Dawn Mission

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NASA Reinstates the Dawn Mission

A mission to two of the largest asteroids, that became a victim of the 2007 NASA budget, was today reinstated.

The press release is reproduced below:


Erica Hupp/Dean Acosta
Headquarters, Washington
(202) 358-1237/1400

March 27, 2006

RELEASE: 06-108


NASA Reinstates the Dawn Mission

NASA senior management announced a decision Monday to reinstate the Dawn mission, a robotic exploration of two major asteroids. Dawn had been canceled because of technical problems and cost overruns.

The mission, named because it was designed to study objects dating from the dawn of the solar system, would travel to Vesta and Ceres, two of the largest asteroids orbiting the sun between Mars and Jupiter. Dawn will use an electric ion propulsion system and orbit multiple objects.

The mission originally was approved in December 2001 and was set for launch in June 2006. Technical problems and other difficulties delayed the projected launch date to July 2007 and pushed the cost from its original estimate of $373 million to $446 million. The decision to cancel Dawn was made March 2, 2006, after about $257 million already had been spent. An additional expenditure of about $14 million would have been required to terminate the project.

The reinstatement resulted from a review process that is part of new management procedures established by NASA Administrator Michael Griffin. The process is intended to help ensure open debate and thorough evaluation of major decisions regarding space exploration and agency operations.

"We revisited a number of technical and financial challenges and the work being done to address them," said NASA Associate Administrator Rex Geveden, who chaired the review panel. "Our review determined the project team has made substantive progress on many of this mission's technical issues, and, in the end, we have confidence the mission will succeed."

The Dawn decision document will be available on the Web at:

http://www.nasa.gov/formedia

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Source: NASA Press Release 06-108

[ROGER]

In my opinion a sound decision reinstating the program. Instead of spending millions , then moth balling a projects , cut a few of the new less informative works instead. With a limited budget some projects still in the planning stage should be cut rather than ones nearing end assembly and use.

Edited March 31, 2006 by ROGER

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Countdown to Dawn

Growing up in a very small Colorado town, Jennifer Rocca had a fabulous view of the stars through her telescope. For her, as with many kids, space was cool, and she wanted to become an astronaut or an aerospace engineer.

But in an economically depressed town where most didn't attend college, Rocca had few role models. Her high school guidance counselor told her aerospace was not for women.

She didn't want him to be right.


JPL's Jennifer Rocca.
Image credit: JPL
+ Larger image

Today, Rocca is a JPL systems engineer playing a crucial role in the launch of the Dawn mission, scheduled for a June lift-off. As the launch phase lead engineer, she is heading a team of 50 that will monitor the spacecraft during its final hours on Earth and first hours in space.

"We'll be on pins and needles after launch," she says. "The transition from a spacecraft on the launch pad to one in space is very tricky. We'll be taking baby steps with the spacecraft for the first 24 hours."

Overseeing the launch phase requires a precise knowledge of how the spacecraft works. The team is conducting several drills of launch day to ensure that everyone is well rehearsed on what to expect. Rocca has created a step-by-step, four-inch-thick manual of what should happen and when, and what to do if one small step does not go according to plan.

Dawn will be the first spacecraft to travel to and orbit two bodies – Vesta and Ceres, both residents of the asteroid belt. Scientists want to examine asteroids to unravel clues about the origins of our solar system. Ceres has a special appeal since it is the largest member of the belt, which lies between Mars and Jupiter.



Artist's concept of Dawn spacecraft.
Image credit: UCLA
+ Larger image

The Dawn launch won't be Rocca's first encounter with pressure at JPL. She was part of the 2005 Deep Impact mission, in which the spacecraft's impactor was essentially "run over" by the nucleus of comet Tempel 1. Rocca built the mission's single largest sequence, which coordinated final approach maneuvers and imaging by both spacecraft in the final week prior to encounter.

