Good News for Future Moon Bases. There’s Water Inside the Moon

Since the Apollo program wrapped up in the early 1970s, people all around the world have dreamed of the day when we might return to the Moon, and stay there. And in recent years, however, that actual proposals for a lunar settlement have begun to take shape. As a result, a great deal of attention and research has been focused on whether or not the Moon has indigenous sources of water.

Thanks to missions like Chandrayaan-1 and the Lunar Reconnaissance Orbiter (LRO), scientists know that there are vast amounts of surface ice on the Moon. However, according to a new study, researchers from Brown University have found evidence of widespread water within volcanic deposits on the lunar surface. These findings could indicate that there are also vast sources of water within the Moon’s interior.

For their study – titled “Remote Detection of Widespread Indigenous Water in Lunar Pyroclastic Deposits” – Brown researchers Ralph E. Milliken and Shuai Li combined satellite data with new thermal profiles to search for signs of water away from the polar regions. In so doing, they addressed a long-standing theory about the likelihood of water in the Moon’s interior, as well as the predominant theory of how the Moon formed.

Lunar Crater as imaged by NASA’s Moon Mineralogy Mapper. Credit: SRO/NASA/JPL-Caltech/USGS/Brown Univ.

As noted, scientists have known for years that there are large amounts of frozen water in the Moon’s polar regions. At the same time, however, scientists have held that the Moon’s interior must have depleted of water and other volatile compounds billions of years ago. This was based on the widely-accepted hypothesis that the Moon formed after a Mars-sized object (named Theia) collided with Earth and threw up a considerable amount of debris.

Essentially, scientists believed that it was unlikely that any hydrogen – necessary to form water – could have survived the heat of this impact. However, as of a decade ago, new scientific findings began to emerge that cast doubt on this. The first was a 2008 study, where a team of researches (led by Alberto Saal of Brown University) detected trace amounts of water in samples of volcanic glass that were bought back by the Apollo 15 and Apollo 17 missions.

This was followed by a 2011 study (also from Brown University) that indicated how crystalline structures within those beads contained as much water as some basalt mineral deposits here on Earth. These findings were particularly significant, in that they suggested that parts of the Moon’s mantle could contain as much water as Earth’s. The question though was whether these findings represented the norm, or an anomaly.

As Milliken, an associate professor in Brown’s Department of Earth, Environmental, and Planetary Sciences (DEEPS) and the co-author on the paper, summarized in a recent Brown press release:

“The key question is whether those Apollo samples represent the bulk conditions of the lunar interior or instead represent unusual or perhaps anomalous water-rich regions within an otherwise ‘dry’ mantle. By looking at the orbital data, we can examine the large pyroclastic deposits on the Moon that were never sampled by the Apollo or Luna missions. The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the Moon is wet.”

A false colour composite of the distribution of water and hydroxyl molecules over the lunar surface. Credit: ISRO/NASA/JPL-Caltech/Brown Univ/USGS

To resolve this, Milliken and Li consulted orbital data to examine lunar volcanic deposits for signs of water. Basically, orbiters use spectrometers to bounce light off the surfaces of planets and astronomical bodies to see which wavelengths of light are absorbed and which are reflected. This data is therefore able to determine what compounds and minerals are present based on the absorption lines detected.

Using this technique to look for signs of water in lunar volcanic deposits (aka. pyroclastic deposits), however, was a  rather difficult task. During the day, the lunar surface heats up, especially in the latitudes where volcanic deposits are located. As Milliken explained, spectronomers will therefore pick up thermal energy in addition to chemical signatures which this can throw off the readings:

“That thermally emitted radiation happens at the same wavelengths that we need to use to look for water. So in order to say with any confidence that water is present, we first need to account for and remove the thermally emitted component.”

To correct for this, Milliken and Li constructed a detailed temperature profile of the areas of the Moon they were examining. They then examined surface data collected by the Moon Mineralogy Mapper, the spectrographic imager that was part of India’s Chandrayaan-1 mission. They then compared this thermally-corrected surface data to the measurements conducted on the samples returned from the Apollo missions.

