Spacecraft Archive

0

NASA Spacecraft Reveals Recent Geological Activity on the Moon

RELEASE : 12-055 NASA on the Moon WASHINGTON — New images from NASA’s Reconnaissance Orbiter (LRO) show the moon’s crust is being stretched, forming minute valleys in a few small areas on the lunar surface. Scientists propose this geologic activity occurred less than 50 million years ago, which is considered recent compared to the moon’s age of more than 4.5 billion years.

A team of researchers analyzing high-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) show small, narrow trenches typically much longer than they are wide. This indicates the lunar crust is being pulled apart at these locations. These linear valleys, known as graben, form when the moon’s crust stretches, breaks and drops down along two bounding faults. A handful of these graben systems have been found across the lunar surface.

“We think the moon is in a general state of global contraction because of cooling of a still hot interior,” said Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum in Washington, and lead author of a paper on this research appearing in the March issue of the journal Nature Geoscience. “The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form.”

The weak contraction suggests that the moon, unlike the terrestrial planets, did not completely melt in the very early stages of its evolution. Rather, support an alternative view that only the moon’s exterior initially melted forming an ocean of molten rock.

In August 2010, the team used LROC images to identify physical signs of contraction on the lunar surface, in the form of lobe-shaped cliffs known as lobate scarps. The scarps are evidence the moon shrank globally in the geologically recent past and might still be shrinking today. The team saw these scarps widely distributed across the moon and concluded it was shrinking as the interior slowly cooled.

Based on the size of the scarps, it is estimated that the distance between the moon’s center and its surface shrank by approximately 300 feet. The graben were an unexpected discovery and the images provide contradictory evidence that the regions of the lunar crust are also being pulled apart.

“This pulling apart tells us the moon is still active,” said Richard Vondrak, LRO Project Scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “LRO gives us a detailed look at that process.”

As the LRO mission progresses and coverage increases, scientists will have a better picture of how common these young graben are and what other types of tectonic features are nearby. The graben systems the team finds may help scientists refine the state of stress in the lunar crust.

“It was a big surprise when I spotted graben in the far side highlands,” said co-author Mark Robinson of the School of Earth and Space Exploration at Arizona State University, principal investigator of LROC. “I immediately targeted the area for high-resolution stereo images so we could create a three-dimensional view of the graben. It’s exciting when you discover something totally unexpected and only about half the lunar surface has been imaged in high resolution. There is much more of the moon to be explored.”

The research was funded by the LRO mission, currently under NASA’s Science Mission Directorate at NASA Headquarters in Washington. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Md.

For more information about LRO and related images on the finding, visit:

http://www.nasa.gov/mission_pages/LRO/news/lunar-graben.html – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

NASA Spacecraft Reveals New Observations of Interstellar Matter

Dwayne Brown                                   
Headquarters, Washington                                    
202-358-1726
dwayne.c.brown@nasa.gov
Susan Hendrix
Goddard Space Flight Center, Greenbelt, Md.
301-286-7745
susan.m.hendrix@nasa.gov
RELEASE : 12-036 NASA New of WASHINGTON — NASA’s Interstellar Boundary Explorer (IBEX) has captured the best and most complete glimpse yet of what lies beyond the solar system. The new measurements give clues about how and where our solar system formed, the forces that physically shape our solar system, and the history of other stars in the Milky Way.

The Earth-orbiting spacecraft observed four separate types of atoms including hydrogen, oxygen, neon and helium. These interstellar atoms are the byproducts of older stars, which spread across the galaxy and fill the vast space between stars. IBEX determined the distribution of these elements outside the solar system, which are flowing charged and neutral particles that blow through the galaxy, or the so-called interstellar wind.

“IBEX is a small Explorer mission and was built with a modest investment,” said Barbara Giles, director of the Heliophysics Division at NASA Headquarters in Washington. “The science achievements though have been truly remarkable and are a testament to what can be accomplished when we give our nation’s scientists the freedom to innovate.”