She and her colleagues worked for 18 months under intense pressure. "Seeing the images come down was an intense relief and joy. We could see directly the payoff of our engineering for the scientists."

Rocca's first important role on a NASA mission was with the Gravity Recovery and Climate Experiment (Grace) twin Earth-orbiting satellites. She was sent to Germany for two years to oversee installation of the JPL-built instruments. Sixteen-hour days were the norm, but she got lots of hands-on hardware experience and time in the cleanroom, where the spacecraft were assembled.

Before coming to JPL in 2000, Rocca earned a Bachelor of Science degree in Aerospace Engineering Sciences from the University of Colorado in Boulder (1998), and a Master of Science degree in Aerospace and Astronautics at Stanford University (2000). Partly because of her own experiences growing up, Rocca believes it's important to meet with young people and share the excitement and realities of a career involving space.

For young women considering an engineering degree, Rocca notes, "The ratio of men to women is getting a lot better, but it's not easy. If you're in a room of 60 students, and there are four women, you can bet you won't be anonymous. The professor is going to know your name."


Rocca sends the 500th command to the
Deep Impact flyby spacecraft just one week
after launch.
Image credit: Ben Toyoshima
+ Larger image

With an eye to her own future, Rocca regularly updates her application for NASA's astronaut program. As for that guidance counselor back in high school, she makes a point of staying in touch and reminding him that aerospace is indeed a field for women.

Related Links:
+ Dawn site

Source: NASA/JPL - Features

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Dawn Arrives in Florida -- A Little After Dawn

The / Kennedy Space Center press release is reproduced below:

04.10.07

Tabatha Thompson/Dwayne Brown
Headquarters, Washington
202-358-3895/1726

George Diller
Kennedy Space Center, Fla.
321-867-2468

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011

RELEASE: 11-07

Dawn Arrives in Florida -- A Little After Dawn
The Dawn spacecraft arrived at Astrotech Space Operations in Titusville, Fla., at 9 a.m. EDT today. Dawn, NASA's mission into the heart of the asteroid belt, is at the facility for final processing and launch operations. Dawn's launch period opens June 30.

"Dawn only has two more trips to make," said Dawn project manager Keyur Patel of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "One will be in mid-June when it makes the 15-mile journey from the processing facility to the launch pad. The second will be when Dawn rises to begin its eight-year, 3.2-billion-mile odyssey into the heart of the asteroid belt."

The Dawn spacecraft will employ ion propulsion to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres.

Now that Dawn has arrived at Astrotech near NASA's Kennedy Space Center, final prelaunch processing will begin. Technicians will install the spacecraft's batteries, check out the control thrusters and test the spacecraft's instruments. In late April, Dawn's large solar arrays will be attached and then deployed for testing. In early May, a compatibility test will be performed with the Deep Space Network used for tracking and communications. Dawn will then be loaded with fuel to be used for spacecraft control during the mission. Finally, in mid-May, the spacecraft will undergo spin-balance testing. Dawn will then be mated to the upper stage booster and installed into a spacecraft transportation canister for the trip to Cape Canaveral Air Force Station. This is currently scheduled for June 19, when it will be mated to the Delta II rocket at Pad 17-B.

The rocket that will launch Dawn is a Delta II 7925-H manufactured by the United Launch Alliance; it is a heavier-lift model of the standard Delta II that uses larger solid rocket boosters. The first stage is scheduled to be erected on Pad 17-B in late May. Then the nine strap-on solid rocket boosters will be raised and attached. The second stage, which burns hypergolic propellants, will be hoisted atop the first stage in the first week of June. The fairing which surrounds the spacecraft will then be hoisted into the clean room of the mobile service tower.

Next, engineers will perform several tests of the Delta II. In mid-June, as a leak check, the first stage will be loaded with liquid oxygen during a simulated countdown. The next day, a simulated flight test will be performed, simulating the vehicle's post-liftoff flight events without fuel aboard. The electrical and mechanical systems of the entire Delta II will be exercised during this test. Once the Dawn payload is atop the launch vehicle, a final major test will be conducted: an integrated test of the Delta II and Dawn working together. This will be a combined minus and plus count, simulating all events as they will occur on launch day, but without propellants aboard the vehicle.