Colored areas indicate elevated water content compared with surrounding terrains. Yellows and reds indicate the richest water content. Credit: Milliken lab/Brown University

What they found was that areas of the Moon’s surface that had been previously mapped showed evidence of water in nearly all the large pyroclastic deposits. This included the deposits that were near the Apollo 15 and 17 landing sites where the lunar samples were obtained. From this, they determined that these samples were not anomalous in nature, and that water is distributed across the lunar surface.

What’s more, these findings could indicate that the Moon’s mantle is water-rich as well. Beyond being good news for future lunar missions, and the construction of a lunar settlement, these results could lead to a rethinking of how the Moon formed. This research was part of Shuai Li’s – a recent graduate of the University of Brown and the lead author on the study – Ph.D thesis. As he said of the study’s findings:

“The growing evidence for water inside the Moon suggest that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the Moon had completely solidified. The exact origin of water in the lunar interior is still a big question.

What’s more, Li indicated that lunar water that is located in volcanic deposits could be a boon for future lunar missions. “Other studies have suggested the presence of water ice in shadowed regions at the lunar poles, but the pyroclastic deposits are at locations that may be easier to access,” he said. “Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative.”

The blue areas show locations on the Moon’s south pole where water ice is likely to exist. Credit: NASA/GSFC

Between NASA, the ESA, Roscosmos, the ISRO and the China National Space Administration (CNSA), there are no shortage of plans to explore the Moon in the future, not to mention establishing a permanent base there. Knowing there’s abundant surface water (and maybe more in the interior as well) is therefore very good news.  This water could be used to create hydrazine fuel, which would significantly reduce the costs of individual missions to the Moon.

It also makes the idea of a stopover base on the Moon, where ships traveling deeper into space could refuel and resupply – a move which would shave billions off of deep-space missions. An abundant source of local water could also ensure a ready supply of drinking and irrigation water for future lunar outposts. This would also reduce costs by ensuring that not all supplies would need to be shipped from Earth.

On top of all that, the ability to conduct experiments into how plants grow in reduced gravity would yield valuable information that could be used for long-term missions to Mars and other Solar bodies. It could therefore be said, without a trace of exaggeration, that water on the Moon is the key to future space missions.

The research was funded by the NASA Lunar Advanced Science and Exploration Research (LASER) program, which seeks to enhance lunar basic science and lunar exploration science.

Further Reading: Brown University

Moon’s Insides Still Hot, Hot, Hot After Billions Of Years Of Formation: Study

Rather than being dead inside, the Moon still has a warm interior that is due to the effect of the Earth’s gravity on our closest major celestial neighbor, a new study says. The results came after looking at results from the SELENE (SELenological and ENgineering Explorer) spacecraft as well as other missions exploring the Moon.

“I believe that our research results have brought about new questions. For example, how can the bottom of the lunar mantle maintain its softer state for a long time? To answer this question, we would like to further investigate the internal structure and heat-generating mechanism inside the Moon in detail,” stated Yuji Harada, the principal investigator of the research team.

“Another question has come up: How has the conversion from the tidal energy to the heat energy in the soft layer affected the motion of the Moon relative to the Earth, and also the cooling of the Moon?” he added. “We would like to resolve those problems as well so that we can thoroughly understand how the Moon was born and has evolved.”

A diagram of the moon's interior showing its viscosity (the thickness of its interior liquid) as well as parameters of its internal density. Credit: NAOJ
A diagram of the moon’s interior showing its viscosity (the thickness of its interior liquid) as well as parameters of its internal density. Credit: NAOJ

Clues to the Moon’s interior come from examining how the Earth’s gravity deforms its inside through tidal forces. Models show that tidal changes within the moon are likely due to a “soft layer” deep within the lunar mantle. Scientists learned that the Moon has a core (inner portion, made up of metal) and a mantle (made up of rock) through the Apollo missions, which saw astronauts deploy seismic devices that revealed the interior structure.

