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Unmanned Spaceflight.com > Other Missions > Cometary and Asteroid Missions > Rosetta
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stone
Today a member of the camera science team put up the first images of the comet on his office door. So the camera works. He said on the image is M107 and the comet could this be?
Paolo
here you go: GOTCHA! ROSETTA SETS SIGHTS ON COMET
Explorer1
Hello again, Rosetta! Glad to see the cameras on Philae are checking out.

http://blogs.esa.int/rosetta/2014/04/15/new-mission-selfie/
stone
I talked to a few engineers today and they say they are in the middle of the Lander checkout.
elakdawalla
At a member's suggestion I've now created a dedicated Rosetta subforum. This should now be the active thread for Rosetta discussion. Instrument commissioning is almost over and there hasn't been much discussion, so this thread may morph into the comet approach thread.

Everybody should be reading the Rosetta blog for detailed updates on the mission status; most are written by Emily Baldwin (Space Science Editor for ESA Portal, also @esascience). Including the attached new CIVA selfie, which is cooler in theory than in fact (it's low-res and awfully JPEGgy)

machi
French organization CNES is also good source of news about Rosetta.
Here is for example color test image from Philae's ROLIS camera:



On the image is Rosetta's Multi Layer Insulation.

Here is spectrum from Ptolemy:



peter59
Click to view attachment
Explorer1
http://blogs.esa.int/rosetta/2014/05/14/ro...ady-for-action/

New pictures of C-G will be released soon.
Bjorn Jonsson
And new images have been posted:

http://www.esa.int/Our_Activities/Space_Sc...becoming_active

In short: The comet has started showing a lot of acticity and now has a clear coma. This mission is now getting really interesting to follow...
MahFL
Also a reminder of how hot the Sun is.
brellis
The "Big Burn" is going very well, according to the Big Burn twitter feed. smile.gif
nprev
Eight hours??? Wow!

Could anyone in the know explain why they chose this strategy instead of a bunch of smaller burns done earlier? Is this perhaps an engine duty-cycle thing or something like that?

EDIT: Or perhaps this is done now to facilitate a faster overall journey to the comet?
Holder of the Two Leashes
Second big burn has started.
jamescanvin
And was completed successfully
centsworth_II
QUOTE (nprev @ May 21 2014, 04:25 PM) *
... perhaps this is done now to facilitate a faster overall journey to the comet?
Looks like it to me. According to the Rosetta blog, the main purpose of the big burns is to reduce speed relative to the comet rather than just trajectory correction. So they are "braking" just before arrival. (As I understand it.)
Phil Stooke
Also, if you save up all that delta-v and just do one big burn you have little or no chance to fix any problems - an unexpected safing event for instance. Doing it in several steps lets you recover from any problems more easily.

The first two burns were by far the biggest. With them done successfully, it should be fairly smooth sailing now. And I would think we would be resolving the nucleus very soon. I am so looking forward to the first disk-resolved images.

Phil

machi
OSIRIS will resolve nucleus at the beginning of July. In time of fifth burn (2.7.) Rosetta will be ~52 000 km from the comet and resolution will be ~ 1 km/pix (few image elements across cometary disc).
MahFL
From the website

"Note: In fact, this variability in the actual thrust delivered versus what's planned is one of the reasons why the required orbit corrections are being done in a series of smaller burns. Any variation in one burn can be made up in the next, helping the entire process to be more efficient and optimise the use of fuel."

Explorer1
Big burn coming tomorrow:
http://blogs.esa.int/rosetta/2014/06/17/th...g-burns-part-3/

According to a reply on one of the comments there will be new images this week.
Less than one LD to go!
Paolo
Churyumov-Gerasimenko on 4 June. quieter than before
http://www.esa.int/Our_Activities/Space_Sc..._the_unexpected
MahFL
QUOTE (Paolo @ Jun 19 2014, 01:23 PM) *
Churyumov-Gerasimenko on 4 June. quieter than before


Is going quieter normal, and will it impact the mission ?
djellison
Normal? Yes.
Impact the mission? No.
Paolo
it's time we start taking bets...
will the nucleus look like this or like this?
Phil Stooke
OK, I'll go first. The old shape model, the first you linked to, is too symmetrical for my taste... I'm pretty sure that is an artifact of the modeling. So I vote for the second one. A digital Mars Bar to everybody if I'm wrong.