The NASA Launch Services Program at Kennedy Space Center and the United Launch Alliance are responsible for the launch of the Delta II.

The Dawn mission to Vesta and Ceres is managed by the JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. The University of California Los Angeles is responsible for overall Dawn mission science. Other scientific partners include Los Alamos National Laboratory, New Mexico; German Aerospace Center, Berlin; Max Planck Institute for Solar System Research, Katlenburg, Germany; and Italian National Institute of Astrophysics, Palermo. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.

Additional information about Dawn is online at:

http://dawn.jpl.nasa.gov

For more information about NASA and agency programs on the Internet, visit:

http://www.nasa.gov

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Source: NASA/KSC Press Release 11-07

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Science Mission Update

Hubble Space Telescope: NASA

Dawn mission scientists have been awarded time on the Hubble Space Telescope (HST). In the first accepted proposal, Jian-Yang Li, working with Co-Investigator Lucy McFadden, will observe the UV-absorption band on Ceres. In the second proposal, Mission PI, Chris Russell, will observe 2 Pallas

(a once-in-20-years opportunity due to the asteroid's highly inclined orbit). Chris will be assisted by graduate student Britney Schmidt and the same observing team from past successful Ceres observations. What does this mean for Dawn? The bottom line: the first proposal gives us good science and helps Dawn scientists and engineers plan for arrival at Ceres; the second proposal gives us good comparison data since 2 Pallas is a Vesta-sized body at a Ceres distance from the sun.

Source: NASA/JPL -Dawn - Science

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Dawn Team Prepares Spacecraft for Launch

The pictures above feature recent images of the Dawn spacecraft as tests are being conducted in preparation for launch. The final comprehensive performance tests are being conducted on the spacecraft in Florida to verify that each subsystem is still working correctly.

Source: NASA/JPL -Dawn

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Dawn Spacecraft Prepares for Launch, June 30

June 1, 2007—the final mission operations test with the spacecraft was completed successfully last week. Dawn's solar arrays were attached to the spacecraft and the system for deploying them in space was given one final test, which went very smoothly.

Dawnspacecraft array panel deployed

At Astrotech's Payload Processing Facility, the second array of solar

panels on the Dawn spacecraft is deployed.

Credit: NASA, Jim Grossman

+ Enlarge Image

The first stage of Dawn's Delta-II on Launch Pad 17-B at Cape

Canaveral Air Force Station.

Credit: NASA, Jim Grossman

+ Enlarge Image

Source: NASA/JPL -Dawn

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Solar Array Damage Won't Stop Dawn

06.14.07 -- NASA is investigating damage to one of Dawn's solar array wings after a technician's tool hit it. The damage is minor and will not delay the mission's launch on July 7, 2007.

Source: NASA - Missions - Dawn

Edited June 16, 2007 by Waspie_Dwarf

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Solar Array Damage Won't Stop Dawn

06.15.07 -- Technicians will be making minor repairs to one of Dawn's solar array wings after a technician's tool hit it. The repairs will be made during the coming weekend and will not delay the mission's launch on July 7, 2007.

Photo Credit: Orbital Sciences

+ View Larger Image

Source: NASA - Missions - Dawn

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Voyage to the Giant Asteroids

June 15, 2007: The asteroid belt between Mars and Jupiter is like the solar system's cluttered old attic. The dusty, forgotten objects there are relics from a time long ago, each asteroid with its own story to tell about the solar system's beginnings.

see captionThese are stories planetary scientists want to hear. Much is still unknown about our solar system's distant past. We learn the basic story in school: A vast disc of gas and dust around the sun slowly gathered into larger and larger chunks, eventually forming the planets we know today. But how exactly did this happen, and why did it produce the kinds of worlds that it did, including a certain blue planet well-suited for life?