“The previous studies indicated that there is the possibility that a part of the rock at the deepest part inside the lunar mantle may be molten. This research result supports the above possibility since partially molten rock becomes softer,” the National Astronomical Observatory of Japan stated. “This research has proven for the first time that the deepest part of the lunar mantle is soft, based upon the agreement between observation results and the theoretical calculations.”

Researchers believe the heat occurs in a soft layer that is deep within the mantle, and not throughout the entire Moon. They said that possible future research directions could include why it is only this layer that remains soft, and how tidal energy changes the Moon’s cooling and its relative motion to Earth.

The research was published in Nature Geoscience.

Source: National Astronomical Observatory of Japan

Twin NASA Science Probes Start Lunar Gravity Mapping

[/caption]

NASA’s twin lunar orbiting GRAIL (Gravity Recovery and Interior Laboratory) spacecraft christened Ebb and Flow have kicked off their science collection phase aimed at precisely mapping our Moon’s gravity field, interior composition and evolution, the science team informed Universe Today.

“GRAIL’s science mapping phase officially began Tuesday (March 6) and we are collecting science data,” said Maria Zuber, GRAIL principal investigator of the Massachusetts Institute of Technology in Cambridge, to Universe Today.

“It is impossible to overstate how thrilled and excited we are !”

“The data appear to be of excellent quality,” Zuber told me.

GRAIL’s goal is to provide researchers with a better understanding of how the Moon, Earth and other rocky planets in the solar system formed and evolved over its 4.5 billion years of history.

NASA’s Dawn spacecraft is currently mapping the gravity field of Asteroid Vesta in high resolution from low orbit.

Despite more than 100 missions to the Moon there is still a lot we don’t know about the Moon says Zuber, like why the near side is flooded with magma and smooth and the back side is rough, not smooth and completely different.

South pole of the far side of the moon as seen as seen in this 1st image from the MoonKAM camera aboard GRAIL mission’s Ebb spacecraft. Credit: NASA/JPL-Caltech

The formation-flying spacecraft will make detailed science measurements from lunar orbit with unparalleled precision to within 1 micron – the width of a human red blood cell – by transmitting Ka-band radio signals between each other and Earth to help unlock the mysteries of the Moon’s deep interior.

“We’ve worked on calibrating the alignment of the Ka-band antennae to establish the optimal alignment. We’ve verified the data pipeline and are spending a lot of time working with the raw data to make sure that we understand its intricacies,” Zuber explained.

The washing-machine sized probes have been flying in tandem around the Moon since entering lunar orbit in back to back maneuvers over the New Year’s weekend. Engineers have spent the past two months navigating the spaceship duo into lower, near-polar and near-circular orbits with an average altitude of 34 miles (55 kilometers), that are optimized for science data collection, and simultaneously checking out the spacecraft systems.

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

Ebb and Flow were launched to the Moon on September 10, 2011 aboard a Delta II rocket from Cape Canaveral, Florida and took a circuitous 3.5 month low energy path to the moon to minimize the overall costs. The Apollo astronauts reached the Moon in just 3 days.

I asked Zuber to describe the team’s activities putting the mirror image probes to work peering to the central core of our nearest neighbor in unprecedented detail.

“Last Wednesday (Feb. 29) we achieved the science orbit and on Thursday (March 1) we turned the spacecraft to ‘orbiter point’ configuration to test the instrument and to monitor temperatures and power.”

“When we turned on the instrument we established the satellite-to-satellite radio link immediately. All vital signs were nominal so we left the spacecraft in orbiter point configuration and have been collecting science data since then. At the same time, we’ve continued performing calibrations and monitoring spacecraft and instrument performance, such as temperatures, power, currents, voltages, etc., and all is well,” said Zuber.

Measurements gathered over the next 84 days will be used to create high-resolution maps of the Moon’s near side and far side gravitational fields that are 100 to 1000 times more precise than ever before and that will enable researchers to deduce the internal structure and composition of our nearest neighbor from the outer surface crust down to the deep hidden core.

As one satellite follows the other, in the same orbit, they will perform high precision range-rate measurements to precisely measure the changing distance between each other. As they fly over areas of greater and lesser gravity caused by visible features such as mountains, craters and masses hidden beneath the lunar surface, the distance between the two spacecraft will change slightly.