In a series of science papers appearing in the Astrophysics Journal on Jan. 31, scientists report finding 74 oxygen atoms for every 20 neon atoms in the interstellar wind. In our own solar system, there are 111 oxygen atoms for every 20 neon atoms. This translates to more oxygen in any part of the solar system than in nearby interstellar space.

“Our solar system is different than the space right outside it, suggesting two possibilities,” says David McComas, IBEX principal investigator, at the Southwest Research Institute in San Antonio. “Either the solar system evolved in a separate, more oxygen-rich part of the galaxy than where we currently reside, or a great deal of critical, life-giving oxygen lies trapped in interstellar dust grains or ices, unable to move freely throughout space.”

The new results hold clues about the history of material in the universe. While the big bang initially created hydrogen and helium, only the supernovae explosions at the end of a star’s life can spread the heavier elements of oxygen and neon through the galaxy. Knowing the amounts of elements in space may help scientists map how our galaxy evolved and changed over time.

Scientists want to understand the composition of the boundary region that separates the nearest reaches of our galaxy, called the local interstellar medium, from our heliosphere. The heliosphere acts as a protective bubble that shields our solar system from most of the dangerous galactic cosmic radiation that otherwise would enter the solar system from interstellar space.

IBEX measured the interstellar wind traveling at a slower speed than previously measured by the Ulysses spacecraft, and from a different direction. The improved measurements from IBEX show a 20 percent difference in how much pressure the interstellar wind exerts on our heliosphere.

“Measuring the pressure on our heliosphere from the material in the galaxy and from the magnetic fields out there will help determine the size and shape of our solar system as it travels through the galaxy,” says Eric Christian, IBEX mission scientist, at NASA’s Goddard Space Flight Center in Greenbelt, Md.

The IBEX spacecraft was launched in October 2008. Its science objective is to discover the nature of the interactions between the solar wind and the interstellar medium at the edge of our solar system.

The Southwest Research Institute developed and leads the IBEX mission with a team of national and international partners. The spacecraft is one of NASA’s series of low-cost, rapidly developed missions in the Small Explorers Program. Goddard manages the program for the agency’s Science Mission Directorate at NASA Headquarters in Washington.

For more information about IBEX, visit:

http://www.nasa.gov/ibex – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

NASA Spacecraft Returns First Video from Far Side Of The Moon

RELEASE : 12-040 NASA First from Far Side Of The Moon WASHINGTON — A camera aboard one of NASA’s twin Gravity Recovery And Interior Laboratory (GRAIL) spacecraft has returned its first unique view of the far side of the moon. MoonKAM, or Moon Knowledge Acquired by Middle school , will be used by nationwide to select images for study.

GRAIL consists of two identical spacecraft, recently named Ebb and Flow, each of which is equipped with a MoonKAM. The images were taken as part of a test of Ebb’s MoonKAM on Jan. 19. The GRAIL project plans to test the MoonKAM aboard Flow at a later date.

To view the 30-second video clip, visit:

http://go.nasa.gov/zZXAPs In the video, the north pole of the moon is visible at the top of the screen as the spacecraft flies toward the lunar south pole. One of the first prominent features seen on the lower third of the moon is the Mare Orientale, a 560 mile-wide (900 kilometer) impact basin that straddles both the moon’s near and far side.

The clip ends with rugged terrain just short of the lunar south pole. To the left of center, near the bottom of the screen, is the 93 mile-wide (149 kilometer) Drygalski crater with a distinctive star-shaped formation in the middle. The formation is a central peak, created many billions of years ago by a comet or asteroid impact.

“The quality of the video is excellent and should energize our MoonKAM students as they prepare to explore the moon,” said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge.

The twin spacecraft successfully achieved lunar last New Year’s Eve and New Year’s Day. Previously named GRAIL-A and -B, the washing machine-sized spacecraft received their new from fourth graders at the Emily Dickinson Elementary School in Bozeman, Mont., following a nationwide student-naming contest.

