NASA launches Twin Lunar Probes to Unravel Moons Core

Blastoff of Delta II Heavy rocket and twin GRAIL Lunar Mappers on Sept 10 blast off unveiled at night at Launch Pad 17B. GRAIL liftoff was postponed to Sept. 10 at 8:29 a.m EDT after high levels winds scrubbed the Sept 8 launch attempt. Credit: Ken Kremer

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NASA renewed its focus on ground breaking science today with the thunderous blastoff of a pair of lunar bound spacecraft that will map the moons interior with unparalled precision and which will fundamentally alter our understanding of how the moon and other rocky bodies in our solar system – including Earth – formed and evolved over 4.5 Billion years.

Today’s (Sept. 10) launch of the twin lunar Gravity Recovery and Interior Laboratory (GRAIL) spacecraft atop the mightiest Delta II rocket from Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT was a nail biter to the end, coming after a two day weather delay due to excessively high upper level winds that scrubbed the first launch attempt on Sept. 8, and nearly forced a repeat cancellation this morning.

Liftoff of the nearly identical GRAIL A and B lunar gravity mappers from Space Launch Complex 17B took place on the second of two possible launch attempts after the first attempt was again waived off because the winds again violated the launch constraints.

GRAIL A and B gravity mappers rocket to the moon atop a Delta II Heavy booster on Sept. 10 from Cape Canaveral, Florida. View to Space Launch Complex 17 gantry from Press Site 1.

Credit: Ken Kremer (kenkremer.com)


After the final “GO” was given, the Delta II Heavy booster suddenly roared to life and put on a spectacular show spewing smoke, flames and ash as it pushed off the pad and shot skywards atop a rapidly growing plume of exhaust and rumbling thunder into a nearly cloudless sky.

The solar powered dynamic duo were propelled to space by the last ever Delta II rocket slated to depart Earth from Cape Canaveral, Florida. After more than 50 years of highly reliable service starting in 1960, the venerable Delta II family will be retired after one final launch in October from Vandenberg Air Force Base in California.

GRAIL and Delta II rocket soar to space.
View to Space Launch Complex 17 Pad A & Pad B (right) from Press Site 1. Credit: Ken Kremer

On this special occasion the media were allowed to a witness the launch from Press Site 1 – a location just 1.5 miles away from the pad with a gorgeous and unobstructed view to the base of the pad which magnified the tremendous roar of the rocket engines.

“Since the earliest humans looked skyward, they have been fascinated by the moon,” said GRAIL principal investigator Maria Zuber from the Massachusetts Institute of Technology in Cambridge. “GRAIL will take lunar exploration to a new level, providing an unprecedented characterization of the moon’s interior that will advance understanding of how the moon formed and evolved.”

Delta II arcs over atop long exhaust plume casting shadow for long lunar journey. Credit: Ken Kremer

The spacecraft separation and deployment of the solar arrays worked exactly as planned, the mission team reported at a post launch briefing for reporters. Both probes are power positive and healthy.

GRAIL A and B are now speeding towards the moon on a low energy path that will take about 3.5 months compared to just three days for the Apollo astronauts. The slower and longer path covering more than 2.5 million miles (4 million kilometers) enables the spacecraft to use a smaller engine and carry less fuel for the braking maneuver required to place the probes into a polar elliptical orbit when they arrive at the moon about 25 hours apart on New Year’s Eve and New Year’s Day 2012.

“Our GRAIL twins have Earth in their rearview mirrors and the moon in their sights,” said David Lehman, GRAIL project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “The mission team is ready to test, analyze and fine-tune our spacecraft over the next three-and-a-half months on our journey to lunar orbit.”

During the 82 day science phase, the primary objective of is to study the moons interior from crust to core and map its gravity field by 100 to 1000 times better than ever before. GRAIL A and GRAIL B will fly in tandem formation in near circular polar orbit at an altitude of some 50 km above the lunar surface as the moon rotates beneath three times.

GRAIL lunar twins depart Earth for the Moon
All 3 Air-lit solids have ignited after all 6 ground lit solids have been jettisoned.Credit: Ken Kremer

The mission will provide unprecedented insight into the structure and composition of moon from crust to core, unlock the mysteries of the lunar interior and advance our understanding of the thermal evolution of the moon that can be applied to the other terrestrial planets in our solar system, including Mercury, Venus, Earth and Mars.

