Dawn dead in Ceres orbit, ran out of fuel Oct 2018

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In summary, the Dawn spacecraft observed Ceres for an hour on Jan. 13, from a distance of 238,000 miles (383,000 kilometres). A little more than half of its surface was observed at a resolution of 27 pixels. This video shows bright and dark features.
  • #946
Ahuna Mons with multiple double craters in attendance. ~450'/pixel
Impressive buttresses, aretes, columns or whatever they are. Curious talus or glacis, for want of a better word, at bases of the largest ones.
ceres5a.jpg


Chained craters, center right, lower right
ceres5b.jpg


For laughs
220px-Krak_des_Chevaliers_14.jpg
 
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  • #947
Dotini said:
Ahuna Mons with multiple double craters in attendance. ~450'/pixel
Impressive buttresses, aretes, columns or whatever they are. Curious talus or glacis, for want of a better word, at bases of the largest ones.
Ahuna Mons close up.PNG

A little closer view here, all the features you mentioned and another of those weird artifacts. I believe the term Talus is the appropriate word for the flanks of this thing. Pretty cool real estate, I hope the geology of this gets explained.
 
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  • #948
And a couple of late comers that were recently posted on the JPL site. :smile:

PIA20673_hires.jpg


PIA20674_May23_lg.jpg
 
  • #949
5/24 Image release.
PIA20675.jpg

Image was taken on 4/17/16 at an altitude of approximately 240 miles or 385 Kilometers
 
  • #950
Released on 5/25/16, taken same day and altitude as post #950
Expecting more data to be released soon.

PIA20676.jpg
 
  • #951
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)
2016
May 26 - Dawn Completes Another Mapping Campaign

"Dawn has completed the photography of the Ceres landscapes it began on April 11,
pointing its camera slightly ahead and to the left. Combining pictures from that
perspective with the earlier pictures looking straight down makes stereo views.

The spacecraft is now transmitting its last set of pictures and other data to Earth. After
it finishes tomorrow, it will begin a new photography campaign, this time taking
pictures with the camera looking slightly ahead and to the right. These pictures will
form new stereo views, allowing further refinements in topographical maps of the alien
terrain.

Since arriving in orbit on March 6, 2015, Dawn has now completed more than 1,000
revolutions around the dwarf planet".
 
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  • #952
PIA20677.jpg
 
  • #953
:partytime:May Journal's out!
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

2016
May 31 - "Dawn Continuing to Study Ceres
Dawn is transmitting its latest pictures and spectra of Ceres to NASA's Deep
Space Network.The spacecraft is healthy and all systems are working well.
Early tomorrow morning it will resume observing the dwarf planet.

The May Dawn Journal explains how scientists use Dawn's photographs of
craters to measure the age of geological features. It also presents some
surprising information about samples on Earth from Vesta, which Dawn
explored in 2011-2012."

PIA20679_hires.jpg

May Dawn Journal
 
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  • #954
JPL seems to be releasing an image per day so I will in the future save up three or four days worth before posting them. While zooming on today's image I noticed a familiar artifact so I have posted a couple of shots showing it fairly clearly, I'm wondering if it's micro meteor damage or what it might be, any
ideas ?

PIA20680_Jun1_lg.jpg


ceres zoom June 1st.PNG


Ahuna Mons close up.PNG
 
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  • #955
1oldman2 said:
JPL seems to be releasing an image per day so I will in the future save up three or four days worth before posting them. While zooming on today's image I noticed a familiar artifact so I have posted a couple of shots showing it fairly clearly, I'm wondering if it's micro meteor damage or what it might be, any
ideas ?

...
I'm guessing, dust on the lens. We've seen similar artifacts in the past.

One more problem to solve, on our endeavors: extraterrestrial windshield wipers. :smile:
 
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  • #956
OmCheeto said:
extraterrestrial windshield wipers. :smile:
I have a patent on that!
 
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  • #957
It's odd that this artifact is triangular, and the previous ones were donut shaped: [ref: page 23, May 18, 2015]

Dr. Rayman graciously explained everything back then:

May 19, 2015 12:42 PM
Hi [Om],

I don’t have time now to look at the forum (I have only ever visited it very briefly), but the images do have artifacts. Some are the result of dust that occasionally separates from the spacecraft and, being small and out of focus, can look larger than it really is. We have observed this throughout the mission, but the flux of dust is very low and it does not compromise the scientific value of the images. There are also electronic artifacts from the CCD. Most spacecraft experience both, and image processing removes them. We are releasing images that have not yet gone through the (time-consuming) full processing, although ultimately all the data, both uncorrected and fully corrected, calibrated, will be released. Of course, all images are scrutinized for moons and other real phenomena, but we know with 100% confidence that none of the stuff we see is anything other than an artifact.