Thousands of fourth- to eighth-grade students will select target areas on the lunar surface and send requests to the GRAIL MoonKAM Mission Operations Center in San Diego. Photos of the target areas will be sent back by the satellites for students to study. The MoonKAM program is led by Sally Ride, America’s first woman in space. Her team at Sally Ride Science and undergraduate students at the University of California in San Diego will engage middle schools across the country in the GRAIL mission and lunar exploration. GRAIL is NASA’s first planetary mission carrying instruments fully dedicated to education and public outreach.

“We have had great response from schools the country, more than 2,500 signed up to participate so far,” Ride said. “In mid-March, the first pictures of the moon will be taken by students using MoonKAM. I expect this will excite many students about possible careers in science and engineering.”

Launched in September 2011, Ebb and Flow periodically perform trajectory correction maneuvers that, over time, will lower their orbits to near-circular ones with an altitude of about 34 miles (55 kilometers). During their science mission, the duo will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.

NASA’s Jet Propulsion Laboratory in Pasadena, Calif., manages the GRAIL mission for NASA’s Science Mission Directorate in Washington. The GRAIL mission is part of the Discovery Program managed at NASA’s Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit:

http://www.nasa.gov/grail
Information about MoonKAM is available at: https://moonkam.ucsd.edu/ – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

Montana Students Submit Winning Names for NASA Lunar Spacecraft

RELEASE : 12-019 for NASA WASHINGTON — Twin NASA that achieved around the moon New Year’s Eve and New Year’s Day have new thanks to elementary students in Bozeman, . Their winning entry, “Ebb and Flow,” was selected as part of a nation-wide school contest that began in October 2011.

The names were submitted by fourth graders from the Emily Dickinson Elementary School. Nearly 900 classrooms with more than 11,000 students from 45 states, Puerto Rico and the District of Columbia, participated in the contest. Previously named Gravity Recovery And Interior Laboratory, or A and B, the washing machine-sized spacecraft begin science operations in March.

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

Zuber and Sally Ride, America’s first woman in space and CEO of Sally Ride Science in San Diego, selected the names following the contest, which attracted 890 proposals via the Internet and mail. The contest ideas from students ages 5 to 18 enrolled in U.S. schools. Although everything from spelling and grammar to creativity were considered, Zuber and Ride primarily took into account the quality of submitted essays.

“With submissions from all over the United States and even some from abroad, there were a lot of great entries to review,” Ride said. “This contest generated a great deal of excitement in classrooms across America, and along with it an opportunity to use that excitement to teach science.”

GRAIL is NASA’s first planetary mission carrying instruments fully dedicated to education and public outreach. Each spacecraft carries a small camera called GRAIL MoonKAM (Moon Knowledge Acquired by Middle school students). Thousands of 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.

The winning prize for the Dickinson students is to choose the first camera images. Dickinson is one of nearly 2,000 schools registered for the MoonKAM program, which is led by Ride and her team at Sally Ride Science in collaboration with undergraduate students at the University of California in San Diego.

“These spacecraft represent not only great science but great inspiration for our future,” said Jim Green, director of NASA’s Planetary Science Division in Washington. “As they study our lunar neighbor, Ebb and Flow will undergo nearly the same motion as the tides we feel here on Earth.”

Launched in September 2011, Ebb and Flow will be placed in a near-polar, near-circular orbit with an altitude of about 34 miles (55 kilometers). During their science mission, the duo will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.

NASA’s Jet Propulsion Laboratory in Pasadena, Calif., manages the GRAIL mission for NASA’s Science Mission Directorate in Washington. The GRAIL mission is part of the Discovery Program managed at NASA’s Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

To read the winning submission visit:

https://moonkam.ucsd.edu/about/spacecraft_names

Information about MoonKAM is available online at:

https://moonkam.ucsd.edu

For more information about GRAIL visit:

http://www.nasa.gov/grail

or

http://grail.nasa.gov

– end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

NASA’S Orion Spacecraft to Land in Oklahoma, Texas and Alabama

ADVISORY : M12-006 NASA’S to Land in , and WASHINGTON — A test version of NASA’s spacecraft soon will make a cross-country journey, giving residents in three states the chance to see a full scale test version of the vehicle that will take humans into deep space.

