Showing posts with label in-orbit. Show all posts
Showing posts with label in-orbit. Show all posts

Thursday, January 17, 2013

CHINA's Openly Aggressive Strategy to Dominate Space

China is making increasingly aggressive plans to launch 20 spacecrafts this year,2013.

This will include the country's third lunar probe Chang'e-3 and manned spacecraft Shenzhou-10, China Aerospace Science and Technology Corporation (CASC) announced.

The country is scheduled to conduct a manned space docking test between orbiting target module Tiangong-1 and Shenzhou-10, the corporation said during an internal work conference.

The Chang'e-3 moon probe is expected to land and stay there during the second stage of the country's lunar probe program, it said.

According to CASC, by 2020, China will have more than 200 spacecrafts operating in orbit, accounting for about 20 percent of the world's total.

How many of the countries who are already under threat from China's expansionist plans will suffer as a consequence of their imposed domination of the space above the Earth's atmosphere?

What safeguards can be put in place to prevent their militarisation of Space and to make the Earth's atmospheric zone a de-militarised zone (DMZ)?

Sunday, July 8, 2012

Europe's Satellites: Galileo pathfinder GIOVE-A retires

Galileo's Giove-A satellite. It remains operational and will still be maintained from SSTL's Mission Control Centre in Guildford, during which time SSTL will continue to collect data on the radiation environment in MEO

Surrey Satellite Technology Ltd (SSTL) has put the GIOVE-A satellite into retirement, ending a successful extended mission for the European Commission's Galileo satellite navigation programme under the supervision of the European Space Agency (ESA).

The first 'Galileo In-Orbit Validation Element', GIOVE-A, was launched on 28th December 2005 by Soyuz rocket from Baikonur in Kazakhstan, securing vital frequency filings with the International Telecommunications Union (ITU) on the 12th January 2006 that enabled the satellite navigation programme to proceed.

GIOVE-A was completed by SSTL within a record 29-month schedule from contract to launch for a budget of Euro 28m. Its original mission was extended, having already outlived its 27 month design life and been declared a full mission success by ESA in 2008.

The main objectives of the GIOVE-A mission were the on-board characterisation of a highly accurate prototype rubidium atomic clock, modeling the Medium Earth Orbit (MEO) radiation environment and the possible effects of radiation on future Galileo spacecraft, and of course the generation of the first Galileo navigation signals in space.

Those Galileo test signals from GIOVE-A have proved a very useful resource for manufacturers of Galileo receivers worldwide, allowing them to easily test their designs against a realistic version of the final Galileo navigation signal.

Now more than six years after launch, SSTL's operations team finally switched off the Galileo payload on 30th June.

The spacecraft has been manoeuvred about 100 kilometers higher than its operating orbit of 23,222 kilometers to make way for the first 22 Fully Operational Capability (FOC) satellites that are now being completed by OHB Technology and SSTL.

The satellite remains operational and will still be maintained from SSTL's Mission Control Centre in Guildford, during which time SSTL will continue to collect data on the radiation environment in MEO.

This document has been produced under funding of the European Union. The views expressed herein can in no way be taken to reflect the official opinion of the European Union and/or ESA.

The Full Operational Capability phase of the Galileo programme is managed and fully funded by the European Commission.

The Commission and ESA have signed a delegation agreement by which ESA acts as design and procurement agent on behalf of the Commission. "Galileo" is a trademark subject to OHIM application number 002742237 by EU and ESA.

Read more about GPS and satellite technology here

Wednesday, June 13, 2012

NASA NuStar: X-ray mission reaches orbit

The Nuclear Spectroscopic Telescope Array begins its mission using high-energy x-rays to uncover some of the most powerful structures in the universe.

Image: NASA via UStream

At noon Eastern time on Wednesday, NuSTAR (Nuclear Spectroscopic Telescope Array) blasted towards low-Earth orbit from a Pegasus XL rocket, after it was dropped from the belly of a carrier jet circling near the Kwajalein Atoll in the Pacific Ocean.