Read Ken’s continuing features about GRAIL
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10

Delta II Heavy rocket and GRAIL Lunar mappers unveiled at night at Launch Pad 17B. GRAIL liftoff was postponed to Sept. 10 at 8:29 a.m EDT after high levels winds scrubbed the Sept 8 launch attempt. Credit: Ken Kremer

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NASA’s Gravity Recovery and Interior Laboratory (GRAIL) moon mapping twins and the mighty Delta II rocket that will blast the high tech physics experiment to space on a lunar science trek were magnificently unveiled in the overnight darkness in anticipation of a liftoff that had originally been planned for the morning of Sept. 8.

Excessively high upper level winds ultimately thwarted Thursday’s launch attempt.

NASA late today has just announced a further postponement by another day to Saturday Sept. 10 to allow engineers additional time to review propulsion system data from Thursday’s detanking operation after the launch attempt was scrubbed to Friday. Additional time is needed by the launch team to review the pertinent data to ensure a safe blastoff of the $496 Million GRAIL mission.

There are two instantaneous launch opportunities at 8:29:45 a.m. and 9:08:52 a.m. EDT at Cape Canaveral, eight minutes earlier than was planned on Sept. 8. The weather forecast for Sept. 10 still shows a 60 percent chance of favorable conditions for a launch attempt.

GRAIL A and B enclosed in nose cone atop Delta II rocket at Cape Canaveral, Florida. Umbilical’s connect from Delta 2 to Fixed Umbilical Tower (FUT).
Credit: Ken Kremer (kenkremer.com)

Despite a rather poor weather prognosis, the heavy space coast cloud cover had almost completely cleared out in the final hours before launch, the surface winds were quite calm and we all expected to witness a thunderous liftoff. But measurements from weather balloons sent aloft indicated that the upper level winds were “red” and violated the launch criteria.

Mobile Service Tower is retracted from around Delta II rocket at Pad 17B. Credit: Ken Kremer

As the launch gantry was quickly retracted at Launch Complex 17B on Sept. 7, the Delta was bathed in xenon spotlights that provided a breathtaking light show as the service structure moved a few hundred feet along rails.

The cocoon like Mobile Service Tower (MST) provides platforms to access the rocket at multiple levels to prepare the vehicle and spacecraft for flight. The MST also protects the rocket from weather and impacts from foreign debris.

The GRAIL A and B mirror image twins ride side by side to space atop the Delta rocket. The washing machine spacecraft weigh about 677 pounds (307 kg) each.

The Delta II rocket stands 128 feet tall and is 8 feet in diameter. The first stage liquid and solid rocket fueled engines will generate about 1.3 million pounds of thrust.

During the Terminal Countdown, the first stage is fueled with cryogenic liquid oxygen and highly refined kerosene (RP-1).

GRAIL is an extraordinary first ever journey to the center of the moon that will — with its instruments from orbit — peer into the moons interior from crust to core and map its gravity field by 100 to 1000 times better than ever before. The mission employs two satellites flying in tandem formation some 50 km in near circular polar orbit above the lunar surface.

GRAIL A and B will perform high precision range-rate measurements between them using a Ka-band instrument. The mission will provide unprecedented insight into the formation and thermal evolution of the moon that can be applied to the other rocky planets in our solar system: Mercury, Venus, Earth and Mars.

After a 3.5 month journey to the moon, the probes will arrive about a day apart on New Year’s Eve and New Year’s Day 2012 for an 82 day science mapping phase as the moon rotates three times beneath the GRAIL orbit.

Photojournalists watch as Mobile Service Tower is retracted from around Delta II rocket at Pad 17B.
Credit: Ken Kremer

Xenon spotlights bathe Delta II rocket as Mobile Service Tower is retracted at Pad 17 and photojournalists watch from nearby at Pad 17B. Credit: Ken Kremer

Read Ken’s continuing features about GRAIL
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8

Delta II Heavy rocket will blast GRAIL missions to the moon from Launch Pad 17B. Delta II rocket and twin GRAIL satellites are enclosed inside the Mobile Service Tower at Cape Canaveral Air Force Station. Credit: Ken Kremer

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Another American rocket Era is about to end. The venerable Delta II rocket, steeped in history, will fly what is almost certainly its final mission from Cape Canaveral. And it will do so quite fittingly by blasting twin satellites to the moon for NASA on a unique path for a truly challenging mission to do “extraordinary science”.

