Dawn Mission, pre-launch disscusion Options

[Guest_Sedna_*]

As most of us know, Dawn is set for launch on June, 20th, 2007. A disc is gonna be sent in the spacecraft, with names of many people around the world recorded inside. Does anybody know when is the disc is gonna be put into the spacecraft, and the most realistic tentative date of launch for the mission? Thanks a lot.

[mars loon]

Does anybody know when is the disc is gonna be put into the spacecraft, and the most realistic tentative date of launch for the mission? Thanks a lot.

The deadline for placing your name on the disk is 4 November 2006

You may "Send your name to the Asteroid Belt" at the JPL DAWN website via this online link:

http://www.dawn-mission.org/DawnCommunity/...d/nameEntry.asp

The launch is currently set for 20 June 2007

ken

[punkboi]

The deadline for placing your name on the disk is 4 November 2006

You may "Send your name to the Asteroid Belt" at the JPL DAWN website via this online link:

http://www.dawn-mission.org/DawnCommunity/...d/nameEntry.asp

The launch is currently set for 20 June 2007

ken

Also... The names are being put on a microchip, FYI... I wonder if that chip will be specially made to protect it from cosmic radiation. Kinda sucks if those names last for only a few hundred years, instead of millions of years like the gold records on the Voyager probes

[JRehling]

Also... The names are being put on a microchip, FYI... I wonder if that chip will be specially made to protect it from cosmic radiation. Kinda sucks if those names last for only a few hundred years, instead of millions of years like the gold records on the Voyager probes

I'll be sure to roll over in my grave when the copy of my name in the asteroid belt loses a letter.

[lyford]

"We came in pe2334 fo% a&& #######mankind."

[Bart]

I noticed in the wikipedia entry on Pallas ( http://en.wikipedia.org/wiki/2_Pallas ) that in the section titled "Observations" it says,

Pallas has not yet been visited by a spacecraft, but if the Dawn probe is successful in studying 1 Ceres and 4 Vesta, its mission may be extended to Pallas.

I'm curious about the veracity of that statement. Has somebody actually analyzed this possibility, will Dawn have enough fuel left over, and how long would it take anyway to get from Ceres to Pallas with ion drives?

Bart

[Stephen]

I noticed in the wikipedia entry on Pallas ( http://en.wikipedia.org/wiki/2_Pallas ) that in the section titled "Observations" it says,
I'm curious about the veracity of that statement. Has somebody actually analyzed this possibility, will Dawn have enough fuel left over, and how long would it take anyway to get from Ceres to Pallas with ion drives?

This doesn't exactly answer your question, but on the second page of this ACM conference paper about Dawn the authors mention that Pallas although it "resides in the same region of the asteroid belt as Ceres" is "much more difficult to reach". They go to say that "measurements at Pallas" would nevertheless be "highly desirable" but concede that "exploring Vesta and Ceres may be sufficient to bracket the properties of large 'minor' planets".

My guess as to the reason Pallas is regarded as "much more difficult to reach" is it's orbital inclination, which is >30 degrees. By contrast Ceres and Vesta are about 10.5 & 7 degrees respectively.

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Stephen

[punkboi]

I'll be sure to roll over in my grave when the copy of my name in the asteroid belt loses a letter.

Yep, the issue is that important... Even moreso than talking about putting an RTG on the MSL or restoring space science funding

[Guest_Myran_*]

In reply to Bart:
If they actually will try to visit Pallas I think they rather will attempt to do a flyby when the asteroid passes near the plane of the ecliptic, rather than actually to keep station with Pallas.

But I can be wrong, the ion engine can change course of the spacecraft to a large degree when given time in this case it needs to be nudged into an inclination of 34,8 degrees. Since the ion engine have very little actual power it will take a lot of time however, we need to think in a timeframe of years.

[Bart]

Myran: That actually makes a lot of sense. Given the similarity in the semi-major axes of the two asteroids, this would only take a modest delta-V. Even getting just a flyby of Pallas would be a major bonus.

I was playing around with the asteroid orbit tools at http://neo.jpl.nasa.gov/orbits/ and it looks like the flyby would occur in the neighborhood of December 2018. There is an earlier opportunity at the descending node around March 2016, but I don't think that gives Dawn enough time to switch orbits.

I'm really excited about this mission! Only five years until Vesta orbit!

Bart

[RNeuhaus]

Fresh news about the Dawn's project status. A bit interesting detail: it is going to have a pair solar panels of close 9 meters each! Versus 4 meters each of MRO and 2 meters of VEX. It will carry about 425, kilograms of Xenon for ion propulsors, -- more than enough to allow it to travel to and orbit its targets So heavy! Besides, it will carry 12 mini-propulsores based of hydrazine in two independent systems consisting of 6 ones as a backup. Each subsystem has about 45 kg of fuel hydrazine. On the other hand, it will carry as many electrical reaction wheels.

So redudant is the altitude control system. They have learned lessons from the missfortune of Hayabusa.



Main source comes from spacedaily.com :Dawn Spacecraft Assembly...

Dawn Mission Home Page

[Rakhir]

Fresh news about the Dawn's project status. A bit interesting detail: it is going to have a pair solar panels of close 9 meters each! Versus 4 meters each of MRO and 2 meters of VEX.

To complete the examples, each solar panel of Rosetta is 14-metres long (32 metres tip-to-tip).

[Guest_AlexBlackwell_*]

I just noticed that the latest issue (October 2006) of the Dawn's Early Light newsletter is online.

[RNeuhaus]

Additional details about Ceres


Now new images of its surface reveal a surprisingly diverse surface terrain, scientists say. Dark and bright spots in the images might be crater impacts, mineral deposits or the effects of space weathering, said Mr Carry.

http://news.bbc.co.uk/2/hi/science/nature/6037844.stm


The Keck results also support Ceres' suspected oblate shape, which scientists say could be the result of as much as 25% water ice in its mantle. If so, the amount may be greater than all the fresh water on Earth. Nasa reinstates Dawn mission "We think Ceres still contains pristine water from when the Solar System was formed," said Dr Dumas.

Planet with lots of water, hence a very cold dwarf planet which has not enough own internal heat to sublimate away the water.

Rodolfo

[Guest_PhilCo126_*]

Looks like too many people want to send their name ...



http://www.dawn-mission.org/DawnCommunity/...d/nameEntry.asp