“GRAIL is great. Everything is in place to get science data now,” said Sami Asmar, a GRAIL co-investigator from NASA’s Jet Propulsion Lab in Pasadena, Calif. “Soon we’ll get a very high resolution and global gravity map of the Moon.”

The data collected will be translated into gravitational field maps of the Moon that will help unravel information about the makeup of the Moon’s core and interior composition.

GRAIL will gather three complete gravity maps over the three month mission which is expected to conclude around May 29. If the probes survive a solar eclipse in June and if NASA funding is available, then they may get a bonus 3 month extended mission.

Ebb and Flow - New Names for the GRAIL Twins in Lunar Orbit
4th Grade Students from Montana (inset) win NASA’s contest to rename the GRAIL A and GRAIL B spacecraft. Artist concept of twin GRAIL spacecraft flying in tandem orbits around the Moon to measure its gravity field Credit: NASA/JPL Montage: Ken Kremer

NASA sponsored a nation-wide student contest for America’s Youth to choose new names for the twin probes originally known as GRAIL A and GRAIL B. 4th graders from the Emily Dickinson Elementary School in Bozeman, Montana submitted the winning entries -Ebb and Flow. The new names won because they astutely describe the probes movements in orbit to collect the science data.

The GRAIL twins are also equipped with a very special camera dubbed MoonKAM (Moon Knowledge Acquired by Middle school students) whose purpose is to inspire kids to study science.

By having their names selected, the 4th graders from Emily Dickinson Elementary have also won the prize to choose the first target on the Moon to photograph with the MoonKAM cameras, which are managed by Dr Sally Ride, America’s first female astronaut.

“MoonKAMs on both Ebb and Flow were turned on Monday, March 5, and all appears well, Zuber said. “The Bozeman 4th graders will have the opportunity to target the first images a week after our science operations begin.”

America’s Youth Christen NASA’s Twin New Lunar Craft – Ebb & Flow

[/caption]

A classroom of America’s Youth from an elementary school in Bozeman, Montana submitted the stellar winning entry in NASA’s nationwide student essay contest to rename the twin GRAIL lunar probes that just achieved orbit around our Moon on New Year’s Eve and New Year’s Day 2012

“Ebb” & “Flow” – are the dynamic duo’s official new names and were selected because they clearly illuminate the science goals of the gravity mapping spacecraft and how the Moon’s influence mightily affects Earth every day in a manner that’s easy for everyone to understand.

“The 28 students of Nina DiMauro’s class at the Emily Dickinson Elementary School have really hit the nail on the head,” said GRAIL principal investigator Prof. Maria Zuber of the Massachusetts Institute of Technology in Cambridge, Mass.

“We asked the youth of America to assist us in getting better names.”

“We chose Ebb and Flow because it’s the daily example of how the Moon’s gravity is working on the Earth,” said Zuber during a media briefing held today (Jan. 17) at NASA Headquarters in Washington, D.C. The terms ebb and flow refer to the movement of the tides on Earth due to the gravitational pull from the Moon.

“We were really impressed that the students drew their inspiration by researching GRAIL and its goal of measuring gravity. Ebb and Flow truly capture the spirit and excitement of our mission.”

Leland Melvin, NASA Associate Administrator for Education, left, Maria Zuber, GRAIL Prinicipal Investigator at the Massachusetts Institute of Technology, and James Green, Director of the Planetary Science Division in the Science Mission Directorate at NASA Headquarters, right, applaud students from Emily Dickinson Elementary School in Bozeman, Mont. during a news conference, Tuesday, Jan. 17, 2012, at NASA Headquarters in Washington. Nine hundred classrooms and more than 11,000 students from 45 states, as well as Puerto Rico and the District of Columbia, participated in a contest that began in October 2011 to name the twin lunar probes. Credit: NASA/Paul E. Alers

Ebb and Flow are flying in tandem around Earth’s only natural satellite, the first time such a feat has ever been attempted.

