The Space Shot

In a brute-force search for ice on the moon, an empty 5,000-pound rocket stage traveling twice as fast as a rifle bullet crashed into a permanently shadowed crater near the moon's south pole Friday, presumably blasting out tons of debris for examination by an instrumented probe that carried out its own kamikaze plunge four minutes later.

While the initial impact at 4:31 a.m. PDT did not prove especially dramatic--it was not even visible in real-time video from the Lunar Crater Observation and Sensing Satellite (LCROSS)--scientists said a camera sensitive to temperature variations clearly recorded the flash of the Centaur rocket's catastrophic crash.

Three successively zoomed-in views showing the impact of a Centaur rocket stage in a dark crater on the moon as viewed by NASA's LCROSS probe minutes before its own destruction.

(Credit: NASA)

More important, spectroscopic data indicated the presence of material of some sort above or near the impact point in a murky crater known as Cabeus, and instruments aboard NASA's Lunar Reconnaissance Orbiter observed the Centaur crater and confirmed a plume of debris. But it was not immediately clear how extensive the plume was or how much material was blasted out.

Principal investigator Anthony Colaprete said it would take several days to analyze the data from the $79 million LCROSS experiment and reach a consensus on whether or not water ice was, or was not, detected.

"Life is full of surprises, we want to be careful and not make a false negative or a false positive claim," he told reporters after the impact. "I'm excited we saw variations in the spectra because that means we saw something, and it was not just blackness. The information's there, we just need to get to it."

Asked if he had seen anything in the initial data to indicate the presence of ice, Colaprete said he had not yet had time to look for the telltale signals.

"We're going to take our time and build up a case for water in the ejecta, if it's there, or a case against it if it's not there," he said. "And then understand if we're seeing variations, what do these variations mean? We've got to understand that before we say anything."

Interestingly, a closeup of the thermal flash of the Centaur impact showed an elongated smear of light and not a concentrated flare as one might expect from a near straight-in impact. Colaprete said his team would look into what that might mean. Topographic data collected by other satellites indicated a relatively flat floor where the impact occurred.

LCROSS was launched June 18 as a companion payload to NASA's $504 million Lunar Reconnaissance Orbiter spacecraft. Working in a 31-mile-high orbit, LRO is designed to create a high-resolution map of the moon's surface to help identify sites for future manned missions.

It also will measure the solar and cosmic radiation that future lunar explorers will face, and map out the surface topology, mineralogy, and chemical composition of Earth's nearest neighbor. One year will be spent scouting future landing sites, followed by three years of purely scientific observations.

While LRO was launched directly to the moon by a powerful Atlas 5 rocket, LCROSS and the booster's empty Centaur upper stage were sent into a looping four-month orbit back around the Earth.

The spacecraft was designed to aim itself and the attached Centaur stage back at the moon, targeting a permanently shadowed crater near the south pole. Mission managers initially selected a crater known as Cabeus A, but after additional analysis of topographic data, the target was switched to nearby Cabeus, a crater measuring some 62 miles across and about 2.5 miles deep.

LCROSS successfully separated from the Centaur stage at 9:50 p.m. Thursday and then rotated 180 degrees to aim its instruments forward. A small rocket firing slowed LCROSS to ensure the proper four-minute separation from the Centaur.

Analysis of telemetry indicated the trajectory was right on the money--the Centaur is believed to have hit the surface within about 210 feet of the planned target--and LCROSS presumably flew through an ejecta cloud of some sort.

"Everything really worked out well," Colaprete said earlier. "The spacecraft flew perfectly, the instruments performed, honestly, better than expected in some cases. We got interesting results. But again, these are just initial results...I can certainly report there was an impact, we saw the impact, we saw the crater and we got good measurements, spectroscopic measurements, which is what we needed of the impact event.

"So we have the data we need to actually address the questions we set out to address."

The search for water ice on the moon is one of the holy grails of modern lunar exploration. Data from other spacecraft, including the Lunar Reconnaissance Orbiter, show the presence of hydrogen, possibly from water ice, in the top three feet or so of lunar soil. Scientists initially believed ice from comets could be expected primarily in permanently shadowed craters near the moon's poles, but more recent data indicated the presence of trace amounts over broad regions.

"It could be water, it could be methane, it could be hydrocarbons or organics," Colaprete said during a pre-impact briefing. "From a scientific standpoint, this is incredibly important. Whatever the moon has collected over the last 3.5 billion years in terms of water, organics, materials from comets, asteroids, the sun, could be trapped in these pockets on the moon. It's a time capsule, it's a window into the past of the entire inner solar system, of Earth."