Above: Inside the Solar Nebula, a painting by
William K. Hartmann, copyright 2001. [More]

To answer these questions, NASA plans to launch a robotic probe named Dawn. Its mission: Fly to two giant asteroids, Ceres and Vesta, and explore them up close for the first time. Liftoff is scheduled for July 2007.

Vesta, for starters

Dawn's first stop is Vesta—an asteroid that may implicate ancient supernovas in the solar system's birth.

Telescopic observations of Vesta and studies of meteorites believed to have come from Vesta suggest that the asteroid may have been partially molten early in its history, allowing heavy elements like iron to sink and form a dense core with a lighter crust on top.

"That's interesting--and a bit puzzling," says Chris Russell, Principal Investigator for Dawn at the University of California, Los Angeles. Melting requires a source of heat such as gravitational energy released when material comes together to make an asteroid. But Vesta is a small world—"too small," he says--only about 530 km across on average. "There would not have been enough gravitational energy to melt the asteroid when it formed."


Above: A Hubble Space Telescope photo of
Vesta. [More]

A supernova (or two) may provide the explanation: Some scientists believe that when Vesta first formed, it was "spiced up" by aluminum-26 and iron-60 created in possibly two supernovas that exploded around the time of the solar system's birth. These forms of iron and aluminum are radioactive isotopes that could have provided the extra heat needed to melt Vesta. Once these radioactive isotopes decayed, the asteroid would have cooled and solidified to its present state.

This idea would explain why Vesta's surface appears to bear the marks of ancient basaltic lava flows and magma oceans, much as Earth's moon does. The supernovas would also change the sequence of events involved in planet formation:

"When I went to school, the thought was that the Earth got together, heated up, and the iron went to the center and the silicate floated on top, producing a core-forming event," Russell says. This view assumes that smaller planetoids that collided and merged to form Earth were amorphous masses that hadn't yet formed their own iron cores. But if chunks of rock the size of Vesta could melt and form dense cores, "it would affect the way the planets and their cores grew and evolved."

If all goes as planned, Dawn would reach Vesta and enter orbit in October 2011. Detailed images of Vesta's surface will reveal traces of its molten past, while spectrometers catalog the minerals and elements that make up its surface. Vesta's gravitational field will be mapped out by the motions of Dawn itself as the probe orbits the asteroid, and that should settle once and for all whether Vesta indeed has an iron core.

On to Ceres

After orbiting Vesta for 7 months, Dawn will undertake a maneuver never before attempted: leave the orbit of one distant body, and fly to and orbit another.

This kind of "asteroid hopping" would be practically impossible if Dawn used conventional rocket fuel. "We would need one of the largest rockets that the US has to carry all the propellant," says Marc Rayman, Project System Engineer for Dawn at NASA's Jet Propulsion Laboratory. Instead, Dawn uses ion propulsion, which requires only one-tenth as much propellant. Dawn’s engines proved themselves onboard an earlier, experimental spacecraft known as Deep Space 1, managed by NASA's New Millennium Program.


Above: A Hubble Space Telescope photo of
Ceres. [More]

Dawn's fuel-efficient ion engines will propel the craft from Vesta, arriving at Ceres by February 2015.

Measuring 950 km in diameter, Ceres is by far the largest object in the asteroid belt. Remarkably, it is not a rocky world like Vesta, but one covered in water ice. "Ceres is going to be a real surprise to us," says Russell. Because it appears to harbor a layer of ice 60 to 120 km thick, the surface of Ceres has probably changed more dramatically over time than Vesta's, obscuring much of its early history. But while Ceres may not offer such an early window onto planet formation, it could teach scientists about the role that water has played in planetary evolution since then. For example, why can some rocky worlds like Ceres and Earth hold on to large amounts of water, while others, like Vesta, end up bone dry?