The X-ray mission, a low-cost NASA mission in its small Explorer line of competitive missions, is expected to discover hundreds of new supermassive black holes that lie in the hearts of distant galaxies.

A lot is riding on NuSTAR — it is one of few missions in sight for X-ray astronomers. Just last week, GEMS, a similar-looking mission that would have gathered polarized X-ray light, was canceled because of budget overruns.

While NuSTAR is no replacement for general purpose X-ray observatories like Chandra and XMM-Newton, it will have unprecedented sensitivity in the “hard”, or high-energy, X-ray part of the spectrum.

Fifteen minutes after launch, the science payload had separated from the rocket. By 12:22 pm EDT, all five of NuSTAR’s solar panels had been deployed successfully.

It will be another week before the most nerve-wracking phase of the mission begins — the 26 minutes during which a deployable mast will unfurl itself so that NuSTAR can reach its full 10-metre focal length.

Sunday, April 29, 2012

NASA Orion Vehicle: Animated video shows spacecraft in orbit

NASA may have pushed back the Orion spacecraft's test flight to 2014, but you can get an early glimpse of the capsule in orbit thanks to this animated video from Full Werks studio.

You'll see the capsule circle the planet before touching down in the Pacific, all with a much better view than you can expect when that actual launch date rolls around.

The animation features audio clips from the original Apollo and, as any NASA-related video worth its salt should, includes a vintage voiceover from space sage Carl Sagan.

Saturday, April 21, 2012

NASA Camilla: One small step for a rubber chicken - video

Last month, when the sun unleashed the most intense radiation storm since 2003, peppering satellites with charged particles and igniting strong auroras around both poles, a group of high school students in Bishop, California, knew just what to do.

They launched a rubber chicken.

The students inflated a helium balloon and used it to send the fowl, named "Camilla," to an altitude of 120,000 ft where she was exposed to high-energy solar protons at point blank range.

"We equipped Camilla with sensors to measure the radiation," says Sam Johnson (age 16) of Bishop Union High School's Earth to Sky student group. "At the apex of our flight, the payload was above 99% of Earth's atmosphere."

Launching a rubber chicken into a solar storm might sound strange, but the students had good reason: They're doing an astrobiology project.

"Later this year, we plan to launch a species of microbes to find out if they can live at the edge of space," explains team member Rachel Molina (age 17). "This was a reconnaissance flight."

Many space enthusiasts are already familiar with Camilla. She's the mascot of NASA's Solar Dynamics Observatory. With help from her keeper, Romeo Durscher of Stanford University, Camilla corresponds with more than 20,000 followers on Twitter, Facebook, and Google+, filling them in on the latest results from NASA's heliophysics missions.

"Camilla's trip to the stratosphere gave us a chance to talk to thousands of people about the radiation storm," says Durscher.

On the outside of her space suit (knitted by Cynthia Coer Butcher from Blue Springs, Missouri), Camilla wore a pair of radiation badges, the same kind medical technicians and nuclear workers wear to assess their dosages.

Read more at NASA

Wednesday, April 11, 2012

Yuri Gagarin's First Orbit of Earth - Video film

The real time recreation of humanity's first human space flight by Russia's Yuri Gagarin in a Soyuz rocket, on 12 April 1961.

This film was created to celebrate our first footsteps into the cosmos.


Wednesday, March 28, 2012

NASA GRAIL: Flying formation - around the moon at 3,600 MPH

An artist's depiction of the NASA GRAIL twins (Ebb and Flow) in lunar orbit. 

During GRAIL's prime mission science phase, the two spacecraft will orbit the moon as high as 31 miles (51 kilometers) and as low as 10 miles (16 kilometers). 

Credit: NASA/Caltech-JPL/MIT

The act of two or more aircraft flying together in a disciplined, synchronized manner is one of the cornerstones of military aviation, as well as just about any organized air show.