As they fly over mountains, craters and basins on the Moon, the spaceships will move back and forth in orbit in an “ebb and flow” like response to the changing lunar gravity field and transmit radio signals to precisely measure the variations to within 1 micron, the width of a red blood cell.

The breakthrough science expected from the mirror image twins will provide unprecedented insight into what lurks mysteriously hidden beneath the surface of our nearest neighbor and deep into the interior.

The winning names from the 4th Graders of Emily Dickinson Elementary School were chosen from essays submitted by nearly 900 classrooms across America with over 11,000 students from 45 states, Puerto Rico and the District of Columbia, Zuber explained.

The students themselves announced “Ebb” and “Flow” in a dramaric live broadcast televised on NASA TV via Skype.

“We are so thrilled that our names were chosen and excited to share this with you. We can’t believe we won! We are so honored. Thank you!” said Ms. DiMauro as the very enthusiastic students spelled out the names by holding up the individual letters one-by-one on big placards from their classroom desks in Montana.

Watch the 4th Grade Kids spell the names in this video!

Until now the pair of probes went by the rather uninspiring monikers of GRAIL “A” and “B”. GRAIL stands for Gravity Recovery And Interior Laboratory.

The twin crafts’ new names were selected jointly by Prof. Zuber and Dr. Sally Ride, America’s first woman astronaut, and announced during today’s NASA briefing.


NASA’s naming competition was open to K-12 students who submitted pairs of names and a short essay to justified their suggestions.

“Ebb” and “Flow” (GRAIL A and GRAIL B) are the size of washing machines and were launched side by side atop a Delta II booster rocket on September 10, 2011 from Cape Canaveral, Florida.

They followed a circuitous 3.5 month low energy path to the Moon to minimize the fuel requirements and overall costs.

So far the probes have completed three burns of their main engines aimed at lowering and circularizing their initial highly elliptical orbits. The orbital period has also been reduced from 11.5 hours to just under 4 hours as of today.

“The science phase begins in early March,” said Zuber. At that time the twins will be flying in tandem at 55 kilometers (34 miles) altitude.

The GRAIL twins are also equipped with a very special camera dubbed MoonKAM (Moon Knowledge Acquired by Middle school students) whose purpose is to inspire kids to study science.

“GRAIL is NASA’s first planetary spacecraft mission carrying instruments entirely dedicated to education and public outreach,” explained Sally Ride. “Over 2100 classrooms have signed up so far to participate.”

Thousands of middle school students in grades five through eight will select target areas on the lunar surface and send requests for study to the GRAIL MoonKAM Mission Operations Center in San Diego which is managed by Dr. Ride in collaboration with undergraduate students at the University of California in San Diego.

By having their names selected, the 4th graders from Emily Dickinson Elementary have also won the prize to choose the first target on the Moon to photograph with the MoonKam cameras, said Ride.

Zuber notes that the first MoonKAM images will be snapped shortly after the 82 day science phase begins on March 8.

Ebb & Flow Achieve Lunar Orbit on New Year’s Weekend 2012
NASA’s twin GRAIL-A & GRAIL-B spacecraft are orbiting the Moon in this astrophoto taken on Jan. 2, 2012 shortly after successful Lunar Orbit Insertions on New Year’s Eve and New Year’s Day 2012.
Credit: Ken Kremer

Read continuing features about GRAIL and the Moon by Ken Kremer here:
Dazzling Photos of the International Space Station Crossing the Moon!
Two new Moons join the Moon – GRAIL Twins Achieve New Year’s Orbits
First GRAIL Twin Enters Lunar Orbit – NASA’s New Year’s Gift to Science
2011: Top Stories from the Best Year Ever for NASA Planetary Science!
NASA’s Unprecedented Science Twins are GO to Orbit our Moon on New Year’s Eve
Student Alert: GRAIL Naming Contest – Essay Deadline November 11
GRAIL Lunar Blastoff Gallery
GRAIL Twins Awesome Launch Videos – A Journey to the Center of the Moon
NASA launches Twin Lunar Probes to Unravel Moons Core
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

[/caption]

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

[/caption]

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