"Vesta will tell us about the earliest epoch, and Ceres will tell us about what happened later," Russell says. Together, they offer two unique stories from our solar system's past, and who-knows-how-many lessons about how the planets came to be.

Author: Patrick Barry | Production Editor: Dr. Tony Phillips | Credit: Science@NASA

____________________________________________

More Information

Dawn -- mission home page

NASA's Future: The Vision for Space Exploration

Source: Science@NASA

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Dawn Spacecraft Prepares for Launch July 7, 2007

On Launch Pad 17-B at Cape Canaveral Air Force Station, workers maneuver the second stage of the Delta II launch vehicle onto the first stage for mating. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy, the strongest rocket in the Delta II class, will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch.

The second stage of the Delta II launch vehicle for the Dawn spacecraft

is lowered into the hole toward the Delta first stage below.

Credit: NASA, Jim Grossman

+ Enlarge Image

Technicians at Astrotech are preparing the Dawn

spacecraft for spin-balance testing. After the test,

Dawn will then be mated to the upper stage

booster, installed into a spacecraft transportation

canister for the trip to Cape Canaveral Air Force

Station and mated to the Delta II rocket at Launch

Pad 17-B.

Credit: NASA, Jim Grossman

+ Enlarge Image

Source: NASA/JPL -Dawn

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Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit

June 20, 2007 10:30 AM (EDT)

News Release Number: STScI-2007-27

ABOUT THIS IMAGE:
These Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt, a region between Mars and Jupiter. The images are helping astronomers plan for the Dawn spacecraft's tour of these hefty asteroids.

On July 7, NASA is scheduled to launch the spacecraft on a four-year journey to the asteroid belt. Once there, Dawn will do some asteroid-hopping, going into orbit around Vesta in 2011 and Ceres in 2015. Dawn will be the first spacecraft to orbit two targets. At least 100,000 asteroids inhabit the asteroid belt, a reservoir of leftover material from the formation of our solar-system planets 4.6 billion years ago.

Dawn also will be the first satellite to tour a dwarf planet. The International Astronomical Union named Ceres one of three dwarf planets in 2006. Ceres is round like planets in our solar system, but it does not clear debris out of its orbit as our planets do.

To prepare for the Dawn spacecraft's visit to Vesta, astronomers used Hubble's Wide Field Planetary Camera 2 to snap new images of the asteroid. The image at right was taken on May 14 and 16, 2007. Using Hubble, astronomers mapped Vesta's southern hemisphere, a region dominated by a giant impact crater formed by a collision billions of years ago. The crater is 285 miles (456 kilometers) across, which is nearly equal to Vesta's 330-mile (530-kilometer) diameter. If Earth had a crater of proportional size, it would fill the Pacific Ocean basin. The impact broke off chunks of rock, producing more than 50 smaller asteroids that astronomers have nicknamed "vestoids." The collision also may have blasted through Vesta's crust. Vesta is about the size of Arizona.

Previous Hubble images of Vesta's southern hemisphere were taken in 1994 and 1996 with the wide-field camera. In this new set of images, Hubble's sharp "eye" can see features as small as about 37 miles (60 kilometers) across. The image shows the difference in brightness and color on the asteroid's surface. These characteristics hint at the large-scale features that the Dawn spacecraft will see when it arrives at Vesta.

Hubble's view reveals extensive global features stretching longitudinally from the northern hemisphere to the southern hemisphere. The image also shows widespread differences in brightness in the east and west, which probably reflects compositional changes. Both of these characteristics could reveal volcanic activity throughout Vesta. The size of these different regions varies. Some are hundreds of miles across.

The brightness differences could be similar to the effect seen on the Moon, where smooth, dark regions are more iron-rich than the brighter highlands that contain minerals richer in calcium and aluminum. When Vesta was forming 4.5 billion years ago, it was heated to the melting temperatures of rock. This heating allowed heavier material to sink to Vesta's center and lighter minerals to rise to the surface.

