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Space Junk as Big a Threat as Space Weapons, Agency Warns

Thu, 23 Dec 2010 15:59:04 -0500

What began as a minor trash problem in space has now developed into a full-blown threat. A recent space security report put the problem of debris on equal footing with weapons as a threat to the future use of space.

Hundreds of thousands of pieces of space junk -- including broken satellites, discarded rocket stages and lost spacewalker tools -- now crowd the corridors of Earth orbit.

These objects could do serious damage to working spacecraft if they were to hit them, and might even pose a risk to people and property on the ground if they fall back to Earth and are large enough to survive re-entering the atmosphere.

The new Space Security 2010 report released by the Space Security Index, an international research consortium, represented space debris as a primary issue. Similar recognition of the orbital trash threat also emerged in the U.S. national space policy unveiled by President Obama in June 2010.

Such growing awareness of the space debris problem builds on stark warnings issued in past years by scientists and military commanders, experts said. It could also pave the way for U.S. agencies and others to better figure out how to clean up Earth orbit.

Consideration of space debris as a major threat may cause the United States to take a more global view on the threat of space weapons, said Brian Weeden, a former U.S. Air Force orbital analyst and now technical adviser for the Secure World Foundation, an organization dedicated to the sustainable use of space.

"This is an important realization, because before that much of the security focus was on threats from hostile actors in space," Weeden explained. "This is the first [national policy] recognition that threats can come from the space environment and nonhostile events."

All those bits of garbage in space could eventually create a floating artificial barrier that endangers spaceflight for any nation, experts said.

The space debris swarm

Even fictional space navigator Han Solo might prefer to risk turbolaser blasts from Imperial starships rather than hazard Earth's growing cloud of space debris, where objects whiz by at up to 4.8 miles per second (7.8 km/s).

The possibility of a damaging collision between spacecraft and orbital junk only continues to grow with more functional and nonfunctional hardware flying above Earth. Both the International Space Station and space shuttle missions have been forced to dodge space debris in the past.

More than 21,000 objects larger than 4 inches (10 centimeters) in diameter are being tracked by the Department of Defense's U.S. Space Surveillance Network. Estimates suggest there are more than 300,000 objects larger than 0.4 inches (1 cm), not including several million smaller pieces.

"The shuttle was more likely to be wiped out by something you didn't see than something you were dodging," said Donald Kessler, a former NASA researcher and now an orbital debris and meteoroid consultant in Asheville, N.C.

But the problem has become much worse since Kessler began studying the issue decades ago with Burton Cour-Palais, a fellow NASA researcher. Their 1978 research described how the debris cloud might continue expanding on its own because of an ever-higher probability of collisions that built upon each past collision.

The Kessler Syndrome

That prediction, known as the Kessler Syndrome, may have already been realized.

China's intentional destruction of an aging weather satellite during a 2007 anti-satellite test created about 2,500 pieces of new debris in Earth orbit.

More recently, a U.S. Iridium communications satellite and a defunct Soviet Cosmos spacecraft were destroyed in an unintended head-on collision in 2009. That incident added more than 1,000 pieces of trackable debris to the mess, adding to the number of possible targets and therefore upping the chances of future collisions.

The overall trackable amount of space debris grew by about 15.6 percent, according to the Space Security 2010 report.

NASA and other U.S. agencies could use national space policy as a chance to aggressively pursue solutions, such as using spacecraft propelled by solar radiation (solar sails) or other objects to take down a few select pieces of debris, experts said.

"If we only bring down four objects per year, we can stabilize [the debris field] if we carefully select those most likely to contribute to debris," Kessler told SPACE.com.

Path to cleaner space

The national space policy shift shows that policymakers have finally begun to take action based on the work of Kessler and other researchers, Weeden said.

"This policy basically sets the playing field for what is to come," Weeden said. "It's an enabler, not the actual solution itself."

The United States and other countries could begin discussing voluntary codes of conduct about how to minimize space debris from new missions, as well as how to clean up old space debris.

But legally binding agreements remain politically unlikely, Weeden cautioned. More plausible is an agreement on a strictly volunteer basis that would require spacefaring countries to put peer pressure on one another to comply.

Change of tune

The criticism of past space weapons tests that have created space debris has already changed how countries plan their actions, said Joan Johnson-Freese, a space policy analyst at the Naval War College in Newport, R.I.

"When the United States tested an anti-satellite (ASAT) weapon in 1985 by destroying its Solwind satellite, and China tested its ASAT in 2007, neither broke any 'rules,'" Johnson-Freese said in an e-mail. "But each created a substantial amount of space debris potentially dangerous to other spacecraft."

Both countries have since changed their policies, and said future tests will be characterized as "missile defense," aimed only at destroying targets that won't leave lingering debris, Johnson-Freese pointed out. "In terms of space debris, it is simply not in U.S. interests to pursue paths that encourage actions that result in debris creation."

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The Future Is Here: Cyborgs Walk Among Us

Thu, 09 Dec 2010 09:40:48 -0500

Bionic beings who are part-human, part-machine may sound like a concept that still belongs in science fiction stories. But experts say that cyborgs are already walking among us, and have been around for quite some time.

When one-eyed filmmaker Robert Spence wanted to sell a documentary film idea of becoming an "EyeBorg," he installed a cheap LED light in his prosthetic eye. The simple addition instantly made his cyborg concept recognizable to potential business partners as he closed in on a possible deal for his documentary.

"Cyborg is your grandma with a hearing aid, her replacement hip, and anyone who runs around with one of those Bluetooth in-ear headsets," said Kosta Grammatis, an engineer who worked with Spence on the EyeBorg project.

That illustrates the gulf between what experts and ordinary people think of when they imagine a cyborg (cybernetic organism). Many experts see a modern world filled with cyborgs, whether they wear exoskeleton robot suits and prosthetic limbs or pacemakers and eyeglasses. Yet the public still prefers the fictional Robocop and Terminator -- science fiction concepts that have not yet become fully realized in the real world. [5 Reasons to Fear Robots]

The stretchy definition of cyborg came up recently in an exhibit at the American Museum of Natural History in New York City, which listed both the villainous Darth Vader of Star Wars fame and the heroic Master Chief from the popular Halo video games as cyborgs.

Few would dispute that Darth Vader fits the cyborg definition. His transformation from troubled Jedi Anakin Skywalker into the dark lord of the Sith forces him to rely upon mechanical limbs and a life support system that gives his breathing its classic menacing edge.

But Master Chief, a genetically enhanced "Spartan" super-soldier who wears an armored power-suit, seems a more unlikely cyborg candidate, according to popular opinion. More than 76 percent of gamers on the website Giant Bomb do not consider Halo's Spartans to be cyborgs, according to an informal poll conducted by LiveScience.

"What a cyborg is, in big part, is a fictional character from the future," Spence said.

From human to cyborg

The futuristic aspect of cyborgs weighs heavily on the popular definition, as Spence quickly realized. His conceptual success with EyeBorg's cheap light comes despite the fact that the prosthetic acts as a separate camera and has no functional connection to his body.

"Nobody calls people with a prosthetic eye cyborgs, but put in a $5 LED light and you look like the Terminator," Spence pointed out.

The Terminator also makes the cyborg list in the American Museum of Natural History's new brain exhibit. But whereas Darth Vader and Master Chief (and Spence) began their lives as humans, the original Terminator is a killer robot coated with living human skin and flesh -- yet sci-fi fans regularly refer to it as a cyborg.

Popular depictions of cyborgs seem to fall all over the spectrum between human and machine. If Master Chief wearing a power-suit is at one end, then Darth Vader sits somewhere in the middle and the Terminator is at the machine end.

Then what about Luke Skywalker, the son of Darth Vader who loses his hand during a lightsaber duel?

"You see Luke Skywalker in a famous ending [of "The Empire Strikes Back"] opening, closing and flexing his hand," Spence said. "That's a classic cyborg moment – he's wondering if he's a cyborg."

Conscious computers

To add to the confusion, the museum's cyborg lineup is rounded out by the Maria "machine-man" from the classic sci-fi film "Metropolis" and the computer HAL from "2001: A Space Odyssey."

HAL's inclusion in particular pushes the definition of a cyborg to an extreme, and raises the question of whether or not an artificial intelligence that gains self-awareness represents some mix between man and machine without any organic parts.

"As far as we are aware, HAL has a machine/computer brain, which pushes us into philosophical questions about whether it can ever completely exhibit human consciousness," said Kevin Warwick, a professor of cybernetics at the University of Reading in England.

A computer that had a brain made from biological neurons would perhaps represent a more likely cyborg, Warwick suggested.

"The 'best' definition I have seen of a Cyborg is a human enhanced well above the norm by technology which is integral to the body – particularly integral to the nervous system/brain," Warwick told LiveScience in an e-mail. "I feel that this is the sort of cyborg depicted/required by science fiction."

That approach fits with Warwick's own self-experimentation as "Captain Cyborg." In 2002, he had a neural interface chip implanted in his arm so that it could directly interpret signals from his nervous system. He later demonstrated the ability to directly control a robot arm and receive feedback from fingertip sensors, and even experimented with a form of electronic telepathy with his wife (who also had an implanted chip).

We are all cyborgs

Still, Warwick said that some definitions would allow any human using any piece of technology -- whether it's glasses, bicycles or pens – to count as a cyborg. Many other experts agreed with the most basic technical definition of a cyborg as a being that combines technology with human biology.