On Sept. 8, the most powerful version of the Delta II, dubbed the Delta II Heavy, is slated to launch NASA’s duo of GRAIL lunar mappers on an unprecedented science mission to unlock the mysteries of the moons deep interior. There are two instantaneous launch windows at 8:37:06 a.m. and 9:16:12 a.m. EDT lasting one second each.

GRAIL simply put, is a journey to the center of the moon,” said Ed Weiler, NASA Associate Administrator of the Science Mission Directorate in Washington,DC at a pre-launch briefing for reporters on Sept. 6.

“It will probe the interior of the moon and map its gravity field by 100 to 1000 times better than ever before. We will learn more about the interior of the moon with GRAIL than all previous lunar missions combined.”

View of Delta II rocket looking out to Atlantic Ocean from upper level of Launch Complex 17. ULA and GRAIL logos painted on side of 8 ft diameter Delta rocket. Credit: Ken Kremer

GRAIL will depart Earth from Space Launch Complex 17B (SLC-17B) at Cape Canaveral Air Force Station, Florida, which is also the last scheduled use of Pad 17B.

GRAIL logo painted on the side of Delta II Rocket 1st Stage. Photo taken from inside upper level of launch gantry. GRAIL stands for Gravity Recovery and Interior Laboratory. Credit: Ken Kremer

“Trying to understand how the moon formed, and how it evolved over its history, is one of the things we’re trying to address with the GRAIL mission,” says Maria Zuber, principal investigator for GRAIL from the Massachusetts Institute of Technology. “But also, (we’re) trying to understand how the moon is an example of how terrestrial planets in general have formed.”

“GRAIL is a mission that will study the inside of the moon from crust to core,” Zuber says.

Delta II Heavy rocket is augmented by 9 wider diameter solid rocket motors providing more thrust. Credit: Ken Kremer

So far there have been 355 launches of the Delta II family, according to NASA’s Delta II Launch Manager Tim Dunn. The Delta II is built by United Launch Alliance.

“GRAIL is the last contracted Delta II mission to be launched from Complex 17. And it will be the 356th overall Delta to be launched. Complex 17 at the Cape has a proud heritage of hosting 258 of those 355 total Delta launches to date.

Hypergolic propellants have been loaded onto the 2nd stage after assessing all the preparations for the rocket, spacecraft, the range and facilities required for launch.

“The Launch Readiness Review was successfully completed and we can proceed with the countdown,” said Dunn.
The Delta II Heavy is augmented with nine larger diameter ATK solid rocket motors.

The Mobile Service Tower will be rolled back from the Delta II rocket tonight, starting at about 10:30 p.m. EDT depending on the weather.

The weather forecast for launch remains very iffy at a 60% percent chance of “NO GO” according to NASA and Air Force officials.

A launch decision will be made tomorrow morning Sept. 8 right after the weather briefing but before fueling begins at 6:30 a.m.

The weather forecast for rollback of the Mobile Service Tower tonight remains generally favorable. There is a 40% chance of a weather issue at 10:30 p.m. which drops to 30% after midnight. Tower rollback can be pushed back about 2 hours without impacting the countdown, says NASA.

Weather remains at 60% NO GO in case of a 24 hour delay but improves over the weekend. The team has about 42 days time in the launch window.

After entering lunar orbit, the two GRAIL spacecraft will fly in a tandem formation just 55 kilometers above the lunar surface with an average separation of 200 km during the three month science phase.

Stay tuned to Universe Today for updates overnight leading to liftoff at 8:37 a.m.

See my photo album from a recent tour of Launch Complex 17 and the Mobile Service Tower

GRAIL Flying in Formation. Using a precision formation-flying technique, the twin GRAIL spacecraft will map the moon's gravity field. The mission also will answer longstanding questions about Earth's moon, including the size of a possible inner core, and it should provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed. GRAIL is a part of NASA's Discovery Program.