Finding ice on the moon could be critical to future exploration or even colonization. With unlimited solar power, ice can be converted into water, oxygen, and hydrogen rocket fuel. Finding ice on the moon also would raise the possibility of similar deposits in similar environments across the solar system.

"Water in terms of exploration is very important," Colaprete said. "Even if we don't go back to the moon, it is a principle resource throughout the solar system. On Mars and beyond. The old Mars mantra was 'follow the water.' And really, that extends in my mind through the entire solar system and the entire universe. And so really, LRO and LCROSS are the first directed, focused steps in that direction on the moon."

Data from a comet-bound NASA probe, a robotic mission to Saturn, and a U.S. instrument aboard an Indian spacecraft have provided clear evidence that at least trace amounts of water exist on the moon's surface, researchers said Thursday.

While scientists have long suspected that water ice from comet impacts is trapped in cold, permanently shadowed craters near the moon's poles, the new data indicates that water molecules form and dissipate across broader areas, even in lunar daylight.

Data from a NASA instrument aboard India's Chandrayaan-1 spacecraft show evidence of water molecules on the surface of the moon. Areas in blue show relatively high concentrations of water near the moon's poles.

(Credit: NASA)

While the data represent a major surprise and a "really profound discovery," one scientist said, researchers cautioned that the moon remains an extremely dry place, by human standards.

"The observations presented here show a combination of hydroxyl, OH (oxygen hydrogen molecules), and H2O (water) that resides in the upper few millimeters of the lunar surface," said Jim Green, director of NASA's Planetary Science Division. "The average amount of water reported, if we were to extract it, is about a quart of water per ton (of surface soil)."

To put it another way, he said, about 16 ounces of water might be present for every 1,000 pounds of surface soil near the moon's poles. For soil near the equator, only about two tablespoons of water is believed to be present in every 1,000 pounds.

"Even the driest deserts on the Earth have more water than are at the poles and the surfaces of the moon," Green said.

But scientists agreed that the results open a new chapter in humanity's understanding of the moon and the processes at work across the entire solar system that could lead to water formation on other airless asteroids and moons.

"Having any water or hydroxyl in the sunlit areas of the moon is as surprising as it is intriguing," Bruce Betts, director of projects for the Planetary Society, said in a statement. "Will such results turn out to be the tip of the iceberg, or will the moon remain a dry desert with slightly more moisture than we thought?"

On a related front, NASA unveiled new findings from the Mars Reconnaissance Orbiter on Thursday that show clear evidence of huge subsurface ice sheets extending from the poles of the Red Planet halfway to its equator.

The buried ice was spotted in debris thrown up in five recent northern hemisphere impact craters. The ice is surprisingly pure and easy to see in high-resolution pictures from the Mars Reconnaissance Orbiter.

Scientists believe that the ice is a remnant of a more humid period in Mars' recent history, when the planet's polar ice caps extended much farther toward the equator.

A recent impact crater on Mars, showing bright ice thrown up from a subsurface layer.

(Credit: NASA)

"Every indication is that this is forming a broad, continuous sheet beneath the surface," said Ken Edgett, a camera team member with Malin Space Science Systems of San Diego. "We have five separate impact sites, all showing more or less the same thing.

"I'd say the volume of water--and this is a guess--the volume of water is probably comparable to the volume we would have in, say, the Greenland ice sheet on the Earth, in the buried ice deposits (and the North Pole ice cap)."

Shane Byrne, a member of the High Resolution Imaging Science Experiment team at the University of Arizona, said the ice sheet is probably about a yard or so thick.

"These buried ice sheets that extend from the poles all the way down to 45 degrees or so (north and south latitude) don't quite cover half of the planet, but (they) come close," he said. "So we're talking about maybe a (half) million cubic kilometers of ice in total."

Water ice is a critical resource for future space travelers, as well as a requirement for the development of life as it is currently known. The presence of ice on Mars is not a surprise, although the purity and extent of the buried ice sheets is. Water on the moon, however, is another matter.

Three spacecraft--India's Chandrayaan-1 lunar orbiter, NASA's Saturn-bound Cassini probe, and the agency's Deep Impact comet mission--all detected evidence of water molecules on the moon's surface. In a surprise, it appears that water molecules are present, even in the heat of direct sunlight.

"Finding water on the moon in daylight is a huge surprise, even if it is only a small amount of water and only in the form of molecules stuck to soil," Jessica Sunshine, an astronomer at the University of Maryland who helped analyze data from NASA's Deep Impact spacecraft, said in a statement. "In the Deep Impact data, we're essentially watching water molecules form and then dissipate right in front of our eyes."

