While waiting for the debut of Ariane 6, postponed – at the earliest – to the end of the year, franceinfo retraces some of its flagship missions.
She is retiring after 27 years of career. The Ariane 5 rocket takes off Friday, June 16 from Kourou, Guyana, for its 117th and final flight. On board are a French military communications satellite (Syracuse 4B) and a German experimental satellite.
The emblematic European rocket will be replaced by its little sister, Ariane 6, but not before the end of 2023, due to technical problems with its Vega-C launcher and the geopolitical situation surrounding the war in Ukraine, which deprives the European Space Agency (ESA) of Russian Soyuz spacecraft. A complicated situation for the agency, temporarily deprived of independent access to space, but which should not make us forget the epic of Ariane 5. A story made up of a few disappointments, but above all of immense contributions to the study of the universe, as franceinfo reminds us in five dates.
June 4, 1996: an inaugural flight of barely 40 seconds
Ariane 5 had a difficult start. In June 4, 1996, his first flight was a bitter failure. Forty seconds after launch, the launcher bursts into the Guyanese sky. Spectators gathered on the beach watch in amazement as the rocket explodes and the four satellites it was to send into orbit.
A few months later, the commission of inquiry created to shed light on the incident noted that “the launcher, which was then at an altitude of some 3,700 meters, deviated from its trajectory, broke up and exploded”. In question: an incompatibility between the new rocket and the navigation software, borrowed from Ariane 4 “as a cost-saving measure”.
This moment “branded us with a hot iron”remembers Hervé Gilibert, then architect of the launcher. “It took two years to get back in flight”, recently told AFP the current technical director of the ArianeGroup prime contractor. Ihe second launch, on October 30, 1997, ended in partial failure. The Teamsat satellite is placed in a lower orbit than expected, but this does not affect its operation.
December 10, 1999: a first commercial flight
In 1998, at the third successful experimental flight, Ariane 5 finally obtains the necessary qualification for its full operation, reports Guyane La 1ère. Startup failures have had “the virtuous effect of keeping us in absolute vigilance over the launches”, still remembers Hervé Gilibert.
The launch of December 10, 1999 marks the beginning of the commercial era of the rocket, which launches with on board the huge XMM-Newton telescope. The latter, placed in a high elliptical orbit, “inundates the scientific community with images and spectra of several hundred thousand cosmic sources”, write four scientists from the National Center for Space Studies (Cnes), who co-author an article for the online media The Conversation. “The mission has long been the most productive of ESA’s science missions, in terms of scientific publications”they continue, before recalling that even today “XMM-Newton still works flawlessly”.
March 2, 2004: Rosetta and Philae fly off for comet Tchouri
After a painful – and ultimate – failure in 2002, Ariane 5 is once again a success. The beginning of the millennium marks its golden age. In 2004, the rocket sent the European probe Rosetta and its Philae lander into space. This ambitious mission plans to send these two jewels of technology in the direction of comet Tchouri, in order to unlock its secrets.
On November 14, 2014, after a 10-year journey that required two tons of fuel to be taken on board, the Philae lander broke away from Rosetta. For seven hours, he travels alone the 20 km that separates him from his new quarters, about 511 million km from Earth. The responsible for the robot landing, Stephan Ulamec, says: “Philae speaks to us, the first thing she told us is that she is well secured, we are on the surface.”
At the end of the mission, in 2016, scientists can look forward to the immense contribution of this mission. “Now we understand much better how comets form”explained Arnaud Boutonnet, expert in flight dynamics at the European Space Agency. “It gave us a lot of information about the water they contain and also about the organic molecules they contain. This allows us to better clarify the formation of the solar system and also to better understand the interaction between comets. and the Earth. Comets bring primordial elements that are necessary for the emergence of life.”
May 14, 2009: the Herschel and Planck telescopes pierce the mysteries of the invisible
For the first time, Ariane 5 embarked, on May 14, 2009, two scientific telescopes. Mobilized for three years, Herschel is responsible for observing cold celestial bodies, inaccessible from ground-based telescopes. In The Conversation, the four scientists list the teachings enabled by Herschel referring in particular to “clouds of water brought twenty-five years earlier into the atmosphere of Jupiter by the collision of comet Shoemaker-Levy 9, nurseries of stars within filaments of dust and gas, cradles of formation of planets and comets around other stars, the omnipresence of water in the universe.”
Planck no longer has to be ashamed of its own performance. In observing the cosmic microwave background – a light emitted 380,000 years after the Big Bang – the telescope has allowed us to learn more about the birth of the universe. Among other things, he helped scientists measure his age: “13.8 billion years with uncertainty of the order of a percent, explains the astrophysicist in The Conversation.
December 25, 2021: the launch of James Webb, a consecration
This launch, carried out on December 25, 2021, undoubtedly testifies to the reputation for reliability of Ariane 5, chosen by NASA to put this big jewel of technology worth 10 billions of dollars. Each snapshot sent by James Webb is an event, as the high-powered telescope opens up a new section of space for scientists, who are now able to see to the farthest reaches of the universe.
In addition to having made it possible to observe an ocean planet for the very first time, James Webb constitutes a window to what lies thousands of light years away and already revolutionized “the model of galaxy formation”explained in January Nicolas Laporte, astrophysicist at the University of Cambridge.
The Cartwheel galaxy, the “Southern Ring Nebula” Or “Eight Shards Nebula”THE “cosmic cliffs” of the Carina Nebula… James Webb shows in an unprecedented level of detail these galaxies and other stardust already photographed by his predecessor, the retired Hubble.
In 2023 again, Ariane 5 helped propel the Juice mission towards Jupiter and its icy moons. What give hope in the next generation, while Ariane 6 is long overdue.