Thursday was the day of the second dress rehearsal for the Stratos II+ rocket and the final rehearsal before shipping to Spain. During the dress rehearsals the Stratos II+ crew practices all the procedures required to launch the rocket as they will be doing in Spain. By practicing all procedures as realistically as possible the team indents to catch errors and conflict and ensures smooth operations once the team is on the pad in Spain. While the first dress rehearsal focused on assembling the rocket and putting it in the tower, Thursdays second rehearsal focused on actually testing all the major systems.
Testing the flight termination system
Last year the flight termination system (FTS) caused a lot of trouble during the launch campaign in Spain. In order to prevent this from happening again the FTS has been completely revised.
The FTS was one of the key systems which was tested during this dress rehearsal. Because the FTS is not only one of the key safety systems but will also prevent the rocket from flying if it does not operate correctly, it is very important to test it and make sure the system works.
Testing the Flight Termination System
Tank heating system
Another system which was installed and tested during the rehearsal is the tank heating system. The tank heating system is used to heat the nitrous oxide in the tank prior to launch. This heating is required to help the system pressurize quickly. While the weather in Spain is generally favorable the tank heating system should speed up procedures considerably.
The tank heating system is comprised out of four IR lamps which you generally find at heated terraces. During static tests we use an electric heating system which somewhat resembles and electric blanket wrapped around the nitrous oxide tanks. It’s undesirable to have a heating system on the rocket because it will add mass and we would have to deal with another connection we need to detach before launch. By placing four IR heaters on the launch rail along we solved these problems. The lamps do not touch the rocket and do not require a complicated umbilical system keeping system complexity low.
Testing the tank heating system by heating up a tank of water