Phil

JohnVV
well i did post a celestia SPICE add on for this
in this thread
http://forum.celestialmatters.org/viewtopi...?f=18&t=578

it is a synthetic noise added


The Original shape file
ftp://naif.jpl.nasa.gov/pub/naif/generic_...ov-gerasimenko/
and
ftp://naif.jpl.nasa.gov/pub/naif/generic_...ko/input_files/
imported into blender
http://forum.celestialmatters.org/viewtopi...p?f=4&t=618



and the .obj file ( rotated to match the above plate file )
djellison
We'll find out when we get there. Once that happens, perhaps there can be a meritorious discussion on the various means of establishing a shape model from light curves and how well they match the actual nucleus.
Phil Stooke
Right, and see the associated note about data availability.

Phil

JohnVV
so in January/February we might have access to the data ,other than published news
djellison
I would urge caution in interpreting any data release schedule. The only thing we've learned over the 11 years since launch is that most of the instrument teams are in no hurry at all to release their data.
elakdawalla
I have high hopes that at least the NAVCAM data will be available on that timeline, and today's release shows it'll be fun to play with. The distant approach phase is much more fun for a comet than it is for an asteroid, for sure!
elakdawalla
They released all the frames from that animation as individual JPEGs (Zip file here). I spent a little while trying to make an animation where the background was black and star density nearer constant but couldn't produce anything I was happy with.
dilo
Emily, I tried too changing luminosity/contrast but resulting movie, reported below, isn't good... at least, it shows the increasing luminosity of approaching nucleus:
Click to view attachment
Note: I used only 11 frames and cropped field in order to have a small GIF to upload.
Gerald
That's the closest I could get within a few hours:


The gif is reduced to 660 pixels to fit into the 2 MB limit (I think) of imgur.
I've used the average brightness of the images as brightness calibration, after subtracting the minimum brightness (RGB channel-wise) over all images (removes vertical streaky artifacts).
Then I (actually a quick and dirty written piece of software) subtracted the minimum brightness (again each RGB channel) over the thus far processed first 21 images to partially clean the images from camera artifacts. This latter processing step probably reduced the brightness of CG a bit more than intended in the beginning of the sequence, but using all images instead has no noticible cleaning effect at all.
I guess, that the overall dark raw images at the end of the sequence cause the flickering, when using the calibration method sketched above; but I had no better easy-to-implement idea.
dilo
Great animation, Gerald! It would be nice to change frames duration in order to have a constant star speed...
Gerald
Good idea!
Here versions for roughly 5 ms and 2.5 ms per vertical pixel motion, hence no constant frame rate:

(The 2.5 ms-per-vertical-pixel version may be challenging for some computers.)

Looks like some frames would be missing; those gaps could be filled by interpolated frames, I didn't do so.
xflare
Did anyone watch the google hangout?

From here they talk about image release policy. http://youtu.be/Ey0UedaFaMs?t=38m25s

Phil Stooke
Getting closer!


Where is Rosetta? On 01 July 2014 Rosetta is 58,557 km from comet 67P/C-G and getting closer.