Humans are and always have been cyborgs, according to George Landow, a digital media scholar at Brown University. He pointed to "the most powerful of all technologies" in the form of language, and also included information technologies such as writing and math.

"Certainly, anyone who uses clothing or an umbrella is a cyborg," Landow said. "Anyone who uses medication, contact lenses, is well into cyborgism, and people like myself who have metal stents in their hearts and artificial lenses inside their eyes (after cataract operations), is definitely a cyborg according to the most conservative, cautious definition."

Todd Winkler, a professor of music at Brown, has even suggested that a pianist is a cyborg. The human musician knows how to play the piano without the instrument, but isn't really a pianist until he or she sits down at the piano.

Where we go from here

Something as mundane as a piano or clothing may indeed count as a cyborg component, but people view such things as commonplace, Spence explained. He suggested that technologies which already serve humans today may never quite satisfy the hankering for a really futuristic cyborg concept.

That implies the popular definition of a cyborg may simply be doomed to forever drift just out of our reach – never in the now, but always somewhere just beyond the future horizon.

"A cyborg is a human being who is augmented by technology," Spence said. "I'd say it's the most useful, super-technical definition, but it's the least fun. A lot of the point of defining a cyborg is to have fun."

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Getting Ready for Tomorrow's Space Wars

Wed, 05 May 2010 13:55:59 -0400

A U.S. Air Force space plane and a failed hypersonic glider tested by the Pentagon represent the latest space missions to raise concerns about weapons in space. But while their exact purpose remains murky, they join a host of new space technology tests that could eventually bring the battlefield into space.

Some space technology demonstrations are more obviously space weapons, such as the anti-satellite missile capabilities tested by the U.S. and China in recent years. India has also begun developing its own anti-satellite program which would combine lasers and an exo-atmospheric kill vehicle, as announced at the beginning of 2010.

The U.S. military and others have also long developed and deployed more neutral space assets such as rockets and satellites for military purposes. In that sense, both the Air Force's X-37B robotic space plane and the HTV-2 hypersonic glider prototype of the Defense Advanced Research Projects Agency (DARPA) could represent similarly ambiguous technologies which may or may not lead to weapons.

"Space has been militarized since before NASA was even created," said Joan Johnson-Freese, a space policy analyst at the Naval War College in Newport, RI. Yet she sees weaponization as a different issue from militarization because "so much space technology is dual use" in terms of having both civilian and military purposes, as well as offensive or defensive use.

Such uncertainty regarding space technology can make it tricky for nations to gauge the purpose or intentions behind new prototypes, including the X-37B space plane or the HTV-2 hypersonic glider.

The U.S. military could even be using the cloak of mystery to deliberately bamboozle and confuse rival militaries, according to John Pike, a military and security analyst who runs GlobalSecurity.org. He suggested that the X-37B and HTV-2 projects could represent the tip of a space weapons program hidden within the Pentagon's secret "black budget," or they might be nothing more than smoke and mirrors.

The devil is in the details

Many existing space technologies play dual roles in both military and civilian life.

The Global Positioning Satellite (GPS) system which started out as military-only has since become common in consumer smartphones and car navigation systems. Modern rocketry grew in part from the technology and scientific minds behind Nazi Germany's V-2 rockets of World War II, and continued to evolve alongside ballistic missile technology.

Even something as basic as a satellite image can be used for either military weapons targeting or civilian crop rotation, Johnson-Freese said. Space plane technology can seem equally ambiguous — the Air Force deputy undersecretary of space programs scoffed at the notion of X-37B paving the way for future space weapons.

"The whole issue is further complicated because beyond technologies like lasers, Rods from God, explosives, etc.... virtually any object traveling in space can be a weapon if it can be maneuvered to run into another object," Johnson-Freese told SPACE.com.

Uncertainty matters a great deal for how other nations view the recent U.S. space plane and hypersonic glider tests, regardless of whether or not the technologies lead to future weapons.

"They are testing capabilities that could certainly be useful to the military if it chose to use them in an offensive manner," Johnson-Freese said. "And the military has been silent on intent."

Intrigue and deception

Pike said the current work under way by the U.S. military leaves plenty of room for misinterpretations or even outright deception, which could be a ploy to distract other nations with military space projects.

"One of them could be a deception program and the other could be the spitting image of the real thing," Pike noted. He said that such misdirection could force other nations' militaries to waste money chasing down dead ends.

Both the Air Force space plane and DARPA's hypersonic glider may have a combined budget of several hundred million dollars per year, Pike estimated. He described such spending as "chump change" compared to the Pentagon's black budget spending in recent years of $6 billion to $8 billion annually — and he pointed to decades worth of known space plane programs which had amounted to little.

"I conclude that the hypersonic trans-atmospheric space plane domain is either unusually badly managed even for government programs, or there's a lot of hocus pocus here," Pike said. "I defy anyone to tell the difference between hocus pocus and mismanagement."

Of course, the U.S. military could theoretically make good use of either the X-47B or HTV-2. An operational space plane could launch quickly as a replacement for recon satellites disabled in the opening salvoes of a conflict, and could "play hide and seek" to avoid being shot down easily. Similarly, a hypersonic aircraft or weapon might allow the U.S. to eliminate threats early on without warning.

Walking the line on weapon bans

The double-edged nature of space technologies has also complicated international efforts to ban entire classes of technologies which might serve as space weapons. Instead, there has been interest in "more modest proposals that focus on behavior, rather than what you are allowed to build or test," said Karl Mueller, a political scientist at the RAND Corporation.

Military use of space looks likely to expand, according to the experts. But Mueller explained that the U.S. military's interest in space has less to do with the dazzling futuristic visions of space planes and more to do with "unglamorous" satellites and orbital sensor systems. Such technologies give situational awareness of all the satellites, spacecraft and debris in orbit.

One such example is the $800 million Space Based Space Surveillance satellite slated for launch in July. It carries an optical telescope to help Air Force ground-based radars track the growing orbital traffic of satellites and space debris — a goal which everyone can appreciate.

"That's true whether you're hawkish and enthusiastic about using force in space, or whether you're dovish and want to maintain the sanctuary of space and maximize peaceful spacefaring," Mueller said.

European Space Lab Entering Uncharted Legal Territory

Thu, 06 Dec 2007 07:58:08 -0500

If astronauts onboard the International Space Station (ISS) run afoul of the law more than 200 miles (321 kilometers) above Earth, their fate usually depends on where in the orbital lab the incident occurred.

That legal framework will become a bit more complicated when a new European Space Agency (ESA) module becomes part of ISS this month.

The space station currently exists as a legal patchwork of about 16 sovereign territories — modules and hardware belonging to the United States, Russia, Canada, Europe and Japan — joined together to form one orbital research platform.

Each nation has legal authority over its part of the space station, as stated in the Outer Space Treaty of 1967.

But no single European nation's law will hold sway over the ESA's Columbus laboratory module, which is slated to launch into orbit aboard the space shuttle Atlantis Dec. 6, and there is no one overarching European law.

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However, astronaut lawbreakers won't languish in limbo.

Earlier this year, European legal experts agreed on a set of legal rules for Columbus during an conference entitled "Humans in Outer Space — Interdisciplinary Odysseys."

Should tempers flare and astronauts end up in fisticuffs inside Columbus, the perpetrator's fate would be decided by the criminal laws of his or her nation.

But if the brawl occurred in an American, Russian or Japanese section of ISS, the perpetrator's fate could be decided by the criminal laws of his or her victim's nation.

"They decided that if somebody performs an activity which may be considered criminal, it is in the first instance his own country which is able to exercise jurisdiction," said Frans von der Dunk, of the International Institute of Air and Space Law at the University of Leiden, in a written statement.

Although astronauts are an exceptionally well-behaved group, other legal concerns may arise.

An invention created by an enterprising astronaut on ISS will be patented in the nation that has jurisdiction over the module where work took place, not the nation of the inventor.

Innovators onboard Columbus will have a choice of patenting their work in either Germany or Italy — although Europe-wide patent agreements make this distinction less important.

Civil liability on the space station is another issue. If someone on Earth gets hit by a car, they can sue the offending driver.

If astronauts accidentally damage equipment in Columbus while doing their usual duties on the space station, they typically don't have to fear a lawsuit.

"We are all there together, we all have the same purpose to make the ISS into a big success and we don't want that attitude, that mentality, to be disturbed by the threat of one party suing the other," von der Dunk said.

The ESA decision follows a previous cross-waiver agreement that the spirit of international cooperation is more important than minor legal squabbling.

When a solar array on the space station ripped during space shuttle Discovery's mission in October, the involved astronauts and agencies simply planned and executed a repair job instead of pointing fingers.

But "there are a number of exceptions" to the cross-waiver for civil liability, noted Andre Farand, a senior administrator in ESA's legal department, in an e-mail interview.

For instance, injury or death suffered by individual astronauts could still lead to legal claims against the organization which caused the harm.

What murky areas remain in space law may come from the growing presence of private interests, whether through space tourism or even astronauts participating in commercial activities on ISS, said Farand.

For the few space tourists who have visited ISS, Russia proposed the legal rules that other ISS partners then reviewed and agreed on, according to NASA's legal department.

'Space Mail' System Works, but Loses Package

Mon, 17 Dec 2007 10:01:52 -0500

A student-built satellite experiment shattered records by deploying the longest space tether ever flown in space, but the missing return capsule remains a mystery to unravel months later.