What causes the water to form is not yet clear, but Sunshine said the mechanism might involve electrically charged hydrogen ions in the solar wind interacting with oxygen-rich minerals in the lunar soil to form water and hydroxyl molecules.

"We aren't certain yet how this happens," she said, "but our findings suggest a solar-driven cycle in which layers of water only a few molecules thick form, dissipate, and reform on the surface each lunar day.

"This water is formed in the morning, substantially lost by lunar midday, and reformed as the lunar surface cools towards evening."

Finding water on the moon has long been one of the holy grails of modern lunar exploration because solar power and ice deposits, assuming they are close enough to the surface, could provide a source of water, air, and rocket fuel for future moon explorers or colonists.

The discoveries announced this week don't necessarily mean that abundant water supplies are available across the moon's surface--the solar-driven cycle implied by Deep Impact would produce only trace amounts--but they show that the moon isn't the totally dry place scientists long thought it was.

Earlier data indicated possible ice deposits in permanently shadowed craters near the moon's poles, where water from comet impacts could have been trapped over the moon's long history.

In June, NASA launched two new spacecraft to the moon, the $504 million Lunar Reconnaissance Orbiter and the $79 million Lunar Crater Observation and Sensing Satellite, or Lcross.

Orbiting the moon at an altitude of just 31 miles, the LRO spacecraft is designed to map the lunar surface in unprecedented detail to help identify possible landing sites for future manned missions. Lcross is focused specifically on water.

If all goes well, the spent second stage of the rocket that boosted LRO and Lcross to the moon will crash into a permanently shadowed crater on October 9, blasting presumably ice-bearing soil into sunlight for direct analysis by LRO, the Hubble Space Telescope and ground-based observatories. Lcross will fly through the plume, beaming back data before it, too, crashes to the surface.

After two months of checkout and calibration, NASA's $504 million Lunar Reconnaissance Orbiter was maneuvered into a circular 31-mile-high mapping orbit Tuesday, and scientists said Thursday the spacecraft's instruments are delivering intriguing clues about the possible presence of water ice.

"The moon is starting to reveal her secrets, but some of those secrets are tantalizingly complex," said Michael Wargo, NASA's chief lunar scientist.

Scientists expected the spacecraft to find signs of hydrogen--an indicator of possible water ice deposits--in permanently shadowed craters near the moon's south pole. Ice could be expected from cometary impacts over the past few billion years.

In a surprise, high-resolution data from the Lunar Reconnaissance Orbiter, right, shows indications of hydrogen both inside and outside of permanently shadowed craters.

(Credit: NASA)

Indeed, one of LRO's instruments shows the temperature in such craters never rises above about 33 kelvin, or minus 400 degrees Fahrenheit. But in a surprise, the spacecraft is detecting signs of hydrogen both inside and outside of such craters.

The observations confirm "there is hydrogen near the lunar south polar region," said Project Scientist Richard Vondrak. "What it also seems to indicate is that the hydrogen is not confined to permanently shadowed craters. Some of the permanently shadowed craters do indeed contain hydrogen. Others, on the other hand, do not appear to have hydrogen. And in addition, there appear to be concentrations of hydrogen that are not confined to the permanently shadowed regions."

Water ice cannot exist in direct sunlight on the surface of the moon.

"However, it can exist below the surface even if the surface is warm," Vondrak said. "So you may have had water deposited, or some other hydrogen-bearing compound like methane or ammonia, that was deposited from a comet or some other event and then was promptly buried.

"And so you could have this buried hydrogen that then would be lasting for long, long periods of time. It would be very durable there. What we don't know is the abundance and how deep it is buried."

The issue is of critical importance to scientists and engineers who envision someday building permanent research stations on the moon, using solar power to break down mined water ice to provide oxygen, water, and hydrogen rocket fuel. Scientists do not yet know if water ice is, in fact, mixed in with the moon's upper soil, only that hydrogen-bearing material of some sort seems to be present.

Equipped with seven state-of-the-art cameras and other instruments, LRO was built to look for suitable landing sites for future manned missions while creating the most detailed lunar atlas ever assembled.

The 4,200-pound solar-powered spacecraft also will measure the solar and cosmic radiation that future lunar explorers will face and map out the surface topology, mineralogy, and chemical composition of Earth's nearest neighbor. One year will be spent scouting future landing sites followed by three years of purely scientific observations.

LRO was launched by an Atlas 5 rocket from the Cape Canaveral Air Force Station in Florida on June 18 along with a companion spacecraft, the $79 million Lunar Crater Observation and Sensing Satellite, or LCROSS. The two spacecraft separated shortly after launch.

