REXUS-BESPIN

 

On Wednesday, the package with our experiment finally arrived, and it felt like assembling an IKEA cupboard or sth. (Ha haha because we are a Swedish experiment *ba dum tss*)

(face of the mechanicals)

 

Anyhow, we could finally start working for real and after a lot of small fixes to the outer structure (drilling new holes, widen holes and manufacture some extra parts for the ejection mechanism) we were ready to integrate our internal structure to the external one. To be precise, we were ready, Stefan wasn't because we had to do a full system test first, which means going through the full pre-launch and launch/flight time line and triggering all the necessary signals in all the experiments to identify errors in the system because until now, no team was able to test if their experiment would work with the other experiments in combination on the rocket, receiving and sending signals.

 

Good that we did that test, because we noticed that once we are unplugged from the REXUS power line and switch to our internal batteries, we give a lift-off signal to all the other experiments on the rocket. Which is bad. Really bad. After some confusion and more tests we weren't really able to identify the source of the problem and also the experts did not know where the error might stem from. So this is what we will spend time on in January.

 

 

Here you can see the internal structure before it got inserted into the external carbon fiber cylinder. On the bottom there is the PCB structure which is attached to the internal cylinder, containing the main and drouge parachute. The orange string (Dyneema) holds back the spacer which separates the drouge from the main chute. The drouge chute is deployed by means of a CO2 system (middle upper left, red/green) which is triggered by gunpower. The gunpowder explodes and pokes a hole into the CO2 cylinder (covered by black rubber in the upper left, next to the blue camera housing), the CO2 gets directed into the internal cylinder and blows out the drouge through a piece of aluminum foil. The main chute is then deployed by cutting the Dyneema 10s later, by means of a pyro cutter. The rest of the picture are mostly cables...

The integration hasn't been always easy...

 

Test engineers of ZARM fix the assembly (including the bulk head) to the shaker and attach accelerometers.

And gladly, we passed the vibration test. Yay!

Last but not least, a fit check has been done with the rocket's nosecone to clearly verify that we actually fit onto the rocket. And surprise, we also passed this test!