On Sept. 25, hundreds of students worldwide watched remotely as a Russian-built Foton-M3 spacecraft began unwinding a 19.7-mile-long (31.7 km) super-strong space tether no thicker than a string.

The experiment's small Fotino capsule dropped from it toward Earth, preparing to release at the right moment for re-entry into the atmosphere.

The goal was to demonstrate a "space mail" system of delivering packages to Earth using just a tether.

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But the experiment hit a snag when critical telemetry sensors on the tether deployment mechanism shut down. That left the onboard computer unable to control how quickly the space tether unwound from its spool.

Early data suggested the tether reached a length of just 5.3 miles (8.5 km) before cutting the Fotino capsule loose.

"We were kind of disappointed by the fact," said Marco Stelzer, a mission analyst and ground support engineer with the European Space Agency (ESA).

Steizer joined the Young Engineers Satellite (YES2) experiment — sponsored by the ESA Education Office — as a university student when he saw the tether idea promoted by Delta Utec SRC, a private space consultancy company that contracted with ESA.

Almost 500 students from Europe, the United States, Russia, Japan, and Australia worked on YES2.

Hope revived

New telemetry data from the Foton spacecraft saved students from a mission cliffhanger, revealing that the space tether deployment had accelerated rather than slowing down as first thought.

"Later on, we found out that the tether deployed to its full length, even more than originally planned," Stelzer told SPACE.com.

Additional data from the U.S. Space Surveillance Network showed that the Foton spacecraft moved close to a mile higher in orbit when the capsule cut free — as expected when a 19.7-mile-long tether's swinging momentum that launched the capsule also transfers to the much heavier spacecraft.

Where's the capsule?

Having smashed the world record for the longest man-made object flown in space, the YES2 team turned its attention to what happened with the Fotino capsule. The onboard beacon had failed to activate and signal the capsule's final location.

"We have some confidence that the capsule actually came down," said Stelzer, pointing out that a full-length tether deployment would have released the capsule back into Earth's atmosphere.

A U.S. ground station in Alaska did not detect Fotino flying overhead after the tether release, also suggesting the capsule re-entered instead of continuing in a low-Earth-orbit with the Foton spacecraft.

"It may have burnt up on re-entry, it may have crash-landed, it may have touched down in difficult terrain somewhere in Turkmenistan, Kazakhstan or Siberia, or its radio beacon did not transmit," said Roger Walker, YES2 project manager for ESA's Education Office, in a public statement.

More information will come in the next several weeks from other experiments and sensors onboard Foton.

Whatever Fotino's fate, the YES2 team cheered the test of the "space mail" delivery system using the space tether — even if the package was lost along the way.

"We proved that tether technology actually works," Stelzer said.

Future space tethers might not only deliver parcels to Earth, but also swing spacecraft or satellites into different orbits or towards other planets.

The ESA Education Office has additional satellite projects in development, including the European Student Earth Orbiter (ESEO) planned for 2010 and the European Student Moon Orbiter (ESMO) planned for 2011.

Scientists to See If Bacteria Can Survive in Space

Wed, 12 Dec 2007 07:45:34 -0500

Catching a free ride to Mars takes more than sticking out a thumb, but some hardy Earth bacteria could survive as hitchhikers clinging to the outside of spacecraft, studies have shown.

Now a set of experiments going up with space shuttle Atlantis to the International Space Station will test how exposure to the harshness of space might change bacteria during a simulated Mars mission.

"We are interested in understanding what types of damage are induced in cells and their DNA by exposure to space, what types of mutations may be induced, and how these mutations might drive evolutionary adaptation to the extreme selective environment of Mars," said Wayne Nicholson, a University of Florida Institute of Food and Agricultural Sciences astrobiologist working from NASA's Space Life Sciences Laboratory at the Kennedy Space Center.

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Although previous tests exposed different microbes to the space environment for up to six years, Nicholson noted that the experiments mostly "tested whether the bugs could survive long-term exposure to space" as opposed to seeing how the bacteria changed in response to space radiation.

Bacteria that can survive extreme environments interest researchers for several reasons.

Any Earth bacteria that escaped NASA's "clean rooms" and took a trip to Mars might contaminate efforts to find evidence of Martian life.

Looking beyond that, bacteria that can survive long space journeys on comets or interplanetary shards also provide evidence supporting the panspermia theory that the seeds of life are everywhere and can survive hopscotch trips from one space object to the next.

The current shuttle experiment — a collaborative effort between the University of Florida, NASA, the European Space Agency and the German Aerospace Center (DLR) in Cologne — will take place for more than a year on an external space station platform called EXPOSE.

That platform will be installed outside of ESA's Columbus laboratory module upon delivery by space shuttle Atlantis flight STS-122.

"Our immediate goals right now are to hope for a safe launch and deployment, and to work on our simulations and ground control experiments so that we will be completely prepared for processing the samples when they return from Earth orbit," Nicholson said.

European Orbiter Examines Odd Martian Terrain

Fri, 09 Nov 2007 07:51:44 -0500

A European spacecraft has used radar to probe one of the youngest and most mystifying deposits on Mars.

The European Space Agency's Mars Express orbiter studied the Medusae Fossae Formation (MFF), which straddles a divide between the highlands and lowlands near the Martian equator.

MFF deposits have remained an enigma partly because they are "stealth" regions that give no radar echo from certain wavelengths of Earth-based radar.

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But while the deposits absorb radar wavelengths between 1.4 and 5 inches (3.5 to 12.6 centimeters), the Mars Express used its Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) that operates at wavelengths of 164 feet to 328 feet (50 to over 100 meters).

That means MARSIS radar waves can pass through the MFF deposits and bounce off the solid rock beneath, creating a subsurface echo image.

"We didn't know just how thick the MFF deposits really were," said Thomas Watters, the study's lead author at the Center for Earth and Planetary Studies for the Smithsonian Institution's National Air and Space Museum in Washington, D.C. "The new data show that the MFF are massive deposits over 2.5 km [1.5 miles] thick in some places where MARSIS orbits pass over them."

Scientists have proposed a variety of scenarios about the origin and composition of the MFF deposits.

They could be volcanic ash deposits, wind-blown materials eroded from other Martian rocks, or even ice-rich deposits that formed when the spin axis of the planet tilted over and made the equatorial region colder.

MARSIS revealed both the depth and electrical properties of the deposit layers, suggesting that the layers could be poorly packed, fluffy or dusty material.

But scientists are puzzled over how material from wind-blown dust could be kilometers thick and not have compacted under the weight of overlying material.

Although the electrical properties resemble those of water ice layers, there is no other strong evidence for ice remaining at the Mars equator.

The water vapor pressure on Mars is so low that any ice near the surface would quickly evaporate, leaving the mystery of the Medusae Fossae Formation for scientists to ponder.

"If there is water ice at the equator of Mars, it must be buried at least several meters below the surface," said Jeffrey Plaut, MARSIS co-principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It is still early in the game. We may get cleverer with our analysis and interpretation or we may only know when we go there with a drill and see for ourselves."

NASA Book Commemorates 50 Years of Spaceflight

Tue, 09 Oct 2007 07:25:58 -0400

NASA released a new book on Thursday to commemorate the last five decades of achievement in aeronautics, science and technology, and spaceflight since the launch of Soviet satellite Sputnik ushered in the Space Age.

The U.S. space agency is also celebrating its own 50th anniversary in 2008. Sputnik's historic launch on Oct. 4, 1957 led directly to NASA's creation in 1958 when Congress passed the National Aeronautics and Space Act.

"This book has a wonderful collection of imagery that chronicles the first half-century of NASA," said NASA deputy administrator Shana Dale in a statement. "As we view the historic achievement of our first generation of space explorers and see how far we have come in 50 years, we also peer over the horizon to a new era of exploration that will provide us with an outpost on the moon and eventually human exploration of Mars."

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Titled "America in Space" and published by Harry N. Abrams, Inc., New York, the book contains 500 color and black-and-white photographs — many never before published — that were gleaned from NASA archives.

Images show dramatic moments at lift-off as well as the faces behind-the-scenes in mission control, providing vivid illustration of the very human astronauts, scientists, engineers, and administrators.

"Abrams is tremendously proud to have collaborated with NASA to create 'America in Space,' which celebrates some of our nation's greatest achievements and is also a milestone in photographic publishing," said Eric Himmel, Abrams vice president and editor-in-chief. "It was thrilling to see these amazing images materialize from NASA's vast visual archives as the project took shape."

"America in Space" also features a foreword by Apollo 11 commander Neil Armstrong — the first human to walk on the moon on July 20, 1969.

NASA chief historian Steven Dick, lead photo researcher Constance Moore and other officials also contributed to the new book, the space agency said. The book sells for $50.

For more images from the book, click here.

Signs of Once-Habitable Crater Lake Found on Mars

Mon, 10 Mar 2008 09:02:03 -0400

A lake that might once have been habitable may have filled a crater for a long time on early Mars, new spacecraft images reveal.

NASA's Mars Reconnaissance Orbiter (MRO) captured the images that suggest the debris-strewn Holden Crater once held a calm body of water that could have harbored life.

There is so far no convincing evidence life does or ever did exist on Mars, however.

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The crater debris includes a mix of broken boulders and smaller particles called megabreccia.

"Holden crater has some of the best-exposed lake deposits and ancient megabreccia known on Mars," said Alfred McEwen, principal scientist for MRO's HiRISE camera.

