Today the focus of the blog post will be on the flight termination system (FTS) of the Stratos III rocket. We decided to tell you more about this component as just today we found out the delivery of FTS is delayed which significantly influences our plans for the launch. We initially planned to launch the rocket on the 18th of July but we are now forced to move the first launch attempt to the 24th of July at 20:00 CEST.

A digital model of the engine bay including the FTS.

The flight termination system is located in the engine bay which is the section between the oxidizer tank and the combustion chamber of the rocket. Although the FTS system is a very small system of the launcher in terms of size, it is of utmost importance to ensure a safe flight for Stratos III. During the flight we will constantly monitor the rocket. We can see its exact location with radar and have visual tracking to we can see how the flight is going. To make sure that our flight is safe a large part of the sea and airspace are closed off, meaning that no boats or airplanes are allowed in this area. This area is called the safety zone. The size of the safety zone is based on simulations which take into account different wind conditions.

When we see on the radar that the rocket goes off course and could fly outside of the zone, a signal is send from the ground station to the rocket. When this signal is received, a cord in the engine bay separates the engine from the rest of the rocket and breaks the vehicle into pieces, ending the flight prematurely. After this, parts of the rocket will tumble down and land within the safety zone in the Atlantic Ocean.

Stratos III electronics team working on the flight termination system antennas.

As you might think, a system like the FTS must be extremely reliable. The type of system we use on the Stratos III is very similar to systems used on the rockets by NASA. The two antennas that are sticking out of the rocket are the FTS antennas that receive the signal from the ground and give it to the receiver. As the radio signals cannot be transmitted through the carbon fiber fincan, the antennas are sticking out of the side of the rocket.

The antennas and receiver system were tested successfully on Thursday, remarking another milestone in the project. With the flight termination system in the rocket, locals living close to the launch base or sea traffic can watch and enjoy the launch of Stratos III without any worries.

by Fabio Kerstens & Jesse Hummel