ESA
The takeoff of Ariane 5 and the JUICE mission postponed at the last moment
SPACE – Red on the screen and stop counting: the JUICE probe will not leave on board Ariane 5 this Thursday, April 13. Stormy weather, including a too high risk of lightning for the European Space Agency, led to the launch being postponed for at least 24 hours. If all the conditions are met this time, the penultimate launch of an Ariane 5 rocket, with the JUICE mission on board, could take place.
Departing from Kourou, the venerable Ariane launcher is preparing to put the European probe JUICE on the way to Jupiter’s moons. Objective, to study these unknown confines of our neighborhood. It’s the entire Jovian system that will go under the microscope: the gas giant and its 90 moons. In particular to identify whether the three main frozen moons of Jupiter (Europe, Ganymede and Callisto) harbor water in a liquid state, and perhaps life.
A launch to be found live in the window at the top of this article, but which will only be the starting point of an incredible journey. It will take eight years for JUICE to reach its destination, Jupiter and its moons, 630 million kilometers from our Earth, four times longer than Voyage 1 needed to arrive at the same address.
An adventure full of pitfalls
“It’s because Ariane 5 does not allow us to be on a direct trajectory to Jupiter. It’s a very powerful launcher but not enough to go straight there, ” explains Inès Belgacem, postdoctoral researcher at ESA, working on the JUICE mission. The experts have therefore worked on a trajectory allowing the probe of more than six tons designed by Airbus, and its ten instruments to go towards Jupiter even if it means taking more time. For this, they relied on the famous effect of “gravitational slingshot”.
As a result, by 2031, the trip will really not be a straight line. Before arriving around the gas giant, JUICE will pass through the orbit of the Moon, then Venus, then Earth again before heading for Jupiter. At each stage, the robot will have gained speed, like a pebble that is spun in a slingshot before ejecting it.
Such a trip is necessarily a gigantic temperature differential to manage: 250°C in the vicinity of Venus, -230°C in the Jovian system. Added to these extremes is the limited amount of energy available (800 watts via solar panels!) to operate 10 measuring instruments, another factor that the engineers had to manage as closely as possible. As seen on April 13, JUICE’s journey isn’t immune to glitches, and the launch hasn’t even happened yet.
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