Dawn at Dawn

Well, it is time for Round Two!

Recall that (as mentioned in my post with the doom-laden title) the Dawn mission was postponed by several months due to unfavourable launch conditions. Recall also that the celestial window for launching Dawn will not come again for another seventeen years, if it does not launch over the next couple of weeks or so! This is a bit scary therefore.

So the two week launch window is open, and Dawn is on the pad and ready to try to fly tomorrow, at around….. dawn. They’ve been preparing Dawn for this for a while now (you can see in the picture on the right some of the preparations – encasing it in the protective dressing for the rocket launch… I got this picture from this link and you can see more there), and from the press release of yesterday confirming that the mission is a “go”:

“If you live in the Bahamas this is one time you can tell your neighbor, with a straight face, that Dawn will rise in the west,” said Dawn Project Manager Keyur Patel of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Weather permitting, we are go for launch Thursday morning – a little after dawn.”

Dawn’s Sept. 27 launch window is 7:20 to 7:49 a.m. Eastern Daylight Time (4:20 to 4:49 a.m. Pacific Daylight Time). At the moment of liftoff, the Delta II’s first-stage main engine along with six of its nine solid-fuel boosters will ….

They also talk a bit about the science (also see later, below this):

“Visiting both Vesta and Ceres enables a study in extraterrestrial contrasts,” said Dawn Principal Investigator Christopher Russell of the University of California, Los Angeles. “One is rocky and is representative of the building blocks that constructed the planets of the inner solar system. The other may very well be icy and represents the outer planets. Yet, these two very diverse bodies reside in essentially the same neighborhood. It is one of the mysteries Dawn hopes to solve.”

Using the same spacecraft to reconnoiter two different celestial targets makes more than fiscal sense. It makes scientific sense. By utilizing the same set of instruments at two separate destinations, scientists can more accurately formulate comparisons and contrasts. Dawn’s science instrument suite will measure mass, shape, surface topography and tectonic history, elemental and mineral composition, as well as seek out water-bearing minerals. In addition, the Dawn spacecraft itself and the way it orbits both Vesta and Ceres will be used to measure the celestial bodies’ gravity fields.

“Understanding conditions that lead to the formation of planets is a goal of NASA’s mission of exploration,” said David Lindstrom, Dawn program scientist at NASA Headquarters, Washington. “The science returned from Vesta and Ceres could unlock many of the mysteries of the formation of the rocky planets including Earth.”

This is exciting! Let’s all keep our fingers crossed for good luck! There are links to coverage, and even a launch blog at NASA’s site here. There’s even a video there, narrated by Leonard Nimoy that you can find there. It talks about the science, and some of the fun facts about the craft, including it’s ion drive propulsion system.

Now, for much more about the science that Dawn is set to do, we can hear from Amara Graps, one of the regular commenters here at Asymptotia, who (since this is part of her primary field of interest, and she’s on the Dawn team) did a very informative post about this on the scientificblogging site. Pop over to her post and have a look.

Remember now – fingers crossed for good luck!

-cvj

(Thanks to Amara, for several of the links I used here!)