LCROSS is designed to guide the Atlas 5's spent Centaur second stage to an impact in a permanently shadowed crater near the moon's south pole on October 9. Instruments aboard LCROSS, LRO, the Hubble Space Telescope, and at observatories on Earth will study the debris thrown up by the crash to look for evidence of ice.

"It could be water, it could be methane, it could by hydrocarbons or organics," said LCROSS Project Manager Dan Andrews. "And so actually from a scientific standpoint, this is incredibly important. Whatever the moon has collected over the last three-and-a-half billion years in terms of water, organics, materials from comets, asteroids, the sun, could be trapped in these pockets on the moon.

"It's a time capsule, it's a window into the past of the entire inner solar system, of Earth," he said. "I see LCROSS and LRO combined as a gateway, a pathfinder to truly understanding even the origins of volatiles, of water, in the inner solar system. The moon is right there, it's right next to us, we can go there much more easily than a lot of other places and make these studies."

LRO Project Manager Craig Tooley said the lunar orbiter is operating in near flawless fashion, with all seven of its instruments now activated and trained on the moon. The craft was maneuvered from its initially elliptical commissioning orbit into a 31-mile-high circular orbit last Tuesday with a three-minute rocket firing over the south pole.

"Commissioning is now complete and all of our seven instruments as well as our spacecraft (are) essentially performing flawlessly," he said Thursday. "So we are certainly ready to proceed on into the mission."

NASA's embattled Constellation moon program, thought by many to be on life support in the face of ongoing budget cuts, is technically feasible, "soundly" managed, and capable of putting American astronauts back on the moon as planned in the 2020s, the chairman of a manned space review said Tuesday.

But if the Obama administration and Congress fail to restore some $3 billion in lost funding, he said, NASA will be unable to return to the moon or venture beyond the confines of low-Earth orbit.

A NASA graphic showing the proposed Ares 1 rocket intended to boost Orion crew capsules into low-Earth orbit.

(Credit: NASA)

Norman Augustine, former CEO of Lockheed Martin and chairman of Review of U.S. Human Space Flight Plans Committee, told the House Committee on Science and Technology that he would not endorse any one of the panel's five options and their variants, but he agreed there should be "compelling reasons" to cancel a program, like Constellation, that is already in motion.

And neither he nor Edward Crawley, a panel member and engineering professor at the Massachusetts Institute of Technology who oversaw the development of the options submitted to the White House, offered any such compelling reasons.

"There were on our committee a number of people who actually built space flight hardware and their general consensus on the assessment of the Constellation program technically is it has problems, all real programs where you're really building hardware encounter developmental problems, but that we didn't see any...that were not surmountable with proper engineering talent and skill, which we believe NASA can bring to bear," Crawley said.

Rep. Bart Gordon (D-Tenn.), chairman of the Science and Technology committee, observed that Constellation was a congressionally authorized program that represented a significant expenditure to date.

"I don't think you trade what you know for what you don't know if it's equal or a little bit better," Gordon said. "So are you prepared to say that one or all of the other options are substantially better than Constellation and worth having a major turn now?"

"I think it would be our view, just what you said, there should be a compelling reason to change an existing program," Augustine replied. "We believe the existing program, given adequate funds, is executable and would carry out its objectives."

Gordon and virtually every other committee member who spoke Tuesday questioned the wisdom of changing direction and expressed support for trying to come up with the money needed to turn Constellation into reality.

"Mr. Chairman, in many ways it's hard for me to understand why the president is seeking new options at all when there's been an agreed upon plan for several years," said Rep. Ralph Hall (R-Texas), the committee's ranking Republican. "Why don't we just fund the program we've all agreed to? Why should multibillion-dollar bailouts of banks and insurance companies come at the expense of our talented scientists, our engineers, and technicians who make the impossible look easy?

"I think many of us think it would take a very small fraction of our federal budget, just tenths of one percent, to make a significant difference in our human spaceflight goals," Hall said. "But even if that level of funding is not forthcoming, we have to be very careful how we proceed because we have a lot at stake."

Mike Griffin, NASA's former administrator and the man in charge when the Constellation program was developed, put the debate in stark terms. Since 1994, he said, NASA's annual budget has suffered a 20 percent decline in real dollars.

"At this time a year ago, the original budget for exploration had already been eroded by some $12 billion to pay for other things," he said. "The budget submitted this past May erodes that further to the point where some $30 billion has, if those plans go forward, been removed from space exploration.

