JUICE – Behind The Black – Robert Zimmerman

Engineers free stuck radar antenna on Juice probe to Jupiter’s big moons

May 12, 2023 4:24 pm Robert Zimmerman

Engineers have successfully freed the 52-foot wide radar antenna on the Juice probe to Jupiter, shaking it enough to release a pin that was blocking deployment.

The pin was freed by employing “back-to-back jolts”. Imagine when you roll your car back and forth to get it freed from mud or snow. It appears this is what they did with the pin.

Juice will arrive in Jupiter orbit in 2031, where it will make numerous fly-bys of Europa, Calisto, and Ganymede, and then settle into an orbit around Ganymede alone. The radar antenna was essential for probing the ice content of these worlds, below the surface.

Hat tip to reader Mike Nelson.

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Radar antenna on Europe’s JUICE probe to Jupiter stuck

April 29, 2023 8:27 am Robert Zimmerman

European Space Agency officials revealed yesterday that the 52-foot radar antenna on its JUICE probe to Jupiter has failed to deploy as planned, and that they are attempting to shake what they think is a small pin free that is in the way.

Engineers suspect a tiny pin may be protruding. Flight controllers in Germany plan to fire the spacecraft’s engine in hopes of shaking the pin loose. If that doesn’t work, they said they have plenty of time to solve the problem.

Juice, short for Jupiter Icy Moons Explorer, won’t reach the giant planet until 2031. It’s taking a roundabout path to get there, including gravity-assist flybys of Earth and our moon, and Venus.

The radar antenna is needed to peer beneath the icy crust of three Jupiter moons suspected of harboring underground oceans and possibly life, a major goal of the nearly $1.8 billion mission. Its targets include Callisto, Europa and Ganymede, the largest moon in the solar system.

If this antenna cannot be freed, it will prevent JUICE from doing one of its prime missions.

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Arianespace launches JUICE mission to Jupiter

April 14, 2023 9:21 am Robert Zimmerman

Arianespace early today used its Ariane-5 rocket, on its next-to-last launch, to send the European Space Agency’s (ESA) JUICE mission on its way to Jupiter to study its large moons.

It will take eight years for JUICE to get to Jupiter, using flybys of the Earth, Moon, and Venus along the way. This journey might also include a flyby of an asteroid, depending on orbital mechanics and the spacecraft’s condition.

Once at Jupiter it will, from ’31 to ’34, do thirty-five flybys of the Ganymede, Callisto, and Europa, and then enter orbit around Ganymede for most of 2035, before being sent to crash onto the planet to end its mission.

Ariane-5 meanwhile has one more launch, in June. After this Arianespace will not at present have an active large rocket, as its Ariane-6 replacement is not yet flying, its maiden flight presently scheduled for the fourth quarter of this year.

This was also Europe’s first launch in 2023, so it does not get listed on the leader board. The leaders of the 2023 launch race are as follows:

23 SpaceX (with a launch scheduled for tonight)
15 China (with a launch scheduled for tomorrow)
6 Russia
3 Rocket Lab

American private enterprise still leads China 26 to 15, but is now tied with the entire world combined 26 all.

1st water vapor in Ganymede’s atmosphere, detected using data from Hubble

July 26, 2021 9:06 am Robert Zimmerman

Using Hubble data, astronomers have detected the first evidence of water vapor in the atmosphere of Jupiter’s largest moon, Ganymede.

Though larger than the blistering planet Mercury, the Jovian moon Ganymede is no place to go sunbathing. Located ½-billion miles from the Sun, the water ice on its surface is frozen solid in frigid temperatures as low as minus 300 degrees Fahrenheit. This makes the ice as hard as rock. Still, a rain of charged particles from the Sun is enough to turn the ice into water vapor at high noon on Ganymede.

This is the first time such evidence has been found, courtesy of the Hubble Space Telescope’s spectroscopic observations of aurora on Ganymede spanning two decades. The auroras are used to trace the presence of oxygen, which then is linked to the presence of water molecules sputtering off the surface. Ganymede has a deep ocean located an estimated 100 miles below the surface. That’s too deep for water vapor to be leaking out.

This detection has a margin of uncertainty, but it provides a baseline for the up close observations planned for Europe’s JUICE orbiter, set to launch in ’22 and arrive in Jupiter orbit in ’29. JUICE’s study focus will be the three Galilean moons that appear to have lots of ice, Ganymede, Calisto, and Europa.

Europe has decided to build a probe, dubbed JUICE, to study Ganymede, Callisto and Europa, Jupiter’s big icy moons.

May 2, 2012 5:31 pm Robert Zimmerman

Europe has decided to build a probe to study Ganymede, Callisto and Europa, Jupiter’s big icy moons.

Known as JUICE, the Jupiter Icy Moons Explorer, the probe will enter orbit around the gas giant planet in 2030 for a series of flybys of Ganymede, Callisto and Europa. JUICE will brake into orbit around Ganymede, Jupiter’s largest moon, in 2032 for at least one year of close-up research.