IPB

Welcome Guest ( Log In | Register )

19 Pages V   1 2 3 > »   
Reply to this topicStart new topic
Dawn Cruise
SkyeLab
post Sep 27 2007, 12:31 PM
Post #1


Junior Member
**

Group: Members
Posts: 99
Joined: 11-October 04
From: Oxford, UK (Glasgow by birth)
Member No.: 101



Pushing out of Earth orbit now...........

biggrin.gif


--------------------
"There are 10 types of people in the world - those who understand binary code, and those who don't."
Go to the top of the page
 
+Quote Post
elakdawalla
post Sep 27 2007, 02:39 PM
Post #2


Bloggette par Excellence
****

Group: Admin
Posts: 4265
Joined: 4-August 05
From: Pasadena, CA, USA, Earth
Member No.: 454



loon reports from the Cape that AOS happened about 2 hours after launch, at 9:44 EDT. Yay!

Emily


--------------------
My blog - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
Go to the top of the page
 
+Quote Post
ustrax
post Sep 27 2007, 02:55 PM
Post #3


Special Cookie
****

Group: Members
Posts: 2168
Joined: 6-April 05
From: Sintra | Portugal
Member No.: 228



Horst Uwe Keller, Dawn's FC Team Leader reported to spacEurope an hour ago:

"Now we have telemetry! Everything looks OK.
Looks good. Cameras are responding (heaters)."

He added:

"We just talked about it. We (MPS) are now in charge of 6 cameras operating currently in space!
2 on Rosetta, 2 on DAWN, 1 on VEX, 1 on Phoenix and in addition the detector for the microscope on Phoenix.
Looks like a record to me."

He's happy... smile.gif


--------------------
"Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe
Go to the top of the page
 
+Quote Post
climber
post Sep 27 2007, 04:10 PM
Post #4


Senior Member
****

Group: Members
Posts: 2591
Joined: 14-February 06
From: Very close to the Pyrénées Mountains (France)
Member No.: 682



May be little OT...and that's the reason of this post actualy !
We have 8-11 spacecrafts that can be considered in "Cruise phase" at this time (including 2 bound for Mars : Phoenix and Dawn)
Do I miss any?

New Horrizons
Phoenix
Dawn
Roseta
Messenger
Hayabusa
Deep Impact
Stardust
and may be as well :
Voyager 1
Voyager 2
Ulyses

That's quite an achievment. smile.gif I'm wondering if we ever had as many at the same time.
I'm also wondering if, instead of keeping them in their proper section (Mercury,Mars, Pluto, etc…), it'll not be worth to have a section in the Forum that'll show "Cruise phase Spacecrafts".

Advantage will be that we could go there and check down all status instead of having to remember which Spacecraft is where.
Just a thought.

BTW : Go Dawn, Go mars.gif


--------------------
Go to the top of the page
 
+Quote Post
punkboi
post Sep 27 2007, 04:18 PM
Post #5


Member
***

Group: Members
Posts: 520
Joined: 25-October 05
From: California
Member No.: 535



Godspeed, Dawn!


--------------------
Go to the top of the page
 
+Quote Post
dvandorn
post Sep 27 2007, 05:18 PM
Post #6


Senior Member
****

Group: Members
Posts: 3213
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



Well -- I missed the launch (6:34 am is a little early for me these days, and that's when she lofted by my clock), but I just saw a quick replay of the launch at the beginning of the post-launch news conference, and I have to say, that thing heeled over to the left (from the camera angle I saw) pretty good before straightening out and angling to the right onto its correct trajectory. Took off like a bat out of hell, though...

Four issues were just mentioned -- the RCS switched itself from the primary to the secondary system, for reasons yet unknown; the RCS thrusters are running colder than anticipated, which is making the software controls lock them out, but reversion to hardware controls is keeping them running -- the fix is a minor re-set of the software's criteria values; the RCS brackets are running a little warmer than normal, but are cooling down; and there is a slight difference in electricity being generated between the two solar panels.

Those are the only issues that have been discussed.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
stevesliva
post Sep 27 2007, 05:39 PM
Post #7


Senior Member
****

Group: Members
Posts: 1156
Joined: 14-October 05
From: Seattle
Member No.: 530



Amazing! Given the incredible complexity of the post-launch deployments and sequencing in the Planetary Society Blog post by Marc Rayman, I'm amazed that so much goes on without human intervention...
http://planetary.org/blog/article/00001153/

That post has got to be one of the more informative discussions of autonomous operation that I've read. (Other than perhaps the explanations of the incidents when they have gone wrong)
Go to the top of the page
 
+Quote Post
Rakhir
post Sep 27 2007, 08:49 PM
Post #8


Member
***

Group: Members
Posts: 346
Joined: 12-September 05
From: France
Member No.: 495



QUOTE (climber @ Sep 27 2007, 04:10 PM) *
We have 8-11 spacecrafts that can be considered in "Cruise phase" at this time (including 2 bound for Mars : Phoenix and Dawn)
Do I miss any?

