IPB

Welcome Guest ( Log In | Register )

3 Pages V  < 1 2 3 >  
Reply to this topicStart new topic
Dawn's last mission extensions at Ceres, From XMO3 to EOM
Habukaz
post Feb 26 2017, 01:25 PM
Post #16


Member
***

Group: Members
Posts: 415
Joined: 13-November 14
From: Norway
Member No.: 7310



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.


--------------------
Go to the top of the page
 
+Quote Post
Daniele_bianchin...
post Mar 6 2017, 06:24 PM
Post #17


Junior Member
**

Group: Members
Posts: 77
Joined: 26-May 15
From: Rome - Italy
Member No.: 7482



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 -38C
196 K -76C
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....
Go to the top of the page
 
+Quote Post
nprev
post Mar 10 2017, 04:14 PM
Post #18


Senior Member
****

Group: Admin
Posts: 7969
Joined: 8-December 05
From: Los Angeles
Member No.: 602



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


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
Gladstoner
post Apr 9 2017, 08:08 PM
Post #19


Member
***

Group: Members
Posts: 646
Joined: 3-January 08
Member No.: 3995



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.
Go to the top of the page
 
+Quote Post
Holder of the Tw...
post Apr 27 2017, 01:16 PM
Post #20


Member
***

Group: Members
Posts: 453
Joined: 17-November 05
From: Oklahoma
Member No.: 557



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
Go to the top of the page
 
+Quote Post
Explorer1
post May 2 2017, 04:15 AM
Post #21


Senior Member
****

Group: Members
Posts: 1427
Joined: 13-February 10
From: British Columbia
Member No.: 5221



Opposition observation data received! https://dawn.jpl.nasa.gov/mission/status.html
Go to the top of the page
 
+Quote Post
hendric
post May 3 2017, 04:20 PM
Post #22


Director of Galilean Photography
***

Group: Members
Posts: 834
Joined: 15-July 04
From: Austin, TX
Member No.: 93



Man, if I ever win the lottery I'm going to work on making longer-lasting reaction wheels for space missions. sad.gif


--------------------
Space Enthusiast Richard Hendricks
--
"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
Mother Nature is the final inspector of all quality.
Go to the top of the page
 
+Quote Post
djellison
post May 4 2017, 04:37 AM
Post #23


Administrator
****

Group: Chairman
Posts: 14008
Joined: 8-February 04
Member No.: 1



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.
Go to the top of the page
 
+Quote Post
Explorer1
post May 18 2017, 10:08 PM
Post #24


Senior Member
****

Group: Members
Posts: 1427
Joined: 13-February 10
From: British Columbia
Member No.: 5221



Movie from opposition observations released: https://www.jpl.nasa.gov/news/news.php?feature=6845
New journal soon, presumably.
Go to the top of the page
 
+Quote Post
Holder of the Tw...
post Jun 18 2017, 09:31 PM
Post #25


Member
***

Group: Members
Posts: 453
Joined: 17-November 05
From: Oklahoma
Member No.: 557



Dawn's fate to be decided soon. Sending it off to a new asteroid is one option back on the table.

SpaceFlight Now article
Go to the top of the page
 
+Quote Post
hendric
post Jun 19 2017, 05:36 PM
Post #26


Director of Galilean Photography
***

Group: Members
Posts: 834
Joined: 15-July 04
From: Austin, TX
Member No.: 93



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.


--------------------
Space Enthusiast Richard Hendricks
--
"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
Mother Nature is the final inspector of all quality.
Go to the top of the page
 
+Quote Post
jasedm
post Jun 19 2017, 08:29 PM
Post #27


Member
***

Group: Members
Posts: 604
Joined: 22-January 06
Member No.: 655



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 )
Go to the top of the page
 
+Quote Post
nprev
post Jun 19 2017, 11:09 PM
Post #28


Senior Member
****

Group: Admin
Posts: 7969
Joined: 8-December 05
From: Los Angeles
Member No.: 602



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.


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
algorimancer
post Jun 20 2017, 05:25 PM
Post #29


Member
***

Group: Members
Posts: 655
Joined: 20-April 05
From: League City, Texas
Member No.: 285



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.
Go to the top of the page
 
+Quote Post
djellison
post Jun 20 2017, 05:45 PM
Post #30


Administrator
****

Group: Chairman
Posts: 14008
Joined: 8-February 04
Member No.: 1



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.
Go to the top of the page
 
+Quote Post

3 Pages V  < 1 2 3 >
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 23rd August 2017 - 06:14 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.