With the launch site of the Stratos II+ rocket being situated in Spain and the team being based in The Netherlands, we need to get the Stratos II+ across Europe. A rocket of this size is not exactly something you would just put in the trunk of your car and drive off, as the size, amount of equipment and the duration of the three-day long journey being a logistical challenge. Both on Tuesday the 22th and Wednesday the 23th, the team worked around the clock to pack everything which needs to be transported to Spain. This includes the rocket itself including spare parts, all the possible tools both necessary to assemble the rocket and to make unforeseen fixes at the launch site. The launch tower is also disassembled and packed for shipping. Finally there is a whole range of support systems which are required for the launch, tracking and recovery of the rocket that need to be accommodated for.

Packing the combustion chamber of Stratos II+

In order to ensure that all components are shipped without damage and can be transported with ease by truck, we had special crates made last year by Holland Packing. Everything has a designated place in a crate and is properly fastened to minimize movement. On Thursday the 24th the truck started its long journey to the INTA launch site in Spain. While most of the hardware was en route, this however did not mean that work was done in Delft.

Simulation scenarios were still being calculated and analysed, and the last details for the launch planning were being finalised. After a week of anticipation, the first travel group of the Stratos II+ crew flew to Spain, followed by everyone else a few days later. Going to Spain with only a couple of Spanish speakers can impose communicational difficulties, especially if you get lost. Most Spanish people are as fluent in English as our members are in Spanish,  meaning that hand gestures and overly clear pronunciation are key. Unfortunately, they usually reply really loudly in Spanish making the whole thing quite funny but also a bit frustrating from time to time.

First flight group at Brussels airport

For some of us the journey to Spain was not the most comfortable one. The first group flew to Seville from Brussels on the 3rd but was forced to spend the night in Madrid. Luckily they had a fun time exploring some of Madrid’s party clubs. The second group had the misfortune of having to board the plane at 8am in Brussels, meaning they had to wake up at around 3am. Going against typical sleeping habits of university students it came as no surprise that everybody was pretty tired. Even though we hoped for sunny Spain, the weather on Sunday was both disappointing in Seville and at the INTA launch site with lavish rain showers. Despite these minor discomforts, everyone was overly excited to finally be in Spain and prepare for the launch.

Second travel group at the Madrid airport

Spain

As soon as everyone got comfortable in their cabañas (camping houses), the work started. The crates needed unpacking, the rocket and launch tower required assembly, and some last tests had to be performed. Today the 6th of October, a lot of important work is being done. Everyone is getting acquainted with the sun and the few people who were not present at the launch site last year, are getting acquainted with the surroundings as well.

The main plan for today is as follows:

• Finish unpacking the crates.
• The parachute has to be folded to fit into the rocket. This can be quite tricky, as it is important to fold and attach it properly to the coupler and the capsule in order for the parachute to open correctly for successful recovery. If you think doing laundry is hard, imagine folding two double sized bed sheets to fit into a small cylindrical box, with the final diameter not much larger than that of a two liter bottle and only half the height. While folding is expected to take 4 hours or more, it will only take a second to unfold.

Parachute folding

• The assembly of the launch tower is underway since yesterday and needs to be finished. All the parts are attached together and holes need to be drilled in the concrete surface of the launch pad to firmly attach the launch tower to the ground. This is heavy work and also needs to be done with high precision as the launch tower orientation is vital for the rocket flight path. Fortunately, the holes from the last year are still here and can be reused. Putting the parts together is challenging as well. Each part has a specific place in the tower, it is bit like a puzzle, for example each of the four legs is numbered and has to go to the right place. It is also important to make sure the tower is straight, this is checked when the launch tower is on the ground. On Wednesday or Thursday, the launch tower will be erected and checked for any curvatures again.

Launch tower assembly

• The rocket itself is assembled. All the parts need to be cleaned and correctly connected. It is important that the isolation is put in place properly around the propulsion and capsule as they need to be leak tight. One of the interesting parts of the rocket is injector, this is the part trough which, the nitrous oxide as oxidizer gets sprayed into the combustion chamber, where it burns the solid fuel. It is crucial, that this part is cleaned and joined perfectly, if there is any dirt/grease it might start burning and that would be bad.

Injector cleaning

• Perform a clamp band test. The configuration for the clamp bands changed a bit and therefore, a new test is needed. This configuration should be better than the one before. The clamps are used to release the parachutes at the desired moments. In essence the clampbands are a very simple release mechanism, it has only few mechanical parts and that is why it is deemed to be a very reliable one. The clamp releases two parachutes, one at the apogee (50km) and the other, main one at around 3 km (at 90% of the trajectory to the ground traveled). It is very important that this works correctly, so that we can retrieve the rocket.

Assembly of the clamband test

Lastly, we also tested the live stream today and found it be working great. You can find it here! Make sure to tune in for the preparations and finally on October the 13th for the actual launch.