But as amazing as the U.S. Navy's elite Blue Angels or the U.S. Air Force's Thunderbirds are to behold, they remain essentially landlocked, anchored if you will, to our planet and its tenuous atmosphere.

What if you could take the level of precision of these great aviators to, say, the moon?

"Our job is to ensure our two GRAIL spacecraft are flying a very, very accurate trail formation in lunar orbit," said David Lehman, GRAIL project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We need to do this so our scientists can get the data they need."

Essentially, trail formation means one aircraft (or spacecraft in this case), follows directly behind the other. Ebb and Flow, the twins of NASA's GRAIL (Gravity Recovery And Interior Laboratory) mission, are by no means the first to synch up altitude and "air" speed while zipping over the craters, mountains, hills and rills of Earth's natural satellite.

That honour goes to the crew of Apollo 10, who in May 1969 performed a dress rehearsal for the first lunar landing but as accurate as the astronauts aboard lunar module "Snoopy" and command module "Charlie Brown" were in their piloting, it is hard to imagine they could keep as exacting a position as Ebb and Flow.

"It is an apples and oranges comparison," said Lehman. "Lunar formation in Apollo was about getting a crew to the lunar surface, returning to lunar orbit and docking, so they could get back safely to Earth. For GRAIL, the formation flying is about the science, and that is why we have to make our measurements so precisely."

As the GRAIL twins fly over areas of greater and lesser gravity at 3,600 mph (5,800 kilometers per hour), surface features such as mountains and craters, and masses hidden beneath the lunar surface, can influence the distance between the two spacecraft ever so slightly.

How slight a distance change can be measured by the science instrument beaming invisible microwaves back and forth between Ebb and Flow?

How about one-tenth of one micron? Another way to put it is that the GRAIL twins can detect a change in their position down to one half of a human hair (0.000004 inches, or 0.00001 centimeters).

For those of you who are hematologists or vampires (we are not judging here), any change in separation between the two twins greater than one half of a red corpuscle will be duly noted aboard the spacecraft's memory chips for later downlinking to Earth.

Working together, Ebb and Flow will make these measurements while flying over the entirety of the lunar surface.

Thursday, March 22, 2012

NASA Messenger: Mercury mosaic image

The planet Mercury is pictured in this mosaic photograph compiled with images taken from the spacecraft Messenger. 

After its first Mercury solar day (176 Earth days) in orbit, Messenger has nearly completed two of its main global imaging campaigns: a monochrome map at 250m/pixel and an eight-colour, 1-km/pixel map.

Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury's surface features as well as the colour and compositional variations across the planet.

Picture: REUTERS/NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Wednesday, March 21, 2012

MESSENGER Completes Primary Mission at Mercury, Settles in for Another Year

MESSENGER Mercury Orbit Insertion AnimationWith more than 99% of Mercury's surface imaged under similar illumination and viewing conditions, and with final spacecraft performance and final spacecraft orbit data available, MESSENGER's mission design team has updated the animation of MESSENGER's Mercury orbit insertion (MOI) maneuver. 

The largest and most important propulsive maneuver of the mission, MOI used more than 31% of the total propellant to transition the spacecraft's orbit center from the Sun to Mercury. 

About 2.5 weeks after MOI, after sufficient opportunity to monitor spacecraft health, temperature, and functionality, the primary science phase of the mission began.

This updated animation includes Mercury surface images from MESSENGER and a few extremely small areas with images from Mariner 10 flybys of Mercury in 1974 and 1975. 


"This animation features the best reconstructed orientation of the spacecraft, renderings of thruster flames as they occurred each second of MOI, as well as other details about the progress and orbit location relative to Mercury," says MESSENGER Mission Design Lead Engineer Jim McAdams. 

The new MOI animation and a counterpart from March 2011 may be viewed near the end of the animations listed here.