Astronomers combined images of Vesta in two colors to study the variations in iron-bearing minerals. From these minerals, they hope to learn more about Vesta's surface structure and composition. Astronomers expect that Dawn will provide rich details about the asteroid's surface and interior structure.

The Hubble image of Ceres on the left reveals bright and dark regions on the asteroid's surface that could be topographic features, such as craters, and/or areas containing different surface material. Large impacts may have caused some of these features and potentially added new material to the landscape. The Texas-sized asteroid holds about 30 to 40 percent of the mass in the asteroid belt.

Ceres' round shape suggests that its interior is layered like those of terrestrial planets such as Earth. The asteroid may have a rocky inner core, an icy mantle, and a thin, dusty outer crust. The asteroid may even have water locked beneath its surface. It is approximately 590 miles (950 kilometers) across and was the first asteroid discovered in 1801.

The observations were made in visible and ultraviolet light between December 2003 and January 2004 with the Advanced Camera for Surveys. The color variations in the image show either a difference in texture or composition on Ceres' surface. Astronomers need the close-up views of the Dawn spacecraft to determine the characteristics of these regional differences.

For additional information, contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Md.
(Phone: 410-338-4514; E-mail: villard@stsci.edu)

Dr. Lucy McFadden
University of Maryland, College Park, Md.
(Phone: 301-405-2081; E-mail: mcfadden@astro.umd.edu)

Object Names: Ceres, 1 Ceres, Vesta, 4 Vesta

Image Type: Astronomical

Credits for Vesta: NASA; ESA; L. McFadden and J.Y. Li (University of Maryland, College Park); M. Mutchler and Z. Levay (Space Telescope Science Institute, Baltimore); P. Thomas (Cornell University); J. Parker and E.F. Young (Southwest Research Institute); and C.T. Russell and B. Schmidt (University of California, Los Angeles)

Credits for Ceres: NASA; ESA; J. Parker (Southwest Research Institute); P. Thomas (Cornell University); L. McFadden (University of Maryland, College Park); and M. Mutchler and Z. Levay (Space Telescope Science Institute)

Source: HubbleSite - Newsdesk Edited June 21, 2007 by Waspie_Dwarf

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The Many Faces of Vesta

News Release Number: STScI-2007-27

ABOUT THIS IMAGE:

To prepare for the Dawn spacecraft's visit to Vesta, astronomers used Hubble's Wide Field Planetary Camera 2 to snap new images of the asteroid. These images were taken on May 14 and 16, 2007. Each frame shows time in hours and minutes based on Vesta's 5.34-hour rotation period. Using Hubble, astronomers mapped Vesta's southern hemisphere, a region dominated by a giant impact crater formed by a collision billions of years ago. The crater is 285 miles (456 kilometers) across, which is nearly equal to Vesta's 330-mile (530-kilometer) diameter.

Hubble's sharp "eye" can see features as small as about 37 miles (60 kilometers) across. The images show the difference in brightness and color on the asteroid's surface. These characteristics hint at the large-scale features that the Dawn spacecraft will see when it arrives at Vesta in 2011.

Hubble's view reveals extensive global features stretching longitudinally from the northern hemisphere to the southern hemisphere. The images also show widespread differences in brightness in the east and west, which probably reflects compositional changes. Both of these characteristics could reveal volcanic activity throughout Vesta. The size of these different regions varies. Some are hundreds of miles across.

The brightness differences could be similar to the effect seen on the Moon, where smooth, dark regions are more iron-rich than the brighter highlands that contain minerals richer in calcium and aluminum. When Vesta was forming 4.5 billion years ago, it was heated to the melting temperatures of rock. This heating allowed heavier material to sink to Vesta's center and lighter minerals to rise to the surface.

