An obvious problem is that Jupiter's poles never get much sunlight due to Jupiter's low axial tilt (~3°). Compare this to Saturn's ~27°. Obviously the poles are not in darkness but they are more difficult to image and you cannot image a big around around the pole in a single image (or over a period of several minutes). Vertical relief is also less pronounced on Jupiter since the atmosphere is more 'compressed' than Saturn's.

I would imagine that IR-band imaging would be an inflexible requirement, then.

Last I'd heard, it'll be pointing perpendicular to the spin axis, much like most other instruments.



Strictly speaking, *between* +/-3 hours from perijove.



My understanding is that since JunoCam is riding along for EPO (education & public outreach), it won't be particularly radiation "hard." I don't think anybody's expecting it to last past the first dozen orbits or so.



Sure hope so...

Lorne

I dug out an article from June of 2005.

New robotic probe planned for Jupiter.

A new article for Juno:
Juno Gets A Little Bigger With One More Payload For Jovian Delivery - http://www.spacedaily.com/reports/Juno_Get...livery_999.html

I'm wondering with some questions, could anybody help me out?
- This will be the farthest solar-powered s/c ever ventured outside Mars's orbit, isn't it? I'm not sure if Rosetta crosses Jupiter's orbit or not?
- How big the solar panels will be to give adequate power output from Jupiter for the 8-proposed instruments?
- This is from the article: "This will let it "thread the needle" through Jupiter's most intense doughnut-shaped radiation belts" - what does it mean? Are there some areas in Jupiter's radiation belts where the radiation level is lower than others?

Rosetta will go out to 5.2 AU from the Sun, which is about at Jupiter's orbit. The difference, though, is that (if I'm not mistaken) Rosetta will just spend some time there on it's way to a comet, while Juno will actually be conducting science at 5.2 AU.



Huge.

You might want to check this site out (it's Juno's public outreach web site).



The idea is that by being in a polar orbit, the spacecraft can skim below the radiation belts on one side of Jupiter, and above them on the other side. Well, most of them, anyway. The Juno site has a good diagram here.

Hope this helps...

This site suggests three panels of ~2m by 9m. Assuming 50 square metres of panels operating at ~20% efficiency and at 5.2 AU, the power available is going to be around 500W - about the same as from Galileo's 2 RTGs.

Andy

20% efficiency is conservative, the state of the art is now ~41%. The panels on the MER's were around 23% so I'd assume that the best space rated arrays are substantially better than that now.

Thanks Lorne Ipsum, that really helps

There's also the issue of how much of that 3 x 9 x 2 m area is actually filled with arrays. Technically a 54m^2 area, but what's the packing density of the arrays going to be like - how much will be taken up with hinges etc... 8% is probably a fairly good guess, making it 50m^2 - and that's where the 500W comes from

What I want to know is what the downlink will be like

Doug

Talking of solar power, I remembered that Deep Space 1 used the innovative solar concentrator arrays for its mission but not sure about the improvement over conventional solar panels. Anybody knows the result of the test? Has this new technology been applied to other spacecrafts?

The lack of photographic images will make it easy to meet the
needs of the other instruments, won't it? Also, aren't scientific
observations limited to a small part of the orbit? There should
be no trouble getting down all the data that Juno can produce.
IMHO

Does anyone know what the current space rated solar panels are at? The Boeing press release is a laboratory result for Earth surface applications. Does rating panels for space result in higher or lower efficiency?

Bruce Moomaw has a couple articles worth checking out:

http://www.spacedaily.com/reports/Juno_Get...livery_999.html

Basically, the italians proposed a second meteorology cam for Juno, together with an infrared cam/spectrometer, and a Ka-band transponder to improve radio tracking.

The meteorology cam was rejected as too similar to JunoCam, but the IR instrument's provisionally accepted, as is the transponder. If the IR instrument does fly, it patches what to me has seemed a major hole in the mission's instrumentation: The ability to see and measure with good resolution cloud structures and the "hot spots" of downwelling (like the one the Galileo probe fell into) that are water and ammonia depleted relative to the deep atmospheric average. This gives the linkage between visible cloud patterns/meteorology, deeper cloud structure, and the to-be-microwave-mapped sub-cloud atmosphere distribution of water and ammonia.

GO FOR IT!

also, on lunar robotic exploration and budget/political/patronage chicanery:
http://www.space-travel.com/reports/NASA_B...ferred_999.html

This Boeing\Spectrolab marketing page indicates that 28.3% is the current state of the art for space rated cells with 33% expected by 2009.

To put the 40.7% number in perspective 34% was the R&D state of the art in 2000 so it appears to take around a decade to go from state of the art to sufficiently mature to become available in a space rated array.

The optical concentrator approach has a major drawback as it requires much more accurate sun pointing. I suspect that that would rule the approach out for any craft in a reasonably tight orbit of a planet but that's just a hunch.