The navigation of Stratos III

Project Stratos began as a way for students to break boundaries and eventually reach space. This July Stratos III will launch from Spain, having as a main objective to break the European amateur rocketry altitude record. Breaking this altitude record means that DARE will be a step closer to reaching space with a rocket designed and made by students. All this, however, would not have been possible without a working navigation system.

The guidance, navigation and control (GNC) subsystem is one of the main systems in aerospace vehicles, including rockets, which, as part of the name suggests, is used to guide vehicles to their desired location within a predetermined path while always being able to be controlled. Stratos III will make use of a navigation system, which means that for determining the trajectory of Stratos III as well as its altitude, this system is of utmost importance. For the navigation system to fully work, the communication between the rocket and the ground station needs to be noise-free and uninterrupted.

A way of knowing the location of the rocket is by means of a global navigation satellite system (GNSS). Stratos III is equipped with a GNSS receiver, which was kindly offered by our partner and sponsor Septentrio. Since Septentrio produces GNSS receivers that provide very high accuracy for a reliable knowledge in position, the exact position of Stratos will be estimated to the highest possible degree.

Another valuable partner that has made the development of Stratos possible is SES, which is the world-leading satellite operator. SES has been providing communication services to different entities ranging from broadcasters to governmental institutions.

Furthermore, Stratos will also be running an experiment onboard whose goal is to demonstrate real-time flight trajectory estimation and prediction. This will be done with the use of a Kalman filter to fuse the data coming in from the different onboard sensors in order to obtain an estimate on the current position and velocity of the rocket. This information is then given to the guidance sub-system, where a simulation program will then calculate the rest of the trajectory and give a prediction of the landing location. If successful, these tools could be used as part of a future Flight Termination Criteria or a navigation & control system.

On a final note, we would like to thank once again our sponsors SES and Septentrio for their help and contribution to Project Stratos. As mentioned before, the elements they provided were of high utility for the realisation of the navigation system.


By Aaron de Windt and Zyanya Rabilotta