Read Ken’s continuing features about GRAIL

NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad

GRAIL Lunar Twins hoisted to top of Launch Pad 17B at Cape Canaveral. NASA's twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft are lifted to the top of their launch pad at Space Launch Complex 17B at Cape Canaveral Air Force Station in Florida and were mated to their Delta II Heavy Booster Rocket. They are wrapped in plastic to prevent contamination outside the clean room. Launch is scheduled for Sept. 8. Credit: NASA/Kim Shiflett

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With blastoff just 2 ½ weeks away, NASA’s GRAIL lunar twins completed a major milestone towards launch today (Aug. 18) when they were mated to the top of the Delta II Heavy rocket that will boost them to the moon. Launch is slated for Sept. 8 at 8:37 a.m. EDT.

This morning the tightly wrapped $496 Million duo took their last trip on Earth before beginning their nearly four month journey to the Moon. GRAIL A & GRAIL B were carefully transported 15 miles (25 km) from the clean room processing facility at the Astrotech Space Operation’s payload processing facility in Titusville, Fla to Space Launch Complex 17B (SLC-17B) at Cape Canaveral Air Force Station in Florida.

“The GRAIL spacecraft transportation convoy to SLC-17B departed Astrotech at 11:55 p.m. EDT on Wednesday, Aug. 17, “ said Tim Dunn, NASA’s Delta II Launch Director in an interview with Universe Today. “The spacecraft, inside the handling can, arrived at the launch pad, SLC-17B, at 4:00 a.m. this morning.”

“The spacecraft was then hoisted by the Mobile Service Tower crane onto the Delta II launch vehicle and the spacecraft mate was complete at 9:30 a.m.”

Crane lifts GRAIL A & B to the top of the Mobile Service Tower on Aug. 18. The probes are wrapped in protective plastic sheeting inside the handling can. Credit: NASA/Kim Shiflett

Technicians joined the nearly identical and side by side mounted spacecraft onto the top of the guidance section adapter of the Delta’s second stage. The Delta II was built by United Launch Alliance (ULA).

“Tomorrow, the GRAIL spacecraft team will perform functional testing on both the GRAIL A and GRAIL B spacecraft,” Dunn told me.

“The next major milestone will be performance of the Integrated Systems Test (IST) on Monday, (8/22/11).

“Today’s spacecraft mate operation was flawlessly executed by the combined ULA and NASA Delta II Team,” said Dunn.

These tests will confirm that the spacecraft is healthy after the fueling and transport operations. After further reviews of the rocket and spacecraft systems the GRAIL team will install the payload fairing around the lunar probes.

NASA’s twin GRAIL Science Probes ready for Lunar Expedition
GRAIL B (left) and GRAIL A (right) spacecraft are mounted side by side on top of a payload adapter inside the clean room at Astrotech Space Operations facility. The spacecraft await lunar launch on Sept. 8, 2011. Credit: Ken Kremer

NASA’s dynamic duo will orbit the moon to determine the structure of the lunar interior from crust to core and to advance understanding of the thermal evolution of the moon.

“We are about to finish one chapter in the GRAIL story and open another,” said Maria Zuber, GRAIL’s principal investigator, based at the Massachusetts Institute of Technology in Cambridge in a statement. “Let me assure you this one is a real page-turner. GRAIL will rewrite the book on the formation of the moon and the beginning of us.”

The GRAIL launch will be the last for a Delta II in Florida.

GRAIL A & B lunar twins arrive at Pad 17B. Credit: NASA/Kim Shiflett

Technicians hoist GRAIL A & B lunar twins inside the handling can at Pad 17B. Credit: NASA/Kim Shiflett

Read my prior features about GRAIL
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

NASA’s twin GRAIL Science Probes ready for Lunar Expedition. GRAIL B (left) and GRAIL A (right) spacecraft are mounted side by side on top of a payload adapter inside the clean room at Astrotech Space Operations facility. The spacecraft await lunar launch on Sept. 8, 2011. Credit: Ken Kremer

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NASA’s GRAIL twins – dubbed GRAIL-A & GRAIL-B – are ready to embark on America’s next science expedition to the moon in less than 1 month’s time from Cape Canaveral Air Force Station, Fla.

The twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft have been exhaustively tested, fueled for flight and mounted side-by-side on a specially designed payload adapter inside the controlled environment of a clean room at the Astrotech Space Operations facility in nearby Titusville, Fla.

