What a spectacle these first moments of his 8-year journey to the frozen moons of Jupiter ! The penultimate takeoff ofAriadne 5 has kept all its promises, after a short one-day delay. And even though the deployment has only just begun, one of the most stressful stages of the mission has passed.
As with the James Webb Telescope, the trajectory exceeded expectations.
She takes off, end of the terrestrial adventure
General relief. First, for the teams from Arianespace and the Guiana Space Center with this first major campaign of the year, for the engineers, researchers and technicians from Airbus Defense & Space who designed and assembled the JUICE probe. But also, of course, for the European Space Agency, which was sending one of the most ambitious missions of its existence to Jupiter. The “Jupiter Icy Moons Explorer” took off on Friday April 14 at 2:14 p.m., after a 24-hour delay and a first countdown that showed no ground faults: only the weather did not want to cooperate, with a significant risk of thunderstorms and lightning. This time, the launch chronology has come to an end, with the ignition of the Vulcain 2.0 engine, then that of the two Ariane 5 EAP boosters, and the departure of the European rocket. The latter spun in a few seconds towards the clouds, which did not prevent all concerned from keeping their eyes riveted on the sky and the telemetry.
JUICE leaves precisely for Jupiter
Ariane 5 followed the planned trajectory exactly. After 2 minutes and 16 seconds of flight, the two solid boosters were ejected, then the central stage, supplied with oxygen and liquid hydrogen, continued its climb until T+8 minutes and 44 seconds. The cap ejected, it only remained to accelerate very precisely towards the target point, moving JUICE away from Earth’s orbit. After 27 minutes and 44 seconds of mission, the probe was ejected without problem, and everyone could applaud. Even if the suspense, for ESA and all the non-launcher teams, lasted more than an hour: the probe was capricious enough to wait before contacting the ground stations! Fortunately, the sequel is just as happy, since in the hours that followed, the European agency was able to confirm that the solar panels were deployed and that the probe was communicating as expected.
Liftoff is always a stressful and important moment for a probe whose total journey will reach about 6 billion kilometers over the next decade. It was all the more so since Ariane 5 is nearing the end of its career, this being its penultimate take-off. Still, it was not a standard flight. As for the James Webb telescope, the BepiColombo or Rosetta probe, the launcher had some small custom modifications. Particular attention that paid off, since the director of Arianespace has since communicated on the precision achieved. Ariane 5 was so precise that the first maneuver planned for JUICE was abandoned: there is no need for it, the probe will therefore be able to save some of its precious fuel.
A little health check, and you’re good to go
Contrary to what one might imagine, the start of the mission was rather calm, the days following take-off being used to do a “check-up” of JUICE. The deployments of the antennas and instruments have not yet taken place, and will take place only in a few days and weeks, reserving us beautiful images for later (the probe has several cameras specially installed for the deployments). There will follow a period of tests to verify that the 10 scientific instruments on board are ready for their mission which will not enter its critical phase until 8 years from now, upon arrival in the Jovian system. There remains indeed a lot of time and several very important maneuvers before being able to study Europa, Callisto and especially Ganymede, the most imposing of the moons of our Solar System.
JUICE will return to say hello, with several flybys planned to gain speed, its path not being in a straight line towards Jupiter. The next passage will take place in August 2024, and it will also be a first for the ESA as for the other probes, because it is a double gravitational assistance, from the Earth and the Moon. JUICE will then have to prepare for a second “exotic” flyby for a probe destined for the Jovian system: that of the planet Venus in August 2025. By then, we will have time to find out where the mission is. But no matter what, she is off to a good start!
Source : Sky & Telescope
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