"Both contain minerals that formed in the presence of water and mark potentially habitable environments," he added. "This would be an excellent place to send a rover or sample-return mission to make major advances in understanding if Mars supported life."

That mission could be NASA's Mars Science Laboratory, set for launch next year. The Holden Crater is one of six landing sites under consideration.

The Holden impact crater formed inside a larger impact basin that was crisscrossed by large, natural channels.

Blocks as large as 164 feet (50 meters) were blasted from the basin by the impact, before falling back to the surface to form the megabreccia layer.

Water later settled a layer of fine-grained sediment on top of the megabreccia, including clay that could preserve any signs of life that might have existed.

"If we were looking on Earth for an environment that preserves signatures related to habitability, this is one of the kinds of environments we would look at," said John Grant, Hi-RISE scientist.

That clay may have remained hidden except for a stroke of luck, when the Holden crater rim crumbled under the force of nearly 960 cubic miles of water (4,000 cubic kilometers) that it was holding back.

The resulting flood tore up blocks the size of football fields and left boulder-filled debris, according to Grant, but also revealed parts of the clay layer.

The first long watery period at Holden Crater probably lasted thousands of years, while the second lake that formed after the crater rim was breached may have lasted just hundreds of years, Grant added.

Most evidence for long periods of wet conditions on Mars rests in the planet's earliest history, according to HiRISE scientists. Water may have only flowed later on during catastrophic events such as impacts on the planet surface.

NASA to Smash Moon With Double Sledgehammer

Thu, 28 Feb 2008 07:38:31 -0500

Scientists are priming two spacecraft to slam into the moon's South Pole to see if the lunar double whammy reveals hidden water ice.

The Earth-on-moon violence may raise eyebrows, but NASA's history shows that such missions can yield extremely useful scientific observations.

"I think that people are apprehensive about it because it seems violent or crude, but it's very economical," said Tony Colaprete, the principal investigator for the mission at NASA's Ames Research Center at Moffett Field, Calif.

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NASA's previous Lunar Prospector mission detected large amounts of hydrogen at the moon's poles before crashing itself into a crater at the lunar South Pole.

Now the much larger Lunar Crater and Observation Sensing Satellite (LCROSS) mission, set for a February 2009 moon crash, will take aim and discover whether some of that hydrogen is locked away in the form of frozen water.

LCROSS will piggyback on the Lunar Reconnaissance Orbiter (LRO) mission for an Oct. 28 launch atop an Atlas 5 rocket equipped with a Centaur upper stage.

While the launch will ferry LRO to the moon in about four days, LCROSS is in for a three-month journey to reach its proper moon smashing position.

Once within range, the Centaur upper stage doubles as the main 4,400 pound (2,000 kg) impactor spacecraft for LCROSS.

The smaller Shepherding Spacecraft will guide Centaur towards its target crater, before dropping back to watch — and later fly through — the plume of moon dust and debris kicked up by Centaur's impact.

The shepherding vehicle is packed with a light photometer, a visible light camera and four infrared cameras to study the Centaur's lunar plume before it turns itself into a second impactor and strikes a different crater about four minutes later.

"This payload delivery represents a new way of doing business for the center and the agency in general," said Daniel Andrews, LCROSS project manager at Ames, in a statement. "LCROSS primarily is using commercial-off-the-shelf instruments on this mission to meet the mission's accelerated development schedule and cost restraints."

Figuring out the final destinations for the $79 million LCROSS mission is "like trying to drive to San Francisco and not knowing where it is on the map," Colaprete said.

He and other mission scientists hope to use observations from LRO and the Japanese Kaguya (Selene) lunar orbiter to map crater locations before LCROSS dives in.

"Nobody has ever been to the poles of the moon, and there are very unique craters — similar to Mercury — where sunlight doesn't reach the bottom," Colaprete said.

Earth-based radar has also helped illuminate some permanently shadowed craters.

By the time LCROSS arrives, it can zero in on its 19 mile (30 km) wide targets within 328 feet (100 meters).

Scientists want the impactor spacecraft to hit smooth, flat areas away from large rocks, which would ideally allow the impact plume to rise up out of the crater shadows into sunlight. That in turn lets LRO and Earth-based telescopes see the results.

"By understanding what's in these craters, we're examining a fossil record of the early solar system and would occurred at Earth 3 billion years ago," Colaprete said.

LCROSS is currently aiming at target craters Faustini and Shoemaker, which Colaprete likened to "fantastic time capsules" at 3 billion and 3.5 billion years old respectively.

LCROSS researchers anticipate a more than a 90 percent chance that the impactors will find some form of hydrogen at the poles.

The off-chance exists that the impactors will hit a newer crater that lacks water — yet scientists can learn about the distribution of hydrogen either way.

"We take [what we learn] to the next step, whether it's rovers or more impactors," Colaprete said.

This comes as the latest mission to apply brute force to science.

The Deep Impact mission made history in 2005 by sending a probe crashing into comet Tempel 1.

Besides Lunar Prospector's grazing strike on the moon in 1999, the European Space Agency's Smart-1 satellite dove more recently into the lunar surface in 2006.

LCROSS will take a much more head-on approach than either Lunar Prospector or Smart-1, slamming into the moon's craters at a steep angle while traveling with greater mass at 1.6 miles per second (2.5 km/s).

The overall energy of the impact will equal 100 times that of Lunar Prospector and kick up 1,102 tons of debris and dust.

"It's a cost-effective, relatively low-risk way of doing initial exploration," Colaprete said, comparing the mission's approach to mountain prospectors who used crude sticks of dynamite to blow up gully walls and sift for gold.

Scientists are discussing similar missions for exploring asteroids and planets such as Mars.

Nevertheless, Colaprete said they "may want to touch the moon a bit more softly" after LCROSS has its day.

German Lab Builds Three-Dimensional Images of Mars

Fri, 15 Feb 2008 13:50:57 -0500

The towering 3-D features of Martian canyons and highlands are about to stand out like never before, thanks to data from a high-resolution camera on the Mars Express orbiter.

These data, collected by the camera on the European Space Agency's Mars Express, are allowing scientists to create so-called Digital Terrain Models (DTMs) to look around the Martian surface from different directions and angles, as opposed to the usual bird's-eye view from above provided by previous Mars orbiter cameras.

The new data sets have now been released on the Internet, the European Space Agency announced this week.

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"Understanding the topography of Mars is essential to understanding its geology," said Gerhard Neukum, HRSC lead scientist at the Freie Universität (FU) in Berlin, Germany.

Creating the data for such digital models requires spacecraft to study the same Martian feature at least twice, each time from a different angle. Most previous efforts to do this have involved spacecraft making two orbital passes over features.

The Mars Express High Resolution Stereo Camera (HRSC) only needs one overhead pass to capture images of a feature from three different angles — on approach, directly overhead and receding into the distance.

The camera also obtains altitude measurements for its high-resolution images.

All that data is processed by the German Space Agency (DLR) and FU Berlin for several years before digital models of the Martian surface can start to emerge.

Now researchers are selecting the best data to "stitch them together" and develop digital models on a "global scale," Fred Jansen, Mars Express senior manager, told SPACE.com.

The newly released DTMs allow researchers to instantly gauge the slope of hillsides or the height of cliffs, as well as the altitude and slope of lava flows or desert plains.

"This data is essential for understanding how water or lava flowed across Mars," Neukum said.

It also helps planetary scientists better interpret Martian data from other instruments and missions, such as the Mars Advanced Radar for Subsurface and Ionosphere Sounding.

"Once we know where the surface is, we can correctly interpret the radar echoes we get from below it," said Angelo Rossi, HRSC scientist.

Lower orbits of Mars Express allow for more detailed pictures. The Mars Express mission will continue collecting such data until at least 2009.

NASA Chooses New Spacesuit Maker for Moon Missions

Tue, 17 Jun 2008 07:42:31 -0400

Americans may have to wrap their heads around a new spacesuit for future moonwalkers in 2020.

NASA's new spacesuit will come in two versions that protect future astronauts on the surface of the moon, as well as during travel to and from the International Space Station.

The initial $183.8 million spacesuit contract to design, develop and test the new spacesuit through September 2014 was awarded to Oceaneering International Inc. of Houston, Texas, the agency announced Thursday.

"We're ready to put them to work and put boot prints back on the moon," said Glenn Lutz, project manager for the Constellation Spacesuit System at NASA's Johnson Space Center in Houston in a teleconference.

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One version of the Constellation spacesuit will outfit as many as six astronauts traveling up to the space station in the Orion spacecraft, the capsule-based successor to NASA's three space shuttles after their planned 2010 retirement.

Astronauts can then reconfigure parts of their suit around a second version's torso, which is specifically designed for providing more mobility on the moon, before climbing into an Altair lander to head to the lunar surface.

The overall suit design is aimed at protecting against abrasive lunar dust, not to mention micrometeorites for emergency spacewalk activities.

Apollo astronauts had to hop around on the moon due to their stiff older suits, but the Constellation spacesuit will give future astronauts a new step as they roam about the lunar surface during missions lasting up to six months, NASA engineers said.

"Our design approach is to make it like walking across the desert floor to look at your favorite rock," Lutz said.

He added that the new suits would allow astronauts to walk more normally and focus on performing lunar geology and other work, although he commended Apollo astronauts for "figuring out how to ambulate across the surface" in their older, bulkier suits.

Different Constellation spacesuit sizes will allow almost any astronaut, short or tall, to fit inside.

The current spacesuit used for spacewalks, the Extravehicular Mobility Unit (EMU), comes in relatively few sizes and cannot fit all astronauts.