The crew module will make stops during a trip from the White Sands Missile Range in New Mexico to the Kennedy Space Center in Florida. The planned stops include Jan. 23-25 at Science Museum Oklahoma in Oklahoma City; Jan. 27-29 at Victory Park and the American Airlines Center in Dallas; and, Jan. 31-Feb. 2 at the U.S. Space and Rocket Center in Huntsville, Ala. Engineers, program officials, astronauts and NASA spokespeople will be available to speak with the media and the public.

The full-scale test vehicle was used by ground crews in advance of the launch abort system flight test that took place in New Mexico in 2010.

Media interested in seeing the spacecraft or scheduling interviews should contact Dan Huot at daniel.g.huot@nasa.gov or by calling the newsroom at NASA’s Johnson Space Center in Houston at 281-483-5111.

Orion will serve as the vehicle that takes astronauts beyond low-Earth . The orbital flight test is scheduled for 2014.

For more information on the each of the sites, visit:

http://www.sciencemuseumok.org/
http://www.americanairlinescenter.com/
http://www.ussrc.com/
To learn more about the Orion, visit: http://www.nasa.gov/orion – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

Media Invited To Final Orion Spacecraft Water Landing Test

ADVISORY : M12-002 to Test HAMPTON, Va. – Media representatives are invited to watch as the Orion crew capsule makes its final landing test on Thursday, Jan. 5, at NASA’s Langley Research Center’s Hydro Impact Basin in Hampton, Va.

Testing began last summer to certify the Orion spacecraft for water landings. Orion will carry astronauts into space, providing emergency abort capability, sustaining the crew during space travel and ensuring safe re-entry and landing.

Since July 2011, engineers have conducted eight tests at different angles, heights and pitches to simulate varying sea conditions and impacts that Orion could face upon landing in the Pacific Ocean.

The test will simulate deployment of all parachutes at a high impact pitch of 43 degrees. The capsule will travel approximately 47 mph before splashing into the basin, where it will likely flip over after impact. While this type of landing scenario is not likely to occur during actual vehicle operation, the test will validate models of how the spacecraft would respond. Like the Apollo spacecraft, Orion will have an on-board system that allows the spacecraft to up-right itself in the ocean.

The Hydro Impact Basin is 115 feet long, 90 feet wide and 20 feet deep. It is located at the west end of Langley’s historic Landing and Impact Research Facility, or Gantry, where Apollo astronauts trained for moonwalks.

Journalists must arrive by 1 p.m. EDT at the NASA Langley main gate. Due to the nature of the testing, an exact drop time cannot be given. If the drop test date changes due to weather or technical reasons, NASA will issue a media advisory.

To ensure access and badging, reporters must contact Amy Johnson by phone at 757-272-9859 or by email at amy.johnson@nasa.gov by 4 p.m. on Wednesday, Jan. 4.

For and still imagery that documents ground breaking of the Hydro Impact Basin through various stages of Orion testing, visit:

http://www.nasa.gov/centers/langley/exploration/hib.html

For more information about Orion, visit:

http://www.nasa.gov/orion– end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

Media Invited to Final Orion Spacecraft Water Landing Test

ADVISORY : M12-002 to Test HAMPTON, Va. – Media representatives are invited to watch as the crew capsule makes its final water landing test on Thursday, Jan. 5, at NASA’s Langley Research Center’s Hydro Impact Basin in Hampton, Va.

Testing began last summer to certify the Orion spacecraft for water landings. Orion will carry astronauts into space, providing emergency abort capability, sustaining the crew during space travel and ensuring safe re-entry and landing.

Since July 2011, engineers have conducted eight tests at different angles, heights and pitches to simulate varying sea conditions and impacts that Orion could face upon landing in the Pacific Ocean.