Astronomers combined images of Vesta in two colors to study the variations in iron-bearing minerals. From these minerals, they hope to learn more about Vesta's surface structure and composition. Astronomers expect that Dawn will provide rich details about the asteroid's surface and interior structure

Object Names: Vesta, 4 Vesta

Image Type: Astronomical/Illustration

Credit: NASA, ESA, and L. McFadden (University of Maryland)

Source: HubbleSite - Newsdesk

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Dawn Spacecraft Prepares for Launch July 7, 2007

Spacecraft Mated to Third Stage, and Second Stage Mated to First Stage, June 18 - 22

The spacecraft was connected to the third stage of the launch vehicle at Astrotech (see photo at bottom). At Space Launch Complex 17B, the second stage was lifted into place on the first stage (see photo below).

The second stage of the Delta II launch vehicle for the Dawn spacecraft

is lowered into the hole toward the Delta first stage below.

Credit: NASA, Jim Grossman

+ Enlarge Image

At Astrotech, workers secure the attachments

of the Dawn spacecraft onto the upper stage

booster.

Credit: NASA, George Shelton

+ Enlarge Image

Source: NASA/JPL -Dawn

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Mission Planners Push Ahead

Image above: Technicians move the Dawn spacecraft toward the third

stage engine of the Delta II rocket that will carry the spacecraft into space.

Photo credit NASA/George Shelton

+ View hi-res image

06.26.07

NASA officials in charge of the Dawn mission to the asteroids Vesta and Ceres said the agency is pressing ahead with plans to launch July 7.

There will be a Flight Readiness Review meeting held on July 3 where mission managers will make a decision about the final launch date

Source: NASA - Missions - Dawn

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Dawn Spacecraft Prepares for Launch July 7, 2007

Dawn Moved to Launch Pad

June 25 - 29

The Dawn spacecraft and third stage were transported from Astrotech to Space Launch Complex 17B at Cape Canaveral and installed on the second stage. Final checkouts and preparations for launch continue on all three stages of the launch vehicle and the spacecraft.

In the image on the right , workers complete encapsulation of the fairing around NASA's Dawn spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent.

On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida,

workers complete encapsulation of the fairing around NASA's Dawn

spacecraft.

Credit: NASA, Amanda Diller

+ Enlarge Image

Source: NASA/JPL -Dawn

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NASA Postpones Launch of Dawn Spacecraft

The / Kennedy Space Center media advisory is reproduced below:

07.05.07

George Diller
Kennedy Space Center, Fla.
321-867-2468

MEDIA ADVISORY: 35-07

NASA Postpones Launch of Dawn Spacecraft

CAPE CANAVERAL - The launch of NASA's Dawn spacecraft aboard a United Launch Alliance Delta II rocket has been postponed 24 hours.

A lightning advisory Thursday morning precluded the start of the Delta II second stage fueling as scheduled and did not clear in time for an afternoon attempt. Fueling has been rescheduled for Friday, July 6.

Fueling on Thursday was also delayed because the temperature of the second stage was too warm for the process to begin. The fairing temperature has been lowered so that oxidizer can be loaded Friday pending acceptable weather. Dawn's launch countdown dress rehearsal has been postponed until Friday. The launch window on Sunday, July 8, extends from 4:04 to 4:33 p.m. EDT. The chance of not meeting the launch weather criteria on Sunday is 60 percent. Required launch telemetry assets downrange will be in place to support the launch.

The Dawn mission science briefing, scheduled for Friday, will be held as planned at 1 p.m. The prelaunch news conference will begin at 1 p.m. Saturday, following the launch readiness review.

For more information about Dawn, visit:

http://www.nasa.gov/dawn

- end -

--------------------------------------------------------------------------------

Source: NASA/KSC Media Advisory 35-07

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Lightning Delays Dawn Launch

Image above: Technicians at Launch Pad 17-B prepare the Dawn

spacecraft atop the Delta II rocket for its launch toward the asteroid belt.

