NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres

DevotedSkeptic writes "NASA's Dawn probe is gearing up to depart the giant asteroid Vesta next week and begin the long trek to the dwarf planet Ceres, the largest object in the asteroid belt. The Dawn spacecraft is slated to leave Vesta on the night of Sept. 4 (early morning Sept. 5 EDT), ending a 14-month stay at the 330-mile-wide (530 kilometers) body. The journey to Ceres should take roughly 2.5 years, with Dawn reaching the dwarf planet in early 2015, researchers said. 'Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions,' Dawn chief engineer and mission director Marc Rayman, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. 'We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.'"

Comments

Good luck Dawn

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We're all counting on you...

Seriously though, Ceres is an awesome target and much more exciting than Vesta. Vesta is a rock. Ceres is half water ice by volume, in low g. Obviously some serious upside potentials there. A vastly superior target to Mars, or just about anywhere else in the solar system.

Re:Good luck Dawn

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Mars has water. A lot of it, right on the surface. Plenty to provide air and water for indefinite human habitation and fuel for the return trip, if you have the energy. That's the good news.

Mars also has a lot of gravity (.38 g). And it's the gravity that's a killer because it's not got enough atmosphere for a decent atmospheric brake. To land a significant (20 ton or better) craft on Mars in condition to lift off again demands that you set her down on the jets, and that is a very unforgiving process that costs a metric boatload of fuel. Whatever source of energy you use is going to have a lot of mass too. The 1 ton of Curiosity is actually as much mass as we can land on Mars right now. To get humans there in any condition to start a colony requires a vast quantity of fuel to shorten the trip and to land. And where are we going to get that fuel? Ceres!

Mars has too much gravity to be a good source of water for fuel in microgravity. You have to burn too much fuel to get it off of Mars. As it is on the return trip the humans are going to have to meet up in Mars orbit with a return booster fuelled by LH2/LO2 from Ceres.

Yeah, Ceres is a good bit further out and it takes longer to get there (to the GP). But the robots don't care. Planetary Resources should get us enough Near-Earth asteroid water to make the fuel to lift the craft out of LEO and send it swiftly on its way to Ceres. At 0.03 g, the water comes off of Ceres nice and easy. Once it comes back to lunar orbit (firing its LH2/LO2 jets) with its kilotons aquatic payload a lot of other things like Mars become realistically possible. There are just not enough near-Earth asteroids of the right type to provide the supply we need for this.

Ceres is the key to everything. If it really has the water.

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