However, the EMU will remain the workhorse for space-station astronauts even after the new Constellation spacesuit comes online — final shuttle flights will store extra EMUs on the space station before the space shuttle's retirement.

The suit requirements aim for a lifespan of six to eight years for suits worn up to the space station, after which they will be used as training suits. The current plan for the lunar surface suits involves leaving or storing the heavy backpacks on the surface of the moon after each mission.

As makers of the new suits, Oceaneering International will also likely get two additional contract options worth $302.1 million and $260 million for designing the lunar suit version and producing the spacesuits through 2018.

"Our team is excited about this tremendous opportunity to assist NASA in pushing the boundaries of space exploration," said Mark Gittleman, Vice President and General Manager of Oceaneering Space Systems, in an announcement.

Both old and new spacesuits tackle similar problems of protecting astronauts in harsh and unforgiving environments, despite expected improvements for the new Constellation suits. That means future spacesuits may just be getting a facelift instead of a complete makeover in look.

"The Apollo suit had a very endearing quality to me when I was growing up," Lutz said, adding that the new Constellation spacesuit would not look drastically different but "it won't be my father's spacesuit."

Asteroid Safely Whizzes Past Mars

Thu, 31 Jan 2008 07:49:31 -0500

An asteroid once thought to be on a collision course with Mars passed the Red Planet Wednesday without incident.

Astronomers first estimated that asteroid 2007 WD5 had as high as a 3.6 percent chance of striking the Red Planet.

Newer observations kept lowering the odds for the 164-foot space rock until Jan. 9, when NASA's Near-Earth Object (NEO) program office effectively ruled out chances of an impact.

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"Mars sees these kinds of near-miss encounters every ten or twenty years, but the impact rate for asteroids this size is about once in a thousand years," said Steve Chesley, an astronomer at the Jet Propulsion Lab in Pasadena, Calif.

Astronomers had hoped the fleet of spacecraft orbiting Mars would get a chance to observe the asteroid plowing into the Martian surface.

The subsequent crater would have roughly equaled the size of the Meteor Crater that formed in northern Arizona 50,000 years ago, with a 0.5-mile diameter.

Such an impact would have also allowed scientists to study the dust cloud from the impact.

"We were hoping for a spectacular show to reveal a lot," Chesley said. "We've actually never seen a significant impact on a terrestrial planet."

Mars is a smaller and harder target for space rocks to hit when compared with Earth, but about five times as many asteroids cross the Martian orbit, according to Chesley.

2007 WD5's path around the sun ranges from just outside Earth's orbit to the outer edge of the asteroid belt between Mars and Jupiter, but will not impact with either Mars or Earth in the next century, JPL researchers said.

The asteroid missed Mars by a distance of approximately 6.5 Mars radii.

Similar near misses occur with Earth. And similarly, astronomers sometimes give odds on a possible impact and then, with further observations, reduce the odds to zero.

In fact, the Mars flyby occurred a day after a 500-foot asteroid flew by Earth at a distance somewhat greater than from the Earth to the Moon.

Chesley and other astronomers considered having one of the Martian rovers eyeball the passing 2007 WD5, but judged the task too difficult for the robotic explorers.

None of the orbiting spacecraft turned their cameras or other equipment on the passing rock, either.

"After we knew it was going to miss, it's really a pretty ordinary asteroid cruising around the solar system," Chesley said.

Mysterious Natural Sculptures Spotted on Mars

Mon, 28 Jan 2008 07:50:11 -0500

Wind-sculpted Martian landscapes raise questions for scientists about the Red Planet's atmosphere and terrain.

Sand dunes are among the "bedforms" or wind-deposited landforms that appear in new images from NASA's Mars Reconnaissance Orbiter (MRO).

However, scientists remain unsure as to whether winds on present-day Mars are strong enough to create such geological features.

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"We're seeing what look like smaller sand bedforms on the tops of larger dunes, and, when we zoom in more, a third set of bedforms topping those," said Nathan Bridges, NASA's Jet Propulsion Laboratory in Pasadena, Calif. "On Earth, small bedforms can form and change on time scales as short as a day."

Other bedforms on Mars take the shape of smaller and more linear ripples, in which sand is mixed with coarser particles.

New details emerged about sediments deposited by winds on the downwind side of rocks. Such "windtails" show which way the most current winds have blown, Bridges said. Only rovers and landers have seen such features before, as opposed to an orbiter.

With the University of Arizona's High Resolution Imaging Science Experiment camera (HiRISE), MRO sees features as small as 20 inches from 155 to 196 miles above the Martian surface.

Researchers can now use HiRISE images to infer wind directions over the entire planet.

Scientists also previously discovered miles-long, wind-scoured ridges called "yardangs" with the first Mars orbiter, Mariner 9, in the early 1970s.

New HiRISE images reveal surface texture and fine-scale features that are giving insight into how yardangs form.

"HiRISE is showing us just how interesting layers in yardangs are," Bridges said. "For example, we see one layer that appears to have rocks in it. You can actually see rocks in the layer, and if you look downslope, you can see rocks that we think have eroded out from that rocky layer above."

New images show that some layers in the yardangs are made of softer materials that have been modified by wind, he added.

The soft material could be volcanic ash deposits, or the dried-up remnants of what once were mixtures of ice and dust, or something else.

"The fact that we see layers that appear to be rocky and layers that are obviously soft says that the process that formed yardangs is no simple process but a complicated sequence of processes," Bridges added.

Some researchers have begun comparing HiRISE images with those taken by NASA's Mars Exploration Rovers, in order to identify previously mysterious features such as dark streaks surrounding Victoria Crater.

Others continue to find surprises while reexamining features once considered common and uninteresting.

"HiRISE keeps showing interesting things about terrains that I expected to be uninteresting," said Alfred McEwen of the University of Arizona Lunar and Planetary Laboratory, HiRISE principal investigator. "I was surprised by the diversity of morphology of the thick dust mantles. Instead of a uniform blanket of smooth dust, there are often intricate patterns due to the action of the wind and perhaps light cementation from atmospheric volatiles."

Sun's Upside-Down Heat Pattern Explained

Wed, 23 Jan 2008 07:54:20 -0500

Powerful magnetic waves have been confirmed for the first time as major players in the process that makes the sun's atmosphere strangely hundreds of times hotter than its already superhot surface.

The magnetic waves — called Alfven waves — can carry enough energy from the sun's active surface to heat its atmosphere, or corona.

"The surface and corona are chock full of these things, and they're very energetic," said Bart de Pontieu, a physicist at the Lockheed Martin Solar and Astrophysics Laboratory in California.

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The sun contains powerful heating and magnetic forces which drive the temperature to tens of thousands of degrees at the surface — yet the quieter corona wreathing the sun reaches temperatures of millions of degrees.

Scientists have speculated that Alfven waves act as energy conveyor belts to heat the sun's atmosphere, but lacked the observational evidence to prove their theories.

De Pontieu and his colleagues changed that by using the Japanese orbiting solar observatory Hinode to peer at the region sandwiched between the sun's surface and corona, called the chromosphere.

Not only did they spot many Alfven waves, but they also estimated the waves carried more than enough energy to sustain the corona's temperatures as well as to power the solar wind (charged particles that constantly stream out from the sun) to speeds of nearly 1 million mph.

However, the chromosphere findings alone could not prove the waves carried their energy into the sun's atmosphere.

"If you observe waves in the chromosphere, that doesn't mean they can get to the corona," De Pontieu told SPACE.com.

Some waves may get reflected back down to the sun instead of passing through the transition region between the surface and atmosphere.

Waves that reach the corona also become more difficult to detect using current instruments, thanks to the long line-of-sight.

De Pontieu's group turned to researchers at the University of Oslo, Norway, who had created a computer simulation representing part of the sun.

Once they knew what to look for, the researchers found magnetic waves within the simulation of the corona that strongly resembled the Alfven waves directly observed in the chromosphere.

Even as the simulations helped establish Alfven waves as energy carriers for the sun's atmosphere and solar wind, the new observational findings will help modelers create improved sun simulations.

"It goes back and forth — we learn from simulations, they learn from us," said De Pontieu.

Many mysteries remain about the sun's restless activities.

De Pontieu's group focused on Alfven waves generated by the sun's heat turbulence, but other researchers examined Alfven waves generated when the sun's magnetic field lines stress and snap back together like invisible magnets.

That reconnection force also creates jets of X-rays that shoot outwards from the sun, as captured by Hinode's instruments.

Scientists still don't know which source of Alfven waves plays a more important role in the heating the sun's atmosphere, but can use the latest findings as a stepping stone.

"We need to study both more, to see which one dominates," noted De Pontieu. "But it's nice for people to know that Alfven waves can do the job."

Space Probes Find Dent in Solar System

Thu, 03 Jul 2008 07:15:14 -0400

Voyager 2's journey toward interstellar space has revealed surprising insights into the energy and magnetic forces at the solar system's outer edge, and confirmed the solar system's squashed shape.

Both Voyager 1 and Voyager 2 continue to send data to Earth more than 30 years after they first launched. During the 1990s, Voyager 1 became the farthest manmade object in space.

Each spacecraft has now crossed the edge of the solar system, known as the termination shock, where the outbound solar wind collides with inbound energetic particles from interstellar space.

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The termination shock surrounds the solar system and encloses a bubble called the heliosphere.

