FENRIR (Free fall Experiment uNit for Reduced-gravity Investigations and Research) is a student experiment based at LTU, which will fly on board one of the cycle 15 REXUS rockets in March 2025. It offers an easy-to-use platform for future free-falling experiments that need to be ejected from sounding rockets. A free-falling unit (FFU) will be ejected from the rocket just before its apogee (∼ 80 km), ensuring about 70 seconds of reduced gravity. To increase the quality of the reduced gravity conditions, an attitude stabilisation system (ATSS) consisting of three reaction wheels will also be included in the FFU. Students aiming to conduct micro-gravity research are seen as potential end-users: thanks to FENRIR’s apparatus, they will have the opportunity to focus only on the mission’s experiment and accompanied electronics, without having to design the entire structure from scratch.

OBJ1

Develop a platform for sounding rockets to eject and conduct free-fall experiments.

OBJ2

Demonstrate that the FFU can be ejected from a sounding rocket in flight.

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Demonstrate that the FFU can be recovered after ejection.

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Accommodate payloads of future sounding rocket experiments as an open-source platform.