"The issue is money. That issue renders moot all other debate as to what other destinations we might pursue, whether they're the moon, near Earth asteroids, Mars or any debate about how we might get there. On the 40th anniversary of Apollo 11, this is a sobering thought...I hope I'm not the only one who finds it shameful we're in this position."

The Constellation program was born in the wake of the 2003 Columbia disaster. The Bush administration decided in January 2004 to finish the International Space Station and to retire the shuttle in 2010. At the same time, NASA was told to begin development of a replacement system that could ferry astronauts to and from the space station and eventually, on to the moon, a system that would be safer and less expensive to operate than the shuttle.

The long-range goal was establishment of Antarctica-type lunar research stations in the early 2020s where astronauts can live and work for months at a time.

NASA's answer to this new direction was the Constellation program. Two rockets were envisioned, the manned Ares 1, designed to boost Apollo-like Orion crew capsules to low-Earth orbit, and the unmanned Ares 5, a huge heavy lift rocket that will carry a four-person lunar lander into space.

The Bush administration did not give NASA much in the way of additional funding to pay for initial Constellation development and the agency was forced to cut back in other areas to kick start the new program.

Given the lack of funding up front, development of the Ares 1 has lagged and now won't be available until at least 2015. During the five-year gap between the end of shuttle operations and the debut of Ares 1/Orion, NASA will be forced to buy seats on Russian Soyuz spacecraft, at $50 million each, to ferry U.S. and international astronauts to and from the space station.

During the presidential campaign, Obama expressed support for the Constellation program and it's long-range goal of returning to the moon. But after his election, the Office of Management and Budget cut another $3.1 billion from NASA's long-range budget, money that was critical to initial development of the new Ares 5 booster. Those cuts, on top of earlier reductions, have left NASA in what the Augustine panel described as an untenable position.

"The reluctant bottom line conclusion of our committee is that the current program as it's being pursued is not executable, that we're on a path that will not lead to a useful, safe human exploration program and the reason for that is the mismatch between the tasks to be performed and the funds available to support those tasks," Augustine said Tuesday.

The Review of U.S. Human Space Flight Plans Committee reviewed NASA's current plans, alternatives, and also considered how long the U.S. agency and its partners should operate the International Space Station. NASA currently has no money in its projected downstream budget to operate the space station beyond 2015.

In its executive summary--the group's final report is not yet complete--the panel did not make any recommendations. Instead, it listed five options, or architectures, and the pros and cons associated with each. The first two options assume NASA is forced to live within current 2010 budget projections.

In one, the shuttle is retired on schedule and the space station is deorbited in 2015 or 2016. Under that scenario, the panel concluded, NASA would not be able to return to the moon until the 2030s or later. In the other "constrained budget" case, the shuttle is retired, the station is extended through 2020, the Ares 1 is canceled and NASA relies instead on the commercial development of new rockets to to carry astronauts to low-Earth orbit. Under that scenario, the panel said, a heavy lift rocket is delayed to the late 2020s and no money is available to develop lunar landing technologies.

The panel's final three options assume NASA's exploration budget is boosted by $3 billion and then allowed to grow each year at 2.4 percent to offset inflation.

Option No. 3 is basically NASA's Constellation program as currently envisioned, with shuttle retirement in early 2011 and no additional money for operation of the International Space Station past 2015. In that case, the panel concluded, NASA could, in fact, return to the moon in the mid 2020s.

Option No. 4 would extend the station through 2020 and retain the moon as the nation's primary target beyond low-Earth orbit. But it would rely on development of commercial access to low-Earth orbit. In one variant, the shuttle is retired and NASA builds an Ares 5 Lite to launch crew and cargo to the moon. In the other, the shuttle program is extended and a new heavy lifter based on shuttle technology is developed for moon flights.

Option No. 5 represents a so-called "flexible path" architecture that would explore the inner solar system with long-duration flights to a variety of targets, ranging from lunar orbit to the moons of Mars. The long-range goals could include lunar landings and eventual flights to Mars itself. This scenario assumes development of commercial launchers, shuttle retirement and no station extension.

Gabrielle Giffords (D-Ariz.), chairwoman of the House subcommittee on space and aeronautics, was critical of the Augustine panel's options, saying "I thought we were going to take a hard, cold, sobering look at the Constellation program and tell us exactly what we needed to do here in Congress, with our budget, in order to maximize the chances of success. But that's not what I see."

"So I guess I'll ask my colleagues on this committee, what are we going to do with this report? I know that we are going to see more details. But in the absence of mismanagement or technological show stoppers...none of which the Augustine panel has indicated has occurred in this program, can any of us in good conscience recommend canceling the exploration systems development programs that Congress has funded and supported over the past four years?"

