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NASA Dawn asteroid mission told to ‘stand down’
mcaplinger
post Nov 21 2005, 07:24 PM
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QUOTE (JRehling @ Nov 21 2005, 09:59 AM)
Because the next time around, you'd have someone promising Venus sample return under a $400mm cap, winning the competition, then saying "Oops" when they run over that before the thing is 1/10 built.
*


Well, obviously a large portion of the proposal evaluation and selection process is assessing the cost realism of the proposal, so it's not like you can just claim anything and be believed. Of course, this cuts both ways -- people can end up claiming that a mission can't possibly be done for a given cost cap when it certainly could, just perhaps not by the organization doing the evaulating. That's one of the factors which IMHO has led to spiraling cost increases in aerospace in general.


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RNeuhaus
post Nov 22 2005, 01:31 AM
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New updates about the DAWN's proyect:

NASA Dawn Mission Status November 2005

In mid-October, the Dawn mission team was asked by NASA Headquarters to cease all work except that which was critical to maintaining the viability of the Dawn mission to launch on a delayed schedule, still achieving all of its scientific objectives. This action was taken in response to concerns about the availability of funding in FY2006 to cover any problems that might arise during environmental and performance testing, particularly with regard to several pieces of subsystem hardware perceived to have experienced significant problems.

There are three items of concern:
1) The Power Processing Units (PPUs) that provide the high voltage power to the thrusters in the ion propulsion system. Not yet has started the test. It would be during on November and December 2005.
2) One of the redundant Attitude Control Electronics (ACE) boxes. Item above.
3) The xenon tank. --> Its solution might be by reducing its capacity of xenon fuel load from 450 to 425 kg to increase the safety margin.


Because of the flexibility afforded by the ion propulsion, Dawn's launch period extends at least into late 2007. The original launch period in June 2006 was chosen based on projected readiness to launch at that time. The baseline trajectory includes a Mars Gravity Assist in 2009, which fixes the timing of subsequent events.

More details: http://www.spaceref.com/news/viewsr.html?pid=18748

Rodolfo
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BPCooper
post Nov 23 2005, 10:03 PM
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NASA has marked the launch as no earlier than Nov. 17 2006 officially now.


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punkboi
post Dec 5 2005, 10:14 PM
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QUOTE (BPCooper @ Nov 23 2005, 03:03 PM)
NASA has marked the launch as no earlier than Nov. 17 2006 officially now.
*


Well... As long as DAWN flies.


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Decepticon
post Dec 17 2005, 01:45 PM
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From the current issue of Astronomy magazine.

I found this neat. I never saw this picture of ceres.

Here's the link. http://www.astronomy.com/asy/default.aspx?c=a&id=3478
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mars loon
post Dec 18 2005, 05:52 AM
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QUOTE (Decepticon @ Dec 17 2005, 01:45 PM)
From the current issue of Astronomy magazine.

I found this neat. I never saw this picture of ceres.

Here's the link. http://www.astronomy.com/asy/default.aspx?c=a&id=3478
*

Here is an earlier news article on this from Spaceflightnow.com.

http://www.spaceflightnow.com/news/n0509/07ceres/

As I wrote in an earlier post in this thread, This scientifically exciting mission should fly !!
Its ridiculous to leave a nearly complete spacecraft on the ground unless there are unresolved technical issues!!

The small cost overrun is within the increase of the new Discovery cost cap.
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punkboi
post Jan 21 2006, 12:35 AM
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Wasn't today (1/20) the day NASA was gonna decide whether or not to continue with the Dawn mission?


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Guest_Sunspot_*
post Jan 21 2006, 10:07 AM
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Guests






Can't see anything on the Dawn website about it: http://dawn.jpl.nasa.gov/
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nprev
post Jan 21 2006, 06:22 PM
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QUOTE (Sunspot @ Jan 21 2006, 03:07 AM)
Can't see anything on the Dawn website about it: http://dawn.jpl.nasa.gov/
*


Saw a blurb that Dawn was delayed on the CNN bottom-screen ticker a few minutes ago... mad.gif


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Rakhir
post Jan 21 2006, 08:58 PM
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Dawn will not launch this year sad.gif
http://www.space.com/missionlaunches/ap_06..._dawn_hold.html

"The planned summer launch of the Dawn spacecraft has been indefinitely postponed"

Rakhir
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punkboi
post Jan 21 2006, 10:30 PM
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QUOTE (Rakhir @ Jan 21 2006, 01:58 PM)
Dawn will not launch this year sad.gif
http://www.space.com/missionlaunches/ap_06..._dawn_hold.html

"The planned summer launch of the Dawn spacecraft has been indefinitely postponed"

Rakhir
*


I didn't want my name sent to the Asteroid Field anyway...

rolleyes.gif tongue.gif

Just kidding.


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BPCooper
post Jan 22 2006, 03:14 AM
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Disappointing news. And one less launch.


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RNeuhaus
post Jan 22 2006, 03:45 AM
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Postponed due to technical problems with new technology of ion engines.

Dawn, however, has suffered several setbacks, including ruptures of two of its fuel tanks during testing, forcing engineers to reduce the amount of xenon gas that will be loaded into the tanks.

The project was capped at $371 million, according to Russell, and when project scientists asked for an extra $40 million last year, NASA ordered the standdown to figure out why it was going over budget.


Rodolfo
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gpurcell
post Jan 22 2006, 04:50 AM
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I suspect this project is done. Sound like there are significant technical problems and no reason to believe that the DAWN team can overcome them at a cost near the capped award.

I wonder how much unexpended funding will be available to roll back into the Discovery program account. Maybe enough for a couple of Missions of Opportunity....
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nprev
post Jan 22 2006, 07:03 AM
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Does Dawn have Hall effect ion thrusters, or is this a completely new design?


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