Monday, March 12, 2012

Lego Space Shuttle: YouTube video


Raul Oaida (from Romania) LEGO tribute to the end of the space shuttle era. Proving that although retired, this machine can still fly, albeit in toy form.

The launch took place from central Germany (easy flight clearance) and reached a max altitude of 35000m. A 1600g meteo balloon filled with helium was used alongside a GoPro Hero, Spot GPS and of course Lego Space Shuttle model 3367.

He launched it on the 31st of December 2011, the equipment was recovered via GPS tracking 240 km S-E from a remote area.

He wishes to thank Steve Sammartino for the opportunity to do this project and the german airtraffic control for the understanding.

Full Story: http://microblade.blogspot.com/2012/03/2001-brick-odyssey.html

Friday, March 9, 2012

Startram the Maglev train: Destination low earth orbit (LEO)

Getting into space is one of the harder tasks to be taken on by humanity.

The present cost of inserting a kilogram (2.2 lb) of cargo by rocket into Low Earth Orbit (LEO) is about US$10,000.

A manned launch to LEO costs about $100,000 per kilogram of passenger (except in China) but who says we have to reach orbit by means of rocket propulsion alone?

Instead, imagine sitting back in a comfortable magnetic levitation (maglev) train and taking a train ride into orbit.

Dr George Maise invented the Startram orbital launch system along with Dr James Powell, who is one of the inventors of superconducting maglev - for which he won the 2002 Franklin Medal in engineering. Startram is in essence a superconducting maglev launch system.


The system would see a spacecraft magnetically levitated to avoid friction, while the same magnetic system is used to accelerate the spacecraft to orbital velocities, just under 9 km/sec (5.6 miles/s).

Maglev passenger trains have carried passengers at nearly 600 kilometers per hour (373 mph) - spacecraft have to be some 50 times faster, but the physics and much of the engineering is the same.

The scope of the project is challenging.

A launch system design for routine passenger flight into LEO should have rather low acceleration - perhaps about 3 g's maximum, which then requires 5 minutes of acceleration to reach LEO transfer velocities. In that period, the spacecraft will have traveled 1,000 miles (1,609 km).

The maglev track must be 1,000 miles in length - similar in size to maglev train tracks being considered for cross-country transportation.

Read more of this article here

Thursday, March 1, 2012

Asteroid 2011 AG5: A Reality Check

Asteroid 2011 AG5 has been receiving a lot of attention lately because of a very unlikely scenario which would place it on an Earth-interception course 28 years from now.

Here is a scientific reality check of this relatively nondescript space rock which is currently ranked a "1" on the 1 to 10 Torino Impact Hazard Scale

As of Feb. 26, 2012, asteroid 2011 AG5 is one of 8,744 near-Earth objects that have been discovered.

It is approximately 460 feet (140 meters) in size and its orbit carries it as far out as beyond Mars' orbit and as close to the sun as halfway between Earth and Venus.

It was discovered on Jan. 8, 2011, by astronomers using a 60-inch Cassegrain reflector telescope located at the summit of Mount Lemmon in the Catalina Mountains north of Tucson, Arizona.

Due to its current location in the daytime sky, observations of 2011 AG5 cannot be made by Earth-based telescopes, so its orbit has not yet been determined to a level where scientists can confidently project its location decades into the future. But that day is coming.

"In September 2013, we have the opportunity to make additional observations of 2011 AG5 when it comes within 91 million miles (147 million kilometers) of Earth," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif.

"It will be an opportunity to observe this space rock and further refine its orbit. Because of the extreme rarity of an impact by a near-Earth asteroid of this size, I fully expect we will be able to significantly reduce or rule out entirely any impact probability for the foreseeable future."

Even better observations will be possible in late 2015.

Sunday, February 26, 2012

NASA: John Glenn speaks to ISS Crew

Senator John Glenn talks, via satellite, with the astronauts on the International Space Station, in Columbus, Ohio. 