Giffords said she did not see "the logic of scrapping what the nation has spent years and billions of dollars to develop."

Keeping the $75 billion International Space Station operational through at least 2020 seems to be a given regardless of which option is ultimately approved. In his written remarks to the Science and Technology Committee, Griffin reflected the views of many when he said "any discussion of decommissioning and deorbiting the ISS is irrelevant to the consideration of serious programmatic options."

The first man on the moon took a moment Monday, on the 40th anniversary of his "giant leap," to remember the Apollo program and the engineering triumph that won the Cold War space race and opened the door to the manned exploration of the solar system.

Speaking at an Apollo celebration at the National Air & Space Museum in Washington, Neil Armstrong enjoyed a standing ovation before sharing his view of the achievement that carried him to the moon, concluding with a simple, heartfelt "Apollo was a good thing to do."

Neil Armstrong's shadow on the moon.

(Credit: NASA)

"Thank you so much," he said from the stage. "Whenever I come to this city, if I have 20 minutes to spare, I come to this building. Not necessarily to look at craft hanging from the ceiling and sitting on the floors. But to absorb, by osmosis or radiation or some unknown mechanism, some of the history that resides here. And it must have worked, because as one young man recently said to me, 'Pop, you're history!'

"So let me take one minute to recount some of those flights that we saw in the video earlier. Forty winters have passed since the first manned flights of the Apollo spacecraft. And so, let's kind of return to that remarkable time between October of 1968 and November of 1969.

"Those 13 months began with the first manned Apollo flight, which demonstrated the ability of its command module to fly longer than the duration of a round trip to the moon. Just two months later, the second flight, in a remarkably bold move, flew to, and orbited, the moon.

"The third flight, in Earth orbit, tested the lunar module in its inaugural flight. Two months later, the fourth flight took a lunar module to lunar orbit in a dress rehearsal that demonstrated the ability of mission control to communicate and track two vehicles in different orbits about the moon.

"The fifth flight completed the final step, demonstrating the ability to descend to, land on, and return from the moon to lunar orbit. The sixth flight, the last flight of 1969m, was nearly operational, landing on the lunar surface precisely alongside the Surveyor 3 spacecraft, which had arrived there two-and-a-half years earlier.

"No flight test program of any complex flying machine was ever conducted so efficiently and with such a small number of flights. Six more ever more complex and difficult flights would continue the Apollo exploration program over the following three years.

"Those successes were very impressive 40 years ago, but they were not miraculous. They were the result of the imagination and inventive minds of the people in the Apollo project since its inception eight years earlier. Those years engendered some of the most challenging, most difficult and most productive work in the history of modern engineering.

"Eight years, including a year and a half of redesign as a consequence of those deficiencies that were responsible for the tragic and fatal fire of the Apollo 1 spacecraft. Creating a strategy, a configuration and a craft to carry men to the moon was staggeringly complex. It required the very best in creativity, determination and perseverance that could be assembled in the American workplace.

"Seldom in recorded history have so many government employees so intensely and for such long hours worked at their chores. And seldom have so many aerospace engineers and craftsmen been so careful, so diligent and so determined.

"It was a superb national enterprise. Our knowledge of the moon increased a thousand-fold and more. Techniques were developed for interplanetary navigation and travel. Our home planet has been seen from afar and that perspective has caused us to think about its - and our - significance.

"Children, inspired by the excitement of space flight, have come to appreciate the wonder of science, the beauty of mathematics, and the precision of engineering. Young minds in our own country and around the world now believe they can do great things. And they can, if they apply themselves as intensely as the Apollo workforce did four decades ago.

"Tonight, we remember a special time. We remember a time, a passion for perfection, we remember a level of achievement, which really surprised us all. Human interest and media coverage this month confirmed that many others remember that time and remember Apollo with some warmth and even a little admiration.

"It left a lasting imprint on society and history. Tonight, we remember and congratulate all those who made it possible. Apollo was a good thing to do."

Four-and-a-half days after launch, NASA's $504 million Lunar Reconnaissance Orbiter fired its main thrusters for 40 minutes early Tuesday, successfully braking into an initially elliptical orbit around the moon.

The critical rocket firing began around 5:47 a.m. EDT and ended as planned at 6:27 a.m., putting the spacecraft into an orbit tilted 30 degrees from the moon's poles with a low point of 136 miles and a high point of 1,926 miles.

A graphic showing LRO's path to the moon and the result of a 40-minute rocket firing Tuesday that slowed the craft enough for capture by the moon's gravity.