Photo credit: NASA/Cory Huston

+ View hi-res image

07.05.07

The launch of the Dawn mission to the asteroid belt was delayed by 24 hours because of a lightning advisory at the launch pad during planned fueling operations. The fueling operations are planned to begin today or Friday, weather permitting. Liftoff of the United Launch Alliance Delta II rocket carrying the Dawn spacecraft is scheduled for Sunday, July 8 in a window running from 4:04 p.m. to 4:33 p.m.

The weather forecast for July 8 calls for a 60 percent chance of violating launch conditions at Launch Complex 17-B at the Cape Canaveral Air Force Station in Florida. Technicians at the launch pad are also pumping cool air into the fairing, or aerodynamic cover, around the Dawn spacecraft to cool it to 58 degrees. The air inside the fairing had warmed to 68 degrees, which was not cold enough to allow fueling of the oxidizer tank in the second stage of the Delta II rocket.

Source: NASA - Missions - Dawn

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Spacecraft: Dawn

Launch Vehicle: Delta II

Launch Location: Cape Canaveral Air Force Station, Florida

Launch Pad: Space Launch Complex 17-B

Launch Date: July 8, 2007

Launch Window: 4:04 – 4:33 p.m. EDT

The Rocket

Image above: A Delta II is readied at Launch Pad 17B

to carry the Dawn spacecraft to the asteroid belt in July.

The rocket will use nine boosters.

Image credit: NASA/KSC

A Delta II-Heavy is scheduled to lift the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II is designed to boost medium-sized satellites and robotic explorers into space.

The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch.

Source: NASA - Dawn - Launch

[Owlscrying]

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.

go

[Waspie_Dwarf]

Dawn Launch Delayed

Image above: The Dawn spacecraft is shown before it was encapsulated

inside a proective fairing or cover atop a Delta II rocket. The spacecaft's

solar array wings are folded so it can fit inside the nose section.

Photo credit: NASA/Amanda Diller

+ View hi-res image

07.05.07

The Dawn spacecraft launch has been postponed until no earlier than Monday, July 9. The launch window for Dawn on Monday will be 3:56 p.m. to 4:26 p.m.

Source: NASA - Missions - Dawn

[Waspie_Dwarf]

Dawn Launch Moves to No Earlier Than Monday July 9

The media advisory is reproduced below:

07.05.07

Tabatha Thompson
Headquarters, Washington
202-358-3895

George Diller
Kennedy Space Center, Fla.
321-867-2468

MEDIA ADVISORY: M07-083

Dawn Launch Moves to No Earlier Than Monday July 9

CAPE CANAVERAL, Fla. - The launch of NASA's Dawn spacecraft aboard a Delta II rocket has been rescheduled to no earlier than Monday, July 9.

Because of difficulties with a downrange telemetry aircraft and the availability of a tracking ship, a launch attempt cannot be made before that time. Also, Friday's weather forecast raised the possibility that the loading of propellants aboard the Delta II rocket's second stage might not be completed in time to support a launch before Monday.

The launch window for Monday is 3:56 p.m. to 4:25 p.m. EDT. According to weather forecasts, there is a 40 percent chance of unfavorable conditions for launch.

If a launch attempt is targeted for Monday, the prelaunch press conference will be held at 1 p.m. on Sunday, July 8, at NASA's Kennedy Space Center press site.

Media should call 321-867-2525 for launch updates, status changes and instructions on how to monitor or attend Sunday's press conference. The press conference and launch will be broadcast live on NASA Television.

For more information about Dawn, visit:

http://www.nasa.gov/dawn

- end -

--------------------------------------------------------------------------------

Source: NASA Media Advisory M07-083

[Bear's Quest]

That great! Are they planning to land on either? What are we hoping to find? Is it going bring any samples back?

[Picturesque Orion]

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.

That great! Are they planning to land on either? What are we hoping to find? Is it going bring any samples back?

Yes. Explore. Yes.

[Waspie_Dwarf]

Are they planning to land on either?

No.

What are we hoping to find?

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

Is it going bring any samples back?

No. It has no sample return capsule

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.

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.