). Further minor design changes are tested as well.

The range test of the HEROS on-board electronics as well as the test for interference with the MIRKA2 electronics which are mounted within the tip of the rocket (black shadow) were successful. No influence between the two electronic systems has been observed. The MIRKA2 satellite transmitter as well as the HEROS transmitter fulfilled the expectations.


      HyEnD Bordelektronik     Reichweiten- und Interferenztest
      HyEnD on-board electronics                                       Range and interference test

After the experiment had been shipped to the Esrange Space Center, Kiruna, Sweden some rework of the activation mechanism had to be performed. Finally, the experiment was integrated under the rocket’s nose cone of HEROS III. Unfortunately, we were not able to send a member of our society to take place in the launch campaign, thus all reworks had to be performed by members of the HyEnD student team. Our sincere gratitude goes to those who worked on our experiment!

HEROS III mounted on the MPL rails in Esrange   

The HEROS III rocket was successfully launched on the 8th of November 2016 at 10:30 MET. The combustion of the hybrid rocket motor showed an excellent performance and the HEROS rocket’s on-board electronics worked as expected. The MIRKA2-HyEnD system was partly successful. The objectives had been to test the satellite transmitter during flight and fly the new GNSS receiver. After activation of the experiment, the system worked as expected. After the time delay expired, the satellite transmitter was activated and started to transmit the sensor data. However, only minutes prior to launch, communication was lost and could not be re-established. Apart from the communication failure, the system worked as expected. Sensor data has been sampled and logged for over 5 hours starting with the activation during integration and ending with the manual deactivation after recovery.


The GNSS module showed a solid performance and exceeded the expectations regarding the short “GPS-lock”. Every commercial GPS module is forced by international law to cease operation if a certain acceleration, vertical speed and sometimes height threshold is exceeded to prevent the use for military or criminal purpose. The yellow curve shows an interpolated trajectory path during the locked phase. Unfortunately, a flaw in the software led to poor formatting of the altitude values after a certain time. The brown curve shows an extrapolated path for the affected period.

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