The next processing step is to encapsulate the lunar probes inside their protective payload fairing. The duo are set to be shipped from Astrotech to their Cape Canaveral launch pad next week on Aug. 16, where they will be mated to an already assembled Delta II booster.

Liftoff of the GRAIL twins is slated for Sept. 8 at 8:37 a.m. EDT by a Delta II Heavy rocket from Launch Complex 17 at Cape Canaveral for a nearly four month voyage to the moon.

After entering lunar orbit, the two GRAIL spacecraft will fly in a tandam formation just 50 kilometers above the lunar surface with an average separation of 200 km during the 90 day science phase.

Side view of twin GRAIL probes
The GRAIL spacecraft are mounted to a 3 inch high Launch Vehicle Adapter Assembly and 20 inch Payload Adapter spacer ring on top of a 30-inch high GSE stand. Credit: Ken Kremer (kenkremer.com)

GRAIL’s mission goal is to map the moon’s gravity field to high precision and thereby deduce the structure of the lunar interior from crust to core. This will also lead to a better understanding of the composition of the moon’s interior, according to Sami Asmar, GRAIL co-investigator from NASA’s Jet Propulsion Laboratory in Pasasdena, Calif., during an interview inside the Astrotech clean room at a photo opportunity for the media. A gravity experiment is also aboard the just launched Jupiter bound Juno spacecraft.

GRAIL Photo Album special taken from inside the Astrotech cleanroom facility.

Twin GRAIL lunar probes inside clean room at Astrotech. Credit: Ken Kremer
Close up of twin lunar probes, GRAIL- B (left) & GRAIL- A (right). Credit: Ken Kremer
GRAIL-B solar panels. Credit: Ken Kremer
GRAIL Science and Launch team inside clean room at Astrotech. Credit: Ken Kremer
GRAIL Co-Investigator Sami Asmar (left) from JPL and Ken Kremer discuss science objectives inside clean room at Astrotech.

Aquarius Satellite Launches to Observe Earth’s Oceans

A picture-perfect launch on a Delta II rocket from Vandeberg Air Force Base in California sent the newest satellite into orbit. The Aquarius/SAC-D spacecraft lifted off June 10, 2011 at 7:20 a.m. PDT (1420 UTC) to gather global measurements of ocean surface salinity, leading to a better understanding of ocean circulation, climate and Earth’s water cycle. NASA’s Aquarius instrument is part of the SAC-D spacecraft built by CONAE, Argentina’s space agency.

Continue reading “Aquarius Satellite Launches to Observe Earth’s Oceans”

Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Virtual Vesta. Taking their best guess, the science team on NASA’s Dawn Asteroid Orbiter have created a series of still images and videos (see below) to simulate what the protoplanet Vesta might look like. The exercise was carried out by mission planners at NASA's Jet Propulsion Laboratory and science team members at the German Aerospace Center and the Planetary Science Institute. Image credit: NASA/JPL-Caltech/ESA/UCLA/DLR/PSI/STScI/UMd

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The excitement is building as NASA’s innovative Dawn spacecraft closes in on its first protoplanetary target, the giant asteroid Vesta, with its camera eyes now wide open. The probe is on target to become the first spacecraft from Earth to orbit a body in the main asteroid belt and is set to arrive about four months from now in late July 2011.

Vesta is the second most massive object in the Asteroid Belt between Mars and Jupiter (map below). Since it is also one of the oldest bodies in our Solar System, scientists are eager to study it and search for clues about the formation and early history of the solar system. Dawn will spend about a year orbiting Vesta. Then it will fire its revolutionay ion thrusters and depart for Ceres, the largest asteroid in our solar system.

Dawn is equipped with three science instruments to photograph and investigate the surface mineralogy and elemental composition of the asteroid. The instruments were provided by the US, Germany and Italy. The spacecraft has just awoken from a six month hibernation phase. All three science instruments have been powered up and reactivated.

Dawn will image about 80 percent of Vesta’s surface at muliple angles with the onboard framing cameras to generate topographical maps. During the year in orbit, the probe will adjust its orbit and map the protoplanet at three different and decreasing altitudes between 650 and 200 kilometers, and thus increasing resolution. The cameras were provided and funded by Germany.

To prepare for the imaging campaign, mission planners from the US and Germany conducted a practice exercise to simulate the mission as though they were mapping Vesta. The effort was coordinated among the science and engineering teams at NASA’s Jet Propulsion Laboratory, the Institute of Planetary Research of the German Aerospace Center (DLR) in Berlin and the Planetary Science Institute in Tuscon, Ariz.