We post a new image every (work) day.

Regards,
marc [Rayman, Dawn chief engineer and mission director at JPL]
bolding mine
 
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  • #958
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)
"June 6 - Dawn Operations Remain Smooth"

"After sending its most recent findings to Earth on June 4-5, Dawn is observing
Ceres again, acquiring new photographs and spectra. The mission has already
surpassed all of its original objectives for exploring the dwarf planet, and it is
continuing to collect bonus data".

PIA20681_hires 2.jpg


PIA20682_hires.jpg


PIA20683_hires.jpg
 
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  • #959
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

"June 9 - Dawn to Adjust Orbit
Dawn started beaming more photographs and spectra to JPL yesterday, and it is continuing
today."

"Every three weeks, the flight team evaluates Dawn's orbit to determine whether an adjustment is
needed. These "orbit maintenance maneuvers" (OMMs) were described in the February Dawn
Journal. Most of the OMMs have not been necessary and so were canceled. Now a small
refinement is needed, and the first part will be executed this afternoon starting shortly after 4:00
PM. Dawn will thrust with its ion engine for about an hour. The spacecraft will perform more
small maneuvers on June 17 and 18."

PIA20646.jpg


PIA20684.jpg


PIA20685.jpg
 
  • #960
1oldman2 said:
Dawn will thrust with its ion engine for about an hour.
For an estimated delta_v of just 20 cm/s.
 
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  • #961
mfb said:
For an estimated delta_v of just 20 cm/s.
That seems an amazingly subtle dance Dawn is doing with Ceres gravity, Thanks for quantifying that.
 
  • #962
The kids at JPL were awarded their trophies on Thursday.


Really glad I became a pen pal with Dr. Rayman.
Really glad that Marcus got me hooked on this mission.

Smart people make good friends. :smile:
 
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  • #963
Wait, what?

Will Dawn Visit a Third Object in the Asteroid Belt?
June 6, 2016
NASA is considering sending the Dawn spacecraft to a third asteroid after it finishes its mission at the dwarf planet Ceres.
...

hmmm... I haven't really been keeping up on the xenon supply... hmmmm...
 
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  • #964
OmCheeto said:
Wait, what?
hmmm... I haven't really been keeping up on the xenon supply... hmmmm...
My thoughts too...
 
  • #965
How did I miss this news?

20 April 2016
NASA’s Dawn probe may visit third asteroid after Ceres and Vesta
...
This summer, Dawn’s Ceres mission will officially end. But earlier this week, principal investigator Chris Russell of the University of California at Los Angeles and his team sent a proposal to NASA for an extension.
...

Perhaps I'll extend my road trip this week, to include Pasadena. I think I need a face to face chat with Mr. Rayman...
 
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  • #966
That would be amazing.

It does make sense, if they have sufficient xenon. Ceres' shadow is approaching, so the current orbit doesn't allow continued operation for too long. I wouldn't expect that Dawn can shift the orbital plane fast enough to make that attractive, going to an eccentric orbit with even lower periapsis is discouraged by the goal to keep the orbit stable, and taking picture #20 of the same spot doesn't give as much science information as the first few pictures anyway.
 
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  • #967
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

June 14 - Dawn Stereo Mapping Proceeding Well

"Yesterday and today the spacecraft transmitted its latest Ceres data to Earth. Now it is taking
more stereo photos to reveal the three dimensional character of the alien landscapes. It is
also continuing to acquire neutron, gamma ray, visible and infrared spectra of Ceres."

PIA20647.jpg


PIA20648.jpg


PIA20649.jpg


PIA20650.jpg


Asteroids are getting a lot of attention lately. :wink:
 
  • #968
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

"June 17 - Dawn To Complete Orbit Adjustment
Dawn has had another very productive week of operations, but it has still
more to do. Occasionally Dawn executes small maneuvers with its ion
engine to keep the orbit synchronized with the observation plans. These
orbit maintenance maneuvers (OMMs) are always performed in two
windows separated by eight or nine days. The first part of the latest OMM
was on June 9. Today the spacecraft will complete the OMM, this time with
two thrust segments. Starting about 4:00 PM, it will use its ion engine for a
little over an hour, and then it will thrust once more for 44 minutes starting
shortly after 1:00 AM tomorrow. The combined effect of all three thrust
segments is to change Dawn's velocity by about 0.8 mph (1.3 kilometers
per hour).

Following the OMM, the spacecraft will point its main antenna at Earth to
transmit more pictures and spectra. On June 19, it will resume observing
Ceres."
 
  • #969
PIA20651.jpg
PIA20652.jpg
PIA20653.jpg
 
  • #970
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

June 24 - Dawn Making More Ceres Measurements

The spacecraft transmitted a large volume of Ceres measurements on June
22-23 and now is collecting even more stereo photos and spectra of the dwarf
planet.

Dawn and Ceres orbit the sun together, independently of Earth. Shortly before
4:00 AM PDT today, the spacecraft was pi astronomical units from Earth, or
about 292 million miles (470 million kilometers). One astronomical unit is the
average distance between Earth and the sun.
 
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  • #972
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  • #973
:partytime:http://www.nasa.gov/feature/jpl/dawn-completes-primary-mission
June 30 - Dawn Completes Prime Mission and Continues Observing Ceres

- from Chief Engineer/ Mission Director, Marc Rayman (JPL)

June 30 - Dawn Completes Prime Mission and Continues Observing Ceres

Today marks the official conclusion of Dawn's prime mission, which began when
the spacecraft left Earth on September 27, 2007. The mission has far surpassed
all of its objectives for exploring protoplanet Vesta and dwarf planet Ceres.
Some interesting statistics and other information on the prime mission are here.

Dawn transmitted a large volume of scientific data to Earth on June 27-28, and it
is continuing to observe Ceres even as the prime mission concludes. On July
1-2, it will transmit more pictures and spectra from its final mapping orbit at an
altitude of 240 miles (385 kilometers).

http://dawn.jpl.nasa.gov/news/news-detail.html?id=6553
 
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  • #974
I guess the recent spectroscopy data makes staying at Ceres more attractive, compared to the idea of going to a third object. But then they will have to do something about the orbit to stay out of the shadow.
 
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  • #975
mfb said:
I guess the recent spectroscopy data makes staying at Ceres more attractive, compared to the idea of going to a third object. But then they will have to do something about the orbit to stay out of the shadow.
I have read one of the main reasons for leaving Ceres orbit is there are rules in place concerning the contamination of other bodies by Earth organisms, thus they don't want Dawn crashing on Ceres. I'm just wondering why that wouldn't apply to a third body as well. In the case of the Juno spacecraft they plan on deorbiting and burning it up in the atmosphere of Jupiter to remove the chance of it contaminating Europa or other satellites of the Jovian system.
 
  • #976
The nominal mission let's Dawn stay in its current orbit. Dawn doesn't go to a lower orbit partially for that reason: the current orbit is expected to be stable for decades, if we think we have to avoid a crash there is enough time to plan and launch a mission that captures Dawn and puts it in a higher orbit (or even completely away from Ceres).
 
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  • #977
OmCheeto said:
How did I miss this news?

Perhaps I'll extend my road trip this week, to include Pasadena. I think I need a face to face chat with Mr. Rayman...

I guess Marc was upset that I didn't come visit. :redface:

...NASA determined that the Dawn spacecraft should remain at the dwarf planet Ceres, rather than changing course to the main belt asteroid Adeona. [ref]

Well, at least we know where they were planning on going.
 
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  • #978
OmCheeto said:
Well, at least we know where they were planning on going.
I can't tell you how pleased I am with this decision! :woot:
 
  • #979
July 6 - Dawn Exploring Ceres in Extended Mission
- from Chief Engineer/ Mission Director, Marc Rayman (JPL)
"NASA Headquarters approved an extension of Dawn's mission at Ceres,
taking advantage of the probe's capabilities to continue making discoveries
about the nature of this fascinating dwarf planet.

Dawn has been acquiring more stereo images and gathering additional
information with all of its spectrometers. The spacecraft began sending its
latest data to Earth early this morning, and it will continue until tomorrow
afternoon when it resumes its observations."

PIA20821.jpg

PIA20822.jpg

PIA20823.jpg

PIA20824.jpg
 
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