I have a dream: visiting the three spaceports in Florida, Kourou and Baikonur, at least once during my lifetime. The pleasure to tour Kennedy Space Center I had already in 2010/2011. Now I am another step closer to fulfill that dream. The European Space Agency ESA had invited me to a press tour of the European spaceport Kourou, or Centre Spatial Guyanais (CSG), how it is called in French, in French Guiana in South America. Many thanks, ESA Germany und ESA Space Transportation.
The purpose of the press trip was to inform about the progress made with the new launch complex and first hardware for the new European launcher Ariane 6. Thus a main part of our program was to visit the construction site of the launch complex for Ariane 6 – called ELA 4. The visit started with an introduction to Ariane 6 and the launch complex by non other than ESA director for Space Transportation Daniel Neuenschwander.
During the tour of the launch complex we had the opportunity to interact with several experts and leading engineers of ESA, CNES and the involved construction companies. Several companies based in Germany are taking part in the construction of the launch complex like MT Aerospace and DONGES SteelTec. I had the privilege to talk mainly with Jean Michel Rizzi, who is in the very important position of being the ESA Ariane 6 Launch Base Lead Engineer. During the talks with him and other experts a lot of information the ELA 4 launch complex was gained.
One of the interesting questions that where answered is why it is actually necessary to build a new launch complex for Ariane 6 and do not use the one for the Ariane 5 launcher after some modifications. You could argue that Ariane 5 and Ariane 6 are quite similar at the first look and therefore no new launch complex is necessary. Constructing a new launch complex does not come for free, it costs a few hundred million Euros.
The situation is much more complicated than you may think it is. One of the main goals of the Ariane 6 program is to reduce the costs for launching payloads into space significantly (by 40-50 percent) in comparison to use Ariane 5 for that purpose. There are many ways to reach that challenging goal. Reducing the costs for the production of Ariane 6 hardware is of major importance. Another important aspect is to minimize operational costs like costs for actual launch preparations. Launch preparations for Ariane 5 at CSG are taking typically three weeks or more. Two relatively tall halls are necessary for these preparations. Processing is done vertically, the main stage of Ariane 5 is erected already for it. In the first hall called BIL the launcher is integrated. The two solid rocket motors are connected with the core stage and the upper stage is mounted on top of the Ariane 5 core stage. All this processing takes place with Ariane 5 standing at the mobile launch table.
As a next step the Ariane 5 on the mobile launch table is moved to the building for the final assembly, the so called BAF building. Here the Ariane 5 is intensively checked before the payload fairing with the payload inside is mated to the launcher. Additionally, all kind of connections between launch table and launcher are made, like umbilicals for power, data, fuel and air to ventilate the payload inside the fairing. Finally, just one day before launch the mobile launch table with the fully assembled Ariane 5 on top is moved to the launch zone of the ELA 3 launch complex.
These prelaunch processing steps for Ariane 6 in comparison to Ariane 5 were optimized to minimize duration and costs. Tall buildings, for instance, are always generating high costs during construction and maintenance. Air conditioning of tall buildings is cost intensive, too. Additionally, working horizontally has several advantages in comparison to working vertically as was learned due to the introduction of horizontal processing for the Soyuz launcher in Kourou. The access to the launcher is much easier and interactions between the engineers are improved as all of them are working at the same level. Therefore it was decided to perform most of the prelaunch processing of Ariane 6 horizontally. Basic launch preparations of Ariane 6 core stage and upper stage as well as the mating process of these stages will be performed horizontally in an assembly hall called BAL.
For the Soyuz launcher not only core and upper stage are mated horizontally in Kourou, the four boosters are mated horizontally as well. This is possible as the Soyuz boosters use liquid propulsion and are obviously not filled with fuel during the mating operations. That is contrary to the solid rocket boosters of Ariane 6. These will contain more than 140 tonnes of solid propellant and cannot be mounted horizontally. Bending loads during the erection process of the Ariane 6 core stage with attached boosters would really be huge. A heavily reinforced core stage would be necessary for this. Obviously that scenario has to be avoided. Thus, only the mated core and upper stage of Ariane 6 will be transported from the BAL building to the launch table in the launch zone, again horizontally. After arriving near the launch table the central stage will be erected vertically.
For mounting the solid rocket boosters and the fairing including the payload a Mobile Gantry is used. For this the Mobile Gantry is moved on rails to cover the launch table with the launcher on top and the service mast as well. Inside the gantry a crane and nine levels with retractable working platforms can be used to have access to the launcher or to install equipment. The solid rocket motors arrive vertically at mobile platforms to be mounted to the core stage inside the gantry three days before launch. Next is to attach the payload inside the fairing to the launcher. This so-called upper composite is lifted by a crane to the top of the upper stage for mating. Connecting lines for power, data, fuel and air between launcher and service mast or launch table is another task to be performed inside the gantry. Note, that this impressive 90 meter tall and 8000 tonnes heavy Mobile Gantry is one of the biggest mobile buildings of the world. It is relocated to a safe distance only hours before the planned launch. After fueling operations have finished the Ariane 6 will be ready for launch soon after.
In this way the launch preparations for Ariane 6 are expected to take only 9 days in comparison to 21 days for Ariane 5. Additionally, several procedures and tests will be automated. This will help to minimize the size of the launch team.
Note, that the strategy to have a mobile gantry has consequences how the launch zone has to be build. All areas where the gantry can be relocated to need a very stable and heavy base to carry the weight of the gantry. That includes the launch pad area. Here the 8000 tonnes of the gantry, 650 tonnes of the launch table and up to 860 tonnes of the launcher (A64 version) need to be carried. Therefore the construction of the affected area is very robust with ten thousands tonnes of concrete and thousands of tonnes of steel applied. Apropos steel: the launch table is a steel construction made in Germany. The aerospace company MT Aerospace/MT Mecatronics has contracted the company DONGES SteelTec to build the table. It was finished already and is expected to arrive in Kourou these days via ship.
How was the status of the ELA4 launch complex during our visit end of January 2018? We got a good impression of all the concrete and steel necessary for this construction, especially for the two flame trenches and the Mobile Gantry. You can find out for yourself taking a tour of the ELA4 launch complex by watching a video I have made for you using my own footage and additional footage kindly provided by ESA:
Have fun watching the video. And if you like it please subscribe to my YouTube channel. I hope to be able to publish several additional videos documenting how the Ariane 6 launcher is becoming reality – the real one and my own mini versions. Thank you.
In Kourou we had the chance to visit several other facilities. One of these was the BIP building with some very special hardware inside: the first units of the solid rocket motor for Ariane 6! Please have a look at my report about the test units of the P120C solid rocket motor.
Dr. Rocket (a.k.a. SpaceHolgar) 😉