Although it is nonetheless seven years from reaching Jupiter, the JUICE mission is continuing apace — and a current test-run simulated the mission’s spacecraft flying by the Jovian icy moon, Callisto.
Having blasted off from Europe’s spaceport in French Guiana a yr in the past, the Jupiter Icy Moons Explorer, often called JUICE for brief, remains to be within the internal photo voltaic system, preparing for a collection of gravity assists that can throw it onto a trajectory permitting it to rendezvous with Jupiter in 2031. Its first port of name would be the big planet’s outermost Galilean moon, Callisto. This can mark the primary of 35 deliberate flybys of the gasoline planet’s moons Callisto, Ganymede and Europa, earlier than the spacecraft settles into orbit round Ganymede.
On the European House Operations Centre (ESOC) in Germany, the mission workforce is already making ready for this primary flyby, however whereas utilizing the engineering mannequin of the spacecraft. That is an actual duplicate of the flight mannequin that is presently cruising by house, with the identical {hardware}, software program and devices. The one distinction is that it’s sat in a clear room in Darmstadt.
Associated: ‘The Making of JUICE’ movie paperwork how scientists constructed a Jupiter-bound spacecraft in opposition to the percentages
The issue that JUICE, and certainly any mission to Jupiter, faces is a time delay – how lengthy it takes radio indicators to achieve the spacecraft from Earth and vice versa. This relay can take 33 minutes when Jupiter is at its closest to Earth (opposition) and 54 minutes when it’s on the opposite aspect of the photo voltaic system. Thus, JUICE is programmed with software program that may assume and plan autonomously with out ready for instructions.
One instance of the place JUICE’s autonomy might be very important is when observing floor options on Callisto throughout flybys. As a result of we will not know JUICE’s precise place when it passes by Callisto’s gravitational area, nevertheless, the onboard laptop should take over and nice tune the spacecraft’s orientation so it will probably goal particular person floor options with its devices to an accuracy of a fraction of a level.
“We want JUICE to have the ability to react with its personal ‘eyes’ and its personal ‘mind,'” stated Ignacio Tanco, who’s JUICE’s Flight Operations Director, in a European House Company press assertion. “When Callisto seems within the area of view of its navigation digital camera, it wants to have the ability to establish essential options on the moon’s floor, rotate itself to level its devices at them, after which proceed rotating to maintain them in view because it flies previous.”
The workforce at ESOC needed to make the engineering mannequin imagine it was actually in house and flying previous Callisto by projecting computer-generated pictures of Callisto into the mannequin’s navigation digital camera. The photographs mimicked the orientation and section that Callisto may have when JUICE does the flyby for actual in 2031.
Giulio Pinzan, who’s the Spacecraft Operations Engineer on the European House Company, likened it to strapping the engineering mannequin to an immersive virtual-reality headset and letting it transfer round that digital house.
“The navigation software program needed to react to those pictures,” stated Pinzan. “If it observed that it was approaching Callisto on the improper angle or dealing with barely the improper route, it needed to try and appropriate these errors with out our assist.”
Three days have been put aside for testing at ESOC, and it was not anticipated to be plain crusing — all the level of those follow runs is to clean out the kinks. Due to the complexity of the duty, it wasn’t possible to check on a software program simulator first, the place a lot of the gremlins may very well be ironed out. As an alternative, the JUICE workforce anticipated to must endure a number of trial and error, in addition to rewriting of software program, to get it to work.
But, the engineering mannequin succeeded on day one, efficiently concentrating on the pictures of Callisto and maintaining locked onto places on the moon’s icy floor because it carried out a digital flyby, rolling to maintain the moon in view.
“We actually must reward our Flight Dynamics workforce,” stated Giulio. “Their mathematical calculations have been spot on and enabled us to cruise by a clear flyby on the very first makes an attempt regardless of the shortage of expertise they might normally acquire from experimenting with the software program simulator. It was superb, actually. They stunned even us.”
The subsequent step for the JUICE mission in the actual world is a Lunar-Earth Gravity Help, or LEGA for brief, in August. First, JUICE will fly previous our moon and steal a few of its orbital momentum, adopted lower than 24 hours later by zipping previous Earth and getting an extra gravity help to extend its velocity. It is the primary time this sort of double gravity help has ever been tried, however as a result of JUICE is likely one of the most large interplanetary spacecraft ever launched, it wants extra assist to get transferring between planets. In 2025, JUICE will get an extra gravity help from Venus, after which two extra flybys of simply the Earth in 2026 and 2029 will give the spacecraft adequate velocity to climb out of the solar’s gravity nicely and head in the direction of Jupiter finally.
