DARE – The Stratos IV Rocket

My name is Jasper-Jan Lut, electronics member of the TU Delft Dreamteam Delft Aerospace Rocket Engineering (DARE).

We are making the Stratos IV rocket. A hybrid engine design standing 8 meters tall that aims to reach an altitude of 100 km (see our previous posts). However, designing such a rocket does not come easy and electrical design solutions that would be considered excellent for standard applications are all of a sudden no longer valid options. Let me elaborate.

Upon launch, the Stratos IV rocket will accelerate with 8 times the force of gravity (8Gs) to a velocity of mach 5 making it move five times faster than the speed of sound. However, such an acceleration and speed will cause massive vibrations and stress on the electrical components inside the rocket. Requiring us to mount and connect everything extremely securely.

To give an example of a mounting problem we encountered. The Stratos IV rocket is a hybrid rocket meaning that it has a big tank filled with oxidiser and a solid propellant in the engine below the tank. These two sections are separated by our main valve.

This main valve is electrically controlled by a motor controller and because of safety reasons it is critical that during our flight we do not lose connection with our main valve. This is where the problem resides. The best commercial of the shelf motor controller available to us uses 2 pressure fit screw mount connectors on either side of the board. Normally this is a perfectly fine solution. However, it is not a connector rated for space applications and in our case the forces and vibrations of the rocket may cause them to detach mid-flight. (See included image.)

Our solution came in the form of a custom PCB shield that contains 2 vibration proof connectors which replace the pressure fit connectors used before. The PCB shield made by our long-term supporter Eurocircuits will be soldered on the motor controller allowing for a relatively simple solution to a critical problem.

The two images below show the vibration proof PCB shield, the motor controller, and the final stack assembly.

Special thanks to Eurocircuits.

With their excellent quality products, we are able to quickly design solutions to our problems.