"The solar wind is blowing outward trying to inflate this bubble, and the pressure from interstellar wind is coming in," said Edward Stone, physicist and Voyager project scientist at Caltech in Pasadena, Calif.

He and other researchers published a series of studies in the journal Nature this week that detail the Voyager findings.

This way and that

Voyager 2 reached the southern edge of the solar system 7 billion miles (76 AU, or astronomical units) from the sun, closer than Voyager 1, which had reached the northern edge 7.8 billion miles (84 AU) from the sun.

That confirms earlier suspicions about the heliosphere bubble being squashed at its southern region.

The reason for that asymmetrical shape rests with an interstellar magnetic field that puts more pressure on the southern region of the solar system — something that may change over 100,000 years as that magnetic field experiences turbulence, Stone said.

Comparing the Voyager 1 crossing in December 2004 with the Voyager 2 crossing in August 2007 allowed scientists to confirm that the second sibling actually crossed the termination shock and passed into the heliosheath, an outer layer of the heliosphere.

But Voyager 2 also carries more working instruments that show the termination shock in full detail.

"We're actually seeing the shock for the first time," said John Richardson, principal scientist for Voyager's Plasma Physics instrument at MIT in Cambridge, Mass.

Voyager 1's plasma detector failed after it passed Saturn, so Voyager 2 provided the first glimpse of what happens to the solar wind's energy as it slams into interstellar space.

The solar wind travels outwards from the sun at supersonic speeds and at temperatures near 17,540 degrees Fahrenheit (10,000 degrees Kelvin).

Scientists had predicted that the solar wind would simultaneously slow down and heat up to a temperature near 1.8 million degrees F (1 million degrees Kelvin), but instead found that it reached just 180,000 degrees F (100,000 degrees Kelvin) at the solar-system boundary.

Hitching a ride

The solar wind's missing energy ended up hitching a ride with interstellar intruders, Richardson said.

Neutral atoms that flowed in from outside the solar system became energized upon entering the heliosheath layer, and then ended up stealing 80 percent of the energy from the solar wind. Researchers have yet to puzzle out the significance of this.

An added mystery remains as to why the solar wind slows down early, as though anticipating running headlong into the termination shock.

Researchers have begun looking into whether the solar wind somehow sheds energy ahead of time.

"Somehow the solar wind knows the shock is coming before it gets there, and theory says that shouldn't be," Richardson noted, adding that the solar wind speed drops from its supersonic speed of about 248 miles per second (400 km/s) to 186 miles per second (300 km/s) even before hitting the edge of the solar system. That speed falls more noticeably to about 93 miles per second (150 km/s) after the termination shock.

Even as researchers continue parsing the Voyager findings, both spacecraft plow onward toward deep space — and beyond all expectations of their original mission.

"My guess is five to seven years to reach interstellar space," Stone said. "There's a very good chance that Voyager I will send the first data back from there."

How Robots Could Explore Other Worlds

Thu, 03 Jul 2008 07:15:16 -0400

A spaceship descends with a thunderous roar and deposits a futuristic probe before taking off again. The Extraterrestrial Vegetation Evaluator (EVE) soon activates and begins flying around, scanning the barren surface for signs of life.

Scientists today can only dream of having a robotic explorer like EVE from the Disney/Pixar film "WALL•E."

But some researchers are working on autonomous spacecraft, airships and rovers that can cooperate intelligently while exploring distant worlds.

"The orbiter gives you global perspective, the aerial platform a more regional perspective, and that helps determine where to deploy ground assets in a targeted fashion," said Wolfgang Fink, a physicist at the California Institute of Technology in Pasadena.

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Fink's vision of "tier-scalable reconnaissance" starts with an orbiting spacecraft to make a global survey for interesting scientific targets, before deciding on its own where to deploy an airship such as a dirigible.

The airship could look even closer at a region to find the best landing site, and finally drop a rover or some other surface explorer. That surface explorer could then move quickly to the target area.

A demonstration of how such a surface explorer might deploy will take place in the Mars Science Laboratory mission, slated for a 2009 launch.

NASA's Sky Crane carrier will hover above the surface of Mars on retrorockets while lowering an SUV-sized rover using a winch and tether.

Some Mars missions have already demonstrated the advantage of coordinating orbiters with surface explorers.

Scientists used data from three Mars orbiters to determine the landing site for NASA's Phoenix Mars Lander, and also turned orbiter cameras on the lander as it descended to the surface.

Of the three orbiters, the Mars Reconnaissance Orbiter has even helped NASA's separate Spirit and Opportunity Rovers navigate around obstacles on the Martian surface.

However, Fink and his collaborators want to take humans out of the loop and develop robots which can decide independently when and where to go.

That becomes crucial for future missions to distant places such as the moons of Saturn or Jupiter, where a command signal from Earth can take over an hour to reach robotic explorers.

The key rests with software algorithms that help robots make command decisions on their own.

Fink's group has begun testing such algorithms by using three small rovers and a camera that looks down on a simulated indoor landscape.

The camera identifies both targets and obstacles, which allows the rovers to deploy and drive around obstacles to reach their targets — all without human intervention.

"Integration is the biggest challenge," Fink noted. "At Caltech, we are now at the point where we're implementing a test-bed outdoors to develop the software to demonstrate this in action."

The outdoors test would involve a miniature airship taking the place of the camera. Researchers from around the world would be able to give commands to the airship via Internet and watch it move and deploy the rovers on its own.

The field tests may pave the way for using similar command software on the proposed NASA and European mission to Titan or Europa. Fink and other researchers involved with the planning have begun discussing how such a mission might shape up by the 2017 launch date.

"A Titan mission would have the orbiter deploying a balloon, and we're already thinking about having a lander," Fink explained. "There you have a three-tier mission."

The tiered approach may eventually take the form of a robot that "does its own reconnaissance, goes out and looks for anomalies, finds something interesting and makes contact with the sender," Fink said, pointing to the Imperial probe from "The Empire Strikes Back" which lands on the ice planet Hoth.

Perhaps best of all, intelligent robots could react quickly to surprises and investigate anomalies — such as a geyser on Saturn's moon Enceladus, or a landslide on Mars.

"Curiosity in itself is not present in any of our machine systems," Fink said, remarking upon WALL•E's childlike tendencies which appear to distract EVE but eventually help her mission. "That curiosity drives action."

Water Discovered in Moon Rock Samples

Thu, 10 Jul 2008 16:55:22 -0400

Water has been found conclusively for the first time inside ancient moon samples brought back by Apollo astronauts.

The discovery may force scientists to rethink the lunar past and future, although uncertainty remains about how much water exists and whether future explorers could extract it.

The water was found inside volcanic glass beads, which represent solidified magma from the early moon's interior.

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The news swept through much of the scientific community even before being detailed in the journal Nature this week.

"This really appears to have changed the rules of the game," said Robin Canup, astrophysicist and director of the Southwest Research Institute in Boulder, Colo., who was not part of the team that made the discovery. "The assumption has been that the moon is dry."

Revising lunar history

Scientists have long assumed the moon was dry because of its violent birth roughly 4.5 billion years ago.

The leading theory holds that a Mars-sized planet smashed into Earth and tore off molten pieces that eventually formed into the moon. Most scientists thought that any water in the developing lunar body would have vaporized and been lost to space.

"If there was a lot of water in the early moon, then that is new for sure," said Ben Bussey, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory who also was not involved in the new study. "People will have to think about that when they think about how the moon evolved."

The earlier thinking about the moon's lack of water meant researchers struggled to even get funding to search for counter-evidence.

"I thought that if we were really lucky we would get to see it," said Alberto Saal, a geochemist at Brown University and lead author on the Nature study. "Like everybody else, I was thinking our chances were low."

A delicate proposal

Saal's group examined lunar samples brought back from the Apollo missions of the 1960s and 1970s. The glass beads range in color from green to yellow-brown to red, depending on their elemental chemistry.

Such beads formed from droplets of molten lava that spewed from fire fountains reaching down deep within the primitive lunar interior.

Saal's group measured the beads' elemental makeup to ensure they came from lunar volcanic activity and not from the impact event that formed the moon.

The researchers also ruled out the chance that such beads could have become contaminated by outside forces such as hydrogen — an element of water — from the solar wind.

Others had tried and failed earlier to find water in similar samples, but one of Saal's collaborators had developed improved detection methods using a technique called secondary ion mass spectrometry (SIMS).

"For the past four decades, the limit for detecting water in lunar samples was about 50 parts per million (ppm) at best," said Erik Hauri, geochemist at the Carnegie Institution in Washington, D.C. and co-author on the study. "We developed a way to detect as little as 5 ppm of water."

The group found up to 46 ppm of water within the glass beads. Saal and his collaborators then used modeling to estimate how much water originally existed in the magma within the moon's interior, knowing some water would have escaped the molten droplets as a gas on the surface.

That led to estimates that the glass beads may contain 745 ppm of water — strikingly similar to solidified lava that came up from the Earth's upper mantle through undersea vents.

However, Saal's group gives 260 ppm of water as the most certain figure for now.

Follow the water

Just finding water at all could lead to a sea-change in how scientists view the early moon — either the moon held onto water from Earth during its violent creation, or else water gathered from elsewhere within 100 million years of the impact event as the moon solidified.

Modeling done on the Earth impact event suggests that our planet would have held onto much of its water, Canup explained. But such models say little about how much the moon could have held onto, and other questions remain unanswered even from this latest study.

