July 5
Los Angeles — NASA this weekend is set to launch a spacecraft that will journey to the asteroid belt that lies between Mars and Jupiter, a mission that involves a rendezvous with two of the solar system’s largest asteroids.

Seeking clues about the birth of the solar system, the Dawn spacecraft will first encounter Vesta, the smaller of the two bodies, four years from now. In 2015, it will meet up with Ceres, which carries the status of both asteroid and, like Pluto, dwarf planet.

Weather permitting, Dawn is set to blast off Sunday afternoon from Cape Canaveral, Fla., on a Delta II rocket.

Vesta and Ceres are believed to have evolved in different parts of the solar system more than 4.5 billion years ago around the same time as the formation of the rocky planets including Mercury, Venus, Earth and Mars. Scientists believe the asteroids’ growth was stunted by Jupiter’s gravitational pull and never had the chance to become full-fledged planets.

Vesta, which measures 326 miles across, is dry and pocked with a deep impact crater in its southern hemisphere. By contrast, Ceres, about twice as large as Vesta, has a dusty surface covered by what appears to be an ice shell and may even contain water inside.

When Dawn reaches each asteroid, first Vesta in 2011, it will orbit each body, photographing the surface and studying the asteroid’s interior makeup, density and magnetism. Pictures and data will be sent back to Earth.

Dawn will be powered by ion propulsion instead of conventional rocket fuel, making it more fuel-efficient and allowing it to cruise between the asteroids and lower itself to about 125 miles above the surface to study them in depth.

Although previous spacecraft have explored smaller asteroids, researchers hope Dawn will shed light on the solar system’s origins.
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That great! Are they planning to land on either? What are we hoping to find? Is it going bring any samples back?

Hmmm this mision can get very dangerrous for the space craft due to micro asteroids orbiting the sun at very high speeds. If one of this small asteroids can rip the ISS then if it hits this space craft it is doomed. Well... lets not be so negative maybe that does not happen, many spacecraft have already goen through the asteroid belt.



Yes. Explore. Yes.

No.


These two bodies have very different compositions so it will be interesting and informative to compare them.


No. It has no sample return capsule



The near Earth environment can actually be more dangerous than the asteroid belt for micro-meteors (many of hem man-made satellite debris). As Dawn is going to be orbiting within the asteroid belt, its orbit velocity will be fairly similar to that of any small object that it meets hence the comparative velocities will low. There is also far less material in the asteroid belt than science fiction movies would imply. So far Pioneers 10 & 11, Voyagers 1 & 2, Galileo, Cassini and New Horizons have all passed through the asteroid belt without a scratch.

Thanks for the info Waspie.