(Credit: NASA)

"All stations, this is flight," said lead flight director Rick Saylor. "Congratulations on a successful LOI (lunar orbit insertion) to return NASA to the moon."

Over the next five days, the Lunar Reconnaissance Orbiter will carry out four additional rocket firings to put the spacecraft in its so-called commissioning orbit with a low point of just 18.5 miles above the moon's south pole and a high point of 134 miles above the north pole. The orbit eventually will be circularized at about 31 miles above the moon.

"The tracking shows we're essentially where we planned to be, we're at the moon," said Craig Tooley, the LRO project manager at NASA's Goddard Space Flight Center. "It went like clockwork. With a mission like this, we spent literally years practicing for every possible contingency to be ready for this. In the end, it went exactly as planned."

LRO will spend two months in its commissioning orbit for instrument checkout and calibration before maneuvering into the desired 31-mile-high mapping orbit.

Equipped with seven state-of-the-art cameras and other instruments, LRO will look for suitable landing sites for future manned missions while creating the most detailed lunar atlas ever assembled.

The two-ton solar-powered spacecraft also will measure the solar and cosmic radiation that future lunar explorers will face and map out the surface topology, mineralogy, and chemical composition of Earth's nearest neighbor. One year will be spent scouting future landing sites followed by three years of purely scientific observations.

A NASA graphic showing the Lunar Reconnaissance Orbiter in orbit around the moon.

(Credit: NASA)

"Over the course of an entire year...we will have a global measurement of the moon and have a new set of data, essentially a new atlas of the moon that has not only measurements of topology and temperature but minerals and then global images of the moon," LRO project scientist Rich Vondrak said before launch.

"One of our primary objectives is to identify safe landing sites for future human return to the moon. The Apollo program accepted risk and was able to have safe landings. We want to return to the moon, make repeated landings in some areas and be able to go there with a higher degree of safety."

Using the data collected by LRO, he said, "we'll get new views of the moon and we will prepare for the next generation of explorers and scientists the handbook, the guidebook for future exploration of the moon."

LRO was launched by an Atlas 5 rocket from the Cape Canaveral Air Force Station last Thursday along with a companion spacecraft, the $79 million Lunar Crater Observation and Sensing Satellite, or LCROSS. The two spacecraft separated shortly after launch.

LCROSS is designed to guide the Atlas 5's spent Centaur second stage to an impact in a permanently shadowed crater near the moon's south pole on October 9. Instruments aboard LCROSS, LRO, the Hubble Space Telescope and at observatories on Earth will study the debris thrown up by the crash to look for evidence of ice, a critical resource for future outposts.

Updated at 2:40 p.m. EDT: Adding the name of the LRO flight director.

An Atlas 5 rocket thundered to life and streaked into space Thursday, hurling two NASA spacecraft toward the moon for a $583 million mission to scout out landing sites for future manned missions and to search for evidence of hidden ice near its frigid poles.

One spacecraft will map the cratered surface from a perilously low 31-mile-high orbit while the other will blast out 350 tons of pulverized rock and soil for chemical analysis, digging a shallow 66-foot-wide crater in a kamikaze crash visible from Earth.

"First, we want to identify safe landing sites," said project scientist Rich Vondrak. "Then, we want to search for resources on the moon. And finally, we want to get better insight into the space radiation environment and how it may be harmful to humans."

Delayed 20 minutes by nearby thunderstorms, the United Launch Alliance Atlas 5 rocket's RD-180 first stage engine ignited at 5:32 p.m., slowly pushing the towering rocket away from launch complex 41 at the Cape Canaveral Air Force Station.

An Atlas 5 rocket takes off on a NASA mission to scout out lunar landing sites and to search for hidden ice near the moon's poles.

(Credit: United Launch Alliance)

Spectacular rocket cam views showed the Atlas 5's fiery exhaust plume against the cloud-draped limb of planet Earth and the deep black of space. Another camera showed the nose cone fairing falling away, exposing the satellite payload to view.

Two firings by the Atlas 5's hydrogen-fueled Centaur second stage successfully boosted the dual-spacecraft payload onto a four-day trajectory to the moon.

The $504 million Lunar Reconnaissance Orbiter, equipped with seven state-of-the-art cameras and other instruments, will look for suitable landing sites for future manned missions while creating the most detailed lunar atlas ever assembled.

The 4,200-pound solar-powered spacecraft also will measure the solar and cosmic radiation that future lunar explorers will face and map out the surface topology, mineralogy and chemical composition of Earth's nearest neighbor. One year will be spent scouting future landing sites followed by three years of purely scientific observations.