Glenn was the first American to orbit Earth, piloting Friendship 7 around it three times in 1962, and also became the oldest person in space, at age 77, by orbiting Earth with six astronauts aboard shuttle Discovery in 1998.
 
Picture: Jay LaPrete/AP

Tuesday, February 21, 2012

ESA Swarm constellation heads north

The Swarm mission will study the complexities of Earth's protective magnetic field. The magnetic field acts as a shield, protecting the planet from charged particles that stream towards Earth in solar winds. Without this shield, life on Earth would be impossible. 

The field is mainly generated deep inside Earth by an ocean of swirling iron that makes up the liquid outer core. How the magnetic field is generated and how it changes over time is complex and not fully understood. But with a new generation of magnetometers, Swarm will provide greater insight into these natural processes and the 'weather' in space. Credits: ESA/AOES Medialab.

The three satellites that make up ESA's Swarm magnetic field mission were unvieled last week to the media. Following a demanding testing programme, the satellites were displayed in the cleanroom before they are shipped to Russia for their July launch.

Swarm is ESA's first constellation of Earth observation satellites designed to measure the magnetic signals from Earth's core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field.

The magnetic shield protects the planet from charged particles that stream in as the solar wind. Without this shield, life on Earth would be impossible.

This shield is generated mainly deep inside Earth by an ocean of swirling iron in the liquid outer core. How the magnetic field is created and how it changes over time is complex and not fully understood.

This force is constantly changing - at the moment, it shows signs of significant weakening.

But with a new generation of sensors, the Swarm constellation will provide greater insight into these natural processes and the 'weather' in space.

Swarm will be ESA's fourth Earth Explorer mission in orbit, following GOCE, SMOS and CryoSat.

In five months, the trio of satellites will be launched together on a Rockot launcher from the Plesetsk Cosmodrome in northern Russia.

Two will orbit very close together at the same altitude - initially at about 460 km - while the third satellite will be in a higher orbit of 530 km.

The different near-polar orbits, along with the various Swarm instruments, improve the sampling in space and time. This helps to distinguish between the effects of different sources of magnetism.

Friday, February 10, 2012

ESA Venus Express: Is Venus shifting gear?

ESA’s Venus Express spacecraft has discovered that our cloud-covered neighbour spins a little slower than previously measured.

Peering through the dense atmosphere in the infrared, the orbiter found surface features were not quite where they should be.

Using the VIRTIS instrument at infrared wavelengths to penetrate the thick cloud cover, scientists studied surface features and discovered that some were displaced by up to 20 km from where they should be given the accepted rotation rate as measured by NASA’s Magellan orbiter in the early 1990s.

These detailed measurements from orbit are helping scientists determine whether Venus has a solid or liquid core, which will help our understanding of the planet’s creation and how it evolved.

If Venus has a solid core, its mass must be more concentrated towards the centre. In this case, the planet’s rotation would react less to external forces.

The most important of those forces is due to the dense atmosphere – more than 90 times the pressure of Earth’s and high-speed weather systems, which are believed to change the planet’s rotation rate through friction with the surface.

Earth experiences a similar effect, where it is largely caused by wind and tides. The length of an Earth day can change by roughly a millisecond and depends seasonally with wind patterns and temperatures over the course of a year.

In the 1980s and 1990s, the Venera and Magellan orbiters made radar maps of the surface of Venus, long shrouded in mystery as well as a dense, crushing and poisonous atmosphere. These maps gave us our first detailed global view of this unique and hostile world.

Over its four-year mission, Magellan was able to watch features rotate under the spacecraft, allowing scientists to determine the length of the day on Venus as being equal to 243.0185 Earth days. .

However, surface features seen by Venus Express some 16 years later could only be lined up with those observed by Magellan if the length of the Venus day is on average 6.5 minutes longer than Magellan measured.