"The major uncertainty I see is whether they're sampling something that tells us about the bulk composition of the moon, or whether they have sampled materials produced by a more limited water-rich part of the moon's interior," Canup said.

Knowing whether water is highly abundant or relatively scarce within the moon could also have implications for lunar exploration, but not for near-future missions such as NASA's Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS).

The latter mission is slated to crash two spacecraft into the moon's south pole in early 2009, in an attempt to find evidence of water ice hidden in the lunar craters.

Any surface water ice likely formed from comets and other external bodies crashing into the moon and releasing their water, Bussey said, although he acknowledged the chance that some water vapor drifted to the poles during the moon's early history.

Saal's group will attempt to clear up some of those questions as they examine samples from more Apollo missions.

For now, their work stands as an example of continuing to squeeze science out of an unexpected link between the past and future.

"I think it's exciting that you keep getting results out of the Apollo samples." Bussey said.

Strange Scars on Mars Suggest Recent Glaciers

Mon, 28 Apr 2008 07:41:17 -0400

A vanished glacier with a mysterious calling card suggests Mars went through many ice ages in its very recent past.

A fresh look at images from the Mars Reconnaissance Orbiter indicates thick glaciers may have existed in the past 100 million years in the planet's equatorial region, but vanished after planetary wobbles changed the climate in certain areas.

"We've gone from seeing Mars as a dead planet for three-plus billion years to one that has been alive in recent times," said Jay Dickson, a geologist at Brown University and lead author of the study. "[The finding] has changed our perspective from a planet that has been dry and dead to one that is icy and active."

Strange flow

Dickson and other researchers looked at a dead-ended box canyon that slopes down into a larger valley, and discovered glacial deposits of rocks marking a glacier's advance heading upslope into the canyon — something which seems physically impossible.

Here's how it happened, according to the team's calculations: An ice pack at least .62 miles (1 kilometer) thick filled the larger valley to a height exceeding that of the box canyon walls.

Glacial ice flowed in the larger valley upstream of the box canyon. So when the glacier reached the box canyon, the ice actually pushed uphill into it.

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When the glacier ice retreated, it left behind the mystery of the box canyon and a freshly-paved surface that suggests a recent event.

"We don't see many craters on the glacial deposits," Dickson told SPACE.com. "That's a yardstick we can use for measuring geological age."

Craters on Mars, caused by meteor impacts, remain for hundreds of millions of years, and their prevalence in an area can, like a wrinkled face, indicate an old surface. Newer surfaces lack the multitudes of scars.

Multiple episodes

The finding further suggests that Mars has endured repeated periods of glacial activity instead of just one single event, Dickson said, whose new work on this topic is detailed in the May issue of the journal Geology.

The past presence of glaciers could also spark further debate about whether water flowed recently on Mars, given that pressure from the weight of glaciers can melt ice. However, no direct evidence of recent flowing water has been found.

"We don't yet see evidence for melt water at this location, but the fact that there was so much ice here expands our understanding of how active Mars climate has been," said Dickson.

NASA Mulls Nuclear Power for Moon Base

Thu, 18 Sep 2008 06:59:14 -0400

Nuclear power could make a comeback beyond Earth if NASA goes forward with a proposed a fission reactor in its future moon base.

A fission-powered system could generate up to 40 kilowatts and give any lunar outpost enough power to supply eight houses on Earth.

More importantly, astronauts will require a reliable and steady energy source on the moon and Mars.

"The problem with power on the moon is that, depending on where you're located, you may have 14 days of darkness," said Lee Mason, an engineer at NASA's Glenn Research Center in Cleveland, Ohio, who heads the project. "We think nuclear offers some advantages there in terms of a continuous power source in sun or darkness."

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Engineers envision a nuclear reactor buried under the surface of the moon so that lunar soil, known as regolith, can act as shielding against the reactor's radiation.

Power converters would sit atop a tower jutting above the surface, changing the reactor's heat energy into electrical energy for astronauts to use.

The tower would also boast two 50-foot (15-meter) panels made of polymer composite material that could give off excess heat from the nuclear reactor.

Far-flung robotic missions, such as the Cassini orbiter currently orbiting Saturn, have relied on a different nuclear technology, Radioisotope Thermoelectric Generators (RTG), which draws on the energy from the natural decay of radioactive plutonium.

Current RTGs produce roughly 100 watts of electricity, in comparison to the tens of thousands of watts produced by nuclear fission reactors that split uranium atoms.

NASA previously launched just one nuclear reactor into space in 1965, but the experimental SNAP-10A reactor shut down after just 43 days of operation.

Nuclear power made a brief reappearance in the Jupiter Icy Moons Orbiter (JIMO) proposal, but the mission was scrapped in 2005 due to budget constraints.

"JIMO was a little ahead of its time, a very ambitious program, and it didn't just quite fit in with the budget projections," Mason told SPACE.com.

Now the moon base proposal offers a new possibility, but Mason's NASA Glenn team must first decide which power converter engine to use for any nuclear reactor.

One design, a piston Stirling design from Sunpower Inc., of Athens, Ohio, uses two back-to-back piston engines that cancel out each other's mechanical vibration.

The second design, by Barber Nichols Inc. of Arvada, Colo., relies on a closed Brayton cycle engine that has a rotary system not unlike jet turbine engines. Both power converters can produce 12 kilowatts, or roughly 40 kilowatts in a pack of four.

NASA engineers hope to test the efficiency of power converters without the nuclear reactor in 2012 or 2013. A non-nuclear reactor simulator would provide the heat source for the tech demonstration on Earth, courtesy of NASA's Marshall Space Flight Center in Huntsville, Ala.

The space agency continues to ponder non-nuclear options such as solar power for a future lunar base.

If NASA does use a nuclear reactor, it will resemble reactor technology that the U.S. Department of Energy (DOE) "has operated for many years," said John Warren, executive head of NASA's Space Power Systems Program in Washington, D.C.

Mason said that the project should finish on schedule if it continues receiving the $10 million funding shared between NASA and the DOE.

"We would like to design a system that can last eight years without any maintenance whatsoever," Mason said. "The technology is there to achieve that."

Our Sun May Be a 'Galactic Hitchhiker'

Tue, 23 Sep 2008 11:32:28 -0400

Astronomers have long believed that most stars are homebodies that stick close to their birthplaces.

But a new simulation supports the suggestion that our sun might have once hitchhiked through the galaxy.

Where our sun or another star ends up migrating seems to depend on its position in a spinning spiral galaxy.

Stars tagging along behind a massive spiral arm can get a gravitational speed boost that sends them into a bigger orbit around the galactic center.

The stars leading in front of a spiral arm may end up getting slowed by the arm's gravitational pull and fall back into a smaller orbit.

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"Our simulation is still like a toy model, but a step more complex than the ones observing migrations before," said Rok Roskar, an astronomer at the University of Washington in Seattle.

Previous simulations followed star migration in a preset galaxy.

The new computer model goes back 9 billion years to track a galaxy's evolution from a giant cloud of gas. It also follows individual stars from before birth until they die in a fiery supernova.

Stars could travel from deep within the interior of a galaxy to its outer edges, and might even get passed around in a "spiral arm relay," Roskar told SPACE.com.

Our sun currently has an orbit near the outer edge of the galaxy.

New simulation runs confirmed earlier work that showed how star orbits can remain circular despite expanding or shrinking.

That counters assumptions that the gravitational tug-of-war would push and pull orbits into wilder elliptical shapes.

The older research also undermines the assumption that a more elliptical or disturbed orbit reflects the older age of a star.

"You can have a circular orbit for an old star that has been whacked around by many spiral arms," Roskar said.

Such simulations may help explain observations made by NASA's Hubble Space Telescope, which had raised another puzzle for astronomers.

Conventional knowledge states that stars get younger and younger further out in a galactic disk, but Hubble turned up evidence that stars are actually much older beyond a certain point in the outer galaxy.

Roskar and other researchers think that the older stars lurking in the galactic fringe represent wandering wayfarers rather than local residents.

"Older stars have had time to get out there," Roskar noted.

Wandering stars could also shake up the notion of galactic habitable zones. Such safe areas would not have the chaos and radiation of star nurseries, but would have enough heavy metals from previous stars to support planets conducive to life.

Yet such zones could not be stationary as the galaxy itself changes, or if our sun has migrated across many different parts of the galaxy.

"It seems impossible to talk about a galactic habitable zone without context," Roskar said. "Our sun has a very circular orbit, so some assumed it's always been where it is. To me, it's not so clear that's true."

The new simulation is detailed in the Sept. 10 edition of the Astrophysical Journal Letters.

Physicists: Faster-Than-Light Travel Might Be Possible

Thu, 14 Aug 2008 09:07:44 -0400

Travel by bubble might seem more appropriate for witches in Oz, but two physicists suggest that a future spaceship could fold a space-time bubble around itself to travel faster than the speed of light.

We're talking about the very distant future, of course.

The idea involves manipulating dark energy — the mysterious force behind the universe's ongoing expansion — to propel a spaceship forward without breaking the laws of physics.

"Think of it like a surfer riding a wave," said Gerald Cleaver, a physicist at Baylor University. "The ship would be pushed by the spatial bubble and the bubble would be traveling faster than the speed of light."

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In theory, the universe grew faster than the speed of light for a very short time after the Big Bang, driven by the dark energy that represents about 74 percent of the total mass-energy budget in the universe.

Dark matter constitutes 22 percent of the budget, and normal matter (stars, planets and everything you see) makes up the remaining 4 percent or so.

