Europa Clipper Development, Build And Prelaunch Activities Options

[nprev]

The spacecraft has entered its preliminary design review phase, so I think it's time to begin discussion of what promises to be a fascinating journey to one of the most interesting destinations in the Solar System. Dr. Robert Pappalardo, the mission's chief scientist, delivered an overview of Europa as well as a top-level description of instrumentation and objectives during a talk tonight at the Griffith Observatory as part of their monthly "All Space Considered" series, so that serves as a good starting point. His presentation starts at 29:35.

As a reminder, please carefully review rule 1.3 before commenting. In fact, please review all of them. Thanks!


Europa Clipper Presentation (29:35)

[volcanopele]

I will note that the current tour SPICE kernel is on the NAIF kernel site. If you know how to use something like spiceypy, one could create a python script that gives you all the flybys.......

[StargazeInWonder]

Here is a map that aggregates all of the ground tracks, which displayed an impressively dense grid-like coverage of the entire surface, though with some concentrations reflecting the realities of orbital geometry.

https://www.hou.usra.edu/meetings/lpsc2023/pdf/1518.pdf

It notes, at a high level, that the early orbits will focus on the anti-Jupiter hemisphere and then the later orbits will focus on the sub-Jupiter hemisphere.

Other commentary is here.

https://www.nasaspaceflight.com/2024/04/ec-jpl-interview/

https://europa.nasa.gov/mission/timeline/

Because the main mission coverage is a bit uneven spatially, there's the prospect that features that seem intriguing given coverage from the main mission could be the targets of specific focus during any possible extended mission. This will introduce luck and chance as factors – will there be uniquely interesting features that just happen to be located near/far from the closest ground tracks, and how will the spacecraft hold up as radiation damage takes its toll? I think the subtext is that potential targets for any future landers will be of prime interest, and only time will tell if there are uniquely promising locations for a lander (as on Mars) or if there are, effectively, many areas that are more or less equally intriguing. We already know that there are isolated areas with more recent exposure to subsurface activity than is typical, but we don't have sufficient coverage from Galileo to characterize what might be the best locations.

The overlap with JUICE is important context, should both missions function perfectly. This would make EC's coverage of Ganymede and JUICE's coverage of Europa seemingly less important, but the instrument suites are not exactly identical, so perhaps those differences will be highlighted by circumstances where each observes the "other" moon. And it highlights the importance of the observations of Callisto, which is not the primary target of either mission, but will be visited a total of 21 times by these two orbiters, which would seem to offer the potential for excellent and definitive coverage (Galileo flew by Callisto only 3 times in the primary missions and 8 times in all). In fact, both EC and JUICE will each fly by Callisto more times than Galileo ever did.

[StargazeInWonder]

To the point, I think, of Steve's question, I took a look at the Galileo-era maps of the four Galileans and how coverage has varied, which is to say the least considerable. For each, portions have been mapped at scales of 1km/pixel or much better, while other large portions have been imaged at no better than 5km/pixel.

The successful completion of EC and JUICE will utterly supersede current imagery for Europa and Ganymede, and the contributions of each mission to "the other" moon in that pair will be essentially redundant, in terms of mapping. (I'm curious if the two different radar instruments will produce interestingly complimentary data in cases where the ground tracks cross.)

Neither will approach Io closely, but will potentially come as close to Io as Europa is to Io. That won't advance our global maps of Io except in the sense that Io's time-varying vulcanism makes even remote observations potentially interesting.

Callisto is the wildcard. As long as the flybys aren't completely undermined by redundant geometry, nightside closest approaches and/or policies against performing observations, those 21 combined flybys – nearly half as many as EC will make of Europa – should amount to the definitive exploration of Callisto. ESA is quite focused on their end of this; note that the mission name itself is not specific to Ganymede and Callisto is indeed a primary target of the mission, even if it's not as primary as Ganymede. Some interesting and fun discussion here:

https://www.esa.int/Enabling_Support/Operat...isto_flyby_test