(ESA: http://sci.esa.int/home/ )

Phil
Paolo
first hints of a shape
http://blogs.esa.int/rosetta/2014/07/03/th...ixel-at-a-time/
dilo
QUOTE (Paolo @ Jul 3 2014, 02:30 PM) *
first hints of a shape

Processed versions of June, 27 image (de-pixelized through gaussian filter, then false-colors):
Click to view attachment Click to view attachment
If my figures are right, based on Osiris Narrow-angle spec (0.0186 mrad/pixel) and on the distance, image resolution is 1.6km/pixel, so the nucleus is probably over-exposed because its true image should measure a couple of pixel while it appears 3 times larger...
xflare
hmm based on the public comments here http://www.bbc.co.uk/news/science-environment-28146472 ESA might need to release more images. Although for people with a casual or little interest in the mission, an occasional image each week is probably sufficient. huh.gif
Paolo
from http://blogs.esa.int/rosetta/2014/06/25/co...igation-camera/

QUOTE
we plan to share more NAVCAM images with you as we get closer to the comet. Because NAVCAM and the OSIRIS wide-angle camera have comparable resolution, we have an agreement with the OSIRIS team to try and avoid publishing too much NAVCAM data immediately, as they could be used to yield science data similar to that coming from OSIRIS. All Rosetta science instrument data have a proprietary period of 6 months, after which they will be publicly available in our archives, and thus all NAVCAM data will also be available no later than that.


I have a bad feeling about this... I think we are going to see another wave of "why they don't share all their images in real time" like we last saw in December for Chang'e 3.
Ron Hobbs
This is neat image from the Rosetta folks. One of the things I like to do in my outreach talks is give a sense of scale. This is an informative graphic in that regard.

It really is a flying mountain of ice and dust.



Bjorn Jonsson
New images obtained on July 4:

http://blogs.esa.int/rosetta/2014/07/10/th...rosettas-comet/

The comet's shape is starting to become apparent. Not unexpectedly, it's at least a bit irregular. Referring to the end of the text in the above link, I get the impression that it is more round/lumpy than long/skinny but I'd really like to know the phase angle in these images.
dilo
Thanks Bjorn for highlight.
Here below my processed version with gaussian de-pixelization and false-color coding... to me, it appear a tri-lobate shape (vaguely recalling a water molecule!) but we need to go a little bit closer to be sure.
Click to view attachment
Phil Stooke
Despite the appearance of complete over-exposure on the nucleus, there is some subtle detail which can be brought out by careful processing. But it may be spurious! - so you can't really interpret anything from it.

Phil

Click to view attachment
Gerald
One more try, just to stimulate imagination, will be obsolete within a few days, certainly:
Click to view attachment
The rotation axis looks a bit like to be pointing almost horizontally (tilt between 20 and 25), like indicated by the tentative green line:
Click to view attachment
xflare
With those images being taken a week ago, I would bet they are probably resolving surface features now.
MahFL
Shouldn't we have a new topic ?, we are past the commissioning phase.
elakdawalla
This thread isn't very full yet, though it might need renaming to include approach imaging. I think it would make sense to start a new thread at the official date of the Mapping Phase, which is given here as August 18.

CODE
.====================================================================
|     Phase       |Start Date|Main Event| End Date |Dur |SunDist(AU)|
|=================|==========|==========|==========|====|===========|
{snip}
|-----------------|----------|----------|----------|----|-----------|
|Cruise 6 (DSHM)  |14/07/2011|          |22/01/2014| 917| 4.49-5.29 |
|-----------------|----------|----------|----------|----|-----------|
|Rendez-vousMan2  |23/01/2014|          |17/08/2014| 206| 3.53-4.49 |
|  ->RVM2         |          |23/05/2014|          |    |           |
|-----------------|----------|----------|----------|----|-----------|
|Global Mapping   |18/08/2014|          |19/10/2014| 63 | 3.15-3.53 |
|and Close        |          |          |          |    |           |
|Observation      |          |          |          |    |           |
|-----------------|----------|----------|----------|----|-----------|
|Lander Delivery  |20/10/2014|          |16/11/2014| 28 | 2.97-3.15 |
|->Lander Delivery|          |11/11/2014|          |    |           |
|-----------------|----------|----------|----------|----|-----------|
|Comet Escort     |17/11/2014|          |31/12/2015| 410| 1.24-2.97 |
'-------------------------------------------------------------------'
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