The test will simulate deployment of all parachutes at a high impact pitch of 43 degrees. The capsule will travel approximately 47 mph before splashing into the basin, where it will likely flip over after impact. While this type of landing scenario is not likely to occur during actual vehicle operation, the test will validate models of how the spacecraft would respond. Like the Apollo spacecraft, Orion will have an on-board system that allows the spacecraft to up-right itself in the ocean.

The Hydro Impact Basin is 115 feet long, 90 feet wide and 20 feet deep. It is located at the west end of Langley’s historic Landing and Impact Research Facility, or Gantry, where Apollo astronauts trained for moonwalks.

Journalists must arrive by 1 p.m. EDT at the NASA Langley main gate. Due to the nature of the testing, an exact drop time cannot be given. If the drop test date changes due to weather or technical reasons, NASA will issue a media advisory.

To ensure access and badging, reporters must contact Amy Johnson by phone at 757-272-9859 or by email at amy.johnson@nasa.gov by 4 p.m. on Wednesday, Jan. 4.

For and still imagery that documents ground breaking of the Hydro Impact Basin through various stages of Orion testing, visit:

http://www.nasa.gov/centers/langley/exploration/hib.html

For more information about Orion, visit:

http://www.nasa.gov/orion– end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

First Of NASA’S Two Grail Spacecraft Enters Orbit Around Moon

Dwayne Brown      
Headquarters, Washington     
202-358-1726                                
dwayne.c.brown@nasa.gov
DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov
Caroline McCall
Massachusetts Institute of Technology, Cambridge
617-253-1682
cmcall5@mit.edu
RELEASE : 11-427 Of NASA’S Two Moon PASADENA, Calif. — The first of two NASA spacecraft to study the moon in unprecedented detail has entered .

NASA’s Gravity Recovery And Interior Laboratory (GRAIL)-A spacecraft successfully completed its planned main engine burn at 2 p.m. PST (5 p.m. EST) today. As of 3 p.m. PST (6 p.m. EST), GRAIL-A is in a 56-mile (90-kilometer) by 5,197-mile (8,363-kilometer) orbit around the moon that takes approximately 11.5 hours to complete.

“My resolution for the new year is to unlock lunar mysteries and understand how the moon, Earth and other rocky planets evolved,” said Maria Zuber, GRAIL principal investigator at the Massachusetts Institute of Technology in Cambridge. “Now, with GRAIL-A successfully placed in orbit around the moon, we are one step closer to achieving that goal.”

The next mission milestone occurs tomorrow when GRAIL-A’s mirror twin, GRAIL-B, performs its own main engine burn to place it in lunar orbit. At 3 p.m. PST (6 p.m. EST) today, GRAIL-B was 30,018 miles (48,309 kilometers) from the moon and closing at a rate of 896 mph (1,442 kph). GRAIL-B’s insertion burn is scheduled to begin tomorrow at 2:05 p.m. PST (5:05 p.m. EST) and will last about 39 minutes.

“With GRAIL-A in lunar orbit we are halfway home,” said David Lehman, GRAIL project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “Tomorrow may be New Year’s everywhere else, but it’s another work day around the moon and here at JPL for the GRAIL team.”

Once both spacecraft are confirmed in orbit and operating, science work will begin in March. The spacecraft will transmit radio signals precisely defining the distance between them as they orbit the moon in formation. As they fly over areas of greater and lesser gravity caused by both visible features, such as mountains and craters, and masses hidden beneath the lunar surface, the distance between the two spacecraft will change slightly.

Scientists will translate this information into a high-resolution map of the moon’s gravitational field. The data will allow scientists to understand what goes on below the lunar surface. This information will increase knowledge of how Earth and its rocky neighbors in the inner solar system developed into the diverse worlds we see today.

