Stratos II colour scheme

The last months the Stratos II capsule team spent a lot time in finishing the design of the Stratos II Capsule. Finally last Monday they presented the final design of to all other DARE members.

The main purpose of the capsule is to provide a safe structure for the payloads and electronics and to bring the complete rocket safely back to Earth. The design of the recovery system was quite challenging, because it is the first time in the history of DARE that we need to recover a rocket from such a high altitude and mass. The solution the capsule team came up with is a double stage parachute system containing a disk gap band drogue parachute and a cross shaped main parachute. The disk gap band parachute will guide the rocket safely through the supersonic descent phase, while the main parachute will make sure that the impact velocity of the capsule will be lower than the maximum 10 m/s.

Stratos-II-parachuting-sequence

The capsule team looked also into the thermal heating of the nosecone. After the maximal heat load was found, it was determined that the maximal stagnation temperature that the nosecone will experience equals approximately 1000 K. To protect the capsule against these high temperatures during flight, the tip of the nosecone will be made out of steel.

Next to that all the different parts of the capsule have to withstand all the loads that will be experienced during the flight of the Stratos II. Therefore a structural analysis was performed/executed on all the structural important parts. As can be seen in the pictures most parts, for example the bulkheads, were put in a FEM software program to check their structural strength.

FEM on a bulkhead analysing the Von Mises stress

Finally a production plan was constructed since several different production methods, including 3D-printing and fiberglass filament winding, need to be applied to manufacturer all the parts of the capsule. After the Christmas holiday the capsule team will start with the production such that this design can soon be launched and bring the Stratos II rocket safely back to Earth.