Reuters/NASA/ESA/AOES/Handout
The Jupiter ICy moons exploration mission JUICE is shown in this artist's rendering provided by NASA, which has selected it as a major contribution to a European Space Agency (ESA) mission to study Jupiter and three of its largest moons in unprecedented detail.
PARIS >> European scientists were set to attempt a first-of-its-kind orbital gymnastics late Monday, using the gravity of the moon and Earth in succession to guide the JUICE spacecraft toward Jupiter in a first-ever double-slingshot maneuver.
Exactly one year after launch, the European Space Agency's Jupiter Icy Moons Explorer (JUICE) will return to Earth on August 19-20, using the braking effect of gravity to steer a shortcut to Venus and then on to Jupiter.
The JUICE spacecraft, built by Airbus, will use a novel dual-role maneuver to first use the moon's gravity to fly towards Earth on a precise trajectory.
This is dangerous because any error during this stage would be amplified later in the mission, when Earth's gravity slows the craft down — and scientists warn this could ruin the spacecraft's eight-year journey to Jupiter and its moons.
“Inherently, this is a little bit difficult because any mistakes need to be corrected, and to do that you need propellant,” JUICE mission manager Nicholas Altobelli said in an interview.
Scientists have been using “gravity assist” methods for decades to navigate the solar system while conserving propellant.
They pass by planets and moons, using their gravity to speed up, slow down, or change course.
But this week's Moon-Earth flyby will be the first time such a maneuver has been performed twice in succession.
If successful, JUICE is on track to reach Jupiter and its three large ocean-bearing moons — Callisto, Europa, and Ganymede — in 2031, with the help of three more solo gravity assist missions: to Venus in 2025, and Earth again in 2026 and 2029.
ESA scientists looked at several options for getting the juice to Jupiter without the impractically large rockets needed to get the juice there without any gravitational help.
Altobelli said the moon's gravity could be used to redirect the probe's course so it catches Earth early in its orbit around the sun, slowing it down but speeding it up as it passes behind the planet.
That allows ESA planners to target Venus and take advantage of its extremely powerful slingshot effect.
“The Moon's position around the Earth is very favorable… so we are being opportunistic,” Altobelli told Reuters.
Following on from NASA's Galileo mission to Jupiter in the 1990s, the ESA-led JUICE mission will orbit the solar system's largest planet, flyby its three large icy moons, and finally orbit Ganymede to investigate its potential for supporting life.
“That means studying the conditions and understanding whether those moons are potential habitable sites and whether they have favorable conditions for life as we know it,” Altobelli said.