JPL manages the GRAIL mission for NASA’s Science Mission Directorate at the agency’s headquarters in Washington. The GRAIL mission is part of the Discovery Program managed at NASA’s Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit:

http://www.nasa.gov/grail – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here

0

NASA Twin Spacecraft On Final Approach For Moon Orbit

Dwayne Brown
Headquarters, Washington
202-358-1726      
dwayne.c.brown@nasa.gov
DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov
Caroline McCall
Massachusetts Institute of Technology, Cambridge
617-253-1682
cmcall5@mit.edu
RELEASE : 11-426 NASA Twin On For Moon PASADENA, Calif. — NASA’s twin spacecraft to study the moon from crust to core are nearing their New Year’s Eve and New Year’s Day main-engine burns to place the duo in .

Named Gravity Recovery And Interior Laboratory (), the spacecraft are scheduled to be placed in orbit beginning at 1:21 p.m. PST (4:21 p.m. EST) for -A on Dec. 31, and 2:05 p.m. PST (5:05 p.m. EST) on Jan. 1 for -B.

“Our team may not get to partake in a traditional New Year’s celebration, but I expect seeing our two spacecraft safely in lunar orbit should give us all the excitement and feeling of euphoria anyone in this line of work would ever need,” said David Lehman, project manager for GRAIL at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

The distance from Earth to the moon is approximately 250,000 miles (402,336 kilometers). NASA’s Apollo crews took about three days to travel to the moon. Launched from Cape Canaveral Air Force Station Sept. 10, 2011, the GRAIL spacecraft are taking about 30 times that long and covering more than 2.5 million miles (4 million kilometers) to get there.

This low-energy, long-duration trajectory has given mission planners and controllers more time to assess the spacecraft’s health. The path also allowed a vital component of the spacecraft’s single science instrument, the Ultra Stable Oscillator, to be continuously powered for several months. This will allow it to reach a stable operating temperature long before it begins making science measurements in lunar orbit.

“This mission will rewrite the textbooks on the evolution of the moon,” said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT) in Cambridge. “Our two spacecraft are operating so well during their journey that we have performed a full test of our science instrument and confirmed the performance required to meet our science objectives.”

As of Dec. 28, GRAIL-A is 65,860 miles (106,000 kilometers) from the moon and closing at a speed of 745 mph (1,200 kph). GRAIL-B is 79,540 miles (128,000 kilometers) from the moon and closing at a speed of 763 mph (1,228 kph).

During their final approaches to the moon, both orbiters move toward it from the south, flying nearly over the lunar south pole. The lunar orbit insertion burn for GRAIL-A will take approximately 40 minutes and change the spacecraft’s velocity by about 427 mph (688 kph). GRAIL-B’s insertion burn 25 hours later will last about 39 minutes and is expected to change the probe’s velocity by 430 mph (691 kph).

The insertion maneuvers will place each orbiter into a near-polar, elliptical orbit with a period of 11.5 hours. Over the following weeks, the GRAIL team will execute a series of burns with each spacecraft to reduce their orbital period from 11.5 hours down to just under two hours. At the start of the science phase in March 2012, the two GRAILs will be in a near-polar, near-circular orbit with an altitude of about 34 miles (55 kilometers).

When science collection begins, the spacecraft will transmit radio signals precisely defining the distance between them as they orbit the moon. As they fly over areas of greater and lesser gravity, caused both by visible features such as mountains and craters and by masses hidden beneath the lunar surface. they will move slightly toward and away from each other. An instrument aboard each spacecraft will measure the changes in their relative velocity very precisely, and scientists will translate this information into a high-resolution map of the Moon’s gravitational field. The data will allow mission scientists to understand what goes on below the surface. This information will increase our knowledge of how Earth and its rocky neighbors in the inner solar system developed into the diverse worlds we see today.

JPL manages the GRAIL mission. MIT is home to the mission’s principal investigator, Maria Zuber. The GRAIL mission is part of the Discovery Program managed at NASA’s Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit:

http://www.nasa.gov/grail – end – text-only version of this release

NASA press releases and other information are available automatically by sending a blank e-mail message to hqnews-subscribe@mediaservices.nasa.gov. To unsubscribe from this mailing list, send a blank e-mail message to hqnews-unsubscribe@mediaservices.nasa.gov.

Back to NASA Newsroom | Back to NASA Homepage

View the original article here