Monday, February 6, 2012

NASA Juno Spacecraft Refines its Path to Jupiter

NASA's Juno spacecraft passes in front of Jupiter in this artist's depiction. 

Juno, the second mission in NASA's New Frontiers program, will improve our understanding of the solar system by advancing studies of the origin and evolution of Jupiter. Image credit: NASA/JPL-Caltech.

NASA's solar-powered Juno spacecraft successfully refined its flight path Wednesday with the mission's first trajectory correction maneuver.

The maneuver took place on Feb. 1. It is the first of a dozen planned rocket firings that, over the next five years, will keep Juno on course for its rendezvous with Jupiter.

"We had a maneuver planned soon after launch but our Atlas V rocket gave us such a good ride we didn't need to make any trajectory changes," said Rick Nybakken, Juno project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"It is good to get another first under our belt. This burn couldn't have gone any better."

The trajectory correction maneuver, which adjusts the spacecraft's flight path, began at 10:10 a.m. PST (1:10 p.m. EST) on Feb. 1. The Juno spacecraft's thrusters fired for 25 minutes, consumed about 6.9 pounds (3.11 kilograms) of fuel and changed the spacecraft's speed by 3.9 feet, or 1.2 meters, per second.

The next big maneuver for Juno will occur in late August of 2012 when Juno executes its first of two deep space maneuvers to set the stage for its Earth flyby - and gravity assist - on its way to Jupiter.

Launched on Aug. 5, 2011, Juno is 182 days and 279 million miles (449 million kilometers) into its five-year, 1,740-million-mile (2,800-million-kilometer) journey to Jupiter.

Once in orbit, the spacecraft will orbit the planet's poles 33 times and use its collection of eight science instruments to probe beneath the gas giant's obscuring cloud cover to learn more about Jupiter's origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

Saturday, January 14, 2012

ESA ISS Image: In Earth Orbit

The ISS flies from West to East, at an angle of 51.6 degrees to the Equator. One orbit takes 90 minutes.

This is the crew's screen shot of the ISS's in-orbit, navigational and trajectory information.

Credit: ESA/NASA

Tuesday, January 10, 2012

Russian Phobos Grunt Probe: Latest In-Orbit Images

Latest Phobos-Grunt true colour images with good colour rendition between solar panels and the body.

Tuesday, January 3, 2012

NASA Grail: Second Lunar Probe enters orbit and unites with First

The second of NASA's two Gravity Recovery And Interior Laboratory (GRAIL) spacecraft has successfully completed its planned main engine burn and is now in lunar orbit. Working together, GRAIL-A and GRAIL-B will study the moon as never before.

"NASA greets the new year with a new mission of exploration," said NASA Administrator Charles Bolden.

"The twin GRAIL spacecraft will vastly expand our knowledge of our moon and the evolution of our own planet. We begin this year reminding people around the world that NASA does big, bold things in order to reach for new heights and reveal the unknown."

GRAIL-B achieved lunar orbit at 2:43 p.m. PST (5:43 p.m. EST) today. GRAIL-A successfully completed its burn yesterday at 2 p.m. PST (5 p.m. EST). The insertion maneuvers placed the spacecraft into a near-

polar, elliptical orbit with an orbital period of approximately 11.5 hours. Over the coming weeks, the GRAIL team will execute a series of burns with each spacecraft to reduce their orbital period 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).

During GRAIL's science mission, the two spacecraft will transmit radio signals precisely defining the distance between them. As they fly over areas of greater and lesser gravity caused by 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.

Sunday, January 1, 2012

NASA Grail: First Lunar Probe enters orbit

The first of two NASA spacecraft to study the moon in unprecedented detail has entered lunar orbit.

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 an orbit of 56 miles by 5,197 miles (90 kilometers by 8,363 kilometers) 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 kilometers per hour). GRAIL-B's insertion burn is scheduled to begin tomorrow, Jan. 1, 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 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.