Strange as it sounds, current evidence supports the notion that the fabric of space-time can expand faster than the speed of light, because the reality in which light travels is itself expanding.

Cleaver and Richard Obousy, a Baylor graduate student, tapped the latest idea in string theory to devise how to manipulate dark energy and accelerate a spaceship.

Their notion is based on the Alcubierre drive, which proposes expanding space-time behind the spaceship while also shrinking space-time in front.

String theorists had believed that a total of 10 dimensions exist, including height, width, length and time.

The other six dimensions exist largely as unknowns, but everything is based on hypothetical one-dimensional strings.

A newer theory, called M-theory, suggests that those strings all vibrate in yet another dimension.

Manipulating that additional dimension would alter dark energy in terms of height, width, and length, Cleaver and Obousy theorize.

Such a capability would permit the altering of space-time for a spaceship, taking advantage of dark energy's effect on the universe.

"The dark energy is simultaneously decreased just in front of the ship to decrease (and bring to a stop) the expansion rate of the universe in front of the ship," Cleaver told SPACE.com. "If the dark energy can be made negative directly in front of the ship, then space in front of the ship would locally contract."

This loophole means that the spaceship would not conflict with Einstein's Theory of Relativity, which states that objects accelerating to the speed of light require an infinite amount of energy.

However, the Baylor physicists estimate that manipulating dark energy through the extra dimension requires energy equivalent to the converting the entire mass of Jupiter into pure energy — enough to move a ship measuring roughly 33 feet (10 meters) by 33 feet by 33 feet.

"That is an enormous amount of energy," Cleaver said. "We are still a very long ways off before we could create something to harness that type of energy."

The workaround solution may leave fans of Einstein pleased. But for now, faster-than-light travel remains, like Oz, a pleasant fantasy.

Europeans Aim to Build Own Manned Spacecraft

Thu, 16 Oct 2008 07:52:04 -0400

Plenty of European astronauts and hardware have gone up to the space station or to other orbits around Earth, but now the European Space Agency (ESA) is thinking of ways to get them back down on their own.

A Vega rocket on the drawing boards is slated to carry ESA's Intermediate eXperimental Vehicle (IXV) into space in 2012. The stubby white-and-black spacecraft is designed to use two rear flaps in a paddling motion to steer itself during atmospheric reentry.

Such a demonstration craft could perhaps pave the way for Europe to return its astronauts to Earth without relying on the U.S. or Russian space programs.

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The U.S. itself faces a four-year gap in manned spaceflight capability after the space shuttle retires in 2010, and will have to rely on the Russian Soyuz spacecraft.

"With ATV [Automated Transfer Vehicle] and Columbus, the European space laboratory, we believe Europe has now become one of the major players in manned space exploration," said John Ellwood, ATV mission manager.

He added that the European Union's Council of Ministers would meet in November to set space policy for the next several years.

Europe's ATV currently serves as an unmanned space delivery vehicle, with the first, named Jules Verne, successfully completing its mission and undergoing a fiery death in the Earth's atmosphere.

But now ESA wants to push forward with developing an ATV variant that could undergo re-entry and safely return cargo or astronauts.

"ESA does not plan to develop a reusable re-entry system on the basis of the ATV, but rather an expendable re-entry vehicle," said Marco Caporicci, head of transport and re-entry systems for the ESA Human Spaceflight Directorate.

The Advanced Re-entry Vehicle (ARV) would use Europe's Ariane 5 rocket, which is not reusable.

An expendable service module would boost the ARV into orbit and guide the re-entry module to reenter Earth's atmosphere.

ESA has not tried to develop a reusable launch system or service module because of the low number of European spaceflights, Caporicci said. But the re-entry capsule would conceptually resemble NASA's Apollo or upcoming Orion capsules, with some changes.

"We believe that the shape selected, with a cone angle of 20 degrees, would allow more internal volume than for the classical Apollo shape," Caporicci told SPACE.com.

Caporicci cautioned that "ARV does not play a role in closing the gap between shuttle and Orion," and that the IXV and ARV programs would each follow their own separate development tracks.

However, space enthusiasts can cheer the notion that Europe may someday join the United States, Russia and China in launching astronauts and returning them safely to Earth.

Spacecraft Swings by Mercury for Second Time

Tue, 07 Oct 2008 07:23:42 -0400

A NASA probe made its second Mercury flyby early Monday as closes in on the closest planet to the sun.

The MESSENGER spacecraft was due to pick up a gravitational boost during the rendezvous today at 4:45 a.m. EDT (0845 GMT) that will help it settle into orbit around Mercury in 2011.

But scientists also directed MESSENGER's cameras and sensors to capture new images and data from areas of the planet that remained uncharted after its first flyby on Jan. 14.

"Mercury has been a real anomaly in that, up until now, we have not seen the entire surface on one of the bodies closest to the Earth," said Sean Solomon, MESSENGER's principal investigator at the Carnegie Institution of Washington, during a teleconference last week.

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At its closest approach, MESSENGER, short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging, was expected to swing within 125 miles (200 km) of the planet's surface.

Mission controllers expected to lose contact with the spacecraft at certain times while it twisted and turned for better views of Mercury. MESSENGER also switched from solar to battery power for 17 minutes while flying through the planetary shadow.

Scientists eagerly await the new images from never-before-seen regions of Mercury, which add up to about 30 percent of the planet's surface.

The spacecraft was slated to snap 629 images specifically for nine large image mosaics that will help scientists begin mapping Mercury.

Researchers hope to begin receiving new data from MESSENGER about 21 hours after it leaves Mercury's shadow, in the very early morning hours of U.S. EDT on Tuesday.

MESSENGER is the first spacecraft in 33 years to encounter Mercury up close since NASA's Mariner probe buzzed the planet three times in 1974 and 1975.

The new spacecraft swung by Earth once and Venus twice since launching in August 2004, and has now completed two of three Mercury flybys before going into orbit around the planet.

Mission controllers saved on precious propellant by taking advantage of the solar wind's force to alter the probe's trajectory. The flyby solar sailing maneuvers marked the successful execution of a "3-D complex exercise in threading the needle," Solomon said.

MESSENGER's first flyby on settled an old scientific debate by showing how volcanoes have shaped the planet's flat, smooth plains. It also detected Mercury's magnetic field, which is shaped by the solar wind's bombardment into a tear drop with the flat face toward the sun.

The second flyby today allowed the spacecraft to peer at the opposite side of the planet.

Spacecraft Set to Swing By Mercury Monday

Fri, 03 Oct 2008 07:36:15 -0400

A space probe is headed for a second swing past Mercury to pick up a gravitational boost and eventually become the first spacecraft to orbit the closest planet to our sun.

Scientists expect to get more than 1,200 pictures when NASA's MESSENGER spacecraft zips past Mercury early Monday, which would help reveal most of planet's remaining unmapped terrain.

The flyby should also provide a gravity assist that will prepare MESSENGER to enter orbit around Mercury in March 2011.

"For needles with smaller and smaller eyes, this team is getting better and better," said Sean Solomon, MESSENGER's principal investigator at the Carnegie Institution of Washington, during a Wednesday teleconference.

He described the maneuvers as a "threading exercise" requiring the highest precision.

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MESSENGER, short for the bulky name MErcury Surface, Space ENvironment, GEochemistry, and Ranging, should pass 125 miles (200 km) above Mercury, or roughly the same as the separation distance during a first flyby on Jan. 14.

Its cameras and instruments will cover 30 percent of the planet surface, including never-before-seen areas on the western side of the planet opposite to the first flyby's coverage.

No spacecraft has caught such close looks at the planet since NASA's Mariner 10 probe, which zipped by Mercury three times in 1974 and 1975.

The earlier Mariner probe managed to map just 45 percent of the planet's surface during its three flybys, while MESSENGER scoped out half of the planet's uncharted surface during its first flyby.

However, MESSENGER still needs to perform an intricate dance with Mercury before it can turn into a full-time photographer.

Each flyby requires precise earlier adjustments to the spacecraft's course that normally use up precious onboard propellant.

Mission planners skirted this issue and saved up more propellant for the spacecraft's later mission by taking advantage of the solar wind.

"MESSENGER is first interplanetary mission to use solar sailing as a means to control its trajectory," said Daniel O'Shaughnessy, the lead MESSENGER navigator at Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

He added that they achieved accuracy within a third of a mile (1 km) using "only the subtle push of sunlight and without a single drop of propellant in over six months."

The spacecraft will begin its 15,000 mph (24,140 kph) flyby in the early morning hours of U.S. EDT on Monday, Oct. 6.

Its team will occasionally lose contact as MESSENGER turns this way and that to take pictures and compile seven large image mosaics of the planet surface.

The closest approach during the roughly 30-hour encounter is set for about 4:45 a.m. EDT (0845 GMT).

A 17-minute power outage will occur as MESSENGER passes into Mercury's shadow, requiring the spacecraft to rely on internal batteries instead of its solar panels.

The first MESSENGER flyby found evidence that volcanoes and not impacts had created Mercury's flat, smooth plains.

It also showed that Mercury's magnetic field is elongated like a tear drop, with the solar wind pushing against the side closest to the sun and pressing it close to the surface.

MESSENGER approaches its upcoming flyby as an experienced planetary hopper, having revisited Earth once and swung by Venus twice since its August 2004 launch.

A third flyby of Mercury is also scheduled for Sept. 2009, before the spacecraft enters orbit in 2011.