Juno at Jupiter, mission events as they unfold Options

[nprev]

This topic will consist of discussion of Juno operations post-JOI until end of mission, currently anticipated in Feb 2018.

[tanjent]

Along with many other space enthusiasts with limited time and attention, I tend to curb my fascination until missions are on station and ready to produce science data. Juno has recently come very close to reaching this status and I am just one of many now feeling a great eagerness to peel Jupiter like an onion and find out what's inside.

The two recent anomalies, even though apparently unconnected, still remind us that no space mission is easy and that alterations of the nominal plan are part of the game. If so, the only option is plenty of patience by the mission team and even more by those of us looking over their shoulders. We have to hope that that the cause of the problems, and some low-risk remedial measures, will become clear during the 54-day cruise out to apojove and back. It will be a relief if the spacecraft enters its planned science orbit, but if the engine problem is not fully understood and they can get the same data from a longer stay in the present orbit, then of course that risk-avoidant option looks pretty attractive.

But because I just can't help myself, I am curious to know if any of the non-photographic science data will be made public in real time, before the end of the mission and the crop of articles that will follow. I can very well understand why this might not be the case. If it takes longer than expected to assemble the full dataset, can we look forward to any interim hints about what is being learned?

[JRehling]

I think, for the most part, Juno will not lend itself well to frequent science updates in the way that missions to Saturn, Mars, etc. have.

The deep-looking spectrometers are going to make observations at every (nominal) perijove, and that data – even from the first perijove alone – may do a pretty good job of answering a lot of the science questions. But the big catch is, the team expected to need to calibrate the analysis as the data came in. They're doing something tricky here, trying to determine the composition of Jupiter's deeper atmosphere by looking right through tens of kilometers of Jupiter's upper atmosphere. The team has already stated that they need to learn how to do this as the mission goes on, so the data we already have (?) may answer the questions, but it's going to be a work in progress to interpret that data. (Kepler was very much this way. The data was on the ground long before the analyses really got going. This was an ongoing process during and after the main mission.)

The radio science exploration of Jupiter's gravitational field will probably play out the same way for different reasons. There's no mystery as to what a single perijove's data will tell us, but the fidelity of the measurements will be refined with multiple observations, and 34 is a lot better than 1. I'm sure we'll have the opportunity for decent advances in understanding after, say, 8 or so perijoves, but it might be mere busywork and/or underwhelming PR for the team to keep releasing vague sets of partial results every month. This is a bit like the orbital alpha/neutron spectrometers on orbiters around the Moon, Mars, and Mercury. Some of the data came with each orbit, but they didn't release it in dribs and drabs, but waited until they had a respectable amount of the final data.

The magnetometer may be an exception to this. There may be something interesting seen right away. Who knows?

So, in a nutshell, I think Juno's going to require our patience. The day will come when we have a really nice data set with beautiful advances in our understanding of Jupiter, but it's not going to come in the form of constant wonderful headlines like Cassini gave us at Saturn. It's pretty amazing, and even surprising, that an orbiter is ultimately the type of mission that is giving us data about the depths of Jupiter. And, if one flyby could have done this fairly well, they might have launched a flyby mission and saved a ton of money.