One more time Ariadne 5 has achieved success with the delivery of two telecommunications satellites on a transfer orbit geostationary: Measat-3d (manufactured by Airbus Space for the Malaysian company Measat), and Gsat-24 (built by the Indian space agency). The rocket took off at 6:03 p.m. local time (11:03 p.m. Paris time). Except for a slight delay, everything went according to plan for a flight that lasted exactly 39 minutes and 57 seconds. It’s a routine flight for Ariane 5, except that it’s one of the last.
The arrival of satellites disrupted by the consequences of the war in Ukraine
Preparation for the launch began on May 13 at Guiana Space Center (CSG). Operations started at Launcher integration building (BIL) where the teams joined the main floor cryogenics (EPC) on the second floor. They also added to the central body the two boosters side, named EAP for powder acceleration stage.
Each of these great pieces were assembled at different sites in Europe. Moreover, the different elements of the European rocket come from all over the Old Continent. The assembly of the EPC is carried out at the Mureaux site, near Paris. The second stage is assembled in Bremen, Germany, while the EAPs come from Italy. The fuel is produced at CSG. Once assembled, Ariane 5 is transferred on May 18 from the BIL to Final assembly building (BAF).
The satellites arrived with a little delay. As a result of the war in Ukraine, the Antonov cargo plane company is in trouble. She usually carries the geostationary satellites (very big) to the CSG. Due to the lack of available aircraft, the first passenger, Measat-3d, came by boat from France. The second, Gsat-24, manufactured by the Indian space agency, arrived by military cargo plane.
Upon arrival at the CSG, the satellites were transported in one of the Payload Preparation Sets, where it is ensured that the trip has not impacted them. Several tests are carried out, as well as inspections by quality engineers, who verify that all procedures have been followed. Finally, the ergoliers fill the tanks of the satellites with their fuel. The operation takes place at the beginning of June for Measat-3d and Gsat-24.
The last excessive preparations
The integration of passenger satellites begins on June 8. Arianespace uses the ingenious Sylda system – Ariane double launch system – to embark two satellites at the same time. This device, unique in the world, makes it possible to halve the heavy cost of an Ariane 5 flight, capable of delivering 10 tons of payload in geostationary orbit.
The Sylda allows you to ride the smallest satellite without touching it in order to land the other one. Ariane 5’s fairing is so large that it can cover and protect everyone from the friction ofair during takeoff. On June 8, Measat-3d (5,648 kilos) was integrated above the Sylda. The next day they are put under the headdress. On June 13, Gsat-24 is integrated above the second stage of Ariane 5. Finally, on June 14, the fairing containing the Sylda and Measat-3d is placed at the top of the launcher, the shell of the Sylda encapsulating Gsat-24 . June 16 is the general rehearsal and the next day the last inspections allow to carry out the launch readiness review, essential to give the fire green on takeoff.
On June 21, it was sunny and warm from the early hours of the morning. We open the gigantic gate of the BAF and the entire Ariane 5 sees the light of day for the first time. For a few hours, the rocket placed on its table mobile is rolled towards its launch pad. It is a long operation requiring rails and a simple standard truck to tow the whole assembly, which weighs 1,400 tonnes!
The long wait before taking off
June 22. Security is reinforced to the maximum on the site. The gendarmes carry out checks while the Foreign Legion ensures that no intrusion disturbs the launch sequence. It must be said that with 500 tonnes of powder in the EAPs, and nearly 200 tonnes of propellant liquids in the central body, Ariane 5 can become a real bomb. In case of evacuation, we park our car back to be ready to leave in an emergency without maneuvering. We don’t skimp on safety!
It’s D-Day. The weather remains overcast and the temperature is more pleasant. It is feared that the show will be short duration if Ariane 5 disappears behind a cloud low a few seconds after takeoff. At the control center Jupiter, the timer advances to the launch time. Behind the numerous screens, Arianespace employees follow all the flight parameters: launcher, launch assembly, safety, backupcommunication, weather report, etc. Customer satellite engineers are there, behind their screens, monitoring the health of their precious satellite. On the other side of the bay window, Arianespace receives its guests and various representatives of customers, agencies and authorities in the stands.