Simulated Vesta from the South Pole
This image shows the scientists' best guess to date of what the surface of the protoplanet Vesta might look like from the south pole, as projected onto a sphere 250 kilometers (160 miles) in radius. It was created as part of an exercise for NASA's Dawn mission involving mission planners at NASA's Jet Propulsion Laboratory and science team members at the Planetary Science Institute in Tuscon, Ariz. Credit: NASA/JPL-Caltech/UCLA/PSI

“We won’t know what Vesta really looks like until Dawn gets there,” said Carol Raymond in a NASA statement. Raymond is Dawn’s deputy principal investigator, based at JPL, who helped orchestrate the activity. “But we needed a way to make sure our imaging plans would give us the best results possible. The products have proven that Dawn’s mapping techniques will reveal a detailed view of this world that we’ve never seen up close before.”

Two teams worked independently and used different techniques to derive the topographical maps from the available data sets. The final results showed only minor differences in spatial resolution and height accuracy.

Using the best available observations from the Hubble Space Telescope and ground based telescopes and computer modeling techniques, they created maps of still images and a rotating animation (below) showing their best guess as to what Vesta’s surface actually looks like. The maps include dimples, bulges and craters based on the accumulated data to simulate topography and thus give a sense of Virtual Vesta in three dimensions (3 D).

“Working through this exercise, the mission planners and the scientists learned that we could improve the overall accuracy of the topographic reconstruction, using a somewhat different observation geometry,” said Nick Mastrodemo, Dawn’s optical navigation lead at JPL. “Since then, Dawn science planners have worked to tweak the plans to implement the lessons of the exercise.”

Dawn launch on September 27, 2007 by a Delta II rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer
Of course no one will know how close these educated guesses come to matching reality until Dawn arrives at Vesta.

The framing camera system consists of two identical cameras developed and built by the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany and the German Aerospace Center (DLR) in Berlin.

“The camera system is working flawlessly. The dry run was a complete success,” said Andreas Nathues, lead investigator for the framing camera at the Max Planck Institute in Katlenburg-Lindau, Germany.

Since the probe came out of hibernation, the mechanical and electrical components were checked out in mid March and found to be in excellent health and the software was updated.

Dawn is a mission of many firsts.

Dawn spacecraft under construction in Cleanroom.
Picture shows close up view of two science instruments;
The twin Framing Cameras at top (white rectangles) and VIR Spectrometer at right. Credit: Ken Kremer
The spacecraft is NASA’s first mission specifically to the Asteroid Belt. It will become the first mission to orbit two solar system bodies.

The revolutionary Dawn mission is powered by exotic ion propulsion which is vastly more efficient than chemical propulsion thrusters. Indeed the ability to orbit two bodies in one mission is only enabled via the use of the ion engines fueled by xenon gas.

Vesta and Ceres are very different worlds that orbit between Mars and Jupiter. Vesta is rocky and may have undergone volcanism whereas Ceres is icy and may even harbor a subsurface ocean conducive to life.

Dawn will be able to comparatively investigate both celestial bodies with the same set of science instruments and try to unlock the mysteries of the beginnings of our solar system and why they are so different.

Dawn is part of NASA’s Discovery program and was launched in September 2007 by a Delta II rocket from Cape Canaveral Air Force Station, Florida.

Virtual Vesta in 2 D.
This image shows a model of the protoplanet Vesta, using scientists' best guess to date of what the surface of the protoplanet might look like. The images incorporate the best data on dimples and bulges of Vesta from ground-based telescopes and NASA's Hubble Space Telescope. The cratering and small-scale surface variations are computer-generated, based on the patterns seen on the Earth's moon, an inner solar system object with a surface appearance that may be similar to Vesta. Credit: NASA/JPL-Caltech/UCLA/PSI
Virtual Vesta in 3 D.
This anaglyph -- best viewed through red-blue glasses -- shows a 3-D model of the protoplanet Vesta, using scientists' best guess to date of what the surface of the protoplanet might look like. Image credit: NASA/JPL-Caltech/UCLA/PSI
Dawn Spacecraft current location approaching Asteroid Vesta on March 21, 2011