NH at Jupiter, Planning the Jupiter encounter Options

[ugordan]

Great image! I didn't expect it to be so noise-free as it turned out. This promises very clear Jupiter imagery indeed. Congrats to the spacecraft team!

Looking at the image, it brings back memories of Cassini...
I couldn't resist -- the image reminds me of a similar Cassini VIMS image, taken at a similar low phase angle. The distance was much lower, but so was the resolution -- I actually magnified the VIMS slightly:



Cassini was approaching from slightly above Jupiter's equator, while NH is closing in from below. Notice how the grayscale images differ in the appearance of the belts and zones. LORRI being a panchromatic imager encompasses a much larger wavelength range than the VIMS approx. true color image here. The spot in front of Jupiter is Europa and its shadow. Only Io is missing to make this a deja vu scene

The next time we see Jupiter in January 2007, it's gonna get BIG!

EDIT: Updated the image with an even more similar shot.

This post has been edited by ugordan: Sep 26 2006, 08:01 PM

[RNeuhaus]

It is noticeable that the NH's LORRI has superior picture quality than ones of Cassini. That is a good news since the pictures from Pluton would be really nice and good after waiting for a long time. All Pluto's picture are blurry just only by now!

Rodolfo

[ugordan]

It is noticeable that the NH's LORRI has superior picture quality than ones of Cassini.

Hold your horses! You can't compare apples and oranges. The Cassini image is taken using the Visual and Infrared Mapping Spectrometer which has a poor spatial resolution. The LORRI imager on the other hand is closer in capabilities to the narrow-angle camera on Cassini in terms of resolution per pixel. I chose a VIMS frame because of the similar pixel size and phase angle those two shots have. By the time Jupiter's phase angle dropped so low, Cassini was so close that a narrow angle Jupiter shot was huge compared to the LORRI shot so it wouldn't be a fair comparison.

[cawest]

how much data will NH get from Jumpiter fly by... ie GB, MB? I'm trying to us it as a score card... any idea on the amount of data on the belt flythrew?

[RNeuhaus]

Hold your horses! You can't compare apples and oranges. The Cassini image is taken using the Visual and Infrared Mapping Spectrometer which has a poor spatial resolution. The LORRI imager on the other hand is closer in capabilities to the narrow-angle camera on Cassini in terms of resolution per pixel. I chose a VIMS frame because of the similar pixel size and phase angle those two shots have. By the time Jupiter's phase angle dropped so low, Cassini was so close that a narrow angle Jupiter shot was huge compared to the LORRI shot so it wouldn't be a fair comparison.

Very good. I was very pleasent to learn it! They are of different flavours! and neither can be compared but you showed us a good example but with a small letter at epiloge about what you have explained in this note

Rodolfo

[john_s]

how much data will NH get from Jupiter fly by... ie GB, MB? I'm trying to us it as a score card... any idea on the amount of data on the belt flythrew?

If we get to do everything currently on the schedule, we'll store about 32 Gbits (4 Gbytes) of raw data on the data recorders from the close encounter period alone, and we should be able to downlink all of that. There will be an additional Gbyte or so from the approach phase, that will be downlinked earlier. However we may end up taking somewhat less data than this, as I've said before, due to limited time for sequence development and testing.

John.

[ugordan]

The more I look at the above image, the more I'm confused. LORRI is panchromatic, but it principally covers the visible wavelength range with a bit of infrared. So why did the image turn out that different compared to a VIMS color image (also integrated from 380-780 nm)? I tried to model LORRI's response based on the graph in the LORRI ground calibration report:


The red line segments are my simplified fits to the curve. The result of integrating the VIMS wavelenghts with the above weighting gives a result practically identical to the grayscale image above. Jupiter's equator looks very unusual in the LORRI frame. Could that be a seasonal change happening?

[Bjorn Jonsson]

The brightness of Jupiter near the equator varies a lot. It was bright during the Cassini flyby, at least compared to the Voyager flybys when it was more similar to the LORRI frame, at least near the equator.

[yg1968]

Trouble ahead?

http://www.space.com/missionlaunches/06113...ons_update.html

This problem worries me:

One nagging engineering issue has already been flagged. New Horizons is using two of its 16 thrusters more than expected, Stern said. “So we’re going to have to limit our appetite and learn to fly the spacecraft a little bit differently…or we’ll use them all up before we get to Pluto.”

[Guest_Analyst_*]

There is no need to worry. It's common practice to count truster duty cycles on spacecraft because valves and other moving parts are qualified for a specific number of cycles. But most trusters work way beyond that arbitragy limit without trouble (Voyager).

Some action would be: analyze the causes, use other trusters more to spread the load, reduce spacecraft deadband during cruise.

Analyst

[Decepticon]

I'm very happy to see the extra attention to Europa!

[Alan Stern]

UMSFers--

FYI NASA has scheduled a press conference regarding the first year of the NH mission and the upcoming Jupiter flyby for Jan 18th.

On the same day, we'll be releasing the Jupiter flyby press kit and an 11-frame movie of Jovian meteorology to be taken by LORRI
early next week.

-Alan

[djellison]

Aaannnd.... a new PI Perspective, but not on the NH website yet -

http://www.spacedaily.com/reports/New_Hori...n_2007_999.html

Thanks for the Press Con. heads up Alan.


Doug