For hours and until the last minutes before takeoff, the EPC and upper stage tanks are filled with oxygen andhydrogen liquids. Gradually, as we approach the final count, the tension rises when a “red” appears on the screen. This is a problem that comes from the launch set. Quickly, the director of operations decides to suspend the timer to see what’s going on. There are two short hours left before deferring to the next day. Time is suspended for several tens of minutes, the live on Youtube remain silent. The sun is starting to set, but it’s waiting for us.
The roar of the last moments
More than forty minutes have passed when the count resumes. Take-off is then set for 6:50 p.m. local time – 11:50 p.m. metropolitan time. Ariane 5 is then in full connection with the elements to give us a great show. The sky cleared up. The final count begins. All eyes are on the launch pad. Ariane 5 takes off. A sun lights up on the launch pad. Like a flying torch, the rocket splits the sky in two, quickly crosses a small cloud and escapes into the hole in the blue sky in a festival of shadow and light. A few seconds after takeoff, the sound reaches us and its power resonates throughout our body.
Two minutes and twenty seconds after liftoff, the EAPs, which have provided the bulk of the thrust so far, are empty. They eject from the central body which continues on its way, pushed by the Vulcain engine. Quite a rare phenomenon in Guyana, we manage to see the ejection from the ground. Two points of light can be seen falling on either side of the large point of light. They will end up at the bottom of the Atlantic Ocean. A minute later, Ariane 5 is now in space. His headdress is useless now that there is no more friction. Both pieces are ejected. Once again, we manage to see these new points from the ground. From the memory of regulars, this is the first time that we have been able to see Ariane 5 for so long from Kourou.
While the Sun has set at CSG, the flight continues. At H+8 min 47 s, the EPC separated from the second stage. He too will end up at the bottom of the ocean. The second floor takes over. At 28 minutes and 40 seconds into the flight, the first passenger satellite – Measat-3d – was ejected. Shortly after, the Sylda was ejected in turn, releasing Gsat-24. The latter will finally be separated from the upper floor at H+39 min 57 s. Shortly after, the operators capture the first signals from their satellite. Mission accomplished, VA257 is a success for Ariane 5, one more for the CSG before starting to navigate troubled waters.
Last straight line before retirement
There are only four Ariane 5 flights left before retirement. Two are planned this year, two more in 2023, the last of which in April for the Juice probe. Some of the equipment is no longer used. Today, only one launch table is used, the second table remains stored outside. ” It could serve as a back-up in the event of obsolescence oranomalythen it will be dismantled says Daniel de Chambure, head of the ESA office in Kourou. Some of the buildings dedicated to Ariane 5 will no longer be used. The dismantling of the BIL is probable. ” You should know that some of these buildings are very tall, all in height, and are big consumers in terms of energy and air conditioning “recalls Daniel. The BAF is still 90 meters high!
All operations on Ariane 5 still require personnel today. A large part of them will be affected on Ariadne 6 or already is. Because even if Ariane 6 has not yet flown, it has been cohabiting with Ariane 5 at CSG for several years. On this subject, Daniel de Chambure smiles: “ I, who am still responsible for Ariane 5, have a problem. I absolutely have to keep the teams of engineers, operators and technicians on Ariane 5. Indeed, the site seems to lack personnel to ensure the transition serenely. A whole generation is leaving with Ariane 5. “ There will be Ariane 5 alumni as there were Ariane 4 alumni says Daniel de Chambure. CSG staff have seen other pitchers come and go before. Bruno Gérard, Director of Arianespace and ArianeGroup in Kourou reminds us: ” It’s still the same job. »
Note: more than 600 European companies are involved in the construction of Ariane 5, including more than 350 small and medium-sized enterprises.
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