Secondary mission
We have two secondary missions: using airbrakes to reduce the descent velocity by increasing the incident surface with air and estimate the distance between our CanSat and other RF sources by measuring the signal strength
the airbrakes
The first secondary mission consists of reducing and adapting the descent velocity by increasing the incident surface of the can with the help of airbrakes.
This prototype consists in the deployment of the vertical sides of the can which are subdivided into two independent parts.
These parts are going to be attached to the inferior side of the top plate by an integrated hinge. Two linear steppers placed symmetrically will push those sides outwards. To do so, two U-shaped pieces that we designed are going to interlock the moving piece of the actuators. Those “U’s” are going to be equipped with an extension that will allow an axis to pass. Another extension will be on the sides of the can. A stick is going to link those two extensions, deploying the airbrakes when the actuator moves.
The sides of the can are cut on the edge to let it turn. Four holes are made to let us insert the axis in the hinges. A rectangle-shaped parts is also taken away to avoid a collision between the extension of the upper part and the side of the can. The linear steppers are SM0804’s. Those steppers are going to be controlled with a DRV8834. They will work in parallel so they can be deployed at the same time.
the radio communication
The second mission is to use the radio communication to estimate the distance between our Cansat and other RF sources (beacons, other CanSats…). This means measuring the received power and use these differences in signal intensity to get an estimate of the distance during the flight. To do that, we are using: