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Dawn's last mission extensions at Ceres, From XMO3 to EOM
Habukaz
post Feb 26 2017, 01:25 PM
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QUOTE (Daniele_bianchino_Italy @ Feb 8 2017, 10:53 AM) *
?
Is expected to map temperatures of Ceres? I expected Already for long time :-/


Some pictures showing temperature have been generated. Here's a few that I am not sure if have been posted to the Photojournal, where you can find the others. Don't know about global or other larger maps, or time series of temperature.


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Daniele_bianchin...
post Mar 6 2017, 06:24 PM
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QUOTE (Habukaz @ Feb 26 2017, 01:25 PM) *
Some pictures showing temperature have been generated. Here's a few that I am not sure if have been posted to the Photojournal, where you can find the others. Don't know about global or other larger maps, or time series of temperature.


Thanks!
235 K -38°C
196 K -76°C
However, the VIR images are of the last year.
Ceres from this year begins to warm. The mission will not arrive to the maximum hot season of Ceres, but it could show more high temperatures in the next months....
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nprev
post Mar 10 2017, 04:14 PM
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ADMIN MODE: Moved four recent posts to the former "Water Vapor on Ceres" thread, which has been retitled "Ceres Geology". I think that discussion will continue long after the Dawn mission is completed. Thanks! smile.gif


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Gladstoner
post Apr 9 2017, 08:08 PM
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Long-range image taken on March 28:

https://photojournal.jpl.nasa.gov/catalog/PIA21401

Attached Image


The brightness of the Occator faculae is pretty subdued at this lighting and viewing angle.
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Holder of the Tw...
post Apr 27 2017, 01:16 PM
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Dawn has lost another (third) reaction wheel. But it looks like the opposition studies scheduled for Saturday the 29th will not be affected.

Dawn Status Report
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Explorer1
post May 2 2017, 04:15 AM
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Opposition observation data received! https://dawn.jpl.nasa.gov/mission/status.html
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hendric
post May 3 2017, 04:20 PM
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Man, if I ever win the lottery I'm going to work on making longer-lasting reaction wheels for space missions. sad.gif


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djellison
post May 4 2017, 04:37 AM
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There are many old spacecraft with great reaction wheels still working fine. But there must have been some batch - some particular hardware version rev that has hit Kepler and Dawn.
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Explorer1
post May 18 2017, 10:08 PM
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Movie from opposition observations released: https://www.jpl.nasa.gov/news/news.php?feature=6845
New journal soon, presumably.
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Holder of the Tw...
post Jun 18 2017, 09:31 PM
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Dawn's fate to be decided soon. Sending it off to a new asteroid is one option back on the table.

SpaceFlight Now article
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hendric
post Jun 19 2017, 05:36 PM
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QUOTE (djellison @ May 3 2017, 10:37 PM) *
There are many old spacecraft with great reaction wheels still working fine. But there must have been some batch - some particular hardware version rev that has hit Kepler and Dawn.


Yep, here's a comment from this article ( https://spaceflightnow.com/2017/06/17/dawn-...ecrafts-future/ )

Benjamin Hunt
Mass and size are always an issue on spacecraft, especially deep space probes. Remember, however, that Dawn is an exception in terms of reliability...while reaction wheels have failed on other missions, they all (I believe) failed *after* completing their primary missions, and usually their extended missions.

That said, the reaction wheels that have failed on Dawn and several other spacecraft that have made the news have been noted as coming from a bad batch made by Ithaco Space Systems. The decreased lifespans weren't understood until it was far too late to do anything about it, except for the Kepler mission; those wheels were sent back to Ithaco for preventative maintenance shortly before launch, but even that didn't fix the problem. Still, Kepler made it 4 years before failure compared to its planned 3.5 year mission, and it is still returning very useful science, even if at a reduced capacity.


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jasedm
post Jun 19 2017, 08:29 PM
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It would be fantastic news if the budget allowed for another asteroid flyby - I'd be pretty surprised though if the idea was approved.

Just a fun thought, would it be possible for Dawn to make it back to Earth? The idea of it matching orbits with the ISS and being examined up close after ten years of spaceflight is strangely thrilling (well to me at least smile.gif )
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nprev
post Jun 19 2017, 11:09 PM
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It'd be possible to make it back to the Earth's vicinity, but probably only as a flyby. I don't see any practical way to get it into near-Earth orbit, even if the attitude control suite was fully operational.

No value added there. An asteroid flyby would be a much, much better option.


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algorimancer
post Jun 20 2017, 05:25 PM
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What about a Europa flyby, with some asteroid flybys en-route? Not sure about the gravity gradient, but it might be more efficient to head inward and get an orbital assist from Mars, or it might not. Given the current state of knowledge about Europa, we could probably learn a lot from a targeted flyby -- and probably 10 or more years before we have an orbiter in place.
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djellison
post Jun 20 2017, 05:45 PM
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Europa? No way it'll survive that far from the Sun and that sort of radiation dose. It really is Adiona, or Ceres. That's honestly all the options.
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