While its cameras will not be able to detect the footprints of the 12 Apollo astronauts who once walked on the moon, they will be able to see the landing stages, rovers and other equipment that were left behind.

LRO's companion, the $79 million Lunar Crater Observation and Sensing Satellite, or Lcross, faces a much shorter lifetime. With LRO on its own, Lcross will maneuver the spent Atlas 5's Centaur second stage into a looping four-month orbit back around the Earth.

If all goes well, Lcross will aim itself and the Centaur back at the moon, targeting a permanently shadowed crater near the south pole for a dramatic crash landing October 9. With LRO looking on from lunar orbit, the 5,000-pound Centaur will hit the dark surface at some 5,600 mph, blasting out a 66-foot-wide crater some 13 feet deep.

The debris excavated by the impact will be blown high above the lunar surface, some of it above the crater's rim and into sunlight for the first time in 2 billion years or more.

Lcross, following close behind the Centaur on a virtually identical course, will fly through the debris cloud, spending four precious minutes studying the composition of the material and looking for signs of water ice with a suite of nine instruments.

Then it, too, will crash to the moon less than 2 miles away after dutifully transmitting its data back to Earth. The Hubble Space Telescope will monitor the impact, as will amateur and professional astronomers in the Western hemisphere, looking for the flash that will signal the Centaur's demise.

The LRO/Lcross mission is NASA's first trip to the moon since the more modest Lunar Prospector was launched in 1998. The new missions are part of NASA's post-Columbia program to send astronauts back to the moon to establish a permanent Antarctica-style research station starting around 2020.

The Bush administration approved the new plan and President Obama endorsed the resumption of moon flights during his campaign.

But earlier this year, the White House Office of Management and Budget cut $3.1 billion from NASA's projected budgets through 2013--money needed to begin development of a heavy-life moon rocket--and the president ordered an independent re-assessment of NASA's long-range goals.

The review panel held its first public hearing Wednesday and its final report is expected by the end of the summer.

Regardless of the ultimate fate of NASA's manned moon program, the two spacecraft launched Thursday promise to greatly advance understanding of the moon's history and evolution, along with making the first serious attempt to identify favorable landing sites for future long-duration visits.

A 'rocket cam' view of the Atlas 5's first stage exhaust plume during the climb to space.

(Credit: NASA TV)

Separating from the Lcross/Centaur shortly after launch, LRO will fly to the moon on its own. After a long rocket firing Tuesday morning to brake into an elliptical orbit, engineers will spend up to two months checking out and calibrating the spacecraft's instruments and maneuvering it into a circular 31-mile-high orbit.

For comparison, the orbits used by Apollo command modules were about 70 miles high.

"As its name says, LRO is all about doing reconnaissance at the moon," said Craig Tooley, the mission's project manager at Goddard. "Reconnaissance, specifically, to bring us back the data and the information we need to plan and execute the human return to the moon.

"An inevitable question I get is 'why do we need LRO? Haven't we done this?' And, indeed, of course, we've been to the moon. But when we went to the moon for Apollo, we went to the equatorial regions and we intentionally planned to not stay for very long.

And even at the onset of our renewed commitment to send human beings to the moon back in 2004, we knew then if we were going to go to the moon with the more ambitious goals we have now of staying longer and perhaps establishing outposts, we were going to go to a different place."

Scientists and engineers thinking about future outposts on the moon are focused on the polar regions, where areas in permanent sunlight offer unlimited solar power. Conversely, permanently shadowed craters nearby offer the prospect of ice deposits and along with them, a source of water, oxygen and hydrogen rocket fuel.

"We actually have much better maps of Mars than we have of our own moon's polar regions," Tooley said. "So the job of filling out that information set, making that atlas complete for planning safe and fruitful return to the moon, that job fell to LRO."

The Lcross mission is much more tightly focused.

Earlier lunar probes detected indirect evidence of water ice in dark polar regions. Scientists believe ice could indeed be trapped in polar craters that never see sunlight, brought in by comet impacts over the billions of years since the moon's formation.

The Centaur impact is designed to blast out material in the top few feet of a shadowed crater's floor where ice deposits are suspected.

"There's data out there which could show it's potentially ice rinks," said Lcross project manager Dan Andrews. "There's data out there that shows it's blocky. There's data out there that could support the fact that there might not be water ice there," said Dan Andrews, the Lcross project manager. "So that illustrates the importance of this mission. Let's go see what it is.

"The benefit of having water ice there is self-evident. The availability of water right there on the moon, availability of producing oxygen, oxidizer for rocket fuel for other missions, it's very, very interesting if water ice is indeed there."