* Astronomy

Blobrana · L

RE: Dawn spacecraft

Blobrana · L

Dawn Approaches Giant Asteroid Vesta

Listen: Windows Media | MP3
Running Time: 00:28:52

Source

Blobrana · L

NASA's Dawn Captures First Image of Nearing Asteroid

Credit NASA

NASA's Dawn spacecraft has obtained its first image of the giant asteroid Vesta, which will help fine-tune navigation during its approach. Dawn is expected to achieve orbit around Vesta on July 16, when the asteroid is about 188 million kilometres from Earth.
The image from Dawn's framing cameras was taken on May 3 when the spacecraft began its approach and was approximately 1.21 million kilometres from Vesta. The asteroid appears as a small, bright pearl against a background of stars. Vesta is also known as a protoplanet, because it is a large body that almost formed into a planet.
Read more

Blobrana · L

Dawn Reaches Milestone Approaching Asteroid Vesta

NASA's Dawn spacecraft has reached its official approach phase to the asteroid Vesta and will begin using cameras for the first time to aid navigation for an expected July 16 orbital encounter. The large asteroid is known as a protoplanet -- a celestial body that almost formed into a planet.
At the start of this three-month final approach to this massive body in the asteroid belt, Dawn is 1.21 million kilometres from Vesta, or about three times the distance between Earth and the moon. During the approach phase, the spacecraft's main activity will be thrusting with a special, hyper-efficient ion engine that uses electricity to ionise and accelerate xenon. The 12-inch-wide ion thrusters provide less thrust than conventional engines, but will provide propulsion for years during the mission and provide far greater capability to change velocity.
Read more

Blobrana · L

Dawn Approaches Asteroid Vesta

After 3 ½ years of thrusting silently through the void, NASA's Dawn spacecraft is on the threshold of a new world. It's deep in the asteroid belt, less than 4 months from giant asteroid Vesta.
Dawn will enter orbit around Vesta in July 2011, becoming the first spacecraft ever to orbit a body in the asteroid belt. After conducting a detailed study of the uncharted alien world for a year, the spacecraft will pull off an even more impressive first. It will leave Vesta, fly to dwarf planet Ceres, and enter orbit there.
Read more

Blobrana · L

Dawn Opens its Eyes, Checks its Instruments

After a hibernation of about six months, the framing cameras on board NASA's Dawn spacecraft have again ventured a look into the stars. The spacecraft also powered up its visible and infrared mapping spectrometer, which investigates surface mineralogy, and the gamma ray and neutron detector, which detects elemental composition. The reactivation prepares the instruments for the May approach and July arrival at Vesta, Dawn's first port of call in the asteroid belt.
Read more

Blobrana · L

Dawn Gets Vesta Target Practice

There is an old chestnut about a pedestrian who once asked a virtuoso violinist near Carnegie Hall how to get to the famed concert venue. The virtuoso's answer: practice!
The same applies to NASA's Dawn mission to the giant asteroid Vesta. In the lead-up to orbiting the second most massive body in the asteroid belt this coming July, Dawn mission planners and scientists have been practicing mapping Vesta's surface, producing still images and a rotating animation that includes the scientists' best guess to date of what the surface might look like.
Read more

Blobrana · L

Dawn Spacecraft Creeping Up on Vesta

Deep in the asteroid belt, Dawn continues thrusting with its ion propulsion system. The spacecraft is making excellent progress in reshaping its orbit around the sun to match that of its destination, the unexplored world Vesta, with arrival now less than five months away.
Read more

Blobrana · L

On Jan. 10, Dawn performed some of the activities that it will execute in its low altitude mapping orbit (LAMO) at Vesta. From the probes vantage point in LAMO, much of the sky will be filled by the ancient protoplanet, only about 180 kilometres away. Vesta will appear as large as a soccer ball from a mere 18 centimetres. Completing one revolution every four hours in LAMO, the spacecraft will devote most of its time to training its scientific instruments on the rocky world beneath it, teasing out the secrets Vesta holds about the dawn of the solar system. Other times, the robotic explorer will loop around the body while aiming its main antenna at distant Earth, transmitting its findings and receiving new instructions
Read more

Blobrana · L

Dawn is maintaining its smooth and steady course through the solar system as it gradually closes in on Vesta. With the utmost patience and persistence, it continues thrusting with its ion propulsion system, heading toward its July rendezvous with the second most massive member of the main asteroid belt. Even as the spacecraft climbs farther from the sun, Earth's orbit is beginning to bring the planet closer to the probe.
Having thrust for two-thirds of its time in space, Dawn has now achieved the velocity equivalent of about 5.5 kilometres per second.
Read more