Already forget Kaguya ? wink.gif
She is still in cruise phase.
(As well as VRAD and Relay sat. unless you count them as part of Kaguya until they are released)
Go to the top of the page
 
+Quote Post
Toma B
post Sep 28 2007, 07:33 AM
Post #9


Member
***

Group: Members
Posts: 617
Joined: 9-May 05
From: Subotica
Member No.: 384



Just as I thought...nobody in the press conference asked question that I am most interested in... blink.gif
Dawn is going to visit two biggest asteroids Ceres and Vesta. It is going to enter orbit around these two but there was some words before that it can do few close flybys of some small asteroids as well.
I guess that planed flybys are all canceled because slips in launch but there should be new ones.
Does anybody know if there are any candidates?


--------------------
The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare

My "Astrophotos" gallery on flickr...
Go to the top of the page
 
+Quote Post
ugordan
post Sep 28 2007, 07:36 AM
Post #10


Senior Member
****

Group: Members
Posts: 3559
Joined: 1-October 05
From: Croatia
Member No.: 523



QUOTE (Toma B @ Sep 28 2007, 09:33 AM) *
I guess that planed flybys are all canceled because slips in launch but there should be new ones.

IIRC, there never were any planned flybys. It will be determined in flight (based on current trajectory, fuel and ion engine performance) what is feasibly reachable and if it's worth the trouble. One of TPS blog entries mentions something about it as I recall.


--------------------
Go to the top of the page
 
+Quote Post
elakdawalla
post Sep 28 2007, 04:35 PM
Post #11


Bloggette par Excellence
****

Group: Admin
Posts: 4265
Joined: 4-August 05
From: Pasadena, CA, USA, Earth
Member No.: 454



QUOTE (Toma B @ Sep 28 2007, 12:33 AM) *
I guess that planed flybys are all canceled because slips in launch but there should be new ones.

Gordan's right, there were no flybys planned in advance, not only because of the uncertainty in launch date but because of uncertainty in performance of the ion engines. And there may well not be any flybys of any real quality unless they get very lucky. Unlike a flyby mission, Dawn can directly translate fuel reserves into a much longer mission at its primary targets. Which is a better use of the xenon, a relatively distant view of a small asteroid or another week spent in orbit at Ceres, or a closer orbit, or a different orbit, etc. etc.? It sounds to me like unless the orbital mechanics gods smile upon them with a really great opportunity that lies fortuitously close to the trajectory, the economics won't work out for any other flybys.

(The answer to this question was on a Planetary Radio show.)

--Emily


--------------------
My blog - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
Go to the top of the page
 
+Quote Post
stevesliva
post Sep 28 2007, 04:57 PM
Post #12


Senior Member
****

Group: Members
Posts: 1156
Joined: 14-October 05
From: Seattle
Member No.: 530



QUOTE (ugordan @ Sep 28 2007, 03:36 AM) *
IIRC, there never were any planned flybys. It will be determined in flight (based on current trajectory, fuel and ion engine performance) what is feasibly reachable and if it's worth the trouble. One of TPS blog entries mentions something about it as I recall.
I recall that as well, nothing was planned or expected until launch. Similar to the New Horizons Jupiter flyby... they didn't plan the launch to coincide with anything but the primary targets.But I am definitely curious to see what they will pass by, and whether the instruments can do useful science on more distant fly-bys.
Go to the top of the page
 
+Quote Post
jabe
post Sep 29 2007, 02:10 AM
Post #13


Member
***

Group: Members
Posts: 163
Joined: 16-March 05
From: Oakville, Ontario, Canada
Member No.: 201



QUOTE (abalone @ Jul 21 2007, 03:00 PM) *
If specific impulse reigns supreme then why do they use Xenon instead of hydrogen

I believe it is the ionization energy as well as storage issues..An ion engine needs ions..Xenon ionization energy is lower than hydrogen so if you can use a little energy to ionize it the rest of the available energy can be used to "spit" the ions out...(As well hydrogen is a diatomic gas so electrons are used in the bonds..no free ones available to excite if my chemistry is right smile.gif ) Helium would be next best but still ionization energy is high)
Go to the top of the page
 
+Quote Post
Greg Hullender
post Sep 29 2007, 05:46 AM
Post #14


Senior Member
****

Group: Members
Posts: 1009
Joined: 29-November 05
From: Seattle, WA, USA
Member No.: 590



jabe: No, that's not it, but this has already been discussed at length here, and the actual answer is well worth reading.

http://www.unmannedspaceflight.com/index.p...3274&st=300

--Greg
Go to the top of the page
 
+Quote Post
jabe
post Sep 29 2007, 11:56 AM
Post #15


Member
***

Group: Members
Posts: 163
Joined: 16-March 05
From: Oakville, Ontario, Canada
Member No.: 201



QUOTE (Greg Hullender @ Sep 29 2007, 05:46 AM) *
jabe: No, that's not it, but this has already been discussed at length here, and the actual answer is well worth reading.

http://www.unmannedspaceflight.com/index.p...3274&st=300

--Greg

Thanks for the link..always wondered why they didn't use helium smile.gif
Go to the top of the page
 
+Quote Post

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

 



RSS Lo-Fi Version